VATIS Update Waste Management . May-Jun 2003

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Waste Management May-Jun 2003

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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Additions to list of controlled chemicals

An international listing of chemicals subject to trade controls will expand to include all forms of asbestos, two forms of lead and three pesticides, if recommendations made by a panel of government-appointed experts is approved under the Rotterdam Convention. The international treaty requires exporting nations trading in the list of hazardous substances to obtain prior informed consent (PIC) of importing nations before proceeding with the trade. Though the Convention has as yet not entered into force, in the interim, governments have agreed to apply the treatys PIC provisions on a voluntary basis. Five industrial chemicals as well as 26 pesticides are subject to the interim PIC procedure. A new pesticide to be included in the PIC list is DNOC, an insecticide, fungicide and weed killer.

TERI Newswire, 1-15 March 2003

Global study on mercury released

According to a report released by the United Nations Environment Programme, mercury poisoning of our planet can be reduced significantly by checking pollution from power stations. The report, compiled by an international team of experts, states that coal-fired power stations and waste incinerators now account for about 1,500 t or 70 per cent of new, quantified, human-made emissions of mercury. The lions share is contributed by developing countries, with emissions from Asia the highest at 860 t.

The report also predicts that with increasing use of fossil fuels to meet growing energy requirements of both developed and developing nations, mercury emissions are expected to rise accordingly if appropriate control technologies are not deployed soon or alternative energy sources are not used. Artisanal mining of gold and silver in an increasing number of less developed nations is another significant source of mercury pollution, releasing an estimated 400-500 t/y of mercury to the air, soil and waterways. Mercury is used to extract precious metals from ores, resulting in elevated exposures and risks for the miners and their families, as well as contamination of the local and regional environment. Other notable sources of mercury releases include cement production, chlor-alkali production, crematories, manufacture of thermometers, fluorescent lamps, electrical switches, as well as rubbish dumps containing wastes like old batteries and similar products.

Also, temperature could influence mercury release from contaminated sediments and soils into rivers, lakes and other fresh waters. Here it can convert into methyl-mercury, one of the most poisonous forms, and build up in fish and other aquatic life forms with potentially harmful impacts on human adults and infants. Several studies have linked brain damage in babies to mercury poisoning of their mothers as a result of consuming tainted fish. Additionally, exposures to mercury can occur through dental amalgams and certain occupational activities. Furthermore, personal use of skin lightening creams and soaps, mercury use for religious, cultural and ritualistic purposes, use in some traditional medicines and vaccines, a few other pharmaceuticals containing mercury preservatives (such as Thimerosal/Thiomersal) and even mercury in the home and working environment contribute to elevated exposures.

Experts who compiled this report have recommended about a dozen immediate actions, including public awareness programmes targeted at sensitive populations like pregnant women, waste disposal facilities for the safe degradation of obsolete, 
mercury-containing pesticides and pollution control systems for power stations. Furthermore, they are asking governments to consider a list of options for addressing the dangers of mercury. These include:
  • Reducing risks by lowering or eliminating production, use and release of mercury;
  • Substituting other non-mercury-based products and processes;
  • Launching talks for a legally binding treaty;
  • Establishing a non-binding global programme of action; and
  • Strengthening teamwork among governments on information sharing, risk communication, assessment and related activities.

Breakthrough in recycling mobile phones

The 6th Meeting of the Conference of the Parties to the Basel Convention (COP-6) yielded a major breakthrough in the form of a public-private sector partnership involving mobile phone manufacturers and the United Nations on environmentally sound management of end-of-life mobile phones. Many of the worlds major manufacturers signed the accord, including Motorola, Nokia, Siemens, Matsushita-Panasonic, Mitsubishi Electric, NEC, Philips, Samsung, LG and Sony Ericsson.

COP-6 adopted the theme Partnerships for Implementation. Among technical guidelines adopted at the conference, the following are of particular relevance to the recycling in-dustry and were closely monitored:
  • Identification and environmentally sound management of plastic wastes and their disposal;
  • Environmentally sound management of complete and partial dismantling of ships; and
  • Environmentally sound management of waste lead-acid batteries.

Viet Nam initiates action against POPs

Viet Nams Ministry of Natural Resources and Environment (MoNRE) has signed a US$500,000 project with the United Nations Development Programme (UNDP) to protect the environment and human health from dangers posed by persistent organic pollutants (POPs), a group of toxic chemicals. The 18-month initiative, funded by the Global Environment Facility (GEF), will be implemented by the National Environment Agency under MoNRE, while UNDP provides technical support. The focus of this programme is to develop and enact the National Implementation Plan of the Stockholm Convention on POPs, ratified by Viet Nam in July 2002. POP pesticides are used in Viet Nam to boost agricultural productivity.

Among various pollutants released as a result of human activity, POPs are the most dangerous. They are highly toxic and cause an array of detrimental effects death, disease and birth defects among humans and animals. POPs can travel long distances from their original sources and have the ability to persist and bio-accumulate in human bodies through the food chain. POPs are used as pesticides, consumed by industry or generated as by-products of various industrial processes. The 12 POPs recognized as requiring the most urgent action are Aldrin, Chlordane, DDT, Dieldrin, Dioxins, Endrin, Furans, Heptachlor, Mirex, Hexachlorobenzene (HCB), Poly-chlorinated Biphenyls (PCBs) and Toxaphene.

The new initiative is intended to help Viet Nam build up the capacity to manage and monitor POPs, thereby protecting and promoting sustainable development. The new project will lay the foundation for treatment infrastructure, that includes disposal technologies for POPs, waste and cleaner production to lower release of POPs into the environment. Initial activities will include setting up a national inventory of pesticides, dioxins, furans and PCBs, as well as an assessment of the economic and social implications and risks posed by POPs to human health and the environment.

Viet Nam INFOTERRA Newsletter, January-March 2003

Scoreboard for IWM

Monitoring and evaluation are two essential tools for integrated waste management (IWM) system. Plans are afoot at the International Environmental Technology Centre (IETC) to introduce an IWM Scoreboard as an effective means for monitoring implementation of waste management systems and measure their performance at the community, institutional and city or national level, whether the focus is on solid waste, wastewater, hazardous waste or a combination of these wastes. The IWM Scoreboard will act as a simple scoring system to record actions undertaken and completed based on what was to be accomplished over a specified period of time. It will use a set of indicators and criteria for scoring, including values and scoring method, which shall be agreed to and understood by participating groups/users.

ASEP Newsletter, December 2002

ADB-funded project to manage garbage

In the Philippines, eight local government units (LGUs) will be among the first beneficiaries of the Asian Development Bank (ADB)-supported Metro Manila Solid Waste Management Project (MMSWMP) that aims to assist LGUs come up with their own 10-year plans to manage solid wastes. The Department of Environment and Natural Resources (DENR) has signed a Memorandum of Agreement (MOA) with ADB officials and the city/municipal mayors of Manila, Muntinlupa, Malabon, Valenzuela, Pasig, Makati, Navotas and Quezon City. A total of 17 LGUs would benefit from the MMSWMP programme.

DENR will provide assistance to the LGUs for setting up a solid waste management system that integrates waste reduction, collection, recycling, information, communication, education and disposal. Under the MOA, DENR will provide adequate number of qualified counterpart staff for the project, including technical guidance in the planning, monitoring and implementation of the project. On the other hand, LGUs will enact necessary legislations to facilitate complete implementation of the programme in nine months. MMSWMP is currently being implemented by DENR, under a grant from ADB, to address the growing urgency of solid waste generation. The project also seeks to build the capabilities of the National Solid Waste Management Commission, the Metro Manila Development Authority and the Department of Health specifically to deal with hospital wastes. In Metro Manila alone, about 6,000 t of garbage is generated daily. Only about 65 per cent of this is collected while the rest is discarded in open municipal dumpsites or vacant sites, burned illegally or disposed in waterways such as creeks, streams and rivers. MMSWMP has helped the cities of Makati and Muntinlupa in their waste characterization process, with six other LGUs following suit.


Japan to raise auto recycling levels

In Japan, the Ministry of Economy, Trade and Industry plans to oblige automakers to recycle about 30 per cent of crushed waste in fiscal 2006. The recycling ratio would later be increased to 50 per cent in fiscal 2010 and approximately 70 per cent five years later. The targets would be formally decided under an automobile recycling law that will be fully in place by the end of 2004.
At present, roughly 80 per cent of scrapped automobiles are recycled, by weight, including parts. The remainder, a mix of different materials like resins and textiles, is crushed. About 550,000-750,000 t of crushed waste is produced annually, most of which is buried in landfill sites. The Japanese auto industry has already set a voluntary target of recycling more than 95 per cent of out-of-use automobiles in 2015. The ministries judged it possible for the industry to achieve this goal, if some 70 per cent of crushed waste is recycled.


China to reduce waste, and air and water pollution

The Minister of State Environmental Protection Administration (SEPA) in China has stated that pollution control would remain as the foremost area in the nations efforts to protect the environment. Discharge of major pollutants, including sulphur dioxide, smoke and dust, would be reduced by over 6 per cent, compared to 2000 levels. The present trend of shutting down heavily polluting small firms and eliminating obsolete techniques and equipment would be continued. Businesses would be urged to adopt cleaner production processes and environment protection departments will scrutinize their impact on the environment. In cities, more water and waste treatment facilities will be set up to mitigate pollution caused on a daily basis. Additionally, efforts will be made to develop environmentally friendly agriculture and large-scale livestock breeding to reduce pollution in rural areas.

Air quality is classified into three levels, with level one meaning near-zero contamination and level three indicating serious pollution. Level two, the national standard, means air is slightly befouled. The administration will also continue to award the title model city for environmental protection to those with good conservation policies and environments. The building of ecological cities, provinces and counties will continue so that sustainable development is achieved regionally.


Waste clean-up projects in Viet Nam

A recent solid waste management seminar organized at HCM City of Viet Nam focused on separating and recycling litter. Several projects on waste treatment presented at this event are scheduled for completion by 2005. HCM City produces about 6,600 t/d of solid wastes litter from households, industries, constructions and clinics. Steps initiated to treat this waste volume have so far not been satisfactory. Though the Transport and Public Work Department embarked on three campaigns on waste sweeping and 18 on waste collection and transportation, the amount of solid waste treated is about 5,400 t. Main waste treatment areas are situated in Dong Tanh and Go Cat, over a total area of 65 ha.

According to the Centre for Environment Technology and Management (CENTEMA), solid waste pollution is a growing threat to the environment. Technology processes for collection, transportation and treatment of solid wastes have been upgraded while dump-filling methods remain woefully inadequate. Dr. Nguyen Luong at the HCM Polytechnic University opines that in order to implement feasible measures, HCM City needs to start sorting wastes promptly and continue experimental programmes. CENTEMA has estimated that by setting up waste sorting factories that incorporate effective technical equipment, waste collection, recycling and selling would yield indirect profits, by saving energy and natural resources.

Viet Nam INFOTERRA Newsletter, January-March 2003

Law mooted for air pollution control

In the Republic of Korea, the Ministry of Environment has pledged to press for a special law aimed at improving the nations air quality. Commercial emissions in Seoul and the nearby Kyonggi areas will be limited while factories and other businesses will be required to progressively lower emissions of pollutants like nitrogen dioxide and particulate matter. All government bureaus will be obligated to purchase vehicles that operate on green energy compressed natural gas and electricity. Tax benefits will be extended to diesel-powered car makers for incorporating pollutant-reducing apparatus in their models. An air quality bill drawn up by the Ministry last year was not passed owing to opposition from economy related ministries. The Ministry will form a task force to enact the law, together with experts, civic groups and the private sector. It has also pledged to draw up a 10-year plan to protect the natural environment from massive land development projects.



Continuous micro-filtration techniques

Memcor Ltd., the United Kingdom, is offering continuous microfiltration plants, with capacity ranging from 0.1 to 325 million l/d, for purifying municipal water and wastewater. The simple, modular units are available in two broad product lines CMF (continuous microfiltration) and CMF -S (continuous microfiltration - submerged). CMF is a pressurized unit utilizing vertical pressure tubes to house the membranes while CMF-S is a submerged arrangement. This immersed option does away with the need for pressure vessels with the membranes being suspended in an open tank. The open tank arrangement can either be an existing tank, thus enabling retrofitting of existing assets, or a new tank constructed from a variety of materials, including concrete. The CMF-S unit enables a markedly small footprint for large to medium throughputs, and lower capital and operational costs.

The Memcor system is a very fine filter, so fine that it removes micro-organisms such as bacteria, algae, viruses and protozoa. A patented self-cleaning air backwash allows the filter to be used on difficult feed streams, such as highly turbid and variable surface waters and partially treated sewage. This is an exclusive feature of Memcor systems that is used in municipal, commercial and industrial applications to purify large volume fluid flows. The systems fulfil a range of specific industry standards such as the ASME Food and Drinking Water Regulations including SI 3145, WRc, DWi, 90/128 EEC, NSF (in the United States), BGA (Germany), MdIS (France), etc. Each filtration unit, comprising up to 20,000 micro-porous membrane filters, is tested before being assembled into a filtration block. Each block is integrity tested before shipment to one of four assembly facilities in the United States, Japan, Australia and the United Kingdom. 

Contact: Mr. Colin Reith, Memcor Ltd., Wirksworth, Derbyshire DE4 4BG, the United Kingdom. Tel: +44 (01629) 823 811; Fax: +44 (01629) 825 169


Telecom switch destroys dioxin

In Japan, Fujitsu Technology has developed a dioxin decomposition process, which is 100 times more effective than currently available processes to break down the carcinogenic compound. The new method integrates plasma and catalyst techniques to render high concentrations of dioxins harmless. The novel reactor comprises a glass tube, with a platinum-plated electrode running down its centre. Several tens of kilovolts are applied between the internal electrode and another electrode outside the glass, then a blend of dioxin and nitrogen gas is pumped into the tube. This technique renders dioxins harmless at concentrations up to 100 g/m3 of nitrogen. Fujitsu is further refining the process by replacing the platinum catalyst with a high-performance ceramic 

Contact: Fujitsu Technology, 4-1-1, Kamikodanaka, Nakahara-ku, Kawasaki, Kanagawa 211 8588, Japan. Tel: +81 (044) 7771 111.


Treatment of high-strength organic  wastes and sludges

AFCSM technology devised by AMT, Switzerland, represents state-of-the-art process stream treatment. This patented procedure amalgamates a proprietary thermophilic biological treatment process together with a solids screening and chemical treatment step to treat highly concentrated organic wastes and/or sludge streams. There is very little or no generation of residual sludges, as is the case generally with most biological processes. It offers the benefits of low biomass yields of anaerobic processes, as well as rapid biodegradation kinetics and stable process control of aerobic systems.

The wastes to be treated is fed into a self-heating, completely mixed, thermophilic reactor. The covered reactor uses jet aeration as a source of oxygen and the temperature is controlled to optimize system performance. Next, effluents from the reactor is shifted to a solids removal system. A portion of the separated solids is returned to the reactor. The remaining solids are then directed to a chemical treatment system prior to being sent back to the thermophilic reactor for further digestion and destruction. Notable features and benefits of this process include:
  • Able to sustain high COD loadings (5,000-60,000+ mg/l);
  • Cost-effective and minimizes or eliminates sludge disposal costs;
  • Effective with high TDS streams;
  • High rates of organic destruction;
  • Systems are usually self-heating with sustained operating temperatures from 50C to 70C; and
  • Existing treatment systems can be easily retrofitted with AFC.
Solid waste treatment, high-strength waste treatment, sludge treatment and reduction, waste minimization, bioremediation and source treatment are some of the application areas. 

Contact: AMT, Grossmattenring 27, CH 5312 Dottingen, Switzerland.Tel: +41 (056) 2454 803; Fax: +41 (056) 2454 808; E-mail: sludge@; Or PMC, 835, Springdale Drive, Suite 201, Exton, PA 19341 2843, the United States.


New process to handle industrial wastes

Unitel Technologies Inc., the United States, has developed a thermo-chemical manufacturing procedure that utilizes waste material as fuel, producing energy as well as useful products. Cement-Lock technology has the unique capability to transform various materials, irrespective of the type and quantity of contaminants or the soil matrix or complex sediment, into cement and other useful products. Extremely diverse types of wastes can be treated, e.g. chemical wastes, incinerator ash, waste from metallurgical industries, sludge from wastewater treatment facilities, contaminated sediments, waste from oil and gas production units, and waste generated during pharmaceutical production. Neither secondary solid wastes nor wastewater is created during the process. The patented method operates at 1,316-1,454C, breaking the bonds of some of the most hard-to-remove chemical contaminants like PCBs, dioxins and furans.

The Cement-Lock process has been demonstrated and applied to a wide variety of contaminated soils, sediments and building debris such as dredged estuarine sediment, contaminated building debris/concrete, sediment/soil tainted by petroleum, PCBs, organic matter, etc. For each of these applications the polluted soil/sediment was decontaminated and simultaneously converted into Ecomelt. Key benefits of Cement-Lock technology include:
  • Treats incinerable as well as non-incinerable wastes simultaneously solid, liquid or gas;
  • Wastes are converted into products for everyday use, thereby eliminating the need for landfills;
  • This process is insensitive to the amount of water and also the amount and type of contaminants present in the waste;
  • Energy used in the process is derived from waste;
  • The cradle-to-grave responsibility of the waste originator is eliminated 
    as the end product is blended cement;
  • All the organic pollutants are efficiently degraded, 
    as per regulations;
  • Inorganic contaminants (metals) are immobilized, with no danger of leaching into groundwater; and
  • Revenues earned from the sale of the products more than adequately cover the cost of operations.

Contact: Mr. Renee L. Comly, Biomass Energy Solutions, P.O. Box 128, Baptistown, New Jersey 08803, the United States. Tel/Fax: +1 (908) 9961 272/9961 257



On-site treatment of hydride wastes

IEM Technologies Ltd., the United Kingdom, is offering Excalibur waste treatment plant for cost-effective, on-site treatment of arsenic as well as phosphorus liquid waste streams. On-site treatment of these waste streams, produced from the abatement of exhaust hydride gases utilized by compound semiconductor manufacturers, guarantees financial, safety and environmental benefits over current disposal practices.

The Excalibur plant allows arsenic and valuable gallium content of the waste to be reclaimed for additional processing. In addition, resale value of Struvite, one of the end products, as an agricultural fertilizer further offsets treatment expenses. While a standard system is designed to handle up to 600 l of liquid effluent in any 24 hour period, the size and capacity of the plant can be tailored to suit individual needs. The plant can be operated either fully automated, through the use of a central control panel, or manually. Contact: IEM Technologies Ltd., Unit 6, Fothergill House, Colley Lane, Industrial Estate, Bridgwater, Somerset TA6 5JJ, the United Kingdom. Tel: +44 (01278) 420 555; Fax: +44 (01278) 420 666




Retrofit for upgrading pollution control unit

In the United States, AirPol Inc. has supplied and installed a dedicated gas suspension absorber (GSA), provided by FLS Inc., upstream of each electrostatic precipitator (ESP) at a mass burn municipal solid waste incinerator facility owned by Wasatech Energy Systems. Wasatechs energy recovery plant comprises two mass burn refractory-lined furnaces. Each unit produces about 52,000 pph of steam at 550 psi and 268C. Originally, each incinerator had an Environmental Element Corp. three-field ESP for regulating particulate emissions. Acid gas was controlled by dry sorbent injection at the economizer inlet. Performance of the dry sorbent injection system was marginal as a result of short retention times and poorly controlled temperatures. The dry sorbent injection also aggravated fouling of the economizer section and increased particulate loading to the ESP.

The semi-dry scrubber system set up on a turnkey basis by AirPol Inc. uses pebbled lime for acid gas removal and powder activated carbon injection as an adsorbent for dioxin/furan and mercury control. In addition, the existing ESP structure was reinforced and larger induced draft fans set up to handle the increased pressure drop across the GSA. A common lime slurry storage and preparation system, carbon storage and delivery system, ash conveying unit, MCC and control system were also included in the contract. For maintaining access to the existing precipitator, a length of ductwork was provided to direct flue gas from the economizer outlet to the GSA reactor and back to the ESP plant.

Test results indicate that performance objectives can be met without carbon injection. However, currently the facility is injecting carbon at a rate of approximately 0.14 kg/t of waste combusted. It has also been demonstrated that metals, particulates, acid gas and even dioxin/furan emissions from the retrofit facility are substantially lesser than required under the now final 40 CFR, Part 60, Subpart BBBB Emission Guidelines for Existing Small Municipal Waste Combustors. The new GSA system has exhibited over 98 per cent efficiency since system start-up.


Converting waste into combustible fuel

In the United States, Enertech Environmental Inc. is offering patented SlurryCarb process that chemically transforms municipal sewage sludge and other wastes into a uniform, pumpable, slurry fuel suitable for combustion, co-firing or reburning in industrial and utility coal boilers. Slurry fuel thus obtained is transported through pipes or tankers to industrial and utility users, where it is stored in tanks and used as a supplement or substitute for current fuel sources such as coal.

In the SlurryCarb process, waste is subjected to specific temperature and pressure conditions in a step called carbonization. Molecular rearrangement of the waste occurs, resulting in molecules that are significantly smaller, more uniform and higher in energy. Also, elements that typically form pollutants during combustion are removed. The result is a high-grade fuel that is cleaner to combust than most coals. This process can generate quality fuel from various low-grade fuels and wastes, including municipal sewage sludge, municipal solid wastes, paper and pulp wastes/sludges, refuse derived fuel, industrial sludges, agricultural residues and wastes, peat, low rank coals, short rotation energy crops, wood and timber industry wastes, and other industrial solid wastes. A unique feature of the SlurryCarb process is that it does not require dewatering and instead utilizes the benefits of fluids processing. Oxygen content of the fuel is reduced while the heating value on a dry basis is increased by over 85 per cent.


New process

Arrow Ecology Ltd., Israel, offers a new process to treat municipal solid waste. The unique ArrowBio technology recovers materials from the waste to produce biogas, a clean and green energy source for transportation and power plants. A full-scale ArrowBio plant comprises a 220 t/d module to process mixed waste, regardless of the extent of separate kerbside collection. At the front-end, the buoyancy of water is exploited to gravitationally separate non-biodegradable and biodegradable components. At the back-end, having the organics in an aqueous flow facilitates the use of an upflow anaerobic sludge blanket (UASB) type bioreactor. The greatly accelerated microbial kinetics of the UASB process give superior performance. Water thus serves the individual purposes of effective front-end separation and expeditious back-end digestion, and links the two.

In the ArrowBio process, traditional recyclables (metal, glass, plastic) are recovered, while the hurdle posed by the multiplicity of biodegradable organics is overcome by conversion into three products high-quality biogas, well-stabilized organic residue not requiring further treatment (soil amendment) and biologically generated water. 

Contact: Arrow Ecology Ltd., Histadruth Ave. 21, P.O.B 25175, Haifa 31250, Israel. Tel: +972 (4) 8412 599; Fax: +972 (4) 8412 586.



Pulverization/size reduction

Herbold Meckesheim GmbH, based in Germany, offers Pulverizer PU 500 (55 kW) model for pulverizing soft to semi-rigid materials at ambient temperature or with nitrate. This unit is mounted modularly and can be equipped with different grinding tools depending on the task.The SML 35/42C Granulator product line in a compact and sound-insulated design is ideal in production lines for immediate size reduction of production rejects such as preforms, bottles, injection moulding waste, etc. The C product line has been constructed such that it can be cleaned easily and within a very short time, in case of product and colour changes. The SMS granulator product line are for heavy-duty applications. It can be equipped with up to six stator knives and, depending on the task, different rotor types can be fitted. Herbold has been further developing the SML series and a new series of low-speed granulators has been added to this line. Key benefits of SML-LS series include low-speed operation to ensure low noise levels and insignificant dust development, appropriate for rejects and skeletal waste, easy to clean, compact design (transportable with fork-lift), feed hopper (standard models in soundproof design), staggered design of knives, knife adjustment outside the machine (even if the knives have been resharpened, the cutting circle will remain constant) and material is discharged via vacuum transport, feed screw, pneumatic transport and Gaylord discharge.

Plastcompactor HV50 is used for compacting materials such as PA fibres, PET film/flakes, foams and stretch films. Operated automatically, this unit prevents the material from being damaged thermally, contrary to other applications. 

Contact: Herbold Meckesheim GmbH, Industriestrae 33, Meckesheim 74909, Germany. Tel: +49 (62) 26932-0;Fax: +49 (62) 26 60 455;



New recycling process for plastics

Suzuka Fuji Xerox Co., Japan, has developed a new recycling process for plastics and polystyrene. Conventional methods blend 20-30 per cent of used materials with 70-80 per cent of virgin ingredients, making the average price of recycled products relatively high compared with new ones. Suzuka process allows used plastics to be recycled on their own, thereby bringing the price of recycled products on par with the new products. This technology can be applied to acrylonitrile-butadiene-styrene utilized in car interiors and home electronics.


New technology

In the United States, Polymer Technology Centre has developed and patented a breakthrough process for plastics recycling that eliminates the need for sorting by type or colour. The new Solid State Shear Pulverization (S3P) process is a continuous one-step process to recycle pre- or post-consumer plastic wastes. S3P yields uniform powders that can be used in various high-quality items.

S3P subjects polymers to high shear and pressure while rapidly removing frictional heat from the process to prevent melting. This method transforms multi-coloured, commingled waste, industrial plastic scrap and virgin resins into a uniform, light-coloured, partially reactive powder of controlled particle size ranging from coarse (2,000 m) to very fine (20 m). Sample products made from this material often demonstrated enhanced mechanical properties (e.g. tensile and flexural strength) than those fabricated from conventional processes. 

Contact: Polymer Technology Centre, Dept. of Chemical Engineering, 2145, Sheridan, Evanston, Illinois 60208 1230, the United States. Tel: +1 (847) 4912 773; Fax: +1 (847) 4913 728




New system

Tempico Inc., the United States, is offering Rotoclave medical waste processing systems that have been designed to accommodate a wide range of treatment needs. Rotoclave system utilizes a pressure vessel with a unique rotating internal drum, which accepts medical wastes in unopened containers and subjects them to agitation. Heat and moisture are introduced in the form of steam generated by the facilitys boiler. The heat initially causes the containers to soften and, during agitation, to rupture and spill their contents into the rotating drum. Here, moisture-absorbable materials get saturated and convey heat through themselves. The combination of high temperature, pressure and moisture, along with a unique agitation method ensures that all materials come into contact with the sterilizing steam. Computer-controlled operation assures that the parameters of time, temperature and pressure required to achieve sterilization are fulfilled and maintained throughout the process.

These automated systems ensure waste sterilization in a closed loop. The end product can be ground and is physically harmless, which can be placed in landfills along with general municipal waste. Up to 80 per cent reduction in waste volume can be achieved. Standard features on all Rotoclave systems (except model 1050 H1) include:
  • Simple touch screen operator control panel;
  • Electrical distribution panel, including PLCs;
  • Steam jet ejector vacuum unit with condensers and condensate holding tank; and
  • Heavy-duty size reduction equipment (grinder).
    Cooling water, steam generation and compressed air systems are needed for stand-alone plants. For on-site installations at hospitals, the existing boiler and cooling tower of the hospital could be utilized.

Contact: Tempico Inc., 1700, West Church Street, Hammond, Louisiana 70401, the United States. Tel: +1 (985) 4299 929; Fax: +1 (985) 4299 740


Disposal of pathological wastes

Canada-based Cape Breton Environmental Systems offers patented technology to dispose biomedical and pathological wastes along with municipal solid waste (MSW). Co-combustion of biomedical waste with MSW in the proprietary waste-to-energy system is considered to be an environmentally sound and cost-effective way to manage biomedical waste. As combustion occurs under carefully controlled conditions, all pathogens are destroyed at very high temperatures and the best available devices are utilized for controlling emissions vented to the atmosphere.

For co-combusting biomedical waste with MSW, special systems and procedures were developed. With this technology, environmental impact is minimized, public confidence in waste-to-energy and combustion of biomedical waste is enhanced, and air emission standards, both present and future, are fulfilled. 

Contact: Mr. Robert Tierman, President, Cape Breton Environmental Systems, 90, Riverview Dr., Sydney, Nova Scotia B1P 6G9, Canada. Tel: +1 (902) 5622 543; Fax: +1 (902) 5672 401.


On-site treatment and disposal

Aegis Bio-Systems in the United States is offering a mobile system for on-site treatment and disposal of medical wastes. The patented JYD-1500 unit incorporates an advanced proprietary shredding plus a steam sterilization system that thoroughly documents all aspects of the treatment cycle. It pre-shreds wastes prior to sterilization and during sterilization, waste is stirred in a pressurized steam-laden environment. This ensures that all the waste surfaces are exposed to 250C saturated steam. Log 6 sterilization healthcare level is achieved.

JYD-1500 employs reusable sealed containers, thereby eliminating recurring costs of disposable holders. Up to 900 kg/h of infectious wastes could be treated when operated at optimal capacity. Transportation expenses are lowered since the weight of wastes is reduced by nearly 85 per cent of its original volume, about 15 per cent more than traditional processes. This unit is more reliable than presently available counterparts since the shredding system is self-cleaning and designed to overcome obstructions that destroy competing systems. A couple or more of these mobile units offer full redundancy and can be operated 24 h a day at one or more sites with zero down time. 

Contact: Aegis Bio-Systems, 2500, South Broadway, Suite 250, Edmond, OK 73013, the United States. Tel: +1 (405) 3414 667




Extraction of metals from PCBs

At the National Taiwan University of Science and Technology, Taiwan, researchers have developed a process to extract copper (Cu) and lead (Pb) from effluents produced during the manufacture of printed circuit boards (PCBs). Sludge from a PCB plant containing high levels of Cu and Pb was characterized and aqueous ammonia solutions were utilized to separate the metals. The maximum extraction efficiency was achieved at a pH of 10. Higher solid-liquid ratio and ammonia concentrations yielded better extraction efficiency. Fractionation experiments exhibited that Cu and Pb were mainly extracted from the iron-manganese oxide-bound and carbonate-bound components.

Extracted sludge complied with the TCLP regulation limit and is classified as a non-hazardous waste. The ammonia extraction process holds good potential in resource recovery and detoxification of wastes. 

Contact: Mr. J. C. Liu, National Taiwan University of Science and Technology, 43, Keelung Road, Section 4, Taipei 106, Taiwan.


Recovering plastics from post-consumer electronics scrap

A demonstration facility to retrieve ABS and PC/ABS from shredded post-consumer computer and television wastes is scheduled to soon begin operation in the United States. Recovery Plastics International (RPI) developed this unit. It can recover 200 t of plastics from 250 t of scrap feed in 24/5 operation each month.

RPI has successfully piloted, along with DaimlerChrysler, a process for recovering plastics from automotive shredder residue (ASR). This technique relies on skin flotation process in which air bubbles get attached to specific materials thereby enabling segregation of polymers with overlapping densities, yielding ABS, PP and filled PP streams that represent about 85 per cent of plastic content in a vehicle. The process also reclaims urethane foam suitable for rebonding, copper and other metals, and produces pellets with the fuel value of wood from sound-deadening-pad lint. Future upgrading may enable economic recycling of Nylon 66.

RPI has adapted the ASR process to demanufacture computers, TVs and other electronics. Since this type of scrap does not contain sufficient metals to justify recovery, the focus is on plastics. Scrap (including circuit boards, metals and various plastics) is shredded and passed through a series of processing steps. Three skin flotation stages remove metals, thermosets, polystyrene, nylon and other thermoplastics. The effluent is treated and then discharged, while the recovered ABS and PC/ABS go through extrusion and pelletizing.

Plastics News, March 2003

Recovery and reuse of e-wastes

A study underway at the Georgia Institute of Technology (GIT) in the United States may offer a model to tackle electronic wastes (e-wastes). Concerns are rising among governments worldwide regarding e-wastes discarded computers, televisions, cell phones, audio equipment and batteries leaching lead and other contaminants that may seep into groundwater. The GIT team has devised a reverse production system that creates infrastructure to recover and reuse every material contained within e-wastes metals such as lead, copper, aluminium and gold, and various plastics, glass and wire. Such closed loop manufacturing and recovery guarantees a win-win situation for everyone. Less of the Earth will be mined for raw materials and groundwater will be protected.
The key to GITs approach is the ongoing development of a mathematical model, which can predict the economic success of recovery efforts. 

Contact: Ms. Jane Sanders, GIT, the United States. Tel: +1 (404) 8942 214; 



Recycling TV tubes

Matsushita Seiko Engineering Co. Ltd., Japan, offers a TV Braun tube culletizer. Braun tubes contain lead and need large amounts of panel and funnel glass during the production process. Extraction of the materials prevents environmental degradation and facilitates economic recycling. Key features of the system include:
  • Glass that is easiest to turn into cullets is culletized in a smelting furnace and glass fragments are put to effective use as blast material;
  •  Panel and funnel glass made of different materials are separated by thermal strain; and
  •  Dry/clean blasting - Impurities on the surface of funnel glass are removed by blasting. Glass powder is utilized as the blast material, instead of alumina or other materials, thereby eliminating the problem of impurities being transported into the smelting furnace. Glass fragments generated in the culletizer are used as the powder substitute to achieve even more economical recycling. 

Contact: Matsushita Seiko Engineering Co. Ltd., ShinOsaka Wako Bldg. 7F, 4-6-18, Miyahara Yodogawa-ku, Osaka 532, Japan. Tel/Fax: +81 (6) 3503 770/3503 775.



Thermal desorption for POP removal

OHM Remediation Services Corp., the United States, offers a patented thermal desorption process for removing organic contaminants from soils, sludges and other solid media. X*TRAX is neither an incinerator nor a pyrolysis system. Chemical oxidation/reactions are prevented by maintaining an inert environment and low treatment temperatures. Organic contaminants are removed as a condensed liquid, which is characterized by a high heat rating. This liquid may then be destroyed in incinerators or used as a supplement fuel.

In the new technique, an externally fired rotary drier volatizes water and organic impurities from the polluted media into a inert carrier gas stream. The nitrogen carrier gas transports water vapour and organic contaminants out of the drier. The carrier gas flows through a duct to the gas treatment system, where organic vapour, water vapour and dust particles are removed and recovered. The gas first passes via a high-energy scrubber, which removes dust particles and 10-30 per cent of the organic contaminants. The gas then passes through two condensers in series, where it is cooled to less than 5C.

Most of the carrier gas is reheated and recycled to the drier. About 5-10 per cent of gas is separated from the main stream, conveyed through a particulate filter and carbon adsorption system, and then discharged to the atmosphere. This discharge allows addition of make-up nitrogen to the system, to keep oxygen concentrations below 4 per cent. Also, the discharge helps maintain a small negative pressure within the system and eliminates leakage of potentially contaminated gases. The volume of gas released from this process is about 700 times less than from an equivalent capacity incinerator.

Contact: Mr. Chetan Trivedi, OHM Remediation Services Corp., 100, West 22nd Street, Suite 101, Lombard, Illinois 60148, the United States. Tel: +1 (630) 2613 958; Fax: +1 (630) 2613 969.


Anaerobic bacterium degrades dioxins

Researchers at Martin-Luther-Universitat Halle-Wittenberg, Germany, have uncovered that an anaerobic bacterium known to degrade chlorobenzenes can break down dioxins also, including extremely hazardous congeners. The team isolated bacterial strains from sediments fouled with dibenzofurans and polychlorinated dibenzo-p-dioxins using polymerase chain reaction. Among bacterial strains that exhibited the ability to dechlorinate dioxins, two strains belonged to the genus Dehalococcoides. One of the strains, CBDB1, is the only known bacterium for dechlorinating chlorobenzenes and the other strain has been shown to convert tetrachloroethane to ethene.

Researchers have established that Dehalococcoides is indeed involved in dioxin dechlorination by studying the capability of CBDB1. They found that CBDB1 can transform several noxious dioxin congeners into less harmful ones, even without the addition of chlorobenzenes, indicating that the bacterium can use dioxins as respiratory electron acceptors. Results suggest that microbes of the Dehalococcoides cluster could be useful in bioremediating dioxin-contaminated sites.


Disposal of polychlorinated biphenyls

Mitsubishi Heavy Industries Limited (MHI), Japan, has developed technology to dispose polychlorinated biphenyls (PCBs). The new hydrothermal decomposition procedure eliminates PCBs without forming harmful by-products. Hydrothermal decomposition occurs under high-temperature, high-pressure water. 
Crystals of sodium carbonates form under this condition and its surface- active sites remove chlorine from 

PCBs. PCB is then oxidized into harmless compounds such as water, sodium chloride and carbon dioxide. MHIs PCB total processing system, approved by the Ministry of Health and Welfare, integrates the hydrothermal decomposition and cleaning of contaminated containers.

Advantages of MHIs PCB total processing system include:
  • Selecting appropriate cleanser: PCB contaminated containers canbe treated using either organic and/or cheap aqueous surfactant solutions, depending on the dirtiness of the object to be cleaned. The containers can be recycled as a material after optimized use of cleanser selection;
  • Application over a wide range of PCB concentration: The same equipment can be used for low to high concentration of PCBs by changing residence time in the reactor;
  • No formation of corrosive compounds: Reliability of equipment is high without corrosive compounds like hydrogen chloride, etc.;
  • Treatment of PCB contaminated paper and wood: Paper, wood, etc. can be slurried and decomposed by hydrothermal decomposition. Additionally, activated carbon and wastes can also be treated; and
  • Decomposition of other organic compounds: Organic impurities that are difficult to dispose off through incineration e.g. cleansing solvent, waste paint, waste fuel, etc. can be easily decomposed.

Contact: Mitsubishi Heavy Industries Ltd., 2-5-1, Marunouchi Chiyoda-ku, Tokyo 100 8315, Japan. Tel: +81 (3) 3212 3111; Fax: +81 (3) 3211 9800


Treatment of PCBs

Material Resource Recovery, based in Canada, offers thermal oxidative process to degrade polychlorinated biphenyls (PCBs). The new system consists of a primary combustion chamber, a secondary combustion chamber (afterburner) and a Venturi and packed tower scrubbing system. PCB materials are placed inside the primary chamber where initial combustion takes place at temperatures of 400-1,000C. All the combustion gases enter the secondary chamber where complete combustion occurs at a minimum of 1,200C. Gases exiting the secondary chamber are passed through a venturi and packed tower scrubbing unit where acidic gases are neutralized and removed.

The destruction/removal efficiency of the process is more than 99.9999 per cent. It complies with all provincial and federal regulations. 

Contact: Material Resource Recovery, P.O. Box No. 683, 2425, Industrial Park Road, Cornwall, Ontario K6H 5T5, Canada. Tel: +1 (613) 9387 575; Fax: +1 (613) 9380 660.


On-site remediation of groundwater

ManTech Environmental Corp., the United States, is offering CleanOX technology for in situ remediation of organic pollution in groundwater and saturated soils, including fuels, solvents, pesticides, etc. The new patented process reduces groundwater contaminants into harmless carbon dioxide and water through an injection method that is significantly cheaper than conventional remediation techniques. Proprietary liquid chemical formulations are injected through monitoring wells into the befouled part of an aquifer. Immediate reductions in the concentration of the following contaminants is feasible: aromatic compounds (BTEX), nitro-aromatic compounds, chlorinated solvents, polychlorinated biphenyls, alcohols (phenols), total petroleum hydrocarbons, polynuclear aromatic hydrocarbons, organic pesticides and mineral oil products.

CleanOX involves the application of a Fenton-like chemistry to create and migrate hydroxyl radicals, which in turn degrade organic impurities into carbon dioxide and water. The technology can be used to set up natural attenuation, source control/removal, hot spot treatment, speedy groundwater treatment, as well as augment existing processes such as SVE/sparging units, groundwater pump and treat, in-well stripping and phytoremediation. Key benefits offered by CleanOX are:
  •  Contaminant reduction in weeks to months;
  • Mobile in situ treatment system that has limited disruption to on-site operations;
  •  The reagents are applied through two-inch diameter monitoring wells;
  •  Applied under buildings and within operational areas;
  •  Requires no capital equipment purchase; and
  •  Eliminates long-term operation and maintenance costs.

Contact: ManTech Environmental Corp., 14290, Sullyfield Circle, Suite 100, Chantilly, VA 20151, the United States. Tel: +1 (703) 8148 366; Fax: +1 (703) 3783 396



Solvent recovery in pharmaceuticals sector

NUCON International Inc., the United States, has developed and commercialized the reverse Brayton Cycle process to control pollution and recover solvents. This latest technology eliminates air polluting emissions and recovers process chemicals for reuse. BRAYSORB and BRAYCYCLE Solvent Recovery Systems (SRSs) are the most reliable, efficient and cost-effective systems that can be employed in most pharmaceutical applications. The BRAYSORB SRS uses an adsorbent bed to concentrate solvents and then strips them with dry nitrogen. This system operates on direct condensation and the recovered solvents are pure, water-free and recyclable.

The skid-mounted systems are factory checked, facilitating easy installation. They are automatically controlled by a PLC under supervision of an industrial computer. Any degree of data interchange and process interface desired by the client can be provided. Solvents that can be recovered and reused include methylene chloride, ethyl alcohol, IPA, etc. 

Contact: NUCON International Inc., 7000, Huntley Road, Columbus, OH 43229 1035, the United States. Tel: +1 (614) 8465 710; Fax: +1 (614) 4310 858


New recovery process based on activated carbon

Nittetsu Chemical Engineering Ltd. (NCE), Japan, offers a solvent recovery process based on activated carbon adsorption method to recover solvents from a large volume of waste gas containing thin solvent. The low-temperature desorption technique can treat solvents such as ketone, anone and THF without degrading or polymerizing. Solvents recovered by this process include alcohols and esters, ketones and amines, as well as high boiling solvents like higher alcohol, dimethyl formide, etc. to manufacture magnetic tape, liquid crystal film, artificial leather, etc.

The novel Reduced Pressure, Low-temperature Solvent Recovery Process saves on steam consumption, prevents polymer formation, avoids ignition problems and also solves corrosion problems. 

Contact: Nittetsu Chemical Engineering Ltd., 4-4-26, Funado Itabashi-ku, Tokyo 174 0041, Japan. Tel/Fax: +81 (3) 5399 3513/3758; 


Recovering solvents

Taikisha Ltd., Japan, is offering two innovative solvent recovery systems Soluse steam desorption and recovery system, and Admat solvent gas adsorption, concentration and recovery unit. Soluse is for solvents that generate noxious gases when oxidized, and for recovery and reuse of costly solvents. It adsorbs and cleans organic solvents as well as chlorinated solvents using activated carbon. The solvent is desorbed by employing saturated steam and the steam-solvent mix is then liquefied through refrigeration condensation and recovered. This system can be used independently or with Admat.

Admat is an exhaust treatment unit that recovers or combusts organic and detergent solvents, and odours emitted by plants in industries such as paint, printing, semiconductors, electronic components, chemicals, precision machinery and pharmaceuticals. In this process, felt-like activated carbon fibre mats are used as the adsorption element. These mats are mounted on a cylindrical mesh to form cassettes, which are attached to the rotor. Adsorption and desorption occur continuously and simultaneously while the rotor turns slowly. Adsorption occurs when unprocessed gases pass through from the outside to the inside of each 
cassette. Desorption, or regeneration, takes place when hot air (at 130C) passes from the inside to the outside of the cassettes. 

Contact: Taikisha Limited, Head Office, Shinjuku-Sumitomo Building, 2-6-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo 163 0212, Japan, Tel/Fax: +81 (03) 3344 1851/3342 5590.



Innovative biotech process

In the United States, Mr. Fatemeh Razavi-Shirazi has developed a novel biotech method to treat contaminated groundwater. The biological permeable barrier (BPB) Biobeads groundwater treatment system enables passive treatment through the use of modified microbes embedded in porous polymer beads that remove organic contaminants. Key features that make this process effective for treating potable water, wastewater and in situ groundwater include:
  • It creates a safe, cost-effective and reliable biological treatment that remains permeable over extended periods of time;
  • It provides a favourable environment for micro-organisms;
  • It is easy to handle and manufacture; and
  • It offers a competitive alternative to currently accepted bioremediation technologies of biostimulation and bioaugmentation.
Contact: Mr. Wil Jacques, Competitive Technologies, the United States. Tel: +1 (203) 2556 044; E-mail: ; Or Mr. Johnnie Johnson, Strategic IR Inc., the United States. Tel: +1 (212) 7546 565



State-of-the-art bioaugmentation

Munox XL-Plus technique offered by Osprey Biotechnics, the United States, can ensure safe, easy and efficient biodegradation of stubborn organics in industrial effluents. This patented inoculant consists of non-pathogenic and naturally occurring bacterial strains specifically isolated for their exceptional capabilities and versatility in reducing a wide range of organic compounds. As part of a treatment and discharge system the bioaugmentation programme, with XL-Plus, is not expensive to implement. Available as an easy-to-handle liquid, all formulation series contain a unique blend of patented bacteria and essential nutrients for boosting organic metabolism and optimizing biodegradation. Munox XL-Plus is manufactured under sterile conditions and stringent quality control protocols before it is released for shipment. 

Contact: Osprey Biotechnics, 1833-A, 57th Street, Sarasota, Florida FL 34243, the United States. Tel: +1 (941) 3512 700; Fax: +1 (941) 3510 026


Website: www.ospreybiotechnics.com3 

Novel EMB system

Membrane Extraction Technology Ltd., the United Kingdom, is offering a novel system for treating aqueous waste streams containing valuable inorganic species and low levels of highly toxic organic molecules. The new extractive membrane bioreactor (EMB) makes use of a combination of membrane extraction technology and biodegradation to separate toxic organic molecules, facilitating the aqueous wastewater to be further processed or disposed safely. For example, concentrated mineral acids such as HCl and AlCl3 solutions that result from Friedel-Crafts acylations and can be sold for water treatment.

EMB processes aqueous streams in a modular compact unit, operating at room temperature and pressure. Since the dense phase elastomeric membrane is permeable only to the hydrophobic organic contaminants, inorganic composition of aqueous streams is prevented from interfering with the micro-organisms. This key feature allows biodegradation to be applied to wastes that would otherwise need more expensive physical-chemical treatments. At the heart of the EMB is a microbial culture that converts toxic chemicals into harmless species. These cultures can also be employed in the EMB-PEROX process, which utilizes a membrane to strip the organics into an air stream prior to biodegradation or in direct air-stripping/biodegradation processes. Benefits offered by EMB include: eliminates production of waste streams; robust and fully automated operation; cost-effective; and process supplied with process guarantee, microbial culture as well as membrane service contract.

Contact: Prof. Andrew Livingston, Managing Director, Membrane Extraction Technology Ltd., c/o Dept. of Chemical Engineering, Imperial College, London SW7 2BY, the United Kingdom. Tel/Fax: +44 (020) 7594 5582/5629; 



Microbes degrade toxic pesticide

Researchers from the University of California at Riverside in the United States and the University of Agriculture, Faisalabad in Pakistan have identified a group of micro-organisms that degrade a common toxic pesticide. Endosulphan, listed as an organochlorine, is registered for use as a pesticide on 60 crops. EPA has classified endosulphan as a Category 1 pesticide with extremely high acute toxicity. It affects the kidney, central nervous system, liver, blood chemistry and parathyroid gland. The new strains provide a valuable source of endosulphan-degrading enzymes and can be used for detoxification of endosulphan in contaminated soils, waste dumps, water bodies and unused or expired stockpiles of the pesticide.



Treatment of PCB contaminated marine sediments

In the United States, Resource Technologies Environmental LLC (RTE) has developed proprietary environmental biotechnology that is being tested for the clean-up of polychlorinated biphenyls (PCBs) in marine sediments. Lab and field tests show that gene expression factor (GEF) treatments can reduce PCBs to near non-detectable levels. PCBs short-circuit microbial genes that are essential for the production of reductive enzymes; a GEF treatment quickly repairs the short circuit. According to RTEs Science Director, PCBs, pesticides and different chlorinated compounds repress microbial gene function and prevent natures microscopic custodians from performing the task of removing pollutants from the environment.


Innovative biological treatment technology

AqWise-Wise Water Technologies Ltd., a multi-disciplinary, research-oriented company based in Israel specializes in biological fixed biofilm processes for wastewater treatment. AqWise and USFilter have teamed up to promote a new technology to the municipal and industrial wastewater treatment industry in Canada and the United States. The Attached Growth Airlift Reactor (AGAR) process ensures high BOD removal rate and intensive nitrogen removal. This cost-effective system employs a unique combination of an attached growth process together with airlift hydraulics, resulting in an efficient and smooth plant operation. It could be utilized for upgrading existing wastewater treatment facilities and to efficiently treat biodegradable industrial wastewater in a small footprint. Key features of the AGAR process include:

  • The aeration basin in this process is divided into a number of process stages, allowing differentiation in the process conditions at each stage. Different composition of microbiological population is developed in each process stage;
  • Biomass carriers placed in the basin create intensified biological activity and provide a sludge retention time suitable for nitrification;
  • Attached growth on the carriers eliminates the need to recycle biomass, resulting in a major reduction of the hydraulic and solids loading on the final clarifiers;
  • Biomass that is sloughed off the carriers has good settling properties, characterized by low sludge volume index; and
  • Airlift hydraulics create an internal circulation flow pattern, imperative for intensive mixing of the whole aeration basin.

Contact: AqWise, POB 8698 Netanya 42504, Israel; Or 24, Giborey Israel Blvd., Netanya, Israel. Tel: +972 (9) 8856 970; Fax: +972 (9) 8856 980


System for ammonia destruction

Branch Environmental Corp. of the United States is offering ammonia destruction system with two basic functions. The first section removes ammonia from groundwater. A solution of sodium hydroxide (NaOH) is mixed with contaminated groundwater to control pH. Treated groundwater is sprayed into the top of a stripping tower and trickles down through a packed bed. Air is blown into the bottom of the tower, exiting at the top. Air and water come into contact through the large surface area provided by the packed bed. Ammonia is transformed from liquid to gaseous phase and exits from the top of the tower with the air stream. The clean water is drained from the bottom of the tower.

In the second part of the process, ammonia is eliminated by catalytic oxidation. The oxidizer includes a heat exchanger, air duct and reaction chamber, electric heater and a bed of catalyst. An electrical heater is utilized to raise the temperature of ammonia-laden air stream prior to entering the catalyst bed. The resulting components, nitrogen and water vapour, are discharged through the heat exchanger to a stack and then into the atmosphere.

Since oxidation occurs at temperatures much lower than with a thermal oxidizer, because of the catalyst, considerable energy is saved. Additionally, catalysts are available for the destruction of other contaminants, including NOx and VOCs. The heat exchanger recovers heat from the hot exhaust air stream and preheats the incoming mixture of cold air and ammonia, thus further saving energy and lowering operating costs. The company is also offering environmental compliance systems for the removal or destruction of air and water contaminants.



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