When looking at sanitation/wastewater treatment and making it economically feasible for more parts of the world, this is very interesting research. Some will say it has roots in the fact that there is “gold” in out crap…
Related links to this research:
…On May 1, a panel of judges awarded the $100,000 National University Clean Energy Business Challenge prize to the Stanford team for its project to convert nitrogen waste into nitrous oxide that is then used for clean power generation….
A new process for the removal of nitrogen from wastewater is introduced. The process involves three steps: (1) partial nitrification of NH4+ to NO2−; (2) partial anoxic reduction of NO2− to N2O; and (3) N2O conversion to N2 with energy recovery by either catalytic decomposition to N2 and O2 or use of N2O to oxidize biogas CH4. Steps 1 and 3 have been previously established at full-scale. Accordingly, bench-scale experiments focused on step 2. Two strategies were evaluated and found to be effective: in the first, Fe(II) was used to abiotically reduce NO2− to N2O; in the second, COD stored as polyhydroxybutyrate (PHB) was used as the electron donor for partial heterotrophic reduction of NO2− to N2O. ….
Normally, we want to discourage these gases from forming,” said Craig Criddle, a professor of civil and environmental engineering and senior fellow at the Woods Institute for the Environment at Stanford. “But by encouraging the formation of nitrous oxide, we can remove harmful nitrogen from the water and simultaneously increase methane production for use as fuel.
- Total N2O emissions-which are believed to come primarily from nitrogen fertilizers used in agricultural production-would account for about 8 percent of California’s total greenhouse gas emissions. (familysurvivalprotocol.com)
- 1st International IWA Conference on Holistic Sludge Management (washlink.wordpress.com)
- Major Advance in Generating Electricity From Wastewater (wakingtimes.com)
- Major Advance in Generating Electricity From Wastewater (myscienceacademy.org)
- The Final Frontier of Water and Wastewater Treatment: Sludge Management Equipment Market Set to Reach $9.9 Billion by 2017 (prweb.com)
Redefining the model for urban sewage treatment / sanitation addressing
Waste recover- Key Chemicals
From the Youtube Site
“Kartik Chandran is an Environmental Engineer. He is currently Associate Professor of Earth and Environmental Engineering at Columbia University, where he leads the Columbia University Biomolecular Environmental Science program and the Wastewater Treatment and Climate Change program. Under his stewardship, the research directions of biological wastewater treatment and biological nitrogen removal were established for the first time ever in the history of Columbia University. Chandran is keenly interested in developing novel models for sustainable sanitation and wastewater treatment, with a specific focus on managing the global nitrogen cycle (one of the grand challenges of the National Academy of Engineering) and linking it to the carbon cycle, the water cycle and the energy cycle. Chandran has received, among other awards, the NSF CAREER award and the Paul Busch Award. He was the recipient of a 2007 National Academies of Science Fellowship and a guest professorship at the Delft University of Technology. In 2011, Chandran began implementing a novel model for sanitation in Africa, supported by the Bill & Melinda Gates Foundation. He also serves on the Board of Trustees of the Water Environment Federation.”
- Gresham’s wastewater treatment plant leading way in power production, alternative energies (oregonlive.com)
- India flush with wastewater treatment opportunities (eco-business.com)
- 300 swimming pools of partly treated sewage dumped into the Thames River (lfpress.com)
- Ivy League Brains Figure Out How to Make Biodegradable Plastic from Greenhouse Gases (cleantechnica.com)
- Sewage-powered hydrogen fueling station opens in CA (reviews.cnet.com)
Summary: Biodigesters convert organic wastes into a nutrient rich liquid fertilizer and biogas, a renewable source of electrical and heat energy. Their use is widespread in developing countries, particularly India, Nepal, China and Vietnam. Biodigesters help families by providing a cheap source of fuel, preventing environmental pollution from runoff from animal pens, and reducing diseases caused by the use of untreated manure as fertilizer.
Biodigesters produce biogas, an alternative fuel source
As organic wastes break down, whether in the ground, a compost heap or landfill, they release methane (a potent greenhouse gas that traps heat at 23 times the rate of carbon dioxide). A biodigester or biogas system is a waste-management solution that traps methane as it is produced, making it available for heating or cooking or even electricity generation. By preventing methane from venting freely into the atmosphere, these systems can help reduce emissions that contribute to climate change.
Biogas is a sustainable substitute for the propane, kerosene, and firewood that many rural families in developing countries use for their domestic energy needs. For those families that buy their fuel, a biodigester can save them hundreds of U.S. dollars every year. For those that gather their own firewood, it can reduce a family’s workload (particularly women and girls) and help prevent the deforestation prevalent in many of these areas.
Biodigesters also create high quality fertilizer
In addition to providing fuel, these systems offer an environmentally friendly way of treating waste. As waste is processed in a biodigester, it is sterilized by methane-producing bacteria and the high-methane environment; over 90% of protozoa, cysts and disease-causing bacteria, such as E. Coli, are killed. The effluent that remains after gas production is a high quality organic fertilizer that can be safely used on food crops. Some studies have shown that this liquid fertilizer has a higher nutritional value than the feedstock initially put in. Families, for whom AIDG has installed biodigesters, have reported seeing the quality of their crops improve dramatically after only one year of using biodigester fertilizer.
- Provide clean and renewable energy. Families use less firewood, decreasing deforestation, save money and have accessible fuel.
- Reduce greenhouse gas emissions. The combustion of biogas produces lower greenhouse gas emissions than typical methane emissions from a waste lagoon or septic system.
- Reduce contamination of surface water, groundwater and other resources.
- Reduce odors and pathogens. Biodigesting sewage can reduce the parasitic and pathogenic bacterial counts by over 90%.
- Convert waste into high quality organic fertilizer. Families can obtain improved crop yields and save money.
- Can accommodate a wide variety of organic wastes including animal manure, night soil, crop stalks, straw, slaughterhouse wastes, biodegradable garbage and wastewater.
While waste needs to be added and effluent removed on a daily basis, biodigesters are typically very reliable systems that require little maintenance.
Biodigesters function poorly in colder climates unless an external heat source is applied. The methanogenic bacteria responsible for generating biogas require temperatures well above freezing (optimal temperature ranges – mesophilic: 30-40°C; thermophilic: 50-60°C), so biodigesters are not ideal in cooler areas.
In order to keep the anaerobic digestion process going continually, biodigesters require a daily amount of work and a consistent source of organic materials:
- Each day, the waste to be added needs to be mixed with water and/or ground to a liquid state. Manure is naturally manure is water-soluble, but kitchen scraps, such as banana and orange peels need to be ground into smaller which can be time consuming.
- Each day, the biodigester effluent needs to be removed from the effluent tank.
Biogas provides 20% more energy than if dung/wastes were burned directly, but much less compared to fuels such as propane and natural gas.
The Bottom Line:
Biodigesters are an excellent technological solution for families and farmers that want a combined sanitation and energy solution, who can manage the daily feeding required to produce adequate biogas, and who have use for lots of fertilizer. more…