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(Environment) Waste Management: Microbe Power!

 
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PostPosted: Fri Jan 13, 2006 2:27 pm    Post subject: (Environment) Waste Management: Microbe Power! Reply with quote






Microbe Power!
David C. Holzman
Environmental Health Perspectives
Volume 113, Number 11, November 2005

Increasingly, problems of rising energy demands, dwindling resources, and pollution concerns are being mitigated by turning waste into usable products. Now some researchers are eyeing organic wastes from homes, food processing, and other sources as an energy feedstock--bacteria including Rhodoferax and Geobacter are being harnessed in devices called microbial fuel cells (MFCs) to break down organic waste products, converting the energy of their chemical bonds into electricity and hydrogen.

Significant Energy Resource

In the United States, 46 trillion liters of household wastewater are treated annually, according to an article by Bruce Logan, director of the Hydrogen Energy Center at The Pennsylvania State University, in the 1 May 2004 issue of Environmental Science & Technology. This costs $25 billion, and the electricity required--mostly for aeration--constitutes 1.5% of the electricity used in the nation, says Lars Angenent, an assistant professor in the Department of Chemical Engineering at Washington University in St. Louis. According to Angenent, most of that energy could be saved by treating wastewater using MFCs. He says one of these devices could produce enough extra energy to power 900 homes by treating the wastes from a single large food processing plant. According to Logan, MFCs would cut the cost of aerating activated sludge in wastewater by as much as 50% of the electricity usage, and should generate 50-90% less solids to be disposed of.

Logan put this potential in context in his 1 May 2004 article when he wrote that the United States consumed 97 quads (short for “quadrillion British thermal units”) of total energy in 2002; of this, 13 quads were generated electricity. Should hydrogen become the transportation fuel of choice, as many believe it will--with most hydrogen produced ultimately from fossil fuels--another 12 quads would be required to make hydrogen from water, he wrote.

According to Logan, all the U.S. household wastewater produced in one year contains 0.11 quad organic matter, livestock production wastewater contains 0.3 quad, and food processing wastewater possibly 0.1 quad. Though small, these amounts are potentially significant, says Scott Sklar, the former executive director of the Solar Energy Industries Association and current president of The Stella Group, an energy generation marketing and policy analysis firm. There will be no one-size-fits-all solution to the nation’s energy problems, he says. Instead, energy will come from many sources, many of them small sources, and power will be created through a patchwork of technologies tailored to local circumstances and needs.

MFCs could also become important energy sources in the lesser developed parts of the world, says Logan. These fuel cells used locally produced fuel, and their power output can be managed locally. “Microbial fuel cells [appear] destined, at least at this moment, to utilize some energy resources that are not otherwise available on an industrial scale, like sea bottom sediments, or some biomass from waste,” says Plamen Atanassov, an assistant professor of chemical engineering at the University of New Mexico. One candidate bacterium for MFCs, Rhodoferax ferrireducens, was first isolated from sediments collected in Oyster Bay, Virginia; Geobacter metallireducens was first isolated from sediments from the Potomac River.

Breakthroughs Boost Prospects

MFCs go back to the early 1900s, says Angenent. It was at a 1996 American Chemical Society meeting titled “Emerging Technologies in Hazardous Waste Management” that Korean scientists Byung Hong Kim and Doo-Hong Park first described the use of a “mediator-less biofuel cell” to treat wastewater. Breakthroughs in the last five years have suggested fresh promise for this technology.

One breakthrough was the discovery, reported in the 18 January 2002 issue of Science by Derek Lovley, a professor in the Department of Microbiology at the University of Massachusetts Amherst, that Geobacter produces electricity. That followed the discovery by German and Australian researchers, published in Bacteriology in July 1998 (issue 14), that in certain iron-reducing bacteria, the cytochromes--specialized enzymes known to transfer electrons to other proteins--span the outer cell membrane, enabling direct transfer of electrons to external metals and the creation of a circuit. This is the ultimate source of electricity in MFCs. These discoveries opened up the possibility of engineering both the bacteria and the electrodes in the MFC to improve electron transfer.

In the 23 June 2005 issue of Nature, Lovley announced the discovery of “nanowires,” literally tiny wires produced by Geobacter, which the bacterium presumably uses to transfer electrons. This discovery opened up further possibilities for electron transfer. He also published a study in the Octobe 2003 issue of Nature Biotechnology showing that Rhodoferax provides a constant flow of electrons while oxidizing glucose at 80% electron efficiency--a boon for drawing power from carbohydrates.

Still another breakthrough was the discovery, published by Park and University of Michigan molecular biologist J. Greg Zeikus in the June 2002 issue of Applied Microbiology and Biotechnology, that one could increase power output in MFCs by about sixfold by using mixed microbial communities rather than pure cultures. This is a big advantage for harvesting energy from wastewater, which is microbially diverse, says Angenent. The question of exactly why this is so is an area Angenent plans to address in future research.

The technology has also seen the benefit of engineering advances. A year ago, in unpublished research, Angenent combined the “upflow” system used in methane digesters with the MFC technology to eliminate the need for mechanical pumping and mixing. In the upflow system, wastewater is piped from above the fuel cell, down, around, and then upwards into the bottom of the anode powered by gravity--the opposite of a syphon. Thus, pumping and mixing become unnecessary.

The first microbial fuel cells produced between 1 and 40 milliwatts per square meter (mW/m2) of anode electrode surface area, says Logan. In just the past year, he says, his laboratory has generated power in the range of up to 500 mW/m2 using domestic wastewater and 1,500 mW/m2 with glucose and air. He adds that researchers in Belgium recently achieved 3,600 mW/m2 using glucose, although they needed a nonrenewable chemical instead of air for their process.

Electric versus Hydrogen

MFCs generate electricity, but can be modified to produce hydrogen instead. In both systems, the source of electricity is the chemical energy contained in the bonds of organic compounds. Bacteria, living in biofilms on the anode, break down the organics, separating electrons from protons. These electrons and protons then travel to the cathode, the former via an external wire, the latter by diffusing through the electrolyte, a substance that does not conduct electricity.

In the electricity-generating MFCs, the protons and electrons combine at the cathode with oxygen to form water. This “uses up” the electrons, allowing more to keep flowing from the anode to the cathode.

In the MFC modified to produce hydrogen, the cathode is kept free of oxygen. But in order to make hydrogen, a thermodynamic barrier must be breached. To overcome this barrier, Logan uses a power source to add voltage into the circuit.

The hydrogen MFC appears to be twice as efficient as the electricity-producing cells, says Logan, because in the latter some oxygen leaks back into the anode. However, adding the voltage in the hydrogen-producing system requires about one-sixth of the energy that is produced as hydrogen. Further losses occur if the hydrogen is converted into other forms of energy. Bottom line: in terms of efficiency for electricity as a final product, neither electricity nor hydrogen production possesses a clear advantage.

The main benefit of hydrogen-producing MFCs is that they would provide additional options to fit production to energy needs, says Logan. For example, hydrogen could be stored to make off-peak electricity or for use as a transportation fuel. “But if you just want to use electricity locally, you are probably better off making electricity to start with,” he says.

Many Technological Challenges

MFC technology is still strictly at the laboratory scale. “[It] doesn’t have its own design principals, and borrows from neighboring technologies,” says Atanassov. “It is absolutely premature to even address [questions of design].”

The cathode oxygen in electricity-producing devices creates a big challenge for MFCs. A “proton exchange membrane” separates anode from cathode, allowing protons to pass, but blocking the larger oxygen molecules from diffusing to the anode. However, some oxygen manages to cross the proton exchange membrane into the anode, where it takes electrons that would otherwise flow in the circuit, reducing the power, says Lovley.

The low power density of MFCs is also a major problem. Researchers working on MFCs measure power density in W/m2, while those working on conventional fuel cells measure power density in W/cm2, a highly illustrative disparity, says Atanassov. That low power density of MFCs means electrodes--which aren’t cheap--must be exceptionally bulky.

Power density is a function of the interface between the microbes and the electrodes, says Harold Bright, a program manager in the Office of Naval Research, which is funding studies on MFCs. “We have fairly slow electron transfer from the bacteria into the electrode.”

Scale-up for commercial uses adds to the challenges. The current laboratory-scale prototypes use materials that aren’t sturdy enough to be used in a commercial system, such as carbon paper and carbon cloth electrodes. Further, experimental MFCs, now smaller than a beer mug, would need to be as big as a mansion (in large part to compensate for the low power density), undoubtedly greatly increasing the distance between anode and cathode. That, in turn, would slow diffusion of hydrogen from the former to the latter, damping efficiency.

To be competitive with methane digester technology, MFCs’ practical predecessor, the power density must more than double the maximum achieved so far, to 8,500 mW/m2, says Angenent. And for this, he says, “another breakthrough is required.”

Advances in microbiology and electrode technology leading to higher rates of electron transfer could improve power density; bacteria could be engineered for better electron transfer. Lovley has been systematically deleting genes for outer membrane cytochromes in order to discern which cytochrome was essential for electricity production. “Now we can determine if engineering Geobacter to produce more of this cytochrome and/or modifying the electrode to better interact with the cytochrome will result in more power production,” he says.

There is ample room for improvement. “If Geobacter could transfer electrons to electrodes as fast as it can to its natural electron acceptor, ferric iron, the rate of electron flow--that is, the current--could possibly be ten thousand times higher,” says Lovley.

The use of wastes as cost-free substrates will further improve economics, says Logan. Wastes are ideal since their disposal, he says, “is already an economic burden.”

Currently, there is virtually no government funding for MFCs except for use in applications such as remote sensors, which are funded by the Navy, the Department of Energy, and the Defense Advanced Research Projects Agency. “The current laboratory systems that we build cost way too much money for the amount of electricity we get back,” Logan admits. “[But] the same was true of solar energy fifty years ago.” Now solar has become an important--if still small--contributor to the nation’s energy supply, and Logan predicts that MFCs will follow suit.

http://ehp.niehs.nih.gov/membe.....tions.html
*************************************************************

Questions to explore further this topic:

Start this lesson with RoboCow!

http://www.agr.gc.ca/pfra/flas.....ocow_e.htm

How do we make our water the best it can be?

http://www.agr.gc.ca/pfra/flas.....farm_e.htm

Microbial Fuel Cell Research

http://www.engr.psu.edu/ce/env.....-Logan.htm
http://www.live.psu.edu/story/7177
http://www.psu.edu/ur/2005/hyd.....photos.htm
http://news.nationalgeographic.....power.html

Video of Microbial Fuel Cell

http://www.nsf.gov/news/news_v.....a_id=55395

What are Geobacter and Rhodoferax?

http://www.geobacter.org/research/microbial/
http://www.nature.com/nbt/jour.....-1151.html
http://www.iit.edu/~ekloppen/

When Greenville Turned Brown (A children's story)

http://www.epa.gov/superfund/kids/green/page1.htm

Recycle City (formerly Dumptown) - Children Activity

http://www.epa.gov/recyclecity/mainmap.htm

What is waste?

http://www.learner.org/exhibits/garbage/intro.html

Wastewater
http://coe.mse.ac.in/kidswater.asp

Sewage
http://www.learner.org/exhibit.....ewage.html

Solid Waste
http://coe.mse.ac.in/kidssolid.asp
http://www.learner.org/exhibit.....waste.html
http://www.sanicon.net/titles/.....?topicId=4

Air Pollution
http://www.lbl.gov/Education/E.....-main.html

What are the various methods of solid waste disposal?

http://www.gdrc.org/uem/waste/disposal.html
http://www.umich.edu/~gs265/so.....sposal.htm
http://web.njit.edu/~hsieh/FED/Landfill.html
http://www.ace.mmu.ac.uk/eae/S.....posal.html
http://www.earthsci.org/teache.....%20Methods
http://edugreen.teri.res.in/ex.....sposal.htm

Factors to consider for solid waste management

http://www.epa.gov/epaoswer/no.....apter3.pdf

A set of lessons for landfills

http://landfill-ed.wasteage.co.....;siteid=27
http://www.epa.gov/epaoswer/no.....apter9.pdf

Incineration: An alternative to landfills

http://www.memagazine.org/back.....trash.html
http://www.ejnet.org/dioxin/eur18717en.pdf

Landfill and Incineration versus Zero Waste

http://www.ecologycenter.org/i.....tunity.pdf

Composting: Another Alternative

http://www.epa.gov/epaoswer/no.....apter7.pdf

What is waste treatment?

http://web.em.doe.gov/em30/wasttrea.html

Waste Treatment to Generate Power

http://www.aie.org.au/pubs/wetwaste.htm
http://www.abetterearth.org/su.....p/210.html
http://www.teriin.org/energy/waste.htm
http://www.tide-india.org/proj.....-waste.asp
http://www.greenhouse.gov.au/c.....parta.html
http://www.epa.gov/epaoswer/no.....apter8.pdf

What is recycling?

http://www.dnr.state.wi.us/org...../waste.htm
http://www.epa.gov/epaoswer/non-hw/muncpl/faq.htm
http://www.epa.gov/epaoswer/no.....apter6.pdf

How can we reduce solid waste?

http://www.epa.gov/epaoswer/no...../index.htm
http://www.nps.gov/dsc/dsgncnstr/gpsd/ch9.html
http://www.epa.gov/epaoswer/no.....apter5.pdf

How can we conserve clean water?

http://www.purdue.edu/dp/envir.....nd.htm#toc
http://www.epa.gov/ow/you/intro.html

GAMES

http://www.epa.gov/superfund/kids/alphabet/a.htm
http://www.epa.gov/epaoswer/os...../index.htm
http://www.epa.gov/epaoswer/os...../index.htm
http://www.yucky.com/flash/index.html
http://www.agr.gc.ca/pfra/flas.....ocow_e.htm
http://www.epa.gov/safewater/k.....agame.html


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PostPosted: Mon Jan 16, 2006 7:23 pm    Post subject: Seattle Storm Water Intensifies Pollution Reply with quote

Seattle Storm Water Intensifies Pollution
By PEGGY ANDERSEN, Associated Press Writer
Mon Jan 16, 4:24 AM ET

So it's been raining for weeks. Where does all that water go? The rain falls on fields, golf courses and lawns, on forests and industrial sites. It mixes with oil, pesticides and other nasty substances before finding its way into area lakes and streams — many of them salmon-bearing — and eventually into Puget Sound.

"Storm water is a source of pollution, because there are pollutants in our environment that the storm water picks up," state Ecology Department spokesman Larry Altose said.

And there's plenty of storm water — it rained for 27 days straight, just shy of the 33-day record, before clearing up Sunday.

Industry, septic tanks and manure-rich dairies are not the only polluters putting salmon runs and killer whales at risk.

Cars leak fluids and spew brake-shoe and tire residue onto the street. Homeowners use pesticides to ensure velvety lawns. Pet owners neglect to clean up after their dogs.

"It's everybody's turn," said Fred Felleman of Ocean Advocates. "It's about caring for your car so it doesn't leak oil, using organic alternatives in the garden."

Runoff used to be a concern primarily for lakes and smaller bodies of water. Now larger bodies are at risk as the population booms.

"We each, in our very small ways — multiplied by the millions of us — are contributing to the overall pollution of our waters," Altose said.

Despite improvements in public utilities, storm water and sewage still gushes into Puget Sound and the Duwamish River from the greater Seattle area during heavy rains.

Most of the sewage has undergone at least basic treatment before its release.

"There's raw sewage in there but it's really diluted," King County wastewater-treatment spokesman Gary Larson said. At the same time, "we don't recommend swimming in any of these areas."

___

On the Net:

Seattle Public Utilities: http://www.seattle.gov/util/services
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PostPosted: Mon Apr 10, 2006 1:16 pm    Post subject: Posthumous award to UP professor for environmental science Reply with quote

Posthumous award to UP professor for environmental science set
Mon Apr 10, 2006
Manila Bulletin

The National Academy of Science and Technology (NAST) is set to give this month a posthumous award to a University of the Philippines (UP) professor for his significant contributions in the field of environmental science.


Dr. Wilfredo Barraquio, who died early this year of heart disease, will receive the Hugh Greenwood Environmental Science Award for his contributions to microbiology and their benefits on the environment, society and rice agriculture.

His award will be received by his wife, Dr. Virginia Barraquio, a professor at the UP Los Baños Dairy Training and Research Institute, on April 20 at the Traders Hotel.

Based on the awardee’s biodata obtained by the Manila Bulletin, Barraquio’s research on the environment focused on the utilization of microbes "in cleaning up the environment of pollutants."

Among Barraquio’s researches on the field includes the isolation of natural samples of microorganisms capable of degrading crude oil.

"Some of these organisms are still stored at the Museum of Natural History, UPLB, available for biotechnological exploitation as component of a bioremediation formulation," the paper said.

The same study also found out that native microbes have the capability to remove specific pollutants in case of an oil spill in a non-polluted site through site fertilization.

Using lahar (ash ejecta), Barraquio also studied nutrient deficient soils and the microbial degradation of aromatic compounds like phenol and synthetic dyes, particularly those used in the paper industries.

"Results of our lahar research have shown that good native microbes are associated tightly and loosely with the roots of wild legumes and talahib that pioneer nutrient-deficient lahar," said Barraquio and his research group.

In another research work, Barraquio’s group was able to isolate bacteria "which could degrade phenol and synthetic dyes under oxygen-limiting conditions and bacteria which are capable of transforming ammonia, nitrite, and nitrate to less hazardous forms."

In rice agriculture, his study on the microbial ecology and activity of nitrogen-fixing bacteria associated with the rhizosphere of paddy rice "paved the way for more intense research in rice heterotrophic nitrogen fixation worldwide."

Prior to the NAST — Hugh Greenwood Environmental Science Award, Barraquio had been granted a graduate scholarship by the National Science Development Board, currently the Department of Science and Technology, in 1973 to 1975; a postgraduate fellowship in Japan by the United Nations Educational, Scientific and Cultural Organization - International Cell Research Organization; McGill University Dalbir Bindra Graduate Fellowship in McGill University, Quebec, Canada; and as an exchange scientist at the University of Tokyo’s Department of Biotechnology in 1992; Osaka University’s Dept. of Biotechnology in 1993; and Tohoku University’s Institute of Genetic Ecology in 2000, all by the Japan Society for the Promotion of Science.

Barraquio also served as president of the Philippine Society for Microbiology from 2004 to 2005.

The NAST - Hugh Greenwood Environmental Science Award, which usually coincides with the Earth Day celebration, is given in recognition of outstanding specific and technological works that contribute to environmental protection and conservation.
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PostPosted: Tue May 23, 2006 1:08 pm    Post subject: Sweet success for pioneering hydrogen energy project Reply with quote

Engineering and Physical Sciences Research Council
23 May 2006

Sweet success for pioneering hydrogen energy project

EPSRC press release
Bacteria that can munch through confectionery could be a valuable source of non-polluting energy in the years ahead, new research has shown.
In a feasibility study funded by the Engineering and Physical Sciences Research Council, bioscientists at the University of Birmingham have demonstrated that these bacteria give off hydrogen gas as they consume high-sugar waste produced by the confectionery industry.

The hydrogen has been used to generate clean electricity via a fuel cell1. Looking to the future, it could also be used to power the hydrogen-fuelled road vehicles of tomorrow. There is increasing recognition that, over the coming decades, hydrogen could provide a mainstream source of energy that is a safe, environmentally friendly alternative to fossil fuels.

This was a highly successful laboratory demonstration of bacterial hydrogen production using confectionery waste as a feedstock. The waste was supplied by Birmingham-based international confectionery and beverage company Cadbury Schweppes plc, a partner in the initiative. An economic assessment undertaken by another partner, C-Tech Innovation Ltd, showed that it should be practical to repeat the process on a larger scale.

As well as energy and environmental benefits, the technique could provide the confectionery industry (and potentially other foodstuff manufacturers) with a useful outlet for waste generated by their manufacturing processes. Much of this waste is currently disposed of in landfill sites.

In this project, diluted nougat and caramel waste was introduced into a 5 litre demonstration reactor (although other similar wastes could be used). The bacteria, which the researchers had identified as potentially having the right sugar-consuming, hydrogen-generating properties, were then added.

The bacteria consumed the sugar, producing hydrogen and organic acids; a second type of bacteria was introduced into a second reactor to convert the organic acids into more hydrogen. The hydrogen produced was fed to a fuel cell, in which it was allowed to react with oxygen in the air to generate electricity. Carbon dioxide produced in the first reactor was captured and disposed of safely, preventing its release into the atmosphere.

Waste biomass left behind by the process was removed, coated with palladium2 and used as a catalyst in another project, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), aimed at identifying ways of removing pollutants such as chromium (VI) and polychlorinated biphenyls (PCBs) from the environment. The reactors used by this parallel initiative also required hydrogen and this was supplied by the confectionery waste initiative too, further underlining the 'green' benefits offered by the new hydrogen production technique.

Professor Lynne Macaskie of the University of Birmingham's School of Biosciences led the research team. "Hydrogen offers huge potential as a carbon-free energy carrier," she comments. "Although only at its initial stages, we've demonstrated a hydrogen-producing, waste-reducing technology that, for example, might be scaled-up in 5-10 years' time for industrial electricity generation and waste treatment processes."

The team is now engaged in follow-up work which will produce a clearer picture of the overall potential for turning a wider range of high-sugar wastes into clean energy using the same basic technique.


###
See the new technology in action at http://bst.portlandpress.com/b.....76add.htm. This video clip shows gas from the reactor being fed to a fuel cell, producing electricity that enables the electric fan to turn.

Notes for Editors

The 15-month feasibility study 'Biological Hydrogen Production from Crops and Sugar Wastes' received EPSRC funding of nearly £24,000.

Bacteria can appear naturally in the environment or can be adapted into new forms in the laboratory. The bacteria used in this study were:

(i) An adapted form of a harmless strain of E. coli originally developed in Germany. The team used this organism to break down the confectionery waste.

(ii) Rhodobacter sphaeroides, a naturally occurring organism. This was used to turn the organic acids into hydrogen.

1 Fuel cells are devices that produce power by harnessing electrochemical reactions between (i) oxygen taken from the air and (ii) hydrogen. The only by-products are clean water and heat. Combined heat and power (CHP) units are the likely route forward for this technology, which is expected to find increasing application in the years ahead, initially in niche markets but then more widely as the units become more cost competitive. With the commercial supply of clean water decreasing, the water generated as a by-product could also find important uses.

2 Palladium is a soft, steel-white, tarnish-resistant, metallic element occurring naturally with platinum, especially in gold, nickel, and copper ores. Because it can absorb large amounts of hydrogen, it is used as a purification filter for hydrogen and a catalyst in hydrogenation.

As well as confectionery waste, the study tested the viability of potato extract as a feedstock for hydrogen-producing bacterial action. This did not yield promising results as the potato starch proved difficult to break down with the bacteria used.

The Engineering and Physical Sciences Research Council (EPSRC) is the UK's main agency for funding research in engineering and the physical sciences. The EPSRC invests more than £500 million a year in research and postgraduate training, to help the nation handle the next generation of technological change. The areas covered range from information technology to structural engineering, and mathematics to materials science. This research forms the basis for future economic development in the UK and improvements for everyone's health, lifestyle and culture. EPSRC also actively promotes public awareness of science and engineering. EPSRC works alongside other Research Councils with responsibility for other areas of research. The Research Councils work collectively on issues of common concern via Research Councils UK. Website address for more information on EPSRC: www.epsrc.ac.uk/
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PostPosted: Wed Jul 26, 2006 5:55 pm    Post subject: UP engineers’ landfill is a dream dump Reply with quote

UP engineers’ landfill is a dream dump

By Gerry Lirio
Inquirer
Last updated 05:53am (Mla time) 07/27/2006

Published on Page A1 of the July 27, 2006 issue of the Philippine Daily Inquirer

IT WILL BE A DREAM DUMP.

Garbage collectors and segregators, and even trucks and drivers will be there in bright, color-coded uniforms -- blue shirts for those who want to get plastic wastes, red for those interested in paper, and green for those looking for broken glass, metals, wiring and other trash.

This is how a group of young engineers from the University of the Philippines at Los Baños (UPLB) envisions a P55-million sanitary landfill project in a 75-hectare mountainous property in Norzagaray, Bulacan, in the next few months.

Once operational, it can service the entire Metro Manila and Bulacan province.

The site in Sitio Tiakad, Barangay San Mateo, is the best ever for a landfill project for its sheer size and strategic location, said the project proponent, chemical engineer Ramon Angelo. “A waste memorial park, a showcase of waste handling in the country,” he said.

“This project will hopefully be a very good example of a facility for proper solid waste management in the country, with all its required components,” said engineer Mylene M. Palaypayon, the team leader.

Angelo said the project was conceptualized in line with the government’s policy to adopt a systematic, comprehensive and sound ecological solid waste management program under Republic Act No. 9003, or the Ecological Solid Waste Management Act of 2000, to ensure public health and protection of the environment.

ECC grant

Officials of the Department of Environment and Natural Resources (DENR) granted an environment clearance certificate for the project on June 23, with a Category 4 grade, the highest given so far to a landfill project. The document allows the proponent to widen the area to 148 hectares of land in the next few years.

All landfills, it is said, are dumps, but not all landfills are dumps. Unlike an ordinary dump, a landfill is covered with a layer of soil after treating every three to four meters of garbage. Aside from soil cover, a landfill, before receiving waste, is spread with composite soil liner to protect the watershed.

A landfill is also treated with enzymes to prevent pests and foul smell.

At least 10 major dumps and landfills service Metro Manila. Among these are Payatas, 23.2 ha; San Mateo, 73 ha; Clark, 85 ha; and Carmona, 63 ha.

A former dump, the 22-ha Smokey Mountain in Tondo, Manila, was closed by the Ramos administration in May 1993. It had a Category 2 rating; San Mateo, Category 3.

The Norzagaray landfill is expected to receive between 2,000 and 3,000 tons of garbage a day, compared with Clark’s 1,500 tons and Payatas, 1,200 tons. The 63-ha Carmona has a daily capacity of only 1,000 tons, while Smokey Mountain had 1,500 tons.

Inverted pyramid

Tons of garbage usually form a huge “pyramid-type mountain” daily in existing dumps and landfills. But in Norzagaray, which is on a mountaintop 80 meters above sea level, it will be an inverted pyramid with an estimated depth of 60 meters.

“We will never have a landslide here, the kind Payatas had experienced years ago,” Angelo said. It will take at least 10 years to fill up the 18.8 ha of the Norzagaray landfill that is currently being developed, and about 20 years for the entire 148-ha property.

Bulacan province has a total waste generation of about 700 tons per day and Quezon City, 1,700 tons. Assuming that all local government units in Bulacan and in Quezon City will tap the new facility, with waste diversion of 15-20 percent per day, the 18.8-ha facility is estimated to have a life span of 10 years with a total volume of 8,820,000 cubic meters.

Construction of the access roads will be finished this month. The landfill can start receiving wastes from neighboring towns and cities in August or September.

This early, two American companies have expressed interest in helping Angelo’s group develop the area. The group will shoulder the project’s initial funds.

Colors galore

Once operational, garbage segregators will wear hard hats, rubber boots, gas masks, goggles and gloves, aside from color-coded uniforms. Supervisors and security people will wear yellow uniforms, while engineers and executives will be in white.

The landfill will be operational 24/7. It can accommodate 200 garbage trucks a day.

To date, however, the Norzagaray landfill has not been authorized to receive hospital and other toxic wastes. “We are capable, but we are not allowed yet. But we do have provisions just in case toxic wastes land upon us by accident,” Angelo said.

Angelo discovered the site while looking for a “mine-out” or a source of soil for areas left by cement mining companies in Norzagaray.

The site is 14 km southeast of Norzagaray’s town proper, bounded in the east by the Sierra Madre mountain range and on the south, by the town of Montalban in Rizal province.

It is accessible not only to Bulacan communities but also to northern Metro Manila and some towns of Rizal. It is 21.5 km from Commonwealth Road in Quezon City and 9 km from the Novaliches-Norzagaray national road in Barangay Igay, San Jose del Monte City in Bulacan.

Forest ambience

If the C-6 road project pushes through, the landfill will have a main entrance there, only 5 km from the town proper of San Mateo.

The area was once considered a rustic place with pristine scenery, good water quality, ambient air and ecologically sound environment.

Based on a study done by Palaypayon’s group, the site, although devoid of any primary forest growths, still has the ambience of forest scenery due to its rolling to hilly terrain, with steep cliffs of high relief in some sections of the deeply incised narrow valleys.

The view from the top still offers a panorama of abundant vegetation. Different varieties of fruit-bearing trees are mixed with secondary forest growths and tropical grasses and shrubs.

Groundwater is considered poor. The water bearing horizons are tight, indicating a very low hydraulic conductivity due to the inherent characteristics of the rock suite in the project.

Angelo abandoned his initial plan to dig soil for mining sites after the owners of the private property said they wanted to develop the rugged terrain into a residential-commercial area. Some of them met with Angelo and his team but chose a custodian to deal with them on the agreement to lease and develop the property.

A team of experts

He later commissioned a former DENR official to draft a proposal, but the work was rejected by the department for its infirmities. The ECC was granted only after a second group, the UPLB team led by Palaypayon and Marloe B. Sundo, submitted a more comprehensive concept design.

Palaypayon is a civil and environment engineer. Sundo is also a civil engineer who majored in transportation engineering. Both teach at UPLB and are experienced in environmental engineering, primarily on landfill design.

“We are working as a team of different technical expertise, one is working on transportation engineering and surveying, one is working on drainage engineering, one on geotechnical engineering, and I am into environmental engineering,” Palaypayon said.

“We are composed of relatively young engineers. But we have our own capacities to technically address the needs of the project,” she said.

First phase

Norzagaray is her team’s second landfill after San Jose del Monte. The first of the project’s three phases will focus on an 8.87-ha portion on the west, bordering the national highway and adjacent to the proposed alignment with C-6.

It will cover all the project components -- sanitary landfill, materials recovery facility, dumping and tipping pads, compost-fertilizer pit and leachate ponds -- as well as access road, drainage facility, administration building, canteen, water supply system and workers’ quarters.

Phases 2 and 3 involve expansion to the rest of the property.
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PostPosted: Thu Aug 10, 2006 5:25 pm    Post subject: How good microorganisms clean our wastes Reply with quote

How good microorganisms clean our wastes: What happens when you flush

STAR SCIENCE By Francis L. De Los Reyes III, Ph.D.The Philippine STAR 08/10/2006
http://www.philstar.com/philst.....104402.htm

Mention "bacteria" and most people think of disease-causing organisms that
should be eradicated at all costs, as evidenced by our massive use of
antibiotics in all forms. However, microorganisms, such as bacteria and
protozoa, have been on Earth much longer than humans (bacteria appeared
about 3.5 billion years ago), and make up most of the Earth's biomass.
Microorganisms can be divided into the three "domains" of life: Bacteria,
Archaea, and Eukarya. Members of the Bacterial and Archaeal domains are
prokaryotic cell forms, and mostly unicellular, while Eukaryal organisms
have true nuclei, and can be multicellular. All three domains are involved
in "cleaning up" the wastes that we humans produce.

The domestic and industrial wastewater, solid wastes, hazardous wastes, and
air contaminants that human activity produces are consumed or converted by
microorganisms to innocuous forms. How do microorganisms do this? As an
example, let's take the case of human ("domestic" or municipal) wastewater.
After your toilet is flushed, the wastewater flows to a septic tank (very
common in Metro Manila) and/or through a series of sewer lines to a
centralized wastewater treatment plant (e.g., the WWTP along Commonwealth
Avenue in Quezon City serves the UP Diliman area). A common measure of
"degree of pollution" or waste strength in wastewater is the amount of
organic carbon present in the wastewater. Because it is very difficult and
time-consuming to determine all the specific chemicals in human wastes as
well as in many waste streams, we measure the waste strength in terms of the
amount of oxygen needed to convert the organic carbon to CO2. We call this
the "Biochemical Oxygen Demand" or BOD. The typical BOD of domestic waste is
around 150-250 mg/L. Industrial wastewaters can have much higher BOD values,
sometimes in the tens of thousands. Before discharging to receiving streams
and rivers, the BOD should be as low as possible, around 10-20 mg/L (this
depends on the applicable regulations). When high BOD wastewater is
discharged into the river, microorganisms present in the river use up all
the dissolved oxygen (DO) in the water. The river turns "septic"; it becomes
black and starts to smell, as anaerobic processes take over. The Pasig River
is the classic example of a river with depleted O2.

At the wastewater treatment plant, a variety of bacterial species (and some
protozoa) are actively "grown" in tanks. These organisms consume the
organics and lower the BOD. To do so, they have to be supplied with enough
oxygen so they can perform the conversion of organics to CO2 and more
bacterial cells. Some of the cells are retained in the system; some are
excess, and have to be removed. The excess biomass, or "sludge" solids,
should be treated (to reduce pathogens and degrade the volatile component),
dewatered, and disposed of properly. Typically, the solids are land-applied
to take advantage of the nutrients (nitrogen and phosphorus) present.
Environmental engineers and WWTP operators design and operate wastewater
treatment plants so that the different factors (e.g., biomass
concentrations, reactor size, flow rates, oxygen levels, etc.) are in
balance and optimized.

Aside from BOD, microorganisms transform nutrients such as nitrogen and
phosphorus and decrease their concentrations in receiving water bodies.
Nitrogen is an important nutrient, and high levels in lakes and rivers may
lead to eutrophication, wherein high productivity causes algal blooms that
then die and deplete the dissolved oxygen as organisms use up the organic
carbon. Some cyanobacteria also produce algal toxins (for example, red tide
poisoning is a manifestation of cyanobacterial growth). Nitrate in drinking
water may lead to methemoglobinemia (blue-baby syndrome), where nitrate is
converted in human saliva to nitrite, which then competes with oxygen in
hemoglobin, thus reducing the O2 in the bloodstream.

In wastewater, nitrogen is usually in the form of ammonia or organic
nitrogen, which is quickly converted to ammonia. Ammonia is used by
autotrophic bacteria (e.g., Nitrosomonas and Nitrosospira) as an electron
donor (substrate), and is oxidized in the presence of O2, to nitrite. This
occurs at the wastewater treatment plant by giving these relatively
slow-growing bacteria enough time to grow in the reactors. The nitrite
produced is then subsequently oxidized by nitrite oxidizing bacteria (e.g.,
Nitrobacter and Nitrospira) to nitrate. The two-step process is collectively
called nitrification. At this point, the nitrate is still dissolved in the
wastewater. To remove nitrate, oxygen is removed from the reactors by
turning off the air supply. Those heterotrophic bacteria that can denitrify
then use the nitrate (instead of O2) as electron acceptor, and convert the
nitrate to gaseous N2. Nitrogen gas is simply released to the atmosphere,
which is 78 percent N2 anyway. There are other nitrogen transformation
processes that occur in Nature and in wastewater treatment plants, but for
the most part, nitrification-denitrification is the major route for nitrogen
in wastewater treatment.

Phosphorus is another nutrient that limits the productivity (read:
eutrophication) of lakes and other water bodies. This is why phosphorus in
the form of phosphates (P) has been removed as an ingredient in most
detergents. However, domestic wastewater still has some P, and industrial
cleaners (e.g., phosphoric acid) contribute phosphorus to waste streams.
Phosphorus can be biologically removed by phosphate accumulating organisms
(PAOs). These organisms apparently store polyphosphates (P polymers) as they
are cycled through anaerobic and aerobic conditions. Under no oxygen
conditions, these organisms take up volatile fatty acids (VFAs) such as
acetate and release phosphate by cleaving polyphosphate molecules. However,
in subsequent aerobic conditions, they take up more phosphate than they
released, resulting in a net P removal from the liquid stream. The stored
polyphosphates are removed when the solids is removed. When treated
properly, the sludge can be used as fertilizer, and the accumulated
phosphates can serve as plant nutrients.

In your backyard septic tank, the bioprocesses are slightly different. The
deeper portions of the septic tank are anaerobic, and here fermentative
bacteria convert the organics to reduced forms, such as volatile fatty
acids. These VFAs are, in turn, converted to methane by methanogenic
organisms that are members of the Archaea. If sulfate is present, the
sulfate is reduced to sulfide by sulfate-reducing bacteria. Hydrogen sulfide
is the gas that gives off the characteristic "rotten egg" smell. Most of the
liquid flows out of the septic tank, ideally into a leachfield (a volume of
soil of adequate proportions). Here, the organic material in wastewater is
converted by soil bacteria to CO2. Over time, the solid byproducts of
anaerobic digestion accumulate in the tank, and that is the time homeowners
have to call in the folks who extract the solids for a fee. These extracted
solids would also have to be disposed of properly.

In Metro Manila, septic tank overflows are typically connected to the sewer
system infrastructure. Very old sewer lines are typically clogged with
sediment, tree roots, and are most likely full of cracks and breaks, and
leaking into the surrounding soil. Since groundwater wells are common, the
possibility of contamination of water sources is high. In general, the
deeper the well, the less chance there is for contamination from septic
tanks. Still, most homeowners in Metro Manila relying on groundwater pumps
should have their drinking water tested for coliform bacteria, the
indicators of fecal contamination. There is a drastic need for upgrading the
very old sewer system infrastructure in Metro Manila.

How about solid waste? In your backyard compost pile, Bacteria and Eukarya
such as fungi break down the complex material to macromolecules and
byproducts such as humus. The processes in compost piles are typically
aerobic, and are simply "accelerated" processes of what would occur
naturally (e.g., on forest floors). Typically, municipal solid waste is
collected and hopefully disposed of in an engineered landfill. The landfill
is really a giant anaerobic solid waste reactor, and anaerobic processes
occur here. Complex material is broken down. For example, paper and other
cellulose-based material are degraded by cellulolytic bacteria that
ultimately convert the cellulose to fatty acids. Fermenting bacteria convert
other complex carbohydrates, proteins, and fats to long chain and short
chain fatty acids (such as acetate), hydrogen, and CO2. Methanogenic
bacteria then use the acetate and CO2 to form methane. In properly designed
landfills, the methane can be captured for energy, or at least burned to
convert the methane to CO2. If left unburned, the released methane can act
as a greenhouse gas (methane is 21 times deadlier as a greenhouse gas than
CO2). Once filled to design capacity after many years of operation,
landfills can be capped and converted to parks and golf courses. In
non-engineered systems, such as open dumps, all you would get is a mountain
of smoking (that's the slowly burning methane) garbage. In either case,
microorganisms are doing what they've been doing for a long time - simply
eating to survive, grow, and produce more biomass. What engineers and
scientists are doing, in both wastewater and solid waste treatment and
disposal, is to harness these microorganisms to clean up our wastes in
engineered, well-designed and operated systems. These waste treatment
systems have to be designed, built, and operated properly. Without them, we
will continue to have black, smelly rivers and smoking, open garbage dumps.
* * *
Francis L. de los Reyes III is an associate professor of Environmental
Engineering at North Carolina State University. He obtained degrees from the
University of the Philippines in Los Baños, Iowa State University, and the
University of Illinois in Urbana-Champaign. He conducts research and teaches
classes in environmental biotechnology, biological waste treatment, and
molecular microbial ecology. He is a member of the Philippine American
Academy of Science and Engineering (PAASE). E-mail at fldelosr@eos.ncsu.edu
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PostPosted: Mon Sep 25, 2006 7:47 pm    Post subject: Better sludge through metagenomics Reply with quote

DOE/Joint Genome Institute
25 September 2006

Better sludge through metagenomics

Researchers seek to master wastewater treatment failures
WALNUT CREEK, CA--Few stop to consider the consequences of their daily ablutions, the washing of clothes, the watering of lawns, and the flush of a toilet. However, wastewater treatment--one of the cornerstones of modern civilization--is the largest microbially-mediated biotechnology process on the planet. When it works, it is a microbial symphony in tune with humanity. When it fails, the consequences can be dire. Researchers from the U.S. Department of Energy Joint Genome Institute (DOE JGI) and collaborators at the University of Wisconsin-Madison, and the Advanced Wastewater Management Centre, University of Queensland, Australia, have published the first metagenomic study of an activated sludge wastewater treatment process. The research appeared online in the September 24 edition of the journal Nature Biotechnology (http://www.nature.com/nbt/journal/vaop/ncurrent/abs/nbt1247.html).

The metagenomic strategy entails generating DNA sequence information directly from samples of sewage sludge to provide a blueprint of the genes and hence the metabolic possibilities of the wastewater environment, with a view to understanding how the system works and predicting and averting failures or crashes.

"This is a first step in a much broader strategy employing a systems biology approach to the study of microbial communities with the goal of designing predictive models to understand how these communities function," said Hector Garcia Martin, lead author of the study and post-doctoral fellow in the DOE JGI's Microbial Ecology Program. "With this information now available, there are opportunities to bioengineer the process to make it more reliable."

Removing excess phosphorus from wastewater can be most economically accomplished by environmentally friendly biological means in a process known as enhanced biological phosphorus removal (EBPR). The researchers were able to obtain a nearly complete genetic blueprint for a key player in this process, the bacterial species Accumulibacter phosphatis.

Activated sludge wastewater treatment processes are used throughout the world to purify trillions of gallons of sewage annually. Many treatment plants employ specialized bacteria to remove the nutrient phosphorus, in an effort to protect lakes and rivers from eutrophication, a deterioration of water quality characterized by excessive algae blooms. Accumulibacter play a vital role in wastewater management, accumulating massive amounts of phosphorus inside their cells.

"Engineers and microbiologists have been trying for 35 years to grow this microbe, with no success," said Trina McMahon, Assistant Professor, Department of Civil and Environmental Engineering, University of Wisconsin, Madison, and one of the study's authors. "Remarkably, through metagenomic techniques, we were able to isolate and acquire the genome sequence of Accumulibacter phosphatis without a pure culture of the organism, which, like most microbes, eludes laboratory culture. We expect that clues hidden in the genome will lead to domestication of this mysterious organism, enabling further studies of its habits and lifestyle.

"The genome sequence will also enable biologists and engineers to understand why and how these organisms accumulate phosphorus, and it will lead to major advances in optimizing and controlling the EBPR wastewater treatment process," McMahon said. "In particular, it makes possible further research into why some wastewater treatment plants occasionally fail. These failures often result in serious pollution of lakes, rivers, and estuaries."

When things go wrong, the environment can be inundated with untreated phosphorous, carbon, and nitrogen--the detritus of human activities--necessitating costly and environmentally taxing remedies and exposing the public to potential disease hazards. The scale is daunting--more than 31 billion gallons of wastewater are treated daily in the U.S. alone. Even a marginal improvement in the process would translate into huge savings and spell relief for environmental engineers.

David Jenkins is Professor Emeritus of Environmental Engineering at the University of California at Berkeley. His research spans some forty years of international professional practice in water and wastewater chemistry and wastewater treatment for government, municipalities, and industry. He has specialized in the chemical precipitation of phosphate from wastewater and sludges, the causes and control of activated sludge bulking and foaming, and biological nutrient removal.

"The findings and tools described in this landmark paper will allow the resolution of many of the questions that have arisen concerning the mechanism by which the enhanced removal of phosphate from wastewater occurs," said Jenkins. "Understanding these mechanisms will undoubtedly lead to more efficient operation of the process and to the development of more robust designs."

Microorganisms are well equipped to do the job, but activated sludge is a black box, at least for those engineers who are dependent on the microbial aspect of the equation. To shed some light on the challenge, the team compared sludge samples from wastewater plants in Madison, Wisconsin, and Brisbane, Australia, that they maintained in laboratory-scale bioreactors to control and monitor the status of the sludge microbial communities.

"We found functions that didn't make sense for the current lifestyle of the organism," said Phil Hugenholtz, head of the JGI's Microbial Ecology Program. "Accumulibacter has all the genes necessary to fix carbon and nitrogen, which it would be compelled to do in a nutrient-poor environment like freshwater, but it presumably wouldn't have much use for in nutrient-rich EBPR sludge. So it got us thinking that these bacteria must be living in natural habitats and that they have become opportunistically adapted to this manmade process, wastewater treatment." It would appear, Hugenholtz went on, that Accumulibacter has been following in humanity's environmental footprints. "The genomes of the bacteria from the two sites were surprisingly similar--practically identical in parts--from samples separated by nearly 9,000 miles."


###
The work was conducted under the auspices of the DOE JGI's Community Sequencing Program (CSP). The goal of the CSP is to provide a world-class sequencing resource for expanding the diversity of disciplines--oceanography, geology and ecology, among others--that can benefit from the application of genomics, particularly at the intersection with DOE mission areas of bioenergy, carbon cycling, and bioremediation. DOE JGI's Genome Biology Program contributed invaluable expertise and insight for the genome analysis and the metabolic reconstruction of the microbial population.

The DOE Joint Genome Institute, supported by the DOE Office of Science, unites the expertise of five DOE national laboratories, Lawrence Berkeley, Lawrence Livermore, Los Alamos, Oak Ridge, and Pacific Northwest, along with the Stanford Human Genome Center to advance genomics in support of the DOE missions related to clean energy generation and environmental characterization and clean-up. DOE JGI's Walnut Creek, Calif. Production Genomics Facility provides integrated high-throughput sequencing and computational analysis that enable systems-based scientific approaches to these challenges. Additional information about DOE JGI can be found at: http://www.jgi.doe.gov/
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PostPosted: Wed Oct 04, 2006 10:08 am    Post subject: UN: Sewage a Growing Problem Reply with quote

UN: Sewage a Growing Problem

By Mike Corder
Associated Press
posted: 04 October 2006
10:08 am ET

THE HAGUE, Netherlands (AP) ─ Untreated sewage pouring into the world's seas and oceans is polluting their water and coastlines and endangering the health and welfare of the people and animals that inhabit them, according to a bleak new U.N. report released Wednesday on the threats to the world's marine environments.

As well as the growing problem of sewage, oceans also are suffering from rising levels of nutrients such as run-off from agricultural land triggering toxic algal blooms that deprive the water of oxygen, destruction of coastal ecosystems such as mangroves and a rising tide of ocean litter, says the State of the Marine Environment report drawn up by the U.N. Environment Program.

“An estimated 80 percent of marine pollution originates from the land and this could rise significantly by 2050 if, as expected, coastal populations double in just over 40 years time and action to combat pollution is not accelerated,'' U.N. Environment Program chief Achim Steiner said.

For the full article:

http://www.livescience.com/env.....ewage.html
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PostPosted: Sun Feb 11, 2007 8:00 am    Post subject: Manure: You May Be Walking on It Soon Reply with quote

Manure: You May Be Walking on It Soon

By David N. Goodman
Associated Press
posted: 10 February 2007
12:56 pm ET

DETROIT (AP)—Home-buyers of tomorrow could find themselves walking across floors made from manure. Researchers at Michigan State University and the U.S. Department of Agriculture insist it's no cow pie in the sky dream. They say that fiber from processed and sterilized cow manure could take the place of sawdust in making fiberboard, which is used to make everything from furniture to flooring to store shelves.

And the resulting product smells just fine.

The researchers hope it could be part of the solution to the nation's 1.5-trillion- to 2-trillion pound annual farm waste disposal problem.

The concept has its skeptics.

For the full article:

http://www.livescience.com/env.....loors.html
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PostPosted: Mon Apr 09, 2007 7:36 am    Post subject: Portable Refinery Makes Fuel from Food Scraps and Trash Reply with quote

Portable Refinery Makes Fuel from Food Scraps and Trash

By Bill Christensen

posted: 08 April 2007
01:04 pm ET

The tactical biorefinery is a portable machine that can convert food waste and inorganic trash into electricity. Purdue University researchers created a unique hybrid design for the U.S. Army. It uses three distinct technologies to perform its magic:


    A bioreactor that uses enzymes and micro-organisms to turn food waste into ethanol

    A gasification unit that turns plastics, paper, and other residual waste into methane and low-grade propane and

    A modified diesel engine that can burn gas, ethanol, and diesel fuel in variable proportions.



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http://www.livescience.com/sci.....inery.html
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PostPosted: Thu May 03, 2007 10:42 am    Post subject: Beer Maker, Scientists to Create Energy Reply with quote

Beer Maker, Scientists to Create Energy

By Rod McGuirk
Associated Press Writer
posted: 02 May 2007
5:20 pm ET

CANBERRA, Australia—Scientists and Australian beer maker Foster's are teaming up to generate clean energy from brewery waste water—by using sugar-consuming bacteria.

The experimental technology was unveiled Wednesday by scientists at Australia's University of Queensland, which was given a $115,000 state government grant to install a microbial fuel cell at a Foster's Group brewery near Brisbane, the capital of Queensland state.

The fuel cell is essentially a battery in which bacteria consume water-soluble brewing waste such as sugar, starch and alcohol.

The battery produces electricity plus clean water, said Prof. Jurg Keller, the university's wastewater expert.

For the full article:

http://www.livescience.com/env.....nergy.html
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PostPosted: Tue Jun 05, 2007 1:11 pm    Post subject: Sediment dredging has fallen short of achieving cleanup goal Reply with quote

The National Academies
5 June 2007

Sediment dredging has fallen short of achieving cleanup goals at many contaminated sites

WASHINGTON -- At many projects to dredge contaminated sediments from U.S. rivers and other bodies of water, it has not been demonstrated that dredging has reduced the long-term risks the sediments pose to people and wildlife, says a new report from the National Research Council. Many dredging projects have had difficulty meeting short-term goals for reducing pollution levels. Whether dredging alone can reduce long-term risks was difficult to determine at many sites because of inadequate monitoring data and other limitations, the report says. It calls on the U.S. Environmental Protection Agency to improve and intensify its monitoring at dredging and other projects intended to remediate contaminated sediments at the nation's Superfund sites.

Dredging's ability to achieve cleanup goals depends on a site's characteristics, the report also concludes. If a particular site has one or more unfavorable conditions -- the presence of debris such as boulders or cables, for example, or bedrock lying beneath the contaminated sediment -- then dredging alone is unlikely to be sufficient. The presence or absence of such conditions should be a major consideration in deciding whether to dredge at a site, said the committee that wrote the report.

Contaminated sediments can be found at the bottoms of many U.S. rivers and other water bodies near former mining, agricultural, or industrial sites. Tainted with polychlorinated biphenyls (PCBs), heavy metals, or other toxic substances, the sediments can pose risks to people, fish, and aquatic animals. Many of these sites are slated for cleanup by EPA under federal Superfund legislation, and a minimum of 14 of them are sediment "megasites" -- sites where the cost of remediating sediments is expected to reach at least $50 million, or has already done so. Decisions about whether to dredge at these sites have proved controversial, so Congress asked the Research Council to evaluate the method's effectiveness. To inform its conclusions, the committee examined 26 dredging projects, five of them at megasites, and evaluated whether they had attained their cleanup and risk-reduction goals.

Dredging is effective at removing contaminated sediment mass permanently from the environment, the report says. But removing mass may not be enough to achieve desired cleanup levels or long-term goals for reducing risks, because dredging inevitably leaves residual contamination behind. Dredging alone achieved expected cleanup results at only a few of the sites the committee analyzed. At many others, capping -- placing a layer of uncontaminated material over the tainted sediments -- was also necessary to contain the remaining contamination at acceptable levels. Assessments of the sites also revealed that the dredging process releases contaminants into the water, which in the short term can have adverse effects on fish and other aquatic animals and could potentially raise health risks in people who consume them.

Dredging remains one of the few approaches available for cleaning up contaminated sediments, the report says, and EPA should continue to consider its use among other methods. In locations where buried contaminated sediments could be dislodged by storms, for example, dredging the sediments to prevent them from being transported may reduce risks. If dredging is used, planners need to recognize that residual contamination and releases of chemicals into the water will invariably occur; they should estimate the effects of these processes in advance, and employ best practices to minimize them, the committee said. Using a combination of methods should also be considered, particularly if a site has any characteristics unfavorable to dredging.

The typical Superfund approach, in which EPA conducts an investigation and a feasibility study that establishes a single path to remediation, is not the best way to choose remedies for these sites, the report says. Given the long time frames and many unknowns involved in cleaning up megasites, adaptive management -- which uses monitoring data to review progress and adjust plans when needed -- should be used to select and implement cleanup methods. In addition, dredging and other remediation projects should be designed to meet long-term goals for reducing risks to people and wildlife, instead of objectives not directly related to risk, such as removing a specified amount of sediment.

The report emphasizes that without adequate monitoring before and after dredging, it is impossible to evaluate the degree to which cleanup objectives have been reached. EPA should invest in better and more consistent measurement tools to monitor conditions in the field reliably and efficiently. Monitoring data should also be made available to the public in electronic form, so that evaluations of remedies' effectiveness can be independently verified.

In addition, to help ensure that megasites with contaminated sediments are cleaned up as effectively as possible, EPA should centralize resources, responsibility, and authority for these sites at the national level, the report recommends. Such a shift would help the agency make sure that monitoring is adequate and that adaptive management and best practices are followed.


###
The report was sponsored by the U.S. Environmental Protection Agency. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, nonprofit institutions that provide science, technology, and health policy advice under a congressional charter. The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering. A committee roster follows.

Copies of Sediment Dredging at Superfund Megasites: Assessing the Effectiveness will be available from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or on the Internet at http://www.nap.edu
Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

[ This news release and report are available at http://national-academies.org ]
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PostPosted: Thu Jun 21, 2007 7:37 am    Post subject: Computer modeling could help chlorine-hungry bacteria break Reply with quote

June 14, 2007
Computer modeling could help chlorine-hungry bacteria break down toxic waste
By Bill Steele

Cornell researchers hope to learn how certain bacteria that break down pollutants do their job and then to make them more effective in cleaning up toxic wastes.

Bacteria called Dehalococcoides ethenogenes, discovered in Ithaca sewage sludge in 1997 by James Gossett, Cornell professor of civil and environmental engineering, and isolated and studied by Stephen Zinder, Cornell professor of microbiology, are now in wide use to detoxify such carcinogenic chemicals as perchloroethylene (PCE) and trichloroethylene (TCE). They do this by removing chlorine atoms from molecules and leaving less-toxic compounds behind.

For the full article:

http://www.news.cornell.edu/st.....es.ws.html
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PostPosted: Tue Jul 03, 2007 9:45 am    Post subject: Today's waste, tomorrow's fuel Reply with quote

Cardiff University
3 July 2007

Today's waste, tomorrow's fuel

Sustainable energy from urban waste
A Cardiff University research collaboration is working to recycle precious metals from road dusts and vehicle exhausts to create greener energy.

The innovative research by scientists from the School of Earth, Ocean and Planetary Science working with the University of Birmingham is to be featured at the Royal Society Summer Science Exhibition (2-5 July).

Catalytic converters which keep exhaust pollutants from vehicles down to an acceptable level all use platinum, however over the years the platinum is slowly lost through exhaust pipes. Dr Hazel Prichard, School of Earth Ocean and Planetary Science estimates that many kilogrammes of platinum is being sprayed onto streets and roads every year.

Dr Prichard said: “Platinum is a vital component not only of catalytic converters but also of fuel cells. Fuel cells are an important new source of clean energy. Platinum is a precious metal and resources are scarce and expensive. Our research is looking at ways of recycling platinum and other precious metals.”

Dr Prichard is working with her team to find locations where platinum is concentrated enough to recover in order to develop cost-effective and sustainable ways to re-use this finite resource. One prime target is the waste containers in road-sweepers.

The research collaboration is also exploring how food wastes, and ‘friendly’ bacteria can be used to create greener energy. Their goal is to see these techniques being applied to produce clean fuel cells to create reliable, greener energy whilst minimising waste.
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PostPosted: Sat Nov 03, 2007 7:11 am    Post subject: Cleaning Up after Livestock Reply with quote

Week of Nov. 3, 2007; Vol. 172, No. 18

Cleaning Up after Livestock
Janet Raloff

As any pet owner knows, the more food that goes into an animal's mouth, the more wastes that eventually spew out the other end. The bigger the animal, the bigger its appetite. So imagine the volumes of manure—often tainted with germs—that farmers must manage for even a small feedlot with perhaps 3,500 head of cattle.

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http://sciencenews.org/articles/20071103/food.asp
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PostPosted: Mon Nov 05, 2007 5:36 pm    Post subject: Invisible Plastic Trash Poses Newfound Threat to Sea Life Reply with quote

Invisible Plastic Trash Poses Newfound Threat to Sea Life

By Charles Q. Choi, Special to LiveScience

posted: 02 November 2007 08:58 am ET

Waterborne plastic debris too small to see and festooned with pollutants could pose a hitherto unknown toxic hazard to sea life.

The oceans are increasingly burdened by visible pollution—garbage—along shorelines and in the open ocean, and also by old fishing nets that entrap and kill marine life. And in recent decades, environmentalists have sounded alarm bells on plastic trash, specifically how large chunks can sicken and kill fish, birds, dolphins, turtles and other marine animals. For instance, the creatures might easily mistake plastics for food, but then suffocate or starve on the stuff.

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http://www.livescience.com/env.....stics.html
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PostPosted: Tue Nov 13, 2007 1:47 pm    Post subject: Biological Reactors Make Hydrogen Fuel from Sewage Reply with quote

Biological Reactors Make Hydrogen Fuel from Sewage
By Charles Q. Choi, Special to LiveScience

posted: 12 November 2007 05:00 pm ET

All kinds of biodegradable garbage—from sewage to leftover food—could yield valuable hydrogen fuel, an alternative to fossil fuels, with the aid of microbes cultivated in special reactors.

When hydrogen is burned, it yields just energy and water. That being an attractive sort of fuel, researchers globally are investigating ways to generate hydrogen en masse in hopes of replacing fossil fuels, the burning of which releases the global warming gas carbon dioxide. Unfortunately, most of the hydrogen available today for use is actually generated from fossil fuels.

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http://www.livescience.com/env.....germs.html
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PostPosted: Mon Dec 03, 2007 2:25 pm    Post subject: New fuel cell cleans up pollution and produces electricity Reply with quote

New fuel cell cleans up pollution and produces electricity
Environmental Science & Technology
3 December 2007

Scientists in Pennsylvania are reporting development of a fuel cell that uses pollution from coal and metal mines to generate electricity, solving a serious environmental problem while providing a new source of energy. They describe successful tests of a laboratory-scale version of the device in a study scheduled for the Dec. 1 issue of ACS’ Environmental Science & Technology, a semi-monthly publication.

In the new study, Bruce E. Logan and colleagues point out that so-called acid-mine drainage (AMD) is a serious environmental problem that threatens the health of plants and animals as well as the safety of drinking-water supplies, due mainly to the high acidity of contaminated waters and its high content of metals, particularly iron. AMD poses difficult and costly environmental clean-up problems.

They describe development of a new type of fuel cell that is based on microbial fuel cells, which are capable of generating electricity from wastewater. Using a solution similar to AMD, they showed that the device efficiently removed dissolved iron from the solution while also generating electricity at power levels similar to conventional microbial fuel cells. Improvements in the fuel cell will lead to more efficient power generation in the future, the researchers say. The iron recovered by the device can be used as a pigment for paints or other products, they note.

ARTICLE #2 FOR IMMEDIATE RELEASE
“Electricity Generation from Synthetic Acid-Mine Drainage (AMD) Water using Fuel Cell Technologies”

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http://pubs.acs.org/cgi-bin/sa.....712221.pdf

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PostPosted: Thu Dec 27, 2007 9:46 am    Post subject: Invention Turns Toxic Waste into Electricity Reply with quote

Invention Turns Toxic Waste into Electricity
By Charles Q. Choi, Special to LiveScience

posted: 26 December 2007 11:13 am ET

New technology could clean toxic messes from mines and create electricity at the same time.

Contaminated water seeping from coal and metal mines is a serious environmental hazard that endangers the safety of drinking water supplies and the health of plants and animals. This caustic pollution—loaded with metals such as arsenic, lead, copper, iron and cadmium—is currently difficult and costly to treat.

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http://www.livescience.com/env.....eanup.html
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PostPosted: Tue Jan 29, 2008 8:37 am    Post subject: Converting sewage into drinking water: Wave of the future? Reply with quote

Converting sewage into drinking water: Wave of the future?
Chemical & Engineering News
28 January 2008

Amid growing water shortages in parts of the United States, more communities are considering tapping their sewage treatment plants as a new source of drinking water. The conversion of wastewater into tap water could help meet increased demand for one of life’s most essential resources, according to an article [http://pubs.acs.org/cen/science/86/8604sci4.html] scheduled for the Jan. 28 issue of Chemical & Engineering News, ACS’s weekly newsmagazine.

C&EN Associate Editor Jyllian Kemsley notes in the article that some communities have used recycled wastewater for decades to replenish their drinking water supplies and wastewater often finds agricultural use for irrigation. Droughts, environmental concerns, and population growth now are forcing water utilities to consider adapting or expanding the practice, Kemsley explains.

Earlier in January, for instance, California approved operation of the Advanced Water Purification Facility (AWPF), the largest water reclamation plant in the nation. It will yield 70 million gallons per day of drinkable water from sewage. That’s about 10 percent of the district’s daily water demand for its 2.3 million residents. Although AWPF’s purification process is complex, it produces clean, pure water that meets or exceeds all drinking water standards, the article notes.

ARTICLE #5 EMBARGOED FOR 9 A.M., EASTERN TIME, Jan. 28, 2008 “Treating Sewage For Drinking Water”

This story will be available on Jan. 28 at http://pubs.acs.org/cen/science/86/8604sci4.html
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PostPosted: Mon Mar 31, 2008 2:44 pm    Post subject: Elevated concentrations of metals in China’s e-waste recycli Reply with quote

Elevated concentrations of metals in China’s e-waste recycling workshops
Environmental Science & Technology
31 March 2008

In a case study on how not to recycle electronic waste (e-waste), scientists in the United States and Hong Kong have documented serious environmental contamination with potentially toxic metals from crude e-waste recycling in a village located in southeast China. Recycling methods used in family-run workshops could pose a serious health risk to residents of the area through ingestion and inhalation of contaminated dust, the researchers say. Their study is scheduled for the April 15 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.

The process of discarding computers and other consumer electronics has emerged as one of the fastest growing segments of the global waste stream. Known as e-waste, these scrapped electronic goods contain lead, copper and other hazardous materials, which can release dangerous toxins that cause air and water contamination. Up to 50-million tons of e-waste is generated worldwide each year — enough to fill a line of garbage collection trucks stretching halfway around the world — according to the United Nations Environment Program.

China is now the destination for 70 percent of the computers, TVs, cell phones, and other e-waste recycled globally each year. Ming H. Wong and colleagues collected dust samples from roads adjacent to e-waste processing workshops in Guiya, China, to find that lead levels were 330 and 371 times higher than non e-waste sites located 5 miles and 19 miles away. Copper levels were 106 and 155 times higher. “Currently, there are no guidelines or regulations for heavy metals in dust. It is hoped that the results can serve as a case study for similar e-waste activities in countries such as Africa, India and Vietnam where e-waste is becoming a growing problem, so that the same mistakes could be prevented.” — JS

ARTICLE #4 FOR IMMEDIATE RELEASE “Heavy Metals Concentrations of Surface Dust from e-Waste Recycling and Its Human Health Implications in Southeast China”

DOWNLOAD FULL TEXT ARTICLE http://dx.doi.org/10.1021/es071873x
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