VATIS Update Waste Management . Sep-Oct 2009

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Waste Management Sep-Oct 2009

ISSN: 0971-5665

VATIS Update Waste Management is published 4 times a year to keep the readers up to date of most of the relevant and latest technological developments and events in the field of Waste Management. The Update is tailored to policy-makers, industries and technology transfer intermediaries.

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New treaty makes ship recycling safer experts

According to an AFP news agency report, dozens of nations signed a new treaty at the recent Hong Kong conference organized by the United Nations International Maritime Organization to make ship recycling safer. The treaty must now be ratified by individual member states.

Environmental activists have called the new deal a step backwards for the environment and the labourers who do dangerous work. The new convention on ship recycling adopted does not stop a toxic ship from being broken on the beach of a developing country, noted the director of an NGO platform on ship breaking. It legitimizes the infamous breaking yards of Pakistan, Bangladesh and India and rewards these exploitive operations while punishing those companies that have invested in safer and cleaner methods, the activists say. Ship breaking in developing countries takes place mostly on soft sand beaches, where access for heavy lifting equipment and emergency vehicles is difficult, if not impossible.

Subsidy policy on home appliance replacement

China has published the details of the old-for-new subsidy policy on household appliances, covering subsidy measures, operation procedure and implementation. According to the new policy, institutions and in-dividuals in the nine pilot cities and provinces (Beijing, Shanghai, Tianjin, Jiangsu, Shandong, Fuzhou, Zhejiang, Guangdong and Changsha), that trade in used household appliances for new ones within the fixed time from 1 June 2009 to 31 May 2010, are entitled to enjoy a subsidy amounting to 10 per cent of the new appliances sale price. The policy covers five product categories, including TV sets, refrigerators (including chest freezers), washing machines, air-conditioners and computers. Consumers will be able to apply for the old-for-new subsidy when purchasing new products, and sellers will examine and verify the application on behalf of the Ministry of Finance and cash the qualified subsidy applications on the spot.

Local recycling plants that won the bid to join the work will enjoy freight subsidies when picking up used products from consumers and sending them to appointed processing enterprises within the fixed time. Provincial and municipal governments are responsible for the regulation and management of the old-for-new campaign, and have to design rules ensuring its smooth implementation. The old-for-new campaign is expected to expand consumption, improve efficiency in energy usage, reduce pollution and accelerate industry upgrading and economic structure adjustment, explains the Minister of Finance.

Holistic approach for River Ganga clean-up

The Government of India set up the National Ganga River Basin Authority (NGRBA) by a notification dated 20 February 2009 as an empowered planning, financing, monitoring and coordinating authority for the Ganga River. NGRBA aims to ensure effective abatement of pollution and conservation of the river by adopting a holistic approach with the river basin as the unit of planning. The ongoing pollution abatement works under the Ganga Action Plan would continue to be implemented.

NGRBAs functions include all measures necessary for planning and execution of programmes for abatement of pollution in the river, including augmentation of sewerage infrastructure; collection, analysis and dissemination of information relating to environmental pollution in Ganga; research on problems of environmental pollution and conservation of Ganga; and promotion of water conservation practices including recycling and reuse, rain water harvesting and decentralized sewage treatment systems. Steps have been initiated for preparation of a river basin management plan, nomination of experts in NGRBA and for creation of a corpus of funds for the Authority.

Biodegradable bag project in Thailand

BASF, the global chemicals giant based in Germany, is leading a pilot project to encourage consumers to use biodegradable bags for waste and compost in Thailand. The pilot project is aimed at encouraging consumers to use biodegradable bags to collect household organic waste and produce high-quality compost that will serve as organic fertilizer for the purpose of soil improvement. National Innovation Agency (NIA) of Thailand, Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ) of Germany and the Thai Bioplastics Industry Association (TBIA) are the other agencies involved in the biodegradable bag project.

Biodegradable plastics present an important contribution to efficient biowaste management, states Mr. Supachai Lorlowhakarn, Director of NIA. Additionally, as a secondary raw material post-composting, it can also be used to provide an economical and ecologically viable utilization possibility fertilizer in this case. NIA plans to develop the bioplastics industry in Thailand. For the production of the biodegradable bags, TBIA will compound starch with BASFs Ecoflex resin, a biodegradable, compostable polyester.

Green bag campaign aims to reduce reliance on plastics

In Hanoi, Viet Nam, the first activity of the Reducing Plastic Bags in Retail Activities to Benefit Consumers, Retailers, Poor Labourers and the Environment project launched by the Centre for Support of Combating Climate Change (SCC) under the Viet Nam Union of Scientific & Technological Association is distributing two cloth shopping bags to each of the households that sign up. Cooperating supermarkets in the capital area will register households and distribute the bags. Each bag has a bar code, and shops and supermarkets participating in the project scan the code on the bag whenever customers use it. Every month or every quarter, the supermarkets will estimate how much money has been saved by the customers who used the reusable bags. Based on the estimated cost saving from lower plastic bag usage, the stores will return 50 per cent of the savings back to the consumers in the form of discounts, gifts or cash.

The SCC estimates that residents use about US$38 million worth of plastic bags each year. Providing cloth bags for the 800,000 families in the city would require a budget of about US$8 million, but if everyone used them it is estimated that US$28 million can be saved every year on plastic bags and the environment will be kept cleaner. The project aims to reduce the usage of plastic bags by 100,000 bags per day in Hanoi by the end of 2009. The next phases of the project include expansion to other cities such as HCM City, Da Nang and Hai Phong with the target of reducing consumption by 1,000,000 plastic bags per day by the end of 2011.

Eco-friendly bags launched in Pakistan

Waste Busters, pioneers in recycling of solid waste in Pakistan, have launched biodegradable plastic bags in Lahore. According to Mr. Asif Farooki, Chief Executive of Waste Busters, despite several efforts the government had been unable to curb the menace of plastic pollution over the last 10 years. Plastic pollution has become a problem of epidemic nature, clogging sewage systems, polluting agriculture fields and, over all, becoming an eye sore in almost all cities and towns in the country.

The new biodegradable plastic bag is modelled on imported Japanese technology. An additive used in the process of producing plastic bags makes them biodegradable. The bags disintegrate in the soil within 60 to 90 days. The chemicals normally used in producing the plastic bags make them non-degradable for over 100 years, thereby leading to pollution. Mr. Farooki expects the government will help make this project successful by making policies that will encourage all plastic manufacturers to use this additive in their processes.

PCB phase-out issues in the Philippines

Environmentalists in the Philippines have called on the government to hasten the phase-out of polychlorinated biphenyls (PCBs) in large transformers and voltage regulators in the power sector. The Stockholm Convention on Persistent Organic Pollutants (POPs) required governments to prohibit the production, import, export and use of all PCBs and implement an action plan to address PCBs, stated Mr. Manny Calonzo of the Ecowaste Coalition. Although the government already has a programme laid out to phase out PCBs, the real problem is fast-tracking it to accomplish the phase-out by 2014, he added.

Ecowaste Coalition has reiterated its support for a programme of the Department of Environment and Natural Resources to ensure that PCBs and other POPs would no longer be used in the country. The pioneering project will demonstrate the efficacy of environmentally sound and safe non-burn approach for managing PCBs and will contribute to both the local and global push to eliminate PCBs and advance chemical safety. The group also launched the PCB Eliminator, a masked hero whose mission is to protect our people and the ecosystem from harm caused by exposure to these harmful substances. The new green crusader joins the other mascot heroes of the waste and pollution watchdog, namely Boy Bayong, an advocate against single use plastic bags, and Super WA (for Walang Aksaya) a champion for zero waste approach.

New wastewater treatment initiative

In Singapore, two research institutes have signed an agreement to engage in actively looking for new means of treating heavily polluted waters. The Nanyang Technological Universitys Nanyang Environment and Water Research Institute (NTU-NEWRI) and Sembcorp Industries have joined hands to come along with an improved method of filtering wastewater. The main goal of the three-year contract is to devise a treatment that would remove entrenched organic matter from the wastes.

About US$1 million will be invested to see the new method is able to remove wastes that do not biodegrade well. President and CEO of Sembcorp Group, Mr. Tang Kin Fei, says We are happy to take our R&D collaboration with NTU-NEWRI a step further with this joint test bed for new wastewater treatment technology. According to the principal investigator of NTU-NEWRI, Associate Professor Volodymyr Ivanov, NTU team has developed a patented process well suited for the treatment of industrial wastewater. This process models natures way of cleaning the water. It is likely that this technology can be more competitive than other technologies.

Plastic bag levy kicks off in Hong Kong

In Hong Kong, China, a HK$0.50 (US$0.07) plastic bag levy has come into effect at all major retailers. This levy is a green tax that is part of government efforts to reduce waste. On average, a resident uses three bags a day. The levy aims to reduce plastic bag usage by 50 per cent. Currently, it applies to about 2,000 big supermarkets and chain stores. If successful, after a year, the levy may be extended to all retail outlets in Hong Kong. It is estimated that residents throw away more than eight billion shopping bags into the territorys landfills every year. Demand for cloth bags has increased since the impending plastic bag levy, and so has green awareness. Green groups are also calling on the government to act on more recycling programmes to tackle different types of waste like electronic components, rubber and other plastics.

New e-waste recycling plant

In India, Mumbai will be home to the first facility for scientific recycling of e-waste generated in the region. Greenpeace reports that Mumbai generates around 50,000 tonnes of e-waste every year. This is expected to increase to 300,000 t/y by 2011. Tenders to set up the facility have been invited by the Mumbai Metropolitan Region Development Authority (MMRDA) and the plant is expected to be operational by 2010. According to the Environment Secretary Ms. Valsa Nair, the pre-feasibility study conducted by IRG Systems has given highly encouraging results.

The e-waste recycling project will be implemented in phases. In the first phase, the plant capacity will be around 7,500 t/y, which will be increased later. Even a resource recovery facility could be started at the plant in the future. Once the plant is functional, the contractor will establish e-waste collection channel in the region.

Green tax to drive bioplastics trend

In Thailand, the National Innovation Agency (NIA) is to propose a plan to the Finance Ministry that would introduce an environmental tax on oil-based plastics by 2010, in an attempt to encourage consumers to use more biodegradable plastics. The move is a part of the national road map for the development of the bioplastics industry, covering the five years from 2008 to 2012. The levy is designed to boost bioplastics demand in Thailand in line with practices in Japan and many European countries.

NIA Innovation Department Director Ms. Wantanee Chongkum states, The environmental tax will make the price of oil-based plastics higher, plus the trend of environmental concern, manufacturers and consumers will shift to biodegradable plastics instead. NIA has employed experts to examine existing environmental taxes and government measures overseas, particularly in Europe, that can be adapted locally. It is working with the Development of the Environment and Energy Foundation to study the possibility of setting up the first degradable-waste plants in Thailand.

Pollution to increase by five fold in 2010

In Viet Nam,the Ministry of Natural Resources and Environment has warned that environmental pollution level in the country will increase by 4-5 times in 2010. The Ministry said that the countrys environment has been considerably degraded over the past decade due to high rates of economic growth, rapid industrialization and urbanization, and wanton exploitation of natural resources. Economic losses caused by environmental pollution are estimated to be equal to 0.3 per cent of the countrys GDP by 2010 and 1.2 per cent by 2020. According to Dr. Phan Dang Tuat, Director of the Institute for Industrial Policy Strategy, the steel industry has the most harmful impact on the environment in Viet Nam. The General Department of Environment has devised a plan to treat chemical-borne environmental pollution in Viet Nam.


Breakthrough in flexible packaging recycling

The Flexible Packaging Association pegs the annual sales of the United States flexible packaging industry at US$25.6 billion. As flexible packaging is the second largest packaging segment in the United States, its disposal is an important part of any discussion about eco-friendly packaging. Polyflow Corp. is working on a technology that will recycle mixed, dirty plastic and rubber waste, without sorting.

According to Mr. Joe Hensel, CEO of Polyflow Corp., the process can even take metallized film. The process does not require metal screws or paper labels to be removed from the packaging before processing. Using high-temperature anaerobic de-polymerization and chemical reactions, the Polyflow process converts mixed waste polymers back into monomers that can be sold to petrochemical companies to make polymers. Major products of the Polyflow process are styrene and its precursors, petroleum blend stock and other hydrocarbons. The company says its technology will be able to produce 0.7 tonne of light hydrocarbon liquid for every tonne of polymer feedstock. Polyflow does admit that at this stage in development, the concept carries processing costs that are about 10 per cent higher than those of a typical major petrochemical company making the same virgin products.

Recycling and repair of thermosets

A new concept developed at the Fraunhofer Institute for Polymeric Materials & Composites, Germany, allows for recycling and repairing of commonly used thermosets in the production of carbon- and glass fibre-reinforced plastics. Existing recycling methods are mainly based on milling and burning while repairing such composite materials is very complex and difficult to implement.

The new Fraunhofer concept makes it possible to decompose the resin of fibre-reinforced parts, in addition to decomposing a selected area that needs to be repaired. The substances obtained from the decomposition process can be reused as basic chemicals and the regained reinforcement that is not damaged or destructured can be used for producing new parts. Corrupted parts can be repaired by applying new resin to the selected area, providing it with identical properties. The decomposition process is initialized by a special chemical agent. The recycled or repaired cyanate-based resins can be adapted to all common manufacturing processes, such as pre-preg, hand lay-up, vacuum bagging, autoclave or resin transfer moulding.

Immobilized microbes digest phthalates

In China, researchers at the College of Environmental Sciences & Engineering, Peking University, and Harbin Institute of Technology have identified and isolated a microbe that can digest one of the most common phthalic acid esters (PAEs) d-n-butyl phthalate. PAEs, commonly known as phthalates, are widely used as additives in polymer manufacture as plasticizers and do not readily degrade in the environment; so they have become widely distributed in natural water, wastewater, soils and sediment. The researchers report that immobilized microbes can break down the harmful phthalates, and may even be used to treat industrial wastewater and prevent these materials from entering the environment.

PAE d-n-butyl phthalate is widely used and is one of the most frequently found in diverse environmental samples, including groundwater, river water, drinking water, open ocean water, soil humates, lake sediments and marine sediments. The research team used acclimation and enrichment techniques to ferment sufficient quantities of the active microbe, obtained from the activated sludge of a wastewater treatment plant. The microbes were enriched and acclimated by incubating in activated sludge. This involves cultivating the microbes in a solution containing phthalate as the only carbon source for the microbes.

Successive divisions of microbial cells quickly lead to the evolution of a strain that can quickly metabolize the phthalate and convert it into the raw materials for microbial growth and reproduction. The researchers then tested the microbe by immobilizing cells on a new type of ceramic honeycomb support. They then measured the before and after concentration of phthalate in a simulated wastewater sample. Initial concentration was 100 mg/l that fell to less than 1 mg/l within two days of treatment with the microbial honeycomb.

Injection process of granulated rubber into blast furnaces

At the Companhia Siderrgica de Tubar in Brazil, researchers have invented and patented a process for utilizing rubber products as thermo-reduction fuel through injection into blast furnaces in place of the traditional solid fuels such as mineral coal, coke and anthracite. This will help the recycling process and decrease emissions of harmful gases. The invention adds value to recent injection techniques, besides helping to generate carbon credits under the Kyoto Protocol for the fact that it will replace mineral coal extracted from the mines. In the process, air blown via the tuyeres reacts with the reductive agents, producing reductive gases responsible for the heat creation and metallic material reduction. The carbon in the rubber will be transformed in carbon dioxide due to its burning. The recycling of rubber material such as tyres would also produce steel scrap, which may used in steel mills.

The process starts by cutting and triturating the rubber. In this step, the tyre steel is separated from the rubber. Through magnetic separation, the steel is sent to the steel mill where it will be consumed as scrap. As a result, the rubber will be sent to the grinder. After finishing the grinding process, the rubber must be stored in a silo. To inject the rubber, it is loaded in a vessel pressurized to a level that is higher than the blast furnace blowing pressure. This would ensure that all granulated rubber is injected into the blast furnace and none returns to the injection system. The injection of the rubber grains can be done separately or together with pulverized coal, as both raw materials have a similar composition. Contact: Companhia Siderrgica de Tubar, Av. Brigadeiro Eduardo Gomes 930-Planalto, DE Carapina-Serra-es-Brasil, Brazil.

Recycling process for polyester material

Invista North America SARL, the United States, has patented a new process for recycling polyester materials. The invented process is for recycling coloured polyester. Under the process, coloured polyester for recycling is depolymerized by the addition of glycol to form the monomer bis hydroxyethyl terephthalate (BHET). BHET is then contacted with activated carbon to remove the colorant partly. The colorant that remains is extracted using water, alcohol or glycol to produce white, purified BHET. The purified BHET is separated from the extraction solvent (water, alcohol or glycol) by filtering, decanting or centrifuging, or any other such process. The purified BHET monomer can then be polymerized to polyethylene terephthalate that meet the food-contact specifications, using a known polymerization process.

Cleaning of impure PET flakes

S+S Separation and Sorting Technology GmbH, Germany, is offering: sorting systems to recycle plastic packaging; inductive metal separators, often used in the production of PET pre-forms or closing caps; and magnetic and metal separators for contamination detection in liquid and pasty products, used during drink production.

The Flake Purifier, which is based on a modular concept, can combine up to three sensors for contamination detection. In addition to the set of third-generation refined sensors for metal and colour separation, it also features a high-performance module to recognise contamination, including different types of plastic. This facilitates the separation of PET flakes from PVC flakes or organic material, such as PLA (previously known to lower the quality of the recycling material dramatically or making high-quality recycling impossible). The intelligent combination with camera sensors enables the Flake Purifier further to identify and separate dark blue and black particles. Inductive sensors detect metal contamination.

Until now, established flake sorters have used only two sensors (metal and colour). The new multi-spectral sensor makes it possible to complete three sorting tasks at the same time. Depending on the application, PET recognition can be programmed as good material or contamination. The new Flake Purifier stands out through its compact and modular design and low power consumption, as no cooling unit is necessary. The equipment can also be ordered with simple sensors, which can be replaced by multi-spectral sensors at any time, should the sorting requirements change. Contact: Ms. Brigitte Rothkopf, S+S Separation and Sorting Technology GmbH, Germany. Tel: +49 (8554) 308 274; E-mail:; Website:


Paving roads with old circuit boards

In China, researchers at Shanghai Jiao Tong University are finding various ways to reuse printed circuit boards from discarded electronics, including as an additive in asphalt. Mr. Xu Zhenmings team stripped the boards of all components, pulverized the remains into a powder and used an electrostatic separator to remove fine bits of any remaining metals, leaving a pulp of glass fibres and resin. The remnants were then added to warmed asphalt, to find out if the pulp would act as a binder.

Binders such as ground tyre rubber and charcoal are typically added to improve asphalts stiffness at high temperatures (to reduce rutting) and its pliability at low temperatures (to prevent cracking). The pulp was found to improve both properties, especially when the powder grains were made as small as possible. Mr. Zhenmings team is testing the modified asphalt to check how it holds up to outdoor conditions over time. It is also experimenting with forming the pulp into sheets that can be made into structures such as park benches and fences. Source:

High-efficiency CRT recycling technology

Japanese companies Panasonic Corp. and Panasonic Eco Technology Centre Co. Ltd. (PETEC) have developed a recycling technology using laser beams to separate the front panel and back part (funnel) of cathode ray tubes (CRTs) used in television (TV) sets. This laser-cut technology allows for separating CRTs quicker and cleaner than before. With this highly-efficient technology, Panasonic is poised to respond to the increasing demand for recycling used CRT TVs, tonnes of which are expected to be thrown away as the shift to digital terrestrial broadcasting is scheduled for completion in 2011 in Japan.

Panasonics CRT recycling technology employs laser radiation to reduce the processing time with much less manual work, allowing one tube to be processed in 50 s, three times faster than the previous method. The laser head of the system has a surface profiling function to maintain a constant distance between the focal point and surface of the glass. With the radiation energy control adjusting the laser beam light intensity to the circumferential velocity, the system achieves a high-quality cut with no mixing between the front and funnel glass. Further, the laser cutter is fully automated to measure the size (14-36 inches) and types (normal and wide) of CRT TVs and process with the laser conditions (38 different sets of conditions) suited to the size and type of each CRT.

Medical use for waste television screens

New research at the University of York, the United Kingdom, suggests that waste material from discarded televisions could be recycled and used in medicine. Polyvinyl alcohol (PVA), a chemical widely used in industry, is a key element of television (TV) sets with liquid crystal display (LCD) technology. When these sets are thrown away, the LCD panels are usually incinerated or buried in landfill sites. Scientists at York have now found a way to recover PVA from television screens and transforming it into a material suitable for use in tissue scaffolds that help parts of the body to regenerate. They can also be used in pills and dressings that are designed to deliver drugs to particular parts of the body. The researchers have developed a technique where recovered material is heated in water using a microwave and washed in ethanol to produce expanded PVA. One of the key properties of this material is that it does not provoke a response from the human bodys immune system, making it suitable for use in biomedicine.

Recycling used circuit boards

Henan ZK Mining & Construction Machinery Co. Ltd., China, offers a complete set of environmental recycling equipment for waste and old circuit boards. The patented equipment adopts advanced and innovative recycling techniques. It pulverizes and recycles waste and old printed circuit boards, household equipment and so forth. The purity of recycled metal can reach to 97 per cent. The main equipment includes crusher, pulverizer, separator, vibrating screen, cyclone collector, etc. Contact: Ms. Christina Zhou, Henan ZK Mining & Construction Machinery Co. Ltd., West Huagong Road, Zhengzhou City, Henan, China. Tel: +86 (1352) 6817 088; Fax: +86 (371) 6789 8596.


Turning medical waste into energy

In the United States, Waste Management Inc. is teaming up with a start-up company, InEnTec, to com-mercialize a technology that turns wastes into energy. The new joint venture, S4 Energy Solutions will try to commercialize plasma gasification technology developed in the 1990s at the Massachusetts Institute of Technology and the Pacific Northwest National Laboratory. The technology uses both traditional gasification and a high-temperature plasma arc to produce synthesis gas that can replace natural gas in electricity generation and chemical production. The process also yields recyclable metal and a glass-like by-product. The technology can handle all types of waste, but some can be processed more efficiently than others. Hazardous wastes are prime candidates for plasma gasification. The new S4 technology is currently scaled to handle 25 t/d, perfect for regional medical waste processing. Eventually, the company plans to process 125 t/d of waste. Contact: Mr. Larry Carpman, InEnTec LLC, United States of America. Tel: +1 (617) 338 6601; E-mail: larry@carp

Medical waste transformed into paving stones

In Viet Nam, Dr. Nguyen Hieu Hiep, Director of Thoi Lai District Hospital, Mekong Delta city of Can Tho, has developed a process to turn glass medical waste into concrete pavement. In this process, medical glass wastes are ground finely and mixed with cement and powdered lime. This mixture is then poured into a paving stone mould. Paving stones thus obtained were tested for safety and strength, with satisfactory results. Dr. Hieps recycling method eliminates the need for land filling and the pollution associated with burning the wastes. Dr. Hiep is conducting research on Solid medical wastes (glass group) treatment machine in cooperation with an engineer, Mr. Hoang Thanh Liem, to improve his invention.

Sterilizer for biomedical wastes

Jain Hydraulics Pvt. Ltd., India, offers an advanced autoclave for sterilizing biomedical waste. The waste is indirectly heated by providing steam in the jacket instead of the main chamber. The moisture in the waste is used to generate the necessary steam pressure for optimum sterilization at low cost. The system works based on the principle of hydrolysis. It is automated and microprocessor-controlled; no human effort is required, except for putting the waste bags inside the vessel. The waste loading door closure is automatic.

Pre-shredding is inside the vessel, resulting in total fragmentation of the waste inside the equipment, thus allowing for maximum penetration of steam to each and every part of the waste. The treated waste is unloaded by the tumbler arm and tumbler tilt; both operate fully synchronized and automated. Final discharge is on to the shredder and then to the storage bins (optional). The waste is treated to achieve a level of 6-LOG, equivalent to 99.999 per cent. Contact: Mr. A. K. Jain, Managing Director, Jain Hydraulics Pvt. Ltd., 10066, Multani Dhanda, 1st Floor, Street No. 1, Paharganj, New Delhi 110 055, India. Tel: +91 (11) 2352 3966, 2362 9689, 2361 0291; Fax: +91 (11) 2550 4343; E-mail:

Common reed treats hospital wastewater

Nhan Ai Hospital is the first hospital in Viet Nam to treat wastewater using common reed (Phragmites communis), which according to scientists will thrive in the Vietnamese weather. The plants roots can help disintegrate organic substances and absorb the heavy metals in hospital wastewater. Tests show that, after following this method of treatment, water reaches the standard for safe discharge into the environment. The method not only avoids generation of foul smell or noise, but also is more economic than methods that employ chemicals. Plants such as common reed have been used for treating wastewater in some other countries, such as Germany and Switzerland.

Method for treatment and recovery of clinical waste

Medical Waste Solutions Ltd., the United Kingdom, has obtained a European patent for an invention that has been developed to circumvent the disadvantages associated with conventional methods of clinical waste treatment. The invention also aimed to convert economically realistic quantities of the waste into easily disposable materials ideally into material that has commercial value. It addresses the problem of disposing of a potentially hazardous and/or infectious waste material while reducing direct and indirect processing and transport costs, to provide a more economic and environment-friendly disposal mode.

The method professes wastes that contain a mix of thermoplastic and non-thermoplastic materials to output a material fit for use as an ingredient in a manufacturing process. The method comprises the steps of:

* Increasing the temperature of the waste through heating, preferably by the introduction of steam;

* Supplying the heated waste to a densifier to compress the waste and ensure optimum heat transfer between the constituent materials; and

* Extruding the densifier waste.

The exposure of the waste to heat by steam minimizes or reduces the hazard posed, while the densification step causes the thermoplastic materials at least partially to surround the non-thermoplastic constituents and thus provide a generally homogenous product for extrusion. The residual non-sterile elements after steam heating will get sterilized during the densification process, when the intimate contact between the materials ensure heat exchange that helps to remove the bacterial, viral, pharmacological or chemical hazards. Contact: Medical Waste Solutions Ltd., Concord House Concord Way, Preston Farm Industrial Estate, Stockton on Tees, Cleveland TS18 3RB, United Kingdom.

Continuous flow waste treatment system

Innovasan Corp., the United States, offers a continuous-flow, volume-scalable waste treatment system for hospitals, surgery centres and other source point generators of fluid medical waste streams. The Interceptor Waste Treatment System product line is being developed with the patents-pending Med-San process to destroy both biological (12 log10 reduction) and pharmaceutical compounds using a cost effective treatment process. Med-San produces a sterile and chemically inert medical waste stream that is safe for direct discharge into municipal sewerage system or the environment.

Two models are under development to support mission requirements within the United States Department of Defence. The F100 Interceptor Waste Treatment System for fixed hospital and shipboard installation and the M50 Interceptor Waste Treatment System for mobile field deployment in harsh environments. Med-San can accommodate waste stream volumes from small to large source point generators. Contact: Innovasan Corp., United States of America. Tel: +1 (865) 6613 008; Fax: +1 (865) 6750 179; E-mail: medicalwastetreatment@innovasan

Hydroclave to treat medical wastes

Hydroclave Systems Corp., Canada, offers what the company describes as a remarkably simple, affordable, patented, proven medical waste treatment process, which achieves high waste sterility, at a low treatment cost. The Hydroclave equipment totally sterilizes the waste, treating all infectious waste, even bulk liquid and pathological waste. It also carries out complete waste dehydration, and large weight and volume reduction. The low temperature steam process has no harmful emissions.

In the process, powerful rotators mix the waste and break it into small pieces. Steam is then introduced into the double wall (jacket) of the vessel to heat the vessel interior, wherein the liquid part of the waste turns to steam. After 20 minutes, the waste and liquids are sterile. The vent is then opened, the vessel is de-pressurized, and the sterile liquid drained into sanitary sewer. Steam heating and mixing continue until all the liquids are evaporated and the waste is dry.

Then mixer rotates in the opposite direction, so that angled blades on the mixer can push the waste out the unloading door. The dry sterile waste can be fine-shredded further or dropped in a waste disposal bin. The Hydroclave can process: bagged waste, sharps containers, liquid containers, cardboard containers, metal objects, as well as pathological waste. Contact: Hydroclave Systems Corp., 662 Norris Court, Kingston, Ontario, Canada K7P 2R9. Tel: +1 (613) 389 8373; Fax: +1 (613) 389 8554; E-mail: info@hydroclave. com.


Nickel recovery in metal-plating industry

The Cleansing Service Group (CSG), the United Kingdom, claims to have developed a process to recover nickel of 99.9 per cent purity from the complex waste generated mainly by the metal-plating industry. CSGs new processing facility at Cadishead near Manchester is the first in the country capable of recovering nickel from spent electroless-nickel solutions.

Mr. Neil Richards, CSGs Director of Processing and Disposal, said: Spent electroless-nickel solutions contain high levels of organics and salts and are notoriously difficult to recover by electrolysis alone. The new method, which has taken nearly a year to develop in conjunction with metal recovery specialist Kurion Technologies, successfully overcomes these problems.

The new method is reported to consistently deliver viable amounts of high-purity nickel. The plant, which was purpose-built at Cadishead to develop and prove the technology, puts the waste solution through a multi-stage pre-treatment chemical process before conventional electrolysis is employed to plate out the nickel. Contact: Cleansing Service Group Ltd., Grange Road, Botley, Southampton, SO30 2GD, United Kingdom.

Reverse osmosis and membrane units

Koch Membrane Systems Inc. (KMS), the United States, has introduced MegaMagnum reverse osmosis (RO) and nanofiltration (NF) systems for industrial and municipal use, and its PURON submerged membrane modules for large-scale membrane bioreactor (MBR) units.

The MegaMagnum RO and NF systems utilize spiral-wound membrane elements, which are claimed to be the largest in area in the world, to reduce significantly the complexity, footprint and installation time of industrial municipal and water treatment systems. Plants that use the system reportedly require only half the area of floor space, compared with a conventional 8-inch rack and use only one-seventh the amount of elements to produce the same volume and quality of water as conventional RO system operating at similar fluxes and pressures. KMS makes MegaMagnum in four configurations with nominal flow capacities ranging from 78,860 to 315,450 l/h.

The 1,500 m2 PURON module has greater membrane packing density, lower energy costs for aeration and simplified installation than other commercially available systems, but provides greater compatibility with them. Additional features such as an optimized permeate extraction manifold and air supply lines reduce the number of piping connections during installation. The new product line enables users to easily retrofit the advanced PURON technology into systems with modules of comparable sizes.

Method to monitor wastewater bacteria

Researchers at Purdue University, the United States, have developed a new technique using sensors to constantly monitor the health of bacteria critical to wastewater treatment facilities and have verified a theory that copper is vital to the proper functioning of a key enzyme in the bacteria. The new process senses minute chemical changes related to bacterial health and reports results immediately, unlike conventional technologies that need laboratory analyses taking at least a day. This immediacy could make it possible to detect when bacteria are about to stop processing waste and correct the problem before toxins are released into waterways, said Dr. Eric McLamore, a civil engineering research associate. The technique is a departure from conventional methods, which require the bacterial biofilms to be damaged in order to be tested. Dr. Marshall Porterfield, an associate professor of agricultural and biological engineering, said that the new approach is both non-invasive and real-time. Dr. M. Katherine Banks, who heads the School of Civil Engineering, is the third member of the team.

The scientists used the method to study a nitrifying bacterium called Nitrosomonas europaea, which converts toxic ammonia from human wastes and fertilizer run-off into compounds called nitrites, which are further broken down by other bacteria into nitrogen gas. Bacterial biofilms, when poisoned or stressed, release ions (including potassium and calcium), which is an early warning signal, Dr. Porterfield said. The filtering flux sensor reveals the ion flux, or the number ions being transported into and out of the biofilm per minute. Sensor data reveal how well the bacteria are absorbing ions from the wastes. This helps avoid uncontrolled flushing of untreated wastes into waterways.

Seashells for heavy metals clean-up

On the banks of the Saigon River in Viet Nam, researchers have completed tests on a new way to combat water pollution that could save millions of lives in coastal cities in the developing world. In factories on the outskirts of Ho Chi Minh City, Dr. Stephan Khler of the Graz University of Technology in Austria and a team of researchers have cleansed water tainted with toxic metals like cadmium, zinc, lead and iron. The team did it using one of the cheapest, most abundant materials around: seashells.

Dr. Khlers team has found that pouring metal and acid-laden water over a bed of crushed clam or mussel shells provides an easy fix. The shells are made of aragonite, a form of calcium carbonate that readily swaps its calcium atoms in favour of heavy metals, locking them into a solid form. The shells are alkaline a pH of 8.3 when dissolved and needs to be maintained so by adding more shells.

The teams technique stems from work in 2003 by Dr. Manuel Prieto of Oviedo University in Spain, who first showed that shells effectively remove cadmium from water. Dr. Khlers team has now expanded that to include more heavy metals, including lead, a potent toxin. Their work in Viet Nam also shows that the technique works on wastewater produced from real-world factory processes.

Bacteria-based system for treating toxic wastewater

Biotechnologists at University of the Philippines Los Baos (UPLB) are at work putting final touches to a prototype bacterial treatment system for wastewater. Dr. Lorele C. Trinidad of BIOTECH, who leads the team developing the bioremediation system, reports that the prototype can remove and at the same time recover precious heavy metals from water discharged during gold processing and leather tanning.

Silver, a valuable metal, can be recovered from the chemical solutions used in gold-smelting. Copper-rich wastewater is produced in the process, and is usually dumped into the river. Dr. Trinidads team found that the wastewater released into the river has 5,000-10,000 ppm of copper, when the limit allowed by the Department of Environment and Natural Resources is only 1.3 ppm. The leather tanning operations use chromium (III) to treat raw animal hide. According to Dr. Trinidad, as much as half of the applied chemical ultimately goes to the river.

Dr. Trinidads team has identified 12 isolates of bacteria with high capability to reduce sulphates and produce hydrogen sulphide gas. These bacteria were used in a small bioremediation system made by the Industrial Technology Development Institute of the Department of Science and Technology. The system employs the hydrogen sulphide gas produced by the bacteria to precipitate and recover chromium and copper from wastewater.

MBR system for industrial wastewater treatment

Titan MBR, an advanced membrane biological reactor (MBR) from CST Wastewater Solutions in Australia, is a low-maintenance wastewater treatment system for municipal and industrial applications. Titan MBR system combines wastewater treatment engineering with submerged flat-plate membrane technology that ensures high permeability and flux rates. According to the company, this combination yields a dynamic MBR wastewater treatment system that provides end-users with quality treatment performance, minimal operational requirements and a robust design.

Titan MBR wastewater treatment systems flat-plate membrane design results in less wear and tear. Its air scouring prevents fouling, and the pressure created by gravity drives the flow through the membranes. Clean water discharges into a clear well, while blocked solids remain suspended in the aeration zone. Diffusers under the module scour the membranes while also providing an air supply to the bacteria.

Titan MBR provides long-term durability, according to the company. The membrane is made of polyvinylidene fluoride and non-woven polyester fabric, which prevents clogging problems experienced in hollow-fibre designs. Vertical membrane surfaces do not touch each other during operation. The design of the membrane prevents breakage experienced in other designs, CST claims, and produces higher flux rates over time. Flat-plate membranes employ less chemicals and equipment for cleaning in place.

The Titan MBR wastewater treatment system provides an effluent quality of < 3 mg/l biological oxygen demand (BOD) and < 1 mg/l total suspended solids (TSS). Turbidity is < 2 Nephelometric Turbidity Units (NTU) and the Total Kjeldahl Nitrogen (TKN) is < 2 mg/l and ammonia < 1 mg/l. Contact: CST Wastewater Solutions, 5 Haughton Street, Linley Point, NSW 2066, Australia. Tel: +61 (2) 9427 1279; Fax: +61 (2) 9427 3354.


Petroleum hydrocarbon remediation

In the United States, EOS Remediation and Delta Consultants have signed an exclusive patent licence agreement that gives EOS exclusive rights to manufacture, use and market Deltas sulphate-enhanced technology for in situ remediation of contaminated groundwater. The patent includes a process for using high concentrations of sulphate to stimulate biodegradation of petroleum hydrocarbons (PHCs), other aromatic hydrocarbons, as well as other contaminants susceptible to sulphate-reducing bacteria.

A recent study by British Petroleum and the United States Environment Protection Agency has concluded that most hydrocarbon plumes are anaerobic and depleted of sulphate. Deltas sulphate-enhanced technology, now marketed by EOS Remediation under the name EAS, stimulates biodegradation by providing a soluble, readily available electron acceptor. Ongoing project results indicate that the technology can cost-effectively turn land once deemed unusable into productive real estate. Contact: EOS Remediation LLC, 1101 Nowell Rd., Raleigh, North Carolina 27607, United States of America.

Bacterial clean-up of heavy metals

A species of bacteria isolated from sediments deep under the Pacific Ocean could provide a powerful clean-up tool for heavy metal pollution. Prof. Gejiao Wang and his team from Huazhong Agricultural University, China, found strain MN32 of Brachybacterium to be extremely effective in removing manganese from solutions, converting it into insoluble manganese oxides. Not only did the bacterium directly oxidize manganese but the resulting oxides themselves also absorbed the metal from the culture solution, making Brachybacterium sp Mn32 a potential candidate for use in bioremediation and cleaning up pollution. As well as it removed manganese from its environment, the Brachybacterium also absorbed zinc and nickel in significant amounts. All of these metals are found as pollutants in water and soils around sites of heavy industries such as steel-making.

Manganese oxides can be manufactured chemically and are known to absorb zinc and nickel; but the oxides produced by this bacterium absorbed 2-3 times more metal. Prof. Wangs team showed that the crystal structure of the bacterial manganese oxides is different to that of the chemically produced ones, with a greater surface area enabling more of the metal ions to be absorbed. The next stage of the research is to immobilize this bacterial strain into a bioreactor to test its ability to remove manganese and other heavy metals in such a system. Success in this would mean an efficient way to clean up heavy metal pollutants.

Marine surfactant soaks up heavy metal

Researchers at the Indian Institute of Technology-Kharagpur have used atomic absorption spectroscopy and various other techniques to demonstrate the effectiveness of a natural surfactant molecule in removing heavy metals from solutions for potential bioremediation applications. The team from the Department of Biotechnology studied a natural product lipopeptide surfactant from a microorganism, Bacillus circulans.

According to Mr. Ramkrishna Sen and colleagues who isolated the lipopeptide biosurfactant in 2008, The biosurfactant produced by marine B. circulans has a potent antimicrobial activity against gram-positive and gram-negative pathogenic and semi-pathogenic microbial strains. They now point out how the same surfactant might be used to help remove heavy metal contaminants from the environment.

The team has tested the efficacy of the biosurfactant from B. circulans in removing heavy metals from solutions. They demonstrated that metal removal is possible even at a biosurfactant concentration below the critical micelle concentration (CMC), contrasting starkly with other studies that suggested micelles were needed for metal removal. The percentage of removal varied with the different concentrations of metals and biosurfactants. In general, a higher concentration of biosurfactants removed more metals. At a concentration five times CMC, almost complete removal of 100 ppm of lead and cadmium occurred.

Cost-effective closure of contaminated sites

Using the enhanced in situ bioremediation technology Oxygen Release Compound (ORC from Regenesis, the United States) and targeted contaminant source removal, remediation professionals restored and secured regulatory closure for 29 petroleum-contaminated sites in Indiana at an estimated cost saving of US$75,000-US$900,000 per site. The clean-ups used an innovative strategy designed to achieve rapid, highly cost-effective site closures through a combination of accelerated in situ bioremediation, risk-based clean-up goals and (where needed) focused source removal.

ORC is a non-toxic, easy-to-handle powder that is typically mixed with water to form a milk-like slurry that is injected directly into contaminated soil and groundwater, where it provides a controlled-release supply of oxygen for as long as 12 months. The increased oxygen level stimulates the growth of naturally occurring aerobic microbes that actually digest the hydrocarbons in the subsurface, leaving only water, carbon dioxide and other harmless end-products. This method of restoring contaminated sites is far less costly and intrusive than the conventional methods. Contact: Regenesis, 1011 Calle Sombra, San Clemente, CA 92673, United States of America.

Pollutant removal and bioremediation at source

Scientists from the City University of Hong Kong, Hong Kong University of Science & Technology and Hong Kong Baptist University, China, have developed a technology for pollutant removal at source. The biological systems using constructed mangrove wetland and immobilized microalgal beads were developed as alternative systems for treating different types of sewage and pollution at source. Greenhouse experiments and a pilot-scale field trial demonstrated the feasibility and efficiency of constructed mangrove wetland to remove organic matter and nutrients from primary-settled municipal sewage.

The treatment efficiency of the constructed mangrove wetland was comparable to, or higher than, that of conventional wetland. An immobilized microalgal system was developed to remove toxic persistent pollutants from industrial wastewater. Pollutant-resistant microalgal species were selected for culture in domestic wastewater. The harvested biomass was immobilized in alginate beads. Bench-scale experiments showed the algal beads were effective in removing industrial pollutants such as heavy metals (copper, zinc, nickel and chromium), organometallic compounds (tributyltin) and persistent organic compounds (polycyclic aromatic hydrocarbons) through biosorption and biodegradation. Desorption process recovered the adsorbed metals, and the beads could be used repeatedly for several adsorption-desorption cycles.

Bacterial remediation of oil spills

A recent study by scientists in China report about microbes that can effectively clean up oil spills without leaving any harmful residues in the environment. Researchers at the College of Water Sciences, Beijing Normal University, working with the Ministry of Environmental Protection of China, studied the activity of enzymes from Bacillus cereus DQ01, the bacterium that can digest the hydrocarbon n-hexadecane. B. cereus was initially isolated from the Daqing oil field in Northeast China, where it had evolved the ability to metabolise this chemical. The new microbe can digest hydrocarbons and the researchers have found the optimal conditions for it to feast on hydrocarbon, thereby pointing the way to a more effective approach to bioremediation of spill sites.

The key step in the degradation of hydrocarbons normally depends on the presence of a multi-component enzyme system. The researchers found that enzymes within the microbial cell and in its inner membrane are responsible for degradation of n-hexadecane. Neutral pH and a temperature of 30C are optimal for the microbe to produce the main degradation enzyme. Also, adding a small amount of a surfactant material, rhamnolipid, can stimulate enzyme production and improve degradation efficiency.

Enhanced bacterial remediation of crude oil-contaminated soil

Researchers from the Department of Biochemistry of the University of Nigeria have studied the potential of using a cocktail of bacteria for enhanced bioremediation of crude oil-contaminated soil. A mixed culture of mutually compatible hydrocarbonoclastic (Pseudomonas sp.) and diazotrophic (Azotobacter vinelandii) bacteria, each at a density of 108 organisms cm-3, was developed for optimized bioremediation of crude oil-contaminated soil. Both bacteria were isolated from soil previously contaminated with crude oil, and thereafter modelled as a unit of mutualistic consortium in situ.

Stabilization of the consortium and hence the optimized bioremediation process occurred when the bacterial growth attained a pseudo-steady state. This was considered to be a result of the symbiotic association between A. vinelandii and Pseudomonas sp., in which the former produced the required concentration of fixed nitrogen compounds needed for the growth of the latter. The proportion of petroleum hydrocarbons degraded by the consortium from the soil ranged from 66.83 per cent to 69.60 per cent, as compared with that of a pure culture of Pseudomonas sp. (23.2 per cent to 44.45 per cent). Hence, the researchers concluded that diazotrophs may be used in the bioremediation of crude oil-contaminated land.


Odour control and VOC abatement

The Mnashell biological air treatment system is a patented process developed by Bord na Mna Environmental Ltd., the United States, to treat high and varying levels of contaminants in air in municipal wastewater treatment, food processing, agri-industrial and other industrial facilities. The Mnashell system comprises a filter with calcareous packing and a continuously recirculating biological liquor. The physical and chemical properties of the filter packing enhance the process, thus allowing for considerably reduced retention times with better performances. Furthermore, the packing maintains the pH and the irrigation water maintains the moisture, thus reducing running costs. Another advantage of the process is the extremely low-back pressure applied by the open media structure.

Advantages of the Mnashell biological air treatment system are:

* Low pressure drop and thus low power consumption; * High efficiency, particularly on water-soluble compounds; * In-built moisture control; * In-built pH control; * Randomly packed aerodynamically shaped media for efficient mass transfer and open structure; * Buffering capacity of a recirculating liquor; and * Long life expectancy of the filter media.

Low-energy VOC abatement solutions

AirProtekt, the air pollution control specialist in the United Kingdom, is leading the way to overcome the negative aspects of climate change by offering tailored volatile organic compounds (VOCs) abatement engineering solutions that feature low energy consumption performance. AirProtekt supplies compact, low-maintenance regenerative thermal oxidation (RTO) systems that offer high thermal efficiencies (up to 97 per cent) while minimizing operating costs.

AirProtekts RTO engineered package typically has a containerized combustion section complete with honeycomb ceramic heat recovery medium, pre-heater, change-over valves and a control system. The RTO solutions are based on the Roxitherm system manufactured by Lufttechnik Bayreuth, the leading German company in air pollution abatement. The system designed to transform odours, hydrocarbons or solvents to carbon dioxide and water uses a thermal oxidation process supported with regenerative heat recovery technology to maximize energy efficiency. More than 90 per cent of the energy required to pre-heat emission gases is recoverable, keeping energy consumption extremely low.

The RTO system is designed with stainless steel or with raw gas pre-heating for corrosive gases and with a hot gas bypass for high concentrations; a special construction form can be selected to tackle condensation. Contact: AirProtekt Limited, Newton Hall, Newton, Cambridgeshire, CB2 5PE, United Kingdom.

Bowl-shaped molecule promises carbon capture

The accidental discovery by a researcher of a new molecule could revolutionize carbon sequestration. The work of Mr. John A. Tossell at the University of Maryland, the United States, could lead to true carbon control with a bowl-shaped molecule. The molecule (a macrocyclic amidourea) manages to capture carbon dioxide (CO2) through an evaporation process that promises not only to remove CO2, but to effectively capture it for later controlled release.

The slow evaporation from a dimethyl sulphoxide (DMSO) solution that disrupts the base pairing containing organic compounds was found to yield a complex CO3 molecule that draws local CO2. The ready formation of this compound suggests a high stability... may be a candidate as a receptor or absorber for atmospheric CO2, says Mr. Tossell. Using water instead of DMSO as solvent or heat would decompose the CO3 to release the CO2. This molecule could serve as a carbon usher, working to isolate and confine CO2, potentially even from the pollution from a power plant that could then be controlled to redirect the CO2 towards combustion. Mr. Tossell suggests that the process may be highly useful for removing CO2 in ambient air, while capturing excess CO2 might be better served by the creation of solid polymeric carbonic acid (CO2 dissolved in water).

Reducing automotive environmental impact

Solvay and its affiliate Inergy Automotive Systems, world leader in fuel systems for the automotive industry, have started producing a selective catalytic reduction (SCR) system at its plant in Rottenburg, Germany, using Adblue, which reduces the concentration of nitrogen oxides in diesel exhaust gases from Audi Q7 TDI. This system meets the rigorous Ultra-Low Emissions Systems standards of the California Air Resources Board.

The Rottenburg plant also started producing fuel systems utilizing the Twin-Sheet Blow-Moulding (TSBM) technology for the BMW 7 series and the Audi A8 series. This technology makes it possible to decrease considerably the evaporation of volatile organic compounds through the plastic walls of the fuel systems, as compared with the already low emission rate from conventional fuel systems. This technological breakthrough is a huge step towards a zero-emission fuel system.

Project reduces emissions at coal-fired power plant

At the coal-powered electric plant of Rochester Public Utilities in the United States, a US$38 million Emission Reduction Project is estimated to reduce the amount of nitrogen oxides, sulphur dioxide, mercury and particulate matter emitted from the plant by 99.9 per cent. Previously, the power plant used an electrostatic precipitator air cleaner in which particles stick to plates. Later, the Silver Lake plant switched to the baghouse method to cut down on emissions. The project has three silo-like structures that house three important components to clean up the emissions from the plants largest, 55 MW generator.

The new system starts by creating more efficient combustion in the 10-storey boiler by using a Rotating Opposed Fire Air, or ROFA box. As pulverized coal enters the boiler, the ROFA box takes in air off the wind box and redistributes the heat. The plant also recovers heat from other processes that helps make combustion efficient. To reduce 50-55 per cent of the nitrogen oxide emitted from the burning coal, urea is added in the boiler process. When the boiler is running at minimum load, the urea supply can be shut off. From there, steam is sent to either the steam line or the turbine that works like an expansion engine to run the generator that creates the power.

The boiler exhaust is sent to a scrubber, to remove 85 per cent of the sulphur dioxide from it. Water is mixed to lime in gravel form, to make slurry as well as to start a chemical reaction that heats up the mixture, which is used to turn sulphur dioxide into calcium sulphate. To do so, an atomizer spins a wheel so fast that the mixture sprays out as a fine mist. Gases from the dry scrubber are sent to the baghouse to be filtered through more than 3,000 long, tube-like bags. The bags are coated with lime cake that can filter 99.9 per cent of the particulates. Contact: The RPU Service Centre, Rochester Public Utilities, 4000 East River Road, Rochester, MN 55906, United States of America. Tel: +1 (507) 2801 500.

High-efficiency wet redox NOx control system

Until the late 1980s, high efficiency wet scrubbing for nitrogen oxides (NOx) was not available commercially, because of the stability and relative insolubility of the nitric oxide (NO) component of NOx. At Duall, the United States, systems engineers recognized this problem and designed a super-efficient NO oxidation system to provide the market place with a total NOx wet scrubbing process. The current competitive nature of the market has made better operating efficiency for this type system a requirement.

Duall, in research collaboration with the University of Michigans Chemical Engineering Department, has developed a unique, high-efficiency wet oxidation/reduction approach to control NOx emissions. Refining and updating this process has led to a new generation of total NOx scrubbers for the chemical process industry. Duall has successfully demonstrated the oxidation efficiency of NO to nitrogen dioxide (NO2) in a eta NOx 2000 system, as well as the simultaneous destruction of sulphur dioxide. Contact: Duall, 1550 Industrial Drive, Owosso, MI 48867, United States of America. Tel: +1 (989) 7258 184; Fax: +1 (989) 7258 188; E-mail: info@duall

Method and system for exhaust gas purification

Air Products and Chemicals Inc., the United States, has patented a new method and system for purifying exhaust gas. The invention relates specially to solvent-laden exhaust gas from refrigerator recycling, wherein the dried, pressurized exhaust gas is cryogenically condensed. The condensed components are separated from the remaining exhaust gas, the cold and purified pressurized exhaust gas is passed through an adsorber to adsorb the remaining condensed components, and the adsorber is purged with a warmed gas stream. Either warmed inert gas stream or purified exhaust gas is employed for purging the adsorber at reduced pressure. The desorbed gas is then recycled. Air Products is a worldwide supplier of industrial gases and equipment, chemicals, and environmental and energy systems. Contact: Air Products and Chemicals Inc., 7201, Hamilton Boulevard, Allentown, PA 18195-1501, United States of America.


Bioremediation of Petroleum Hydrocarbons in Cold Regions

This practical guide to bioremediation in cold regions is designed to assist environmental practitioners, industry and regulators in the remediation of petroleum spills and contaminated sites in cold regions. It contains in-depth discussions on regulations, freezing and frozen ground, identification and adaptations of cold-tolerant bacteria, contaminant transport in cold soils and permafrost, temperature effects on biodegradation, analytical methods, treatability studies and nutritional requirements for bioremediation. The guide emphasises practical and effective bioremediation methods, and discusses emerging technologies. It includes case studies and cost-benefit analyses to aid in decision making, besides feasibility studies and cost estimation. It gives guidance for practical remediation design and implementation, and includes in-depth literature review, giving consolidated, state-of-the-art research and guidance on the topic.

Contact: Cambridge University Press, The Edinburgh Building, Shaftesbury Road, Cambridge, CB2 8RU, United Kingdom. Tel: +44 (1223) 312 393; Fax: +44 (1223) 315 052; E-mail: directcustserve@cambridge. org.

Waste Treatment in the Metal Manufacturing, Forming, Coating and Finishing Industries

This book elucidates new industries and new waste management topics and provides all of the necessary technical information on industrial and hazardous waste treatment. Focusing on new developments in innovative and alternative technologies, it offers in-depth coverage of environmental pollution sources, waste characteristics, facility innovations, design criteria, control technologies, management strategies, process alternatives, costs and effluent standards. It also addresses the regional and global effects of important pollution control practices specific to the process industries. The publication covers hazardous industrial waste treatment, renovation, and reuse in the metal manufacturing, forming, coating, enamelling and finishing industries. It details specific hazardous and industrial wastes from metal industries, and basic and advanced principals and applications.

Contact: CRC Press, United Kingdom. Tel: +44 (1235) 400 524; Fax: +44 (1235) 400 525; E-mail: book.


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