Waste Water Treatment Plant Mud Used As ‘green’ Fuel

Scientists have shown that using mud from waste water treatment plants as a partial alternative fuel can enable cement factories to reduce their CO2 emissions and comply with the Kyoto Protocol, as well as posing no risk to human health and being profitable. These are the results of an environmental impact assessment.

Dependency on oil and coal could be coming to an end. Researchers from the Rovira i Virgili University (URV) have analysed the environmental and human health impacts of an alternative fuel that solves various problems simultaneously. This is the solid waste from the water treatment plants of large cities.

The scientists have carried out the first study into this method at a cement plant in Vallcarca (Catalonia), which has been producing cement for more than 100 years, and they confirm in the latest issue of the journal Environmental Science and Pollution Research that it is “the best option for getting rid of mud that would have had to be dumped elsewhere, while also powering the plant”.

[...] Up to 20% of the fossil fuel energy used at the Catalan plant has now been substituted for the fuel from waste water treatment plant mud.

One of the most important issues for the URV scientists is the reduction in environmental impact, and consequently the health risks for people living near the plants. The experiment with the mud has led to a 140,000 tonne reduction in CO2 emissions between 2003 and 2006, and will have limited the potential deaths from exposure to chemical pollutants. In addition, the study shows that using this green fuel would reduce the cancer rate by 4.56 per million inhabitants.

The researchers say it is essential to carry out separate studies for each plant because “we still don’t know whether this will be positive for the whole cement industry”, according to Domingo. However, if the conditions are right, using mud from waste water treatment plants in cement factories is “a very good solution”, he concludes

Source: Plataforma SINC, ScienceDaily, 23 Jun 2009

Biogas: Chilean water utility inaugurates largest plant in South America

Chilean natural gas distributor Metrogas and water utility Aguas Andinas started up operations at the country’s first biogas plant installed at the Farfana water treatment complex on the outskirts of Santiago. The plant will produce 24Mm3/y of biogas and replace about 14Mm3/y of natural gas. “This is the only place in the world where biogas produced by a water treatment facility ends up being used directly in homes,” Metrogas president Matías Pérez Cruz said, adding that the biogas plant is the largest in South America. Investment in the project totaled 3bn pesos (US$5.3mn).

Source: BNamericas [subscription site], 14 May 2009

Meanwhile in Brazil, officials from the Japan International Cooperation Agency (JICA) and Paraná state water utility Sanepar [have met] to discuss projects to expand power generation sewage treatment plants. [...] Since 2008, Sanepar has been producing electric power from its [Ouro Verde sewage treatment plant in Foz do Iguaçu]. The plant produces energy for its own operations and the surplus is sold to power company Copel. [Sanepar wants to] extend the successful experience of Foz do Iguaçu to all [its] sewage treatment plants.

Source: BNamericas [subscription site], 25 May 2009

Upflow biofilters: treating septic tank effluent in squatter settlement in Nepal

Thirty-one households in Narayan Tole squatter settlement near Maharajgunj of KMC-3 , Kathamdu, have recently constructed ‘up-flow bio-filters’ to treat septic tank effluent. They have constructed two such filters spread in over 342 sq ft area with the financial and technical support of UN-HABITAT Water for Asian Cities Programme Nepal, WaterAid Nepal and Lumanti Support Group for Shelter.

Only 16 households in the area had toilets until a year ago. They used to let their toilet waste mix directly into nearby rivers. [...] All the households in the area now have toilets. They have constructed a 180-metre-long sewer to channel the toilet waste to the filters.

The filter first separates solid and liquid wastes and treats the liquid waste. After the treatment, the waste water [flows] into the rivers while the solid waste remains in the tank. The bio-filters were constructed with Rs. 0.2 million collected from the donors and locals. The locals have formed Narayan Tole Sudhar Samiti (NTSS) to take care of the filters.

Kalpana Karki, treasurer of the Samiti, told that it collects Rs. 35 per month from each household for the maintenance of the filters. [...] “We will use the digested solid waste as fertilizer in our fields,” Karki said.

Related news: Nepal, Kathmandu: squatters seek NGO help to defeat river pollution, Source Weekly, 15 Dec 2008

Source: NGO Forum,10 Feb 2009

South Africa: Joburg Water, University Agree to expand research expertise

Johannesburg Water (JU) and University of Johannesburg (UJ) have signed a Memorandum of Understanding [on collaboration] on water and sanitation research and development projects [...] specifically in water nanotechnologies, water purification, waste water treatment and innovation in water analysis.

Mr Jones Mnisi, Acting Chief Operation Officer, Johannesburg Water (JW). and Prof Derek van der Merwe, Pro Vice-Chancellor and Vice-Principal, University of Johannersburg (UJ) at the signing of the Memorandum of Understanding (MoU) at Johannesburg Water on Friday, 16 January 2009. Photo: UJ.

Read more: Gabi Khumalo, Bua News / allAfrica.com, 16 Jan 2009 ; Johannesburg Water, 16 Jan 2009

Dow’s Reuse of Municipal Wastewater Wins 2008 ICIS Innovation Award

The Dow Chemical Company’s re-use of municipal wastewater at its Benelux site in Terneuzen, The Netherlands was named the winner of the Most Innovative Corporate Social Responsibility Project in the 2008 ICIS Innovation Awards.

[...] The site uses treated household wastewater to produce high pressure steam and, as recycled water, in its cooling tower. This is [claimed to be] the first time that municipal wastewater is being re-used on such a large scale in the industry, exceeding 2.6 million gallons per day. The project is the result of [a public-private partnership] between Dow, the water treatment provider Evides and the Zeeuws-Vlaanderen Water Board.

[...] Dow already [wants to replicate the approach in] other regions such as the Middle East and China, where water is “the most precious commodity.”

Source: European Water News, 11 Nov 2008

Constructed wetlands: model wastewater treatment plant, Nepal

Dhulikhel municipality constructed a community-based wastewater treatment plant cum biogas at Srikhandapur-9, in Kavre district that generates cooking gas for locals, fertilizers for farmers and ultimately sends clean water into the river.

Six-horizontal reed bed treatment systems [wetlands] of 175 cubic meters and two-Bio-gas reactors of 75 cubic meter capacity each have been installed over four-Ropanis of land adjoining the sewage pipe of over 200 households for collection of wastewater.

[...]

The UN-HABITAT [through the Water for Asian Cities programme] and Dhulikhel Municipality supported Rs. 53, 00,000 and Rs. 17, 00, 000, respectively. Environment and Public Health Organization (ENPHO) provided technical assistance and training to locals in maintaining the system. The locals volunteered with masonry and contributed over Rs. 10, 00,000.

[...]

The plant generates over 30-kilogram cooking gas and equal amount of fertilizer everyday when the plant becomes fully operational [in October 2008].

Source: NGO Forum, 29 Sep 2008

Impacts of a participatory approach to assess sustainable sewage treatment technologies for urban fringe of Surat city in India

Vashi, A. N. and Shah, N. C. (2008). Impacts of a participatory approach to assess sustainable sewage treatment technologies for urban fringe of Surat city in India
Water science & technology-WST ; vol. 57, no. 12 ; p. 1957-1962. doi:10.2166/wst.2008.331

Abstract

This paper describes the assessment of the sustainability of a number of different sewage treatment technologies by means of a multi-criteria, participatory method for a scattered settlement of urban fringe of Surat. The special efforts have been made for the broad participation to achieve stronger democracy, better quality of the end product, and a more effective process. The mere participation of technocrats and bureaucrats certainly lead to the greater efficiency in working methods. However, the ultimate goal of sustainable developments of such technologies could not be reached in absence of democratic participation and social learning. Keeping this important aspect in view for assessment of sustainability, the detailed study was conducted in the presence of policy makers and stakeholders, academicians, technical experts, finance managers and NGO, to find out sustainability criteria and indicators for three different sewage treatment technologies: (A) Conventional Activated Sludge Process (B) Extended Aeration System, and (C) Upflow Anaerobic Sludge Blanket (UASB) Reactor followed by Aerated Lagoon and Polishing Pond. Technologies were compared according to four criteria subdivided into twenty operational indicators. Criteria and indicators were evaluated as in a weighted-scale matrix. In India, sustainability criteria used in this type of comparisons are often restricted to a limited set of environmental impacts and financial costs but in this study additional criteria were evaluated including economic, social, and technical aspects. Based on the values assigned by the panel, the Sustainability Index (SI) was calculated for each technology. According to the SI and a predefined scale, sustainability was medium for options A and B, whereas high for option C. The purpose of this study is to provide a basis for the selection of a particular technology based on a rational and democratic assessment of its contribution to sustainability in the local and global context.

IX Latin-American Workshop and Symposium on Anaerobic Digestion, 18-19 Oct 2008, Easter Island, Chile

Anaerobic digestion represents nowadays one of the most cost-effective alternatives for waste (water) treatment, which has experienced a fast development during the last three decades. This Latin-American Workshop and Symposium will offer a selected program including the latest research findings and technological applications on anaerobic wastewater treatment, solids stabilization and biogas production as a renewal energy source.

This event is addressed to researchers, waste managers, consultants, representatives of both public and private sectors, environmental engineers and other related professionals.

Organised by the International Water Association (IWA).

For more information go to the conference web site

Extraordinary Water Purification Technology Wins Orange County 2008 Stockholm Industry Water Award

Pioneering work to develop the world’s largest water purification plant for groundwater recharge has earned the Orange County Water District and the Orange County Sanitation District, California, USA, the 2008 Stockholm Industry Water Award. The prestigious distinction will be presented on August 21 during the 2008 World Water Week in Stockholm.

People expect water to be there when they turn on the faucet. But in growing arid regions like Orange County in Southern California, sufficient water is not naturally guaranteed. Fortunately for the 2.3 million residents living there, the Orange County Water District and the Orange County Sanitation District jointly developed the Groundwater Replenishment (GWR) system, a water purification system which will provide enough water to meet the needs of an additional 500 000 people without diminishing groundwater resources for current or future generations.

The GWR System diverts highly treated sewer water that is currently discharged into the ocean and purifies it through a series of advanced techniques: microfiltration, reverse osmosis, ultraviolet disinfection and hydrogen peroxide. The cleaned water is returned to the groundwater basin to increase both water supply and quality. The GWR system has established a blueprint for large-scale wastewater purification that is already being emulated in dry regions and nations, such as Singapore.

Read more: SIWI, 28 May 2008

Food thickener removes heavy metals from water

A gum membrane made from the seeds of the local konkoli plant – often used as a food thickener – can help remove heavy metals from water. Chemists from Nigeria’s Federal University of Technology say this could be used to clean industrial waste from ore smelting and metal refining.

Osemeahon, S. A., Barminas, J. T, Aliyu, B. A and Nkafamiya, I. I. (2008). Application of grafted membranes for sorption of Cd2+, Fe2+ and Zn2+ ions in aqueous solution. African journal of pure and applied chemistry ; vol. 2, no. 3 ; p. 032-036. Full text