VATIS Update Waste Management . Mar-Apr 2007

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Waste Management Mar-Apr 2007

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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World standards for e-scrap recycling

The United Nations, industry and other partners plan to create world standards for recycling electrical and electronic scrap (e-scrap). This is one of the goals of solving the E-Waste Problem (StEP), a new global public-private initiative. Major high tech manufacturers, including Dell, Hewlett-Packard, Microsoft, Philips, Ericsson and Cisco Systems, join the United Nations, governmental, NGO and academic institutions, along with recycling/refurbishing companies as charter members of the initiative.
Valuable resources in every scrapped product with a battery or plug are being trashed in rising volumes worldwide. Theres more than gold in those mountains of hi-tech scrap. The StEP partnership is committed to salvaging these increasingly precious resources and preventing them from fouling the environment, said Mr. Ruediger Kuehr of the United Nations University (UNU). In addition to well-known precious metals such as palladium, gold and silver, unique and indispensable metals have become increasingly important in electronics.

In many industrializing and developing countries, growing numbers of people earn their living from recycling and salvaging electronic waste. In most cases, though, this is done through so-called backyard practices, often taking place under the most primitive circumstances, exposing workers to extensive health dangers.

A global guide to dismantling e-scrap and maximizing the recovery and controlling recovered substances is a major StEP objective. Inter-related StEP task forces will help shape government policies worldwide and address issues related to redesign and product life expectancy, reuse and recycling, and help build relevant capacity in developing nations. According to Mr. Hans van Ginkel, a United Nations Under Secretary General and UNU Rector, Companies involved in StEP will benefit through globally standardized, safe and environmentally proven processes for disposal, reduction or reuse and recycling of e-scrap. The StEP logo will signal consumers that e-scrap processes associated with the companys products conform to agreed international standards and guidelines.


China combats illegal garbage imports

The State Environmental Protection Administration (SEPA), China, will coordinate with its counterparts in the European Union (EU) and the customs department to crack down on wastes entering illegally into the country. SEPA officials have called on other countries to abide by the Basel Convention, a pact aimed at controlling the illegal transmission of hazardous materials between nations. They would also be working with other departments to improve legislation on waste smuggling and to strengthen the management of imports and reuse of waste.


Waste-derived energy for Viet Nam

Asia Biogas Ltd., the United States, plans to introduce state-of-the-art waste treatment technology that will provide low-cost energy to consumers and industries in Viet Nam. Mr. David Donnelly, the managing director of the company, said that the anaerobic digestion technology would lead to lower energy prices, at least 20 per cent less than the market price. In addition, the company will set a ceiling for its selling price so that customer costs would remain stable during global price fluctuations.

Breweries, large farms, slaughterhouses, seafood processing plants and paper mills are some of the companys potential customers. The total capital to be invested in the Vietnamese market is about US$10 million. Asia Biogas is currently operating 75 projects in the Philippines, Thailand, Indonesia and Malaysia.


Malaysia installs new tyre recycling plant

Advanced Pyrotech Sdn Bhds hi-tech tyre recycling plant in Malaysia is expected to commence operations by the end of this year. Built in Pulau Indah, this would be the second process pyrolysis plant in the country and would be able to handle up to 120 t/d of tyres. Each scrap tyre processed at the plant will yield carbon black (30 per cent), oil (50 per cent), non-condensable inflammable gas (10 per cent) and steel wires (10 per cent).

Advanced Pyrotech is an associate company of Octagon Consolidated Bhd. Octagons Korean partner company is involved in the provision of environmental engineering solutions including incineration, water treatment, pyrolysis, energy plant and flue gas treatment. End products from the pyrolysis process will be exported to Korea. The plant will, in line with the governments call, involve local entrepreneurs in operations such as the transportation of scrap tyres, retreading and recycling of scrap tyres, operations of collection centres and selling the by-products from the pyrolysis process.


Pakistans first effluent treatment plant goes on stream

The Korangi effluent treatment plant is Pakistans first effluent treatment plant. Mr. Tariq Ikram, the Minister of State and CEO of Trade Development Authority Pakistan (TDAP), said the plant was completed within six years in collaboration with TDAP, Pakistan Tanneries Association, the Dutch government as well as the City District Government Karachi (CDGK). The plant would treat effluent sludge and solid waste from tanneries in Korangi industrial area by converting 42,000 m3/d of hazardous water into plain water. About 26,000 m3 of water from Karachi city would also be treated at the plant.

The plant employs UASB technology and can fulfil 70 per cent of its power requirement from generators operating on biogas accumulated by waste treatment. Mr. Ikram said that TDAP contributed 68 per cent of the required finances, while the other collaborators provided the rest.


Pollution control measures in India

The Central Pollution Control Board of India is executing a nationwide programme of ambient air-quality monitoring known as the National Air-Quality Monitoring Programme. Based on the monitoring of ambient air quality, 51 non-attainment cities have been identified in which the prescribed respirable particulate matter levels, specified under the National Ambient Air Quality Standards, are not met.

Specific steps have been taken with regard to controlling vehicular pollution. Also, a road map up to 2010 has been laid down by the Expert Committee on Auto Fuel Policy for controlling vehicular pollution from both new as well as in-use vehicles all over the country. Enforcement of auto-exhaust emission standards for new vehicles at the manufacturing stage is being implemented. The various norms introduced include:
  • Euro-II emission standards and Euro-II compliant fuel for the whole country;
  • Euro-III emission standards and Euro-III compliant fuel for 11 mega cities;
  • Reduction in sulphur and benzene contents in diesel and petrol;
  • Cleaner fuels like compressed natural gas and liquefied petroleum gas in a few polluted cities; and
  • Improved pollution under control certification system.


Korea restricts emissions in metros

In the Republic of Korea, 191 businesses in metropolitan areas will be subjected to emission caps for the air pollutants NOx, SOx and particulate matter from July 2007. As part of an effort to monitor the emissions of such pollutants, all thermal power plants and large emitters, including incinerators, have been mandated to install the telemonitoring system (TMS) and small ones are needed to equip themselves with emission flow meters/controllers.

The sum of emission limits by a reg-ulated emitter gives the emission cap of each business site. Those of each regulated emitter are calculated by multiplying an allotment coefficient by the amount of fuels/materials used. The allotment coefficient is defined as the average emissions per unit usage of fuels/materials in emitters that use the same fuels/materials in the same category of business. In addition, new emitters need to install the best available technology (BAT), while existing ones are to cut the emissions of pollutants to the level of the BAT within five years. The emission standard for BAT is tougher than that for new emitters under the Air Pollution Control Act.


China drafts a rule for e-waste recycling

The Chinese government has drafted a rule that will lead to the creation of a producer-oriented system for collecting and recycling waste electronics equipment (WEE). The draft rule, prepared by the National Development and Reform Commission (NDRC), stipulates that the manufacturers of computers, television sets, washing machines, refrigerators and air-conditioners shall be held responsible for recycling their products. Enterprises that refuse to partake in the recycling programme will face severe punishment, which could include fines that may be up to US$12,500 or have their licences revoked.

According to the draft, the NDRC and the Ministry of Finance would establish a special fund to defray some of the manufacturers costs arising from the programme. Industry professionals have urged manufacturers to focus on eco-design, or to employ environmentally friendly components and production techniques, to help them cut their costs over the long term. The regulation is expected to affect a wide range of appliance and electronics equipment makers from around the world, as China is emerging as both a major manufacturing base and a large market for electronics products and home appliances. The NDRC has set up four WEE recycling pilot projects at factories in Beijing, Tianjin, Qingdao and Hangzhou.



Petroleum from scrap plastics

Researchers at the D.I. Mendeleev Russian Chemical Engineering University have developed a technology to derive petroleum from discarded plastic sachets. According to project manager Prof. Valery Shvets, the concept of processing carbonic wastes into carbohydrates is not new, as engine fuel is being produced using wastes such as turkey skin, feather and grease. However, the research team focused its efforts on obtaining petroleum mainly from synthetic carbonic wastes such as PE, PP, PS and PET scrap.

The new technology involves catalytic thermal treatment of polymeric materials. The basic stages of this process include grinding and melting the wastes. Next, they are mixed with a catalyst powder and subjected to thermal destruction under pressure. The liquid hydrocarbon fraction, which is practically petroleum, is then tapped and collected from the obtained mass. The gaseous fraction could be used as fuel.

A prototype developed produced 1 litre of petroleum and a small quantity of fuel gas from 1 kg of polyethylene waste. The residual fraction of this process is a black viscous substance resembling tar, saturated with the catalyst powder. About a table spoon of this residue is left over per litre of petroleum. In principle, this product can also be used or burned down and the catalyst returned into the process.


Recycling machine for thermoplastics

Hangzhou Holin Plastic Machinery Co., China, offers a machine for recycling thermoplastics such as PE and PS products into grains. Model FS-75 recycling machine has a compact structure and is easy to operate. High-foaming waste material that does not need to be broken down can be directly recycled. FS-75 has a screw diameter of 75 mm, and an extrusion capacity of 30-50 kg per hour. This unit has a screen changer that eliminates the need to stop the machine.

Contact: Hangzhou Holin Plastic Machinery Co., 58, Tongyun Road, Liangzhu Economic Development Zone, Yuhang District, Hangzhou City, Zhejiang Province, 311112 China. Tel: +86 (571) 88747708; Fax: +86 (571) 88 747711.


Food-grade resin from plastic scrap

In the United States, researchers at the North Carolina State University have developed a new chemical reprocessing method that can efficiently convert post-consumer bottle-grade PET into a resin suitable for food-grade applications. The team comprising Dr. George Roberts, Dr. Saad Khan and Ms. Joan Patterson demonstrated that the technology can depolymerize PET to obtain a material that can be cleaned and repolymerized into bottle-grade PET.

The depolymerization process runs continuously in a twin-screw extruder. The extruder melts PET, which allows the high-molecular-weight polymer to react rapidly with ethylene glycol, reducing the polymers molecular weight. Supercritical carbon dioxide reduces the polymers viscosity further as it depolymerizes. The end product is a low-molecular-weight material that can be incorporated into a conventional polyester polymerization process. The technology is near commercialization, with only the final testing with clean flake PET remaining to be done.


Separator for flexible plastics

EKS-PET electrostatic separator, from Hamos GmbH, Germany, is capable of removing almost all PVC from shredded, washed and dried PET flakes to produce a clean fraction that can be used in the manufacture of high-quality products. It has a capacity of 750-3,000 kg/h.

With the EKS-PET separator, the PET-and-PVC mixture is electrically charged the PET particles take on a positive charge and the PVC particles a negative one. The PVC particles are separated electrostatically from PET fraction in a high-voltage field. As almost complete PVC removal is achieved, the EKS-PET model yields high-purity PET. The versatile separator is useful in separating other mixtures, such as HDPE/PP, PS/ABS, PVC/PE and PVC/rubber

Contact: Hamos GmbH, Penzberg, Germany. Tel: +49 (8856) 9261-0; Fax: +49 (8856) 9261-99




Treatment of infectious waste

T & C Devine Ltd., the United States, has patented mobile self-contained apparatus and process for grinding, grating, macerating, chemically disinfecting and drying infectious waste material. A trailer contains a hopper, grinder/grater, an enclosed conveyor unit, drying and filtering apparatus, and sources of power, chemical disinfectant and fresh water.

In this process, bagged infectious waste material is dumped into the hopper, sprayed with sodium hypochlorite disinfectant solution, and fed to the grinder/grater, where the mix is ground, grated and macerated into small particles. The material is sprayed again, immersed in the disinfectant solution, conveyed by an upwardly inclined screw conveyor and thoroughly mixed therein, dried and passed into a vertical screw conveyor, followed by a discharge screw conveyor that discharges the dry confetti-like material. The enclosed system works under negative pressure produced by a suction fan that draws air within the system through a HEPA filter to remove air-borne dust, chemical fumes, odours and bacteria.


Infectious hospital waste management

Ducamp, France, offers an alternative treatment to the all incineration of infectious waste. The new DHS system provides an improved level of efficiency in the collection and disposal of infectious material. It features a unique decontamination process, which renders infectious waste inert and allows such hospital waste to be placed in a landfill or incinerated without any further processing.
Ducamp provides turnkey solutions for the on-site waste management needs of hospitals from bedside collection to final disposal. These are orchestrated systems that ensure ultra-hygienic, 24 hour waste collection, with error-proof traceability of all infectious waste and a new decontamination process that replaces conventional incineration of infectious material. With regard to the collection of waste, the DHS system provides appropriate packaging for each type of material. For optimal efficiency, the waste collection vehicle has a weighing system and houses a complete supply of empty, disinfected containers to replace filled ones. A key feature of the system is a bar code that is applied to each filled container for identification and tracking of waste at all times.

Contact: Groupe Ducamp, DHS, Zone Industrielle N4 - BP 4 - 4, rue du Prsident Lcuyer - 59 880 Saint Saulve, France. Tel: +33 (3) 2724 7142; Fax: +33 (3) 2724 7565



Non-intrusive microwave decontamination

MicroSterile Safe Corp., the United States, has patented a method and apparatus for decontaminating biomedical waste. In this process, the waste is introduced with moisture into a flexible, polymer bag. The waste and moisture is then sealed within the bag and the sealed bag is introduced into a decontamination chamber, where it is subjected to microwave radiation at a preset level and time sufficient to sterilize the waste.

This safe and economic processing system treats infectious waste thermally and by steam processing of the bag and its infectious contents within an enclosed space. The heat required for the steam pressure is generated within the chamber by microwave energy. The red bag is prevented from breaking under steam pressure since it is enclosed within the walls of the microwave cavity.


Industry-specific infectious waste clean-up systems

Enware Australia Ltd. has introduced clean-up systems for industry-specific infectious wastes. These systems allow employers/owners and operators of public and private facilities to fully protect staff while complying with the mandatory legi-slations. The ZeoMed system is designed to provide hygienic handling and disposal for spills that are commonly encountered in the workplace, public and recreational areas such as blood, vomit and body fluids that pose health hazards, including HIV and hepatitis. ZeoMed kits include face masks, medical gloves, apron, absorbent material, scoop, scraper, bright yellow waste bags and antiseptic materials.

Available with contents adapted to the needs of particular industries and facilities, ZeoMed kits provide a complete system to protect employees, contain and remove the spill, and absorb odour and ensure the correct disposal of the spill. The waste products gathered using this system is sealed into bags using a built-in tie to contain them until collected. The ZeoMed kits are 100 per cent non-toxic, have unlimited shelf-life and are approved by the United States Environmental Protection Agency.

Contact: Enware Australia Pty. Ltd., P.O. Box 2545, Taren Point, NSW 2229, Australia. Tel: +61 (2) 9525 9511; Fax: +61 (2) 9525 9536



Medical incinerators

Inciner8 Ltd., the United Kingdom, offers medical incinerators for fast, complete and efficient waste disposal of biomedical wastes. The P60 medical incinerator has two chambers insulated and lined with high- temperature refractory. The digital temperature controls and chart recorder are programmable. Fuel and air inflow can be modulated to lower fuel consumption.
The P60 range of incinerators is designed to burn disposables that can and should be destroyed on-site. These wastes include infectious and contaminated red bag, surgical dressings, plastic test devices and other wastes.

The P60-M2incinerators are engineered to meet strict air emission regulations. P60-4GLP-M2 propane-fired incineration system comes with two burners, a secondary chamber, stack, timer and digital temperature control, with two-second retention. P60-4GN-M2 is a similar system that is fuelled by natural gas.

The systems can be charged up to 680 kg per 10-hour day of typical red bag waste. The primary chamber has a volume of 1.65 cubic metres and the secondary chamber has a volume of 3.88 cubic metres. The secondary pre-heat and operating temperatures are in the range 980- 1090C.

Contact: Inciner8 Limited, Shakespeare House, 37-39 Shakespeare Street, Southport, PR8 5AB, United Kingdom. Tel: +44 (1704) 548508; Fax: +44 (1704) 542461


Cold plasma helps maintain hygiene

A European Union project aims to develop a new method to sterilize medical instruments by employing cold plasma discharges. Scientists working on the BIODECON programme report that unlike existing processes, the plasma discharge destroys bacteria, viruses and prions without any damage to the instruments themselves.
According to Professor Achim von Keudell, BIODECONs project coordinator, conventional methods of cleaning surgical instruments rely on the use of highly toxic chemicals followed by distilled water rinsing. Two major problems encountered in such cases are long treatment time and production of toxic wastes that have to be disposed. Other methods that employ high temperatures could damage the equipment being sterilized. However, polymers, such as those found in implants, cannot be treated by this method.

Prof. Keudells team is exploring the potential of employing plasma at a range of low and high pressures, using a variety of source gases including oxygen, fluorine, hydrogen, nitrogen and argon. A plasma discharge is a gas containing energized and ionized particles, which are created when electricity ignites the gas. The excited particles in the plasma react with and destroy the biomolecules, rendering toxins and pathogenic micro-organisms harmless. An interesting feature of this method is that the surface of the instrument need not be heated for the plasma to take effect, implying that medical equipment can be decontaminated without any fear of it being damaged. However, there are some obstacles to overcome before the plasma procedures are ready for use. For example, if a thick layer of bacteria has to be removed, then the plasma process will take much longer and use up more energy and chemicals. Also, the treatment procedure would have to be adapted to tackle bacteria and biomolecules when enveloped in a matrix like fat, blood or living tissues.

Contact: web-site:



E-waste technology

Printed circuit boards are an ideal target for recycling and reuse since they are self-contained modules of interconnected electronic components formed by a very thin layer of conducting material deposited, or printed on the surface of an insulating board. Mr. Zhenming Xu and colleagues at Shanghai Jiao Tong University, China, report to have developed a recycling and recovery technology designed especially for disposal of printed circuit boards. The technology involves a special method of crushing the scrap PC boards, followed by separation of the metallic and non-metallic materials using an electric field. This technique offers advantages over other methods proposed for recycling PC boards.


Sustainable PCB manufacture

Following the success of research supported by the Sustainable Technologies Initiative (STI), dramatic improvements in the sustainability of printed circuit board (PCB) production are now possible. A major obstacle for many PCB producers is the poor sustainability of conventional production processes. The typical method of etching and deposition of metals such as copper, gold, nickel and tin consumes large quantities of water and chemicals, and gives rise to large amounts of metal-bearing effluents that require expensive treatment before they can be discharged into the environment. Research backed by STI has developed a practical way to recycle and reuse these valuable resources without making fundamental changes in production processes.

In the new process, special electroplating techniques make it possible to capture low levels of metals such as copper and nickel. When the resins become saturated, they can be regenerated and reused, while the liquor containing the concentrated metal ions can be recycled.
The benefits of the technology have been demonstrated in field trials by industries. The ability to filter and purify water in a closed-loop system saved 500,000 l/month. The technology is applicable in other industries like metal finishing, where a wide range of process chemicals is used.

Contact: Intellect, Russell Square House, 10-12 Russell Square, London WC1B 5EE, United Kingdom. Tel: +44 (20) 7395 6704.


Delamination process for electronic scrap, the United States, has patented a process for recycling electronic scrap material comprising a metal provided on a polymeric substrate. The method involves the following stages:
  • Milling flaked electronic scrap with a bead impact material in the presence of water to produce flakes of cleaned polymeric substrate;
  • Adding water to the milled material and separating the flakes of cleaned polymeric substrate from metal-containing material;
  • Dewatering and drying the flakes of cleaned polymeric substrate; and
  • Treating the metal-containing material to recover the metal.


Printed circuit board recycling equipment

Henan Dahua Mining Machinery Co. Ltd., China, offers equipment to recycle printed circuit boards. Main features of the patented system are:
  • Advanced, innovative mechanical recycling techniques used;
  • Purity of the recycled metals can reach 97 per cent;
  • Physical separation of metal and non-metal fractions; and
  • Epoxy resin, bakelite and fibreglass are also recycled for use in floor bricks, decorative materials, insulation materials and furniture.

Contact: Mr. Jolion Xie, Henan Dahua Mining Machinery Co., Zhengshang Road, Zhengzhou City, Henan Province, 450052 China. Tel: +86 (371) 6784 9628; Fax: +86 (371) 67 84 9628



Refining of precious metals

Through its global collection centres, TES-AMM (Europe) Ltd., the United Kingdom, manages collection, disassembly and segregation of various e-waste products into appropriate waste streams for onward processing. Precious metal bearing wastes are pre-processed and densely consolidated for onward processing at the central refinery operation. All relevant data on a clients load is entered and tracked on a unique e-waste tracking software, following a load through the process and enabling the provision of detailed client reports for accountability, security as well as legislation compliance. TES-AMMs integrated process allows for end-to-end recycling solution with one point of management.

Contact: TES-AMM (Europe) Ltd., 3 Drummond Crescent, Riverside Business Park, Irvine KA11 5AN, United Kingdom. Tel: +44 (1294) 314 083; Fax: +44 (1294) 277 764




Cleaning up contaminated soil

The Soil Environment Management Division of the Ministry of Environment, Japan, has developed a new process for cleaning soil tainted by organic chlorine compounds such as PCBs. In the pretreatment phase, granules and stones are removed from the PCB-contaminated soil and the water content adjusted to about 15 per cent. Then the soil is mixed with sodium hydrogen carbonate and heated in a soil reactor at 300-350C to separate water and recover volatile organic compounds as the condensate. The condensate, which contains PCBs and an oil with a high boiling point, is charged to a liquid-phase reactor. An alkali and a catalyst are added to the reaction mixture and heated to decompose the organic chlorine compounds. While the chlorine salts are disposed, liquid end product that is free of chlorine is used as a fuel.

A PCB removal rate of over 99.99 per cent can be achieved while the PCB decomposition rate from the condensate is around 99.999 per cent.

Contact: Soil Environment Management Division, Water Environment Department, Environmental Management Bureau, Ministry of Environment, Japan. Tel: +81 (3) 5521 8319



Post-digestion treatment of cellulosic pulp

International Paper Company, the United States, has developed a post-digestion treatment for cellulosic pulps, particularly Kraft pulps, for the purpose of completing the delignification of the pulp to a target degree of delignification. The treatment reduces the generation of dioxins and other chlorinated organics in the pulp, treatment effluent and/or the paper product produced from the pulp.

The quantity of dioxin or dioxin precursors when a chlorine-containing delignification agent is employed, can be limited to insignificant levels or reduced to less than about 50 per cent of the levels achieved by other commonly used post-digestion treatments. This is achieved by washing the pulp following its digestion with about 2-4 tonnes of dioxin-free wash liquid per tonne of pulp, while simultaneously adjusting the consistency of the pulp to a medium or high consistency. Thereafter, the enhanced consistency pulp is contacted with a chlorination agent. Next, the chlorinated pulp is subjected to further treatment including at least an alkaline extraction step.


Treatment of PCBs and asbestos

In the Republic of Korea, the National Institute of Environmental Research offers plasma pyrolysis gasification vitrification (PPGV) technology for the safe treatment and disposal of PCBs and asbestos. In PPGV, both pyrolysis and melting take place in the same chamber and the technology makes use of the energy from a plasma heating system (PHS).

The main process of plasma pyrolysis involves supplying heat energy generated in the plasma torch to an organic waste, such as low carbonated waste, under anaerobic conditions. This process leads to pyrolysis gasification. Inorganic materials like ash are converted into melted slag by the high temperature. Unless external steam or oxygen is supplied, the carbon will convert into the fixed carbon and graphite material since it is heated to over 2,200C by the plasma torch. The process uses high-temperature plas-ma torch (7,000-12,000C).

Pure and concentrated oxygen is used as a medium for pyrolysis gasification. The reaction chamber for pyrolysis, gasification and melting is monolithic. Dioxin discharge is minimal, and bottom ash and fly-ash are recycled as a slag.

Contact: Plasma Eco-Technology, 613-2, Bulkwang-dong, Eunpyung-gu, Seoul, Republic of Korea. Tel: +82 (2) 3555 822; Fax: +82 (2) 3559 822



Enzymes engineered to degrade POPs

In Canada, INRS-Institut Armand-Frappier reports to have identified some of the structural elements of the biphenyl dioxygenase, which determine the enzyme specificity towards various polychlorinated biphenyl (PCB) congeners. This has facilitated engineering of enhanced enzymes capable of degrading more persistent PCB congeners. The performance of the new breed of modified enzymes is being investigated in lab-scale bioreactors.

Contact: INRS-Institut Armand-Frappier, 531 boul. des Prairies, Laval, Quebec H7V 1B7, Canada. Tel: +1 (450) 68 75 010; Fax: +1 (450) 6865 501



Dioxin reduction

Titanium dioxide (TiO2) is the primary product of DuPonts Titanium Technologies (DTT). The company had set a goal to reduce the generation rates of dioxin and dioxin-like compounds (D&DLC) at its three plants in the United States by 50 per cent. TiO2 is produced through chlorination of titanium-bearing iron ores, followed by oxidation, purification and finishing steps. D&DLC are formed as an unintentional by-product during the chlorination step.

Dioxin reductions were achieved by means of similar programmes at all sites. The essence of the technical effort over the period was to modify certain raw materials to reduce the organic D&DLC precursors that were fed to the process. Other technical programmes involved controlling the process in a way that inhibited the reactions that produce D&DLCs. The basic premise was to reduce the oxygen, chlorine and organic reactants from the area of the process that forms D&DLCs. Nearly all of the programmes in the minimization effort were aimed at source reduction rather than end-of-pipe treatment. DTT is working towards a 90 per cent reduction by 2007-08.


Elimination of halogenated hydrocarbons

Idaho National Laboratory (INL), the United States, has patented a process for eliminating halogenated organic compounds. The process involves removing halogens from the parent organic compound under catalytic reductive conditions in a supercritical solvent. The method can be applied to virtually any halocarbon. It is well-suited for destroying highly substituted halocarbons like PCBs, dioxins, furans, insecticides, herbicides and freons that are otherwise not easily destroyed by conventional technologies, such as incineration. The INL method is an economic alternative to incineration and does not create secondary wastes that could be generated by incomplete combustion.

Contact: Mr. Gary Smith, Senior Account Executive, Technology Transfer and Commercialization, Battelle Energy Alliance, P.O. Box 1625, MS 3805, Idaho Falls, ID 83415 3805, United States of America. Tel: +1 (208) 52 63780



Technique to process harmful PCBs

Scientists in the Republic of Korea have developed a new technique to process large quantities of environmentally hazardous polychlorinated biphenyl (PCB) insulating oils. The team, led by Mr. Lee Myun-joo at the Korea Atomic Energy Research Institute (KAERI), employed a high-density electron beam to expel ions of chlorine from PCBs and change the properties of the compound. This allows the material to be recycled for further use or be incinerated without environmental concerns.

The method developed by the KAERI team is applied under a high-heat and high-pressure environment, and can process large quantities of the insulating oil in relatively short time. PCBs have superior insulation and incombustibility properties and have been used extensively in transformers on power transmission towers and electric power poles. Currently, the only method used around the world to dispose of PCBs is to burn them in special furnaces, but this releases dioxins that cause secondary pollution.



Treatment of non-biodegradable cutting oil wastewater

Researchers from two national universities in the Republic of Korea have investigated the application of an advanced oxidation process to treat cutting oil wastewater produced in the metal surface treatment industry. The optimum conditions to treat non-biodegradable pollutants using the Ultrasonic (US)-Fenton process are: the application rates of H2O2 and FeSO4 are 10 per cent and 3 g/l, respectively; a pH of 3; and ultrasonication time of 30 min.

Non-degradable pollutants such as ethylene diamine tetra-acetic acid (EDTA) and triethanolamine (TEA) were present in the cutting oil waste water. TLC analyses of the two compounds in water treated by the co-agulation process were similar to that of raw water. TLC analyses of the two compounds after the US-Fenton process was different from that of raw water, implying that US-Fenton process decomposed EDTA and TEA.

The researchers found that removal rate of pollutants by the US-Fenton process was higher than that by activated sludge process and coagulation process. The removal rates of COD, SS, T-N and T-P by US-Fenton process were 98 per cent, 93 per cent, 75 per cent and 95 per cent, respectively.

Contact: Dr. D. C. Seo, Division of Applied Life Sciences, Gyeongsang National University, Jinju 660 701, Republic of Korea.



Sludge reduction

AnoxKaldnes, Sweden, has introduced the BASTM biological process for wastewater treatment. The BAS process combines a biofilm stage and a pretreatment step, followed by an activated sludge stage. For industrial wastewater streams that lack phosphorous and ammonia for biomass growth, the AnoxKaldnes BAS process reduces overall sludge production and provides a stable two-stage treatment system.

The biofilm stage consists of AnoxKaldnes Moving BedTM biofilm reactor (MBBR) technology. The MBBR contains a plastic carrier media that move freely in the water tanks. Micro-organisms colonize the media and form a resilient biofilm that consumes 60-70 per cent of the soluble COD. An aeration system provides mixing and the oxygen demand of the micro-organisms in the MBBR. Excess biofilm is continuously removed off the media and carried out with the effluent. The partially treated wastewater moves to the activated sludge stage for further reduction of the organic materials.

Contact: AnoxKaldnes AB, Klosterngsvgen 11A, SE-226 47 Lund, Sweden. Tel: +46 (46) 182150; Fax: +46 (46) 133201



Wastewater treatment technology

Acme Group recently launched its sewage water treatment technology, developed at Acmes R&D labs in Canada and the United States. The technology involves a very efficient and cost-effective tertiary treatment for raw sewage through a fast three-step, optimized chemical process. The process is completely chemical and destroys odour-causing bacteria and pathogens. The chemistry of the raw sewage undergoes rapid change and, after a series of reactions, the raw sewage is transformed into clear, odour-free, bacteria-free recyclable water.

The Acme plant has a smaller footprint than conventional treatment plants. To the construction industry, it offers significant advantages in terms of ease of deployment and reduced capital and operational expenditure, as the Acme plant can be installed in less than two months and the technology is environment-friendly.


On-site wastewater treatment and reuse

In China, researchers at the Xian University of Architecture and Technology are studying a pilot-scale fluidized pellet bed bioreactor, or FPBB, for on-site wastewater treatment and reuse. FPBB integrates chemical coagulation, biological degradation, particle pelletization and separation in a single unit. The use of an inorganic coagulant and organic polymer, along with moderate mechanical agitation, generates spherical particles in the up-flow column, and a well-fluidized bed is formed. With a continuous supply of dissolved oxygen through a recycling loop, an aerobic condition is maintained in the bottom section of the column. In such conditions, the pellets in the FPBB column are compact and have a high density. They are rich in micro-organisms, and have high MLSS and MLVSS concentrations.

The FPBB achieved more than 90 per cent removal of SS, COD, BOD and TP from raw domestic wastewater within a total hydraulic retention time of about 30 minutes. It also exhibited nitrification and denitrification ability and the TN removal could be about 50 per cent when the recycling ratio is increased to 1:1. The quality of the treated water is comparable with the secondary effluent from a conventional activated sludge process.

Contact: Mr. X. C. Wang, School of Environmental and Municipal Engineering, Xian University of Architecture and Technology, No. 13 Yanta Road, Xian 710055, China.



Self-aspirating aerator/mixer

MGD Process Technology Inc., the United States, has recently acquired the patented Turborator technology. The self-aspirating aerator/mixer is an innovative approach to gas/liquid transfer. A simple design allows for a rugged, low-maintenance system that provides superior mixing and aeration with reduced energy costs.

Turborator offers oxygen transfer efficiency higher than most mechanical self-aspirating aerators. Its patented impeller rotates in a liquid, establishing a low-pressure zone behind each blade. This low-pressure zone creates a strong vacuum that draws air down the shaft and dispenses it as fine bubbles into the surrounding liquid.

Tests as per the ASCE Standard for the Measurement of Oxygen Transfer in Clean Water, demonstrated that the oxygen transfer efficiency of Turborator is 18 per cent higher than its counterparts, based on the horsepower delivered at the shaft. Other advantages of gas introduction below the liquid surface include the absence of surface splashing and mist formation, which release pathogens into the atmosphere and can cause build-up of ice in cold weather climates.

Contact: PO Box 654, Boylston, MA 01505, United states of America. Tel: +1 (508) 869 2164; Fax: +1 (419) 831 2927



PEF technology for wastewater treatment

Diversified Technologies Inc. of the United States has introduced a new wastewater treatment system based on pulsed electric field (PEF). This system employs electroporation in cells to accelerate pre-digestion and results in up to 80 per cent less solid waste output. The PEF system destroys cell membranes by applying high-voltage pulses of 1-20 s, 35-50 kV/cm at frequencies up to 2 kHz across the wastewater stream. The PEF system features a treatment chamber, and a separate rack that houses a power supply, pulse modulator, data loggers and the controls. It is available in sizes of 10,000 l/h and above. The system can be easily integrated into existing facilities.

Contact: Mr. Michael A. Kempkes, VP of Marketing, Diversified Technologies Inc., 35, Wiggins Avenue, Bedford, MA 01730 2345, United States of America. Tel: +1 (781) 27 59 444; Fax: +1 (781) 2756 081




FGD treatment for coal-fired generating stations

HPD, Spain, will provide the effluent treatment portion for the flue gas desulphurization (FGD) purge system at the Monfalcone power station for ENDESA Italia. The FGD system is part of an overall effort by ENDESA to reduce emissions and integrate environmentally friendly processes and operational efficiency into the power station, which currently generates 336 MW of power from the use of coal as fuel.

The HPD system uses a two-step process to treat effluent from the FGD scrubbers, to provide a zero liquid discharge (ZLD) solution as required by ENDESA, since no aqueous waste is allowed. The first step involves pretreatment of the purge stream using clarification and softening to reduce suspended solids, calcium, magnesium and heavy metals. The second step involves the use of a two-stage evaporation and crystallization system. In the first stage, falling film evaporators concentrate the stream and recover quality water for reuse in the plant. The brine is further concentrated in the second stage brine crystallizer and more quality water is recycled back into the facility. A non-hygroscopic, solid salt cake is discharged from the ZLD system for proper disposal.



Microbes help clean toxic waste dumps

Researchers from the Florida State University (FSU), the United States, are studying a bioremediation technology to clean up toxic waste dump sites. Toxic wastes from weapons manufacturing between 1951 and 1983 have been buried under 243 acres in an East Tennessee valley. These compounds have been leaching into groundwater, extending in radioactive plumes for miles from the contaminated site.

During the course of a forthcoming five-year study, FSU Associate Prof. Joel Kostka and his team will test the natural method which involves the stimulation of naturally occurring microbes to promote bacterial growth in the soil sub-surface that scrub it off potentially deadly radioactive metal. If the bioremediation process proves successful on the uranium, technetium, nitrates and other potentially lethal leftovers at the site, the process should work to mitigate contamination at more than 7,000 other sites nationwide and do so more economically and effectively than most conventional methods.

The FSU researchers and other research teams from several universities and national laboratories across the country are involved in the clean-up project. Together, these teams will develop models to help predict the rate at which levels of contamination drop when using natural and artificial remediation methods. Sub-surface changes would be closely monitored using geophysical methods that send acoustic, electric and other signals into the ground. Prof. Kostkas team will lead the subsurface microbiology portion of the project.



Permeable reactive barrier technology

A former manufactured gas plant in Southwest England is the site of an operational gas distribution depot. Application of conventionally used remediation strategies was not feasible owing to constraints posed by structures above and below the surface. A permeable reactive barrier (PRB) specifically, a SEquential REactive BARrier (SEREBAR) was selected as the best remediation option for this site.

The SEREBAR is currently treating groundwater contaminated with cyanide, polycyclic aromatic hydrocarbons and petroleum hydrocarbons. The system comprises an impermeable bentonite slurry barrier 200 m long installed across active gas mains to intercept contaminated groundwater and direct it into the capture zone of the SEREBAR system. The groundwater flows into the system through an interceptor and six treatment canisters that remediate the contaminated water using sequential anaerobic and aerobic treatments populated by indigenous bacteria. A back-up system of granular activated carbon is provided. Monitoring of results since start-up show that the contaminants in the discharge are significantly lower than the negotiated clean-up levels.


Bioremediation for petroleum soil/water contamination

CW3M Co. Inc., the United States, has patented methods and compositions that facilitate site-specific bioremediation of groundwater and soil with petroleum contamination. In situ bioremediation involves injecting a biomass including micro-organisms and associated nutrients, minerals and co-solvents directly into the groundwater or soil contaminant plume in strategic locations based on geophysical site characteristics of the sites subsurface. As the biomass slurry comes in contact with the contaminant, degradation begins. The micro-organisms trans-form ingredients of the slurry, plus nutrients from the environment, into cell-building materials and extracellular by-products such as water and carbon dioxide.

The concentration of the individual indigenous micro-organism strains and their relative percentages vary with the concentration of the pollutants in the soil and groundwater. Also, the rate of biodegradation is proportional to the types and concentration of the bacteria available to do the work. Under normal conditions, the bacteria will double as frequently as every 15-20 min until they reach a population of several billion per gram of soil. This method is suitable for contamination resulting from kerosene, diesel oil, fuel oil or petrol, with the total petroleum hydrocarbons being below 50,000 ppm. The hydraulic conductivity of the site has to be greater than 10-7 cm/s.


Fungal strain aids bioremediation

Researchers in Egypt have isolated a fungal strain that exhibits high affinity to adsorb and degrade crude petroleum oil. Nutritional and environmental factors that affect petroleum degradation were evaluated by applying Placketl-Burman design, where K2HPO4, inoculum size and pH were the most significant variables. To optimize the level of the significant factors, Box-Behnken design was carried out and a mathematical model created. Further, a maximum petroleum oil degradation of 98.8 per cent has been proved.

Contact: Mr. Gaballa/Mr. Hussein/Mr. Abdel-Fattah, Mubarak City for Scientific Research & Technology Applications, New Borg El-Arab City, Alexandria 21934, Egypt.


Enhanced control of in situ bioremediation

Gas Technology Institute, the United States, has patented method for the removal of volatile and semi-volatile contaminants from groundwater. In this process, the contaminants are stripped from the groundwater by sparging with an inert carrier gas. The stripped contaminants are then transported to a bioactive zone into which at least one gaseous oxidant and one nutrient are independently injected, to stimulate at least one microbial culture associated with the bioactive zone to remove the stripped contaminants from the bioactive zone.

By decoupling the sparging of the groundwater from the introduction of oxidants and nutrient feed gases into the bioventing bioactive zone of the subsurface, the oxygen and nutrient inputs to the bioactive zone can be adjusted (or carburetted) and controlled independently from the hydrocarbon input to the bioactive zone to achieve good kinetic performance in the bioactive zone while avoiding the problems of plugging of groundwater sparging due to biofilm and precipitate formation.


Vermiculture for eco-friendly remediation

Researchers at the Institute for Ecosystem Studies, Italy, have studied, in laboratory scale, the effects of some bioremediation treatments on polluted soil and the use of specific parameters to study the evolution of biochemical processes that take place during soil decontamination. The bioremediation treatments were: compost; compost plus earthworm, Eisenia fetida; and a cocktail of micro-organisms, enzymes and nu-trients. Soil without treatment was used as the control.

Chemical, physico-chemical, biolo-gical and biochemical parameters were determined to assess the efficiency of the processes involved in the degradation of hydrocarbons. Investigations revealed an intense microbiological activity expressed as carbon dioxide (CO2) generation. The two compost treatments had the highest CO2 release, indicating the availability of organic substrate characterizing the compost.

The organic substrate reduction decreased hydrolytic enzyme activities representative of carbon (-glucosidase), nitrogen (protease) and phosphorus (phosphatase) cycles. The enzyme activities showed their highest values in the treatments with compost. The greatest hydrocarbon reduction was found in the treatments with compost, particularly with earthworms.

Contact: Dr. Grazia Masciandaro, Institute for Ecosystem Studies, Soil Chemistry Research Unit, Via Moruzzi 1, 56124 Pisa, Italy. Tel: +39 (50) 3152 481; Fax: +39 (50) 3152473



Bioremediation of water with chemical contamination

Shell Oil Co., the United States, has developed a process and apparatus for the in situ bioremediation of aquifers contaminated with chemicals, particularly oxygenated chemicals such as MTBE and t-butyl alcohol (TBA). The process involves injecting a microbial culture into the aquifers to degrade the said chemicals. The process uses:
  • A bacterial culture for the aerobic degradation of target chemicals
  • An apparatus for continuously or intermittently delivering bacterial culture to the sub-surface without backflow of soil and other materials; and
  • An oxygen delivery system that injects an oxygen-containing gas at a pressure of at least 5 psig above the hydrostatic pressure at each delivery point, by pulsed injection, at a frequency range of one per week to 10 per day.


Rhizosphere remediation process

Researchers at Han-Yang University in the Republic of Korea have developed a process for treating soils contaminated with explosive materials like TNT or DNT. The low-cost and high-efficiency enhanced rhizosphere remediation technology is different from conventional processes such as phytoremediation.

Indigenous bacteria having the ability to decompose explosives were isolated and identified. By adding these to certain native plants, the team developed a biological treatment process that could effectively treat explosive-contaminated soil. It was found that micro-organisms KT22 exhibited the highest removal efficiency in TNT-contaminated soil, for both liquid and solid contaminants.

Contact: Hanyang University, Republic of Korea.





New gas adsorber

Shinko Pantec Co., Japan, has introduced the AW gas adsorber for removing noxious gas and odours in exhausts using adsorbents. The adsorbents are impregnated with acids, alkalis and catalysts to increase adsorption, thus resulting in almost the same operating cost as that for chemical cleaning methods often used. Alkaline gases (such as ammonia), acidic gases (such as hydrogen sulphide) as well as neutral gases (such as methyl sulphide) can be removed by the use of charcoal impregnated with acid, alkali and catalyst with an efficiency of 99.9 per cent or higher.

If the gas treatment conditions are the same throughout, the amount of adsorbent can be reduced to one-third or one-fifth. The adsorbent is in a cartridge, which makes insertion and removal easy. The adsorbent allows thinner packing to be used, which in turn reduces the cost of replacing the packing and saves on fan power owing to low pressure loss.

Contact: Shinko Pantec Co. Ltd., 9-18 Kaigan 1-chome, Minato-ku, Tokyo 105 0022, Japan. Tel: +81 (3) 3459 5936; Fax: +81 (3) 3459 5808



Zero-emission desulphurization

The Beijing Institute of Environmental Science, China, offers an additives-free desulphurization and denitrification technology for coal-burning boilers. Using the principle of oxidation, this technology has created a combined process for dust removal, desulphurization and denitrification. The process achieves a dust removal rate above 99 per cent and a denitrification rate higher than 90 per cent, basically wiping out nitrogen monoxide (NO). No wastewater or residues are produced. The technology has passed the pilot stage, technical review and trial operation.

The process works on the chemical properties of dust and residues, catalysing sulphur dioxide into sulphuric acid, utilizing the iron oxide in coal dust, before absorbing NO by acidic water, using ferrous iron. The sulphite derived from sulphur dioxide is then used to purify NO wastes. In the final part, sulphuric acid is added to convert the metal oxide in the dust into sulphate.


Treatment of VOCs

The Japan Atomic Energy Agency (JAEA) is developing gas treatment processes using an electron beam (EB), which can effectively generate active species for oxidizing pollutants when irradiated on exhaust gases.
Tests have shown that tetra- and trichloroethylenes (PCE and TCE) were readily decomposed through chain reaction triggered by chlorine atoms produced at the beginning of EB irradiation. Low-dose irradiation is thus adequate to achieve complete oxidation of PCE and TCE even at high input concentrations. Complete oxidation to carbon dioxide was achieved by the combination process of EB irradiation and alkaline treatment.

Contact: Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, #1233 Watanuki-machi, Takasaki, Gunma 370 1292, Japan. Tel: +81 (27) 3469 310; Fax: +81 (27) 3469 687.


Catalytic reduction of NO using methane

A new breakthrough achieved by the scientists at the Ohio State University, the United States, allows the reduction of nitric oxide (NO) to innocuous nitrogen gas cheaply by employing methane as a reduction agent. This patented process has also shown the much-desired ability to reduce NO with high selectivity in the presence of relatively high concentrations of sulphur dioxide, oxygen and water a quality that is not available with many other NO reduction processes.

Contact: Ms. Catherine Wendelken, Technology Licensing and Commercialization, The Ohio State University, #1960 Kenny Road, Columbus, Ohio, OH 43210, United States of America. Tel: +1 (614) 2478 442; Fax: +1 (614) 2928 907



New process for NOx reduction

Haldor Topsoe A/S, Denmark, has developed a selective catalytic reduction (SCR) DeNOx technology for removing oxides of nitrogen (NOx) from off-gases. In the new method, nitric oxide and nitrogen dioxide are reacted with ammonia over a catalyst to form harmless and naturally occurring nitrogen and water vapour.

The SCR process basically comprises a catalytic reactor and a system for ammonia storage and injection. The reducing agent can be either liquid water-free ammonia under pressure or an aqueous ammonia solution at atmospheric pressure. A solution of urea can be used as well. If liquid ammonia is used, the ammonia is volatilized and subsequently diluted with air before being injected into the exhaust gas duct. The SCR DeNOx technology is suitable for coal/oil-fired boilers, lignite-fired boilers, pet coke-fired boilers, gas-fired boilers, diesel engines, gas engines and turbines, waste incinerators, chemical plants, etc.

Contact: Haldor Topsoe A/S, P.O. Box 213, Nymollevej 55, DK-2800 Lyngby, Denmark. Tel: +45 4527 8587



Low-temperature oxidation of CO

PEM fuel cells require very pure hydrogen streams since even very low concentrations of carbon monoxide (CO) can poison the catalysts used in the anode. In hydrogen streams for power fuel cells, CO concentrations must be reduced to less than 10 ppm.

In the United States, researchers at the Ohio State University have investigated low-temperature oxidation of CO on Co/ZrO2 catalyst. This catalyst is able to oxidize CO to carbon dioxide (CO2) with very high selectivity. Additionally, in lean conditions at GHSV = 20,000 h-1, the catalyst was able to achieve complete conversion of 600 ppm CO at room temperature. It also obtained 100 per cent conversion of much higher (1.5 per cent) CO concentrations in lean conditions at a temperature as low as 135C. The catalyst has great potential for use also in lean exhaust and enclosed areas such as coal mines.

Contact: Ms. Catherine Wendelken, Technology Licensing & Commercialization, The Ohio State University, #1960 Kenny Road, Columbus, Ohio, OH 43210, United States of America. Tel: +1 (614) 2478 442; Fax: +1 (614) 2928 907



Dry scrubber

Tri-Mer Corp. in the United States has developed a horizontal cross-flow scrubber to control sulphuric acid fumes from dry charge formation operations. The scrubber relies on mechanical separation and does not use chemicals. It offers collection efficiencies greater than 99 per cent at all loading levels.
The acid fume scrubber technology has been commercialized under the trade name UltraScrubTM. An installation in East Penn will employ six UltraScrub units.

Each has its own stack and fan, but is ducted to a plenum of 9 ft diameter. This configuration allows any unit to be shut down for any purpose and restarted seamlessly. Five units will operate continuously, while the sixth is a maintenance back-up. Each of the acid fume scrubber units, which are UV-stabilized polypropylene, has a capacity of 32,000 cfm.

UltraScrub units have four stages, arranged as a series of cartridges. The scrubber is designed to operate dry at least 99 per cent of the time. To prevent the corrosion of the fan from exposure to sulphuric acid mists, the fan is installed at the back end of the scrubber; fumes drawn through is cleaned before contact with fan.

Contact: Tri-Mer Corp., 1400 Monroe Street, P.O. Box 730, Owosso, MI 48867, United States of America. Tel: +1 (989) 7237 838; Fax: +1 (989) 7237 844



New technologies for gas purification

The Ecopure KPR rotary concentrators from Drr Systems GmbH, Germany, make it possible to remove solvent residues from exhaust gases by adsorption. The heavily laden desorption air stream is combined with the exhaust gas stream from the production process and then treated in an activated carbon unit with steam regeneration to recover solvents.

Ecopure regenerative thermal oxidation plants eliminates the need to replace catalysts, and offers auto-thermal operation with the option of adding a subsequent system to recover heat in the form of steam or thermal oil. The Ecopure Envirojet process removes sticky latex particles from the waste gas stream.

The Ecopure VAR gas/liquid oxidizer is designed to clean exhaust gases from water treatment plants in the chemicals industry. Here the wastewater needing treatment is heated by a high-pressure hot water heat exchanger at a pressure above 100 bar. An effective deNOx system reduces nitrous oxides using selective non-catalytic reduction process.

Contact: Drr Systems GmbH, Otto-Durr-Str. 8, 70435 Stuttgart, Germany. Tel: +49 (711) 136 1402; Fax: +49 (711) 136 1075.



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