VATIS Update Waste Management . Mar-Apr 2006

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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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UNDPs solid waste management project

In Malaysia, a collaborative project between Penang state government (through the Economic Planning Unit, UPEN), UNDP and two local authorities in Penang the Majlis Perbandaran Pulau Pinang (MPPP) and Majlis Perbandaran Seberang Prai (MPSP) was launched on 23 January. Penang was chosen for the Structuring and Institutionalizing Solid Waste Management project due to the states leadership in many activities pertaining to solid waste management, including measures to improve the current system with active participation from its recycling networks. This collaborative project is the first solid waste management project involving MPSP.

The projects goal is to support and speed up sustainable modernization of Penangs urban waste system. The emphasis is on aiding Penang implement a structured approach to waste management, integrating recycling, organics recovery and landfilling, with collection and waste prevention. The project would also play a key role in providing inputs to federal and state level plans on solid waste management. This is the second solid waste management programme undertaken by UNDP in Penang, following the successful Public Private Partnership for Urban Environment (PPPUE) from 2002-2004 which involved stakeholders from MPPP and the private sector.


Chinese measure to battle pollutants

China will take its first big step to combat persistent organic pollutants (POPs), with Zhejiang province in the east a chief beneficiary of the project. A polychlorinated biphenyl (PCB) Management and Disposal Demonstration project is scheduled for launch in Zhejiang and Northeast Chinas Liaoning province in the next four years, a report from the State Environmental Protection Administration (SEPA) states.

The first exemplary project for China to fulfil its commitment to the Stockholm Convention on reducing and preventing POPs, the project would cost more than US$32 million. The Global Environmental Facility will provide US$18 million while the rest will come from Chinese local governments and other countries, such as Italy, said Mr. Zhuang Guotai, vice-director of the Office for Stockholm POPs Convention Implementation under SEPA. SEPA plans to eliminate PCBs by 2025.


Waste management in Bangladesh factories

A recent survey undertaken by the Bangladesh Bureau of Statistics (BBS) reveals that at least 37.5 per cent of the nations industrial units do not have a waste management system and 62.1 per cent lack waste recycling facilities. Environmental Protection Expenditure Survey 05 states that the environment is fast emerging as an important matter globally. In Bangladesh, industries/establishments are not as yet fully conscious about this problem. Also, government monitoring and supervision is not very extensive.

The United Nations Development Programme assisted BBS in this survey, which trained its sights on environment protection systems in industrial units and their outlay for this purpose. Establishments and industries covered by the survey included manufacturing, electricity, agricultural, gas, transport, hotel and health service units.


Viet Nam aims to achieve 70 per cent waste management

A national plan on environmental pollution control, whose goal is to manage 70 per cent of wastes by 2010, has been approved in Viet Nam. The plan outlines Viet Nams strategy to survey and establish statistics on the quantity of waste, types of waste and waste sources found throughout the country.

According to the plan, 90 per cent of waste volume in urban areas and industrial zones must be collected, transported and treated while 10 per cent of dangerous solid medical waste and more than 60 per cent of harmful industrial waste treated by suitable technologies. The plan will also attempt to control environmental pollution caused by weaving, dying, paper manufacturing, footwear and leather manufacturing, food processing and toxic chemicals leftover from the Viet Nam War. The plan also touches on the issue of international pacts on environmental pollution control that Viet Nam has signed or joined and calls for their effective enforcement.

Appliance makers in China to bear waste recycling costs

A new regulation being drafted in China places the onus of recycling products like refrigerators, washing machines, TVs, air-conditioners and computers on their manufacturers. Furthermore, consumers cannot dispose of such appliances at will. The draft Management Regulation on Recycling and Disposal of Used Home Appliances and Electronics Products also includes provisions on mandatory reclamation of five popular home appliances, namely refrigerators, washing machines, air-conditioners, TVs and computers.

The regulation is being drafted by officials at the National Development and Reform Commission (NDRC), Ministry of Information Industry, the Ministry of Commerce and SEPA. When the regulation takes effect, home appliance makers will have to reclaim used products or collect the same for professional waste disposers. At least five million TVs, six million washing machines and four million fridges are discarded each year in the country. NDRC and the Ministry of Finance will set up a special fund to cover some of the manufacturers recycling costs.


Not all waste is toxic!

The Malaysian government has enacted several regulations to manage scheduled wastes. As such, waste generators and supporting service providers must obtain a license to store, treat or recover such wastes. At present, there are 47 licensed recycling and recovery operators in the country.

According to Mr. Peter Ho, a waste management expert, many wastewater treatment sludge, like those from food processing and sewage plants, can be converted into organic fertilizer or compost. For example, waste from oil-based materials have potential use as fuel, owing to their high calorific content. While rules play an important role in protecting the environment, Mr. Ho opines that stringent regulations that do not take cognisance of the fact that Malaysia is far from being a developed nation in terms of environmental management could be counter-productive to the overall objective. He said that the definition of all heavy metals as scheduled waste, and thus needing treatment and disposal, irrespective of the level of metals in the waste or the degree of toxicity of the material, is imposing unnecessary costs on industries to dispose such wastes. It also results in lost opportunities for recycling or recovery of valuable metal in the waste.


Sri Lanka strives to end garbage crisis

In Sri Lanka, a 7-member team has been drawn up by President Mahinda Rajapakse to devise an acceptable solution to the garbage crisis. Led by Provincial Councils and Local Government Minister Mr. Janaka Bandara Tennakoon, the committee includes three mayors and two other ministers. Mr. Jayantha Liyanage, the Colombo Municipal Councils Commissioner and Secretary of the presidential committee, expressed that the commission would propose either the need to announce fresh tenders after Burns Environmental Services Ltd. violated their contract, or else to bring in an incinerator that would be a viable solution for the entire country. About 600-800 t/d of garbage is collected in Colombo.


Garbage bag prices to rise 40 per cent in Korea

The Republic of Korea government will increase the prices of plastic garbage bags by about 40 per cent over the next three years. This step is intended to encourage households and businesses generate less waste. The Ministry of Environment has stated that the price of a 20 l plastic garbage bag for household use would increase to an average of US$0.55 by 2008.

Korean households and businesses are required to purchase and use specific garbage bags issued by their respective municipal authorities when disposing waste. They also need to separate recyclable items from conventional wastes that are put into garbage bags and buried in landfills. Local governments set their own prices for garbage bags whose colours and designs vary from one municipality to another, and the bags issued by one municipal government cannot be used elsewhere.


Japan eases rules on import/export of industrial waste

In Japan, the Environment Ministry intends to ease restrictions that would allow private companies to import and export industrial waste as part of plans for an East-Asia recycling network. Under the new system, companies that export or import waste must ensure that it is properly disposed of or recycled. At present, only municipal governments and others legally responsible for disposing wastes are allowed to import and export such materials.

The ministry expects the relaxed regulations to encourage private sector companies to import such appliances and other items to recycle materials, including indium, a toxic substance widely used in liquid-crystal displays, light-emitting diodes and other products. By disposing of such products through Japans advanced waste disposal technologies, the ministry plans to secure scarce resources while preventing environmental contamination in developing countries. The ministry will also encourage companies to export industrial waste and used products that are in poor demand in Japan or expensive to recycle.



Granulation of thermoplastics

Germanys WEIMA Maschinenbau GmbH has upgraded its two-stage processing plant with features that include both a primary as well as a secondary granulator. The plant is used for economic granulation of engineering thermoplastics such as ABS, PA, PBT, POM, PPA, LCP, PC, etc., especially of glass fibre reinforced grades, in the form of heavy start-up waste lumps or large volume surplus production material with large dimensions. With two-stage granulation, the material to be granulated is pre-granulated in a WLK type single-shaft primary granulator to a size of around 40 mm and then granulated further to a final particle size of about 3-10 mm by a NZ downline secondary granulator, designed specially for secondary granulation of the pre-granulated matter.

Contact: WEIMA Maschinenbau GmbH, Gewerbegebiet, Bustadt D-74360 Ilsfeld, Germany. Tel +49 (70) 6295 70-0; Fax +49 (70) 6295 70-92.


Converting waste plastic into liquid fuel

Cynar Plc., the United Kingdom, is offering a process to convert scrap and waste plastics into synthetic fuel. ThermoFuel system employs liquefaction, pyrolysis as well as the catalytic breakdown of plastics. It can handle almost all plastic wastes currently disposed of in landfills. A major advantage of this extremely high-efficiency process is its ability to handle unsorted and unwashed plastic.

A ThermoFuel plant can produce up to 9,500 l of high-grade synthetic fuel from 10 t of waste plastics, with the system capacity ranging from 10 to 20 t/d. The system comprises a stock infeed system, pyrolysis gasification chamber, condensers, catalytic converter, centrifuge, oil recovery line, off-gas cleaning and adulterant removal. High-efficiency generators can be integrated into the design of the ThermoFuel system to yield up to 1.4 MWh of electrical power from 10 t/d of plastic wastes.

Contact: Cynar Plc., Second Floor, Berkeley Square House, Berkeley Square, London W1J 6BD. Tel: +44 (207) 8876 130; Fax: +44 (207) 8876 100



Sequential recovery of monomers and high-value products

Researchers in the United States have developed a process of using fast pyrolysis in a carrier gas to convert a plastic waste feed stream of mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high-value monomeric constituent occurs prior to pyrolysis of other plastic elements. The following stages are involved in this process:
  • Selecting a first temperature programme range to cause pyrolysis of a specific polymer to its high-value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic elements;
  • Selecting a catalyst and support to treat the aforesaid feed streams to effect acid or base catalysed reaction pathways for maximizing the yield or enhancing separation of the high-value monomeric constituent in a given temperature range;

  • Differentially heating the relevant feed stream at a heat rate within the first temperature programme range to provide differential pyrolysis for selective recovery of the high-value monomeric constituent in optimum quantities prior to pyrolysis of other plastic components;

  • Segregation of the high-value monomeric constituents;

  • Selecting a second and higher temperature range to allow for the pyrolysis of a different high-value monomeric constituent and heating the feed stream differentially at the higher temperature programme range to cause pyrolysis of the different high-value monomer; and

  • Separating the different high-value monomeric constituents.


Contact: Mr. Richard Bolin, CRADA, The National Renewable Energy Laboratory, the United States. Tel: +1 (303) 2753 028.


Polymer waste RDF

In the Republic of Korea, the Ministry of Commerce, Industry and Energy has initiated a project to assess the potential of manufacturing polymer waste RDF. Undertaken by Korea Institute of Machinery and Materials, the project focuses on recycling plastic wastes by using them as a raw material in energy production. This approach lowers costs entailed in disposing plastic wastes while concurrently yielding useful energy.

The project has developed a wind power separator for segregating the waste plastics from incombustible impurities by utilizing variations in specific gravity. Computer simulation analysed the air flow to be reflected in the system design. An analysis of the material balance of the whole process revealed that when mixed waste plastic with 5 per cent water content is the input, magnetic separation could remove only 5 per cent of impurities while the wind separator removed 10 per cent. Also, gaseous substances and particulate matter were lower than standard values.



Infectious wastes: Sterilization/disposal

Winfield Corp., the United States, offers a method to sterilize infectious wastes. In this process, waste is placed in an appropriate disposal apparatus, e.g. an industrial blender, which has an isolated volume for holding and mechanically destroying the waste. A dry granulated medium which could contain a disinfectant constituent e.g. sodium hypochlorite is also placed within the isolated volume together with the infectious waste. The granulated medium may include pH-adjusting elements, deodorant constituents and surfactants, in addition to pigment components for staining the waste during the destruction process. After waste has been ingested into the disposal apparatus, the apparatus is activated to destroy the waste, such as by blending and chopping the waste.


Reclaiming energy

The United States-based Medenergy Corp. has drawn up demonstration projects to exhibit the potential of recovering energy from biomedical wastes. The technology, based on steam reformation technology, can detoxify contaminated and toxic medical wastes on-site.

The demonstration projects will feed up to 4 t/d of waste into rotary kilns, which are steam-heated to around 1,038C. At this high temperature, the chemical composition of waste is modified, rendering it inert while lowering its weight by 80 per cent. This process yields a hydrogen-rich gas, called syngas, that can power fuel cells. Carbon dioxide formed during the process can be used to manufacture, e.g. carborundum for sandpaper and abrasives/aggregate for concrete and asphalt. The footprint of the treatment equipment is approximately 75 ft 300 ft in size and can be stationed with other mechanical equipment.


Bioreactor to dispose of medical wastes

In India, researchers have developed a low-cost and safe solution for the disposal of medical wastes. Based on the tenet of bioconversion, Sujala Biosanitizer provides an effective medical waste disposal technique. It works on the principle of aerobic breakdown of waste rather than on anaerobic decomposition, which normally occurs.

In this method, two concrete bins each measuring 3 ft 3 ft 3 ft are built. Each bin has two openings, one on top to serve as inlet and the other at the front to serve as the exit. The top opening is covered with a wire mesh while a door is fixed to the opening at the front. Coconut fibre is spread all over the bins and then hospital waste, kitchen waste, Sujala powder is added. Next, dry leaves is spread over this waste heap. The system is kept moist at all times. The end product, which can be used as manure, has been compared favourably with garden soil, with regard to microbiological contamination.

Contact: Dr. Nirmala Ganla. Tel: +91 (20) 6693 855



Pathological waste treatment equipment

Honua, the United States, is offering tested and cost-effective treatment systems to treat medical wastes. Pyrolytic DestructorTM is designed specifically to eliminate pathological wastes from surgery and autopsy, chemotherapy wastes, laboratory wastes and pharmaceutical wastes. Autoclaving units are also available to efficiently and cost-effectively render large volumes of medical red bag wastes and sharps non-infectious and safe for disposal. Proprietary heat recovery systems, heat recovery boilers and thermal energy co-generation control equipment are provided to ensure that medical waste treatment facilities employing the Pyrolytic Destructor and autoclave systems together can effectively treat 100 per cent of the waste stream constituents with energy produced from treating 20 per cent of that same waste stream.

Contact: Honua, 1164, Bishop St., Suite 510, Honolulu, Hawaii 96813, United States of America. Tel: +1 (808) 5502 877; Fax: +1 (808) 5502 933.


Steam-heated autoclave

Menora Services Ltd. of Germany offers a solution for treating medical wastes. In this process, waste is placed at the top of an autoclave in which a heavy-duty crusher has been mounted. After crushing the waste material, the autoclave is heated by steam to 138C and the pressure increased to 3.8 bar. The fully automatic process has a cycle time of 40-60 minutes (Clave 1000), depending on the amount of waste. The end product is sterile fragments that may be disposed of in landfills.

The technology reduces the original waste volume by approximately 80 per cent in a safe and cost-effective manner. Contact: Menora Services Ltd., Viktoria, Luise, Platz 7, Berlin 10777, Germany. Tel: +49 (3361) 375 707; Fax: +49 (3361) 374 182.



CD waste recycling system

The Department of Science and Technology-Industrial Technology Development Institute (DOST-ITDI), the Philippines, has developed a recycling process to recover polycarbonates from discarded compact discs (CDs) and optical media to make useful packaging materials. The recycled polycarbonate can be mixed with clay to make a superfine material called polymer-clay nano-composite system, which has several industrial applications, like packaging and flexible housing for electrical parts. Polycarbonate is a type of durable and heat-resistant plastic employed for engineering purposes. It can also be used as top coating for riot shields, glass lenses, films, tools and appliance housings, and printed circuit boards, among others.


Disassembling electronic equipment

In Japan, Sharp Corp. along with NEC Tokin Co. Ltd., Tokai University and Union Seimitsu Co. Ltd. has developed an Easy-Release Screw Fastener that combines a shape-memory alloy washer with a metal screw. The newly developed fastener allows for disassembly of fastened components through the application of heat. Adopting these fasteners in consumer electronics equipment will greatly boost the efficiency of disassembly operations when the discarded equipment gets into the recycling process while contributing to greater resource recovery.

Key features of the Easy-Release technology include:
  • Easy-release screw fasteners use a shape-memory alloy washer in combination with a conventional metal screw. The screw is threaded through the washer and a hole just slightly wider than the diameter of the screw head. When exposed to 100C, the diameter of the washer expands, allowing the fastener to part easily. The shape-memory alloy washer is made using 50 per cent titanium and 50 per cent nickel.
  • Recycling friendly design aimed at higher resource-recovery rates.


Collecting palladium nanocrystals with the help of bacteria

Studies undertaken by researchers at the University of Birmingham, the United Kingdom, has revealed that certain bacteria can act on waste materials to yield palladium crystals. The addition of Escherichia coli and Desulphovibrio desulphuricans to wastewater from discarded catalytic converters and printed circuit boards resulted in the collection of palladium nanocrystals, which were found to be 50 nm wide. Platinum, aluminium and silver were also deposited by the bacteria, and continued working for over three months.


Electronic waste sorter/separator

Austin AI LLC, the United States, offers a cost-effective way to identify hazardous as well as recyclable/valuable material in electronic waste products. The QXR-EW sorting and separation system is a downward looking X-ray fluorescence (XRF) spectrometer with a CCD camera integrated for analysing samples passing on a conveyor. Developed along with one of the worlds most advanced recyclers, the instrument ensures rapid and accurate isolation of a wide range of electronic wastes.

The QXR-EW is typically integrated over a conveyor, downstream from the shredder. Materials passing below the CCD camera are detected, sending a signal to the analyser that a sample is present and to begin analysis. The material type is determined by chemistry and the sample is diverted from the conveyor by linear mechanics for deposition into product collection bins. In this manner, up to 15 different material types can be sorted by grade.

More than a tenfold increment in material sorting can be achieved, with an accuracy of 98 per cent or better. Contact: Austin AI, LLC, 2101, Donley Drive, Ste. 108, Austin, Texas 78758, the United States. Tel/Fax: +1 (512) 8379 400/434



PCB recycling unit

Henan Dahua Mining Machinery Co. Ltd., China, offers a system for recycling printed circuit board (PCB). Key features of this model include:
  • The patented equipment adopts advanced and innovative physical recycling techniques;
  • It crushes, culls and recycles waste and old PCBs;
  • Purity of the recycled metal can reach 97 per cent;
  • Physical separation of metals and non-metals;
  • The amount of copper accounts for more than 17 per cent; and
  • Other epoxy resin, bakelite and fibreglass are recycled for use as floor bricks, decorative materials, insulation materials and furniture.

Contact: Henan Dahua Mining Co. Ltd., 102, Zhongyuan Road, Zhengzhou City, Henan Province 450052 China. Tel: +86 (371) 6780 0567.



Treating chlorinated hydrocarbons

In the United States, researchers have investigated into the potential of getting rid of chlorinated hydrocarbons present in groundwater by injecting nano-iron particles. After bench-scale studies at the Gas Technology Institute and site pilot-scale tests, a full-scale nano-iron application was performed at the Public Service Electric and Gas Co. Trenton Switchyard. The pollutants consisted of 1,1-dichloroethane, 1,1-dichlorethene, 1,1,1-trichloroethane, 1,2-dichloroethane and trichloroethene. At a concentration of up to 30 g/l, a nano-iron slurry was applied to 1.5 acres of the site in two phases of injection approx. 1,360 kg in the first phase and 680 kg during the second. Slurry was applied in a 20 feet injection grid pattern. Post-injection groundwater sampling, analysis and evaluation were performed for each phase.

Full-scale nano-iron injection at the site exhibited significant reduction of the contaminants to levels that made further reduction by monitored natural attenuation reasonable to achieve the New Jersey Depart-
ment of Environmental Protection Groundwater Quality Standards. Both the pilot-scale and full-scale testing programmes were undertaken at the site, under the PSEG Services Corp. management, by PARS Environmental Inc., using funds allocated by Gas Research Institute. This nano-iron technology is available as NanoFe.

Contact PARS Environmental, United States of America. Tel: +1 (609) 8907 277



Catalytic bag filter

Japans Hitachi Plant Engineering and Construction Co. Limited has developed a catalytic bag filter that degrades and removes dioxins that are difficult to remove by traditional methods. The breakthrough involves incorporating a bag filter with a
special catalyst added to the filter fabric. In contrast to conventional systems, equipped with catalytic tower, activated carbon adsorption tower and activated carbon injection, the catalytic bag filter requires no treatment towers, silos or injection apparatus and can be erected in a small area.

Contact: Hitachi Plant Engineering and Construction Co. Limited, 1-14, Uchikanda 1-chome, Chiyoda-ku, Tokyo 101 0047, Japan. Tel: +81 (3) 3576 4114; Fax: +81 (3) 3576 9061.


Decomposing high-density dioxins

A new process capable of degrading environmentally harmful dioxin gases has been developed by Japan Fine Ceramics Centre (JFCC), with the cooperation of Fujitsu Laboratories Ltd. This breakthrough is 100 times more effective than conventional processes. Based on a fusion of plasma and catalyst technologies, the new Plasma-Assisted Catalytic Technology efficiently decomposes and renders dioxin gases harmless.
The toxicity of dioxins depends on the position of the bonds between benzene rings and chlorine, with the compound called 2378TCDD known to be the most toxic.

With plasma-assisted catalytic technology as the foundation, researchers, utilizing a catalyst of platinum and optimizing applied voltage and frequency for the plasma generation, succeeded in breaking down and rendering harmless high-density dioxin gases at concentrations of about 100 m/m3 of N2. 1234TCDD, a compound with similar composition but different chemical properties (i.e. an isomer) as 2378TCDD, was used to evaluate the experiment. A few improvements to the plasma-assisted catalytic technology resulted in an effective process for decomposing dioxins. Researchers were able to verify a decomposition rate of more than 99 per cent and confirmed that the rate of decomposition differed in relation to the applied voltage and frequency.

Contact: Dr. Osamu Ueda, Fujitsu Laboratories Ltd., Japan. Tel/Fax: +81 (46) 2508 811/2488 812



Catalytic degradation of PCDDs, PCDFs and coplanar PCBs

Japans Prefectural University of Hiroshima reports to have achieved highly efficient degradation of polychlorinated aromatic compounds, including polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like compounds such as coplanar polychlorinated biphenyls (co-PCB). Degradation was accomplished in 24 h by a simple stirring operation utilizing safe and high workability metallic calcium, which acts both as a scavenger and reducing agent, and Rh/C catalyst in an alcohol solution under mild conditions in a sealed tube at 25C without any increase in temperature within 0.15 MPa of increasing internal pressure during the reaction.

Reductive dechlorination by metallic calcium and catalytic reduction by Rh/C together with the generated hydrogen gas, exert a synergistic effect on the degradation process. Alcohol was used as a proton source and hydrogen, which was generated by a side reaction, increases the activity of Rh/C catalyst. Through the degradation of 4-chloroanisole in ethyl alcohol, anisole and cyclohexyl methyl ether were obtained in good conversions. Utilizing ethyl alcohol as a solvent, treatment of dioxins and co-PCBs in a solution was very effective for degradation to reduce 2,806 pg TEQ/ml of initial concentration to 31.8 pg TEQ/ml; its yield was 98.5 per cent. Moreover, degradation in methyl alcohol produced a yield of 99.3 per cent. This concentration reached 20.3 pg TEQ/ml under a mild wet process.

Contact: Mr. Y. Mitoma, Department of Environmental Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562, Nanatsuka, Shobara City, Hiroshima 727 0023, Japan.


Decontaminating soil by steam stripping

Researchers at the University of Federal Armed Forces, Germany, have developed a mathematical model that allows for determining the mass transfer and energy needed for decontamination of polyaromatic hydrocarbons from soil by steam stripping. For cleaning soil polluted with polyaromatic hydrocarbons
(PAH), a thermal separation process is applied. This process uses superheated steam that is supplied via a nozzle along with a suspension (approx. 40 per cent soil content) of the contaminated soil into a tube reactor, where the soil suspension is vaporized and PAH stripped from the soil at temperatures of 140-300C. In a cyclone, a solid-vapour separation is carried out and after going through a condenser, PAH and condensed water is separated. For improvement of the economical performance, a heat recovery unit is integrated. This is realized by preheating the water stream supplied to the evaporator by cooling the vapour stream exiting the reactor.

For the mathematical description of the process, removal of PAH from the soil is considered to take place by a desorption process. Sorption isotherms are measured by batch experiments and can be described by isotherms of Langmuir type. A dispersion model is used to describe the mass transfer of the process. The procedure is mathematically modelled for both instationary and stationary operations. A simulation predicted the lowest energy usage at a good cleaning performance at a steam-to-suspension ratio of 5.

Contact: The Institute of Thermodynamics, University of the Federal Armed Forces Hamburg, Holstenhofteg 85, 22049 Hamburg, Germany.


Detoxifying dioxins using e-beams

In Japan, the Radiation Chemistry Research Establishment of JAERI has developed a system that allows for the use of electron beams (EBs) to detoxify dioxins present in flue gases vented by waste incinerators. Japan plans to amend its law for preventing air pollution later this year. As such, the amount of toxic equivalents (TEQ) permitted in flue gases would be sharply reduced from the present emission standard of 80 ng/m3. The typical amount of TEQ/m3 in flue gases from existing incinerators varies between 10 ng for small incinerators with a capacity of <2 t/h and 1 ng for incinerators with a capacity >4 t/h. Incinerators using the new process may reduce these amounts to 5 ng and 0.1 ng, respectively.

In the new procedure, an electron beam is applied to the flue gases, generating highly reactive activated gases like activated oxygen from the ingredients of flue gases, which decompose the chemical structure of dioxins. The EB system makes use of a shielded irradiation chamber accelerator, which is far superior to current bag filters on two counts. First, the process does not produce any toxic residuals and eliminates dioxins at a low concentration. Next, it can be easily installed in existing waste incinerators. Experience with radiation-chemical technology using e-beams like the decomposition of voltaic organic chlorides at factories and desulphurization of flue gases from thermal power facilities were used to develop this process.


Treating pesticide-contaminated soil

RLC Technologies Inc., the United States, offers techology based on an indirect-heated rotary desorber system to treat polluted soil. The indirect-heated rotary desorber uses an oxygen-deficient environment while desorbing/separating volatile and semi-volatile organic compounds from solids. The rotating system is capable of maintaining material temperatures ranging from 315 to 760C. A slightly negative pressure exerted unceasingly on the desorber aids in removing process gases from the desorber and sending it to the vapour recovery unit (VRU). Within the VRU, they undergo treatment in a series of scrubbers and separators where entrained solids, water and hydrocarbon vapours are removed from the gas stream.

The second step in gas treatment is accomplished when effluent from the primary scrubber is passed via a heat exchanger/condenser where the gas temperature is decreased to below 38C. Vapours exiting the heat exchanger at this point include residual non-condensable gases and water vapour. Depending on the local regulatory guidelines and emission rules, these vapours may be discharged into the atmosphere. If it is determined that additional treatment of off-gases is essential, the final gas treatment to remove any residual contaminants can be achieved using activated carbon, bio-filters or thermal oxidation in the anaerobic thermal desorption unit (ATDU) furnace. All condensed vapours from the VRU undergo a separation and cooling procedure once inside the Water Treatment Unit (WTU).

RLC Technologies provides complete plants, including feed system, VRU, ATDU, WTU and associated process controls.

Contact: RLC Technologies Inc., #11023, Washington
Highway, Suite 100, Glen Allen, VA 23059, United States of America. Tel: +1 (804) 5500 405; Fax: +1 (804) 5503 833



Chemical oxidation of PCBs

Researchers at Tampere University of Technology, Finland, modified Fentons reaction to chemically
oxidize polychlorinated biphenyls (PCBs) in polluted lake sediment. For the study, the team employed a central composite rotatable experimental design to study the effects of H2O2 and Fe2+ concentration on PCB decomposition. Experiments were conducted using unstabilized and stabilized H2O2, with KH2PO4 as stabilizer. The effect of using HCl or H2SO4 for pH adjustment was also studied.

Results have shown that up to 87 per cent of PCBs were removed in experiments when unstabilized H2O2 was used with H2SO4 for pH adjustment. Only 54 per cent PCBs were removed when H2SO4 was replaced with HCl. The use of stabilized H2O2 instead of unstabilized H2O2 did not improve reaction efficiency.

Contact: Mr. Tuomo Aunola, The Tampere University of Technology, Environmental Engineering and Biotechnology, P.O. Box 541, FIN 33101 Tampere, Finland. Tel: +358 (3) 3115 3517; Fax: +358 (3) 3115



Process for sediment decontamination

Aleph Group, the United States, has developed an advanced chemical treatment technology called GeoremediationTM. The patented method has been successfully tested for the decontamination of soil, sediments and other wastes with pollutants such as TPHC, PAH, PCBs, heavy metals and dioxins. It employs off-the-shelf equipment and does not produce excess contaminated water and/or air emissions. The end result is environmentally benign, appears and behaves like soil, and can be used as structural or non-structural fill material in transportation and infrastructure construction, land re-habilitation and landfill applications.

Georemediation has been shown to decontaminate soil, sediments and other wastes by mineralizing all types of organic contaminants or converting them into environmentally benign and inert compounds like calcium carbonate and water. The process immobilizes inorganic contaminants through pozzolanic reactions and by incorporation into new insoluble crystalline structures. The proprietary Georemediation reagent has a blend of dispersants, clay pillaring agents, oxidative reagents, metal salt catalysts as well as pozzolans.

Contact: Mr. Ajay Kathuria/Ms. Anita OConnor, BEM Systems Inc., 100 Passaic Ave., Chatham, NJ, the United States. Tel: +1 (908) 5982 600; Fax: +1 (908) 5982 622



Steam stripping TBT and PAH from soil

A steam stripping process has been developed by researchers at the GKSS Research Centre GmbH,
Germany, as an efficient way to treat dredged sediments contaminated by PAH, residues of mineral oils and organotin-compounds (TBT-tributyltin). The steam stripping process is based on spontaneous vaporization caused by changes in temperature and pressure. Alteration of the physical-chemical conditions within the process results in deagglomeration of the aggregates, desorption of the contaminants and vaporization of the contaminants and water. Afterwards, the steam phase contains the contaminants and the clean solid component is separated using a cyclone unit.

This technique has proved capable of decontaminating different types of materials, almost 100 per cent. Drilling muds tainted with mineral oils were cleaned with an efficiency of up to 100 per cent. Decontamination of mercury and PAH from soil washing residues also produced similar results.

Contact: Mr. A. Eschenbach, GKSS National Research Centre GmbH, Max-Planck-Strae, 21502 Geesthacht, Germany.



Treatment of reactive dyes and textile finishing wastewater

Researchers at the University of Salerno, Italy, have investigated the efficacy of treating reactive dyes and textile finishing wastewater using Fentons oxidation (FO). FO was used to decolourize and degrade some reactive dyes (Remazol Black 5, Remazol Red, Remazol Blue, Remazol Yellow) and raw textile finishing industry effluents (S1, S2, S3) containing mainly reactive dyes. The operational conditions for pH varied from 2.5 to 4.0 while temperature ranged from 30 to 50C. The concentrations of FeSO4 and H2O2 varied in a wide range (200-600 mg/l of FeSO4, 300-1,000 mg/l of H2O2) depending on the type of dyes and their mixture and textile additives used in the process.

Results have exhibited that FO is highly effective for colour removal (>99 per cent) of reactive dyes and (87-94 per cent) textile finishing wastewater. It can be applied as a pretreatment and the remaining total dissolved solids (TDS) removed by an additional advanced process, e.g. membrane process.

Contact: Mr. Sureyya Meric, Department of Civil Engineering, Salerno University, Fisciano 84084 (SA), Italy.


High-efficiency treatment for food industry wastewater

EcoDays Co. Ltd., the Republic of Korea, has devised a high-efficiency aerobic bioreactor (ER-1), which is a multi-stage reactor using air-holdup, to treat wastewater produced in the food industry. ER-1 integrates the strengths of continuously stirred tank reactor (CSTR) and plug flow reactor (PFR).

The new reactor, with its unique structure securing space for gas retention in each stage of the reactor, has the flow of modified-PFR type. The bioreactor can achieve optimal condition for particle transfer and/or dissemination (dissolution, air-stripping) since modified-PFR flow converts itself into CSTR flow for each individual stage of the reactor but maintains PFR flow for the overall stage of the reactor.
Specifically, high particle transfer speed could be maintained from maximized translational speed of the wastewater by relative speed of fluids in each stage of the reactor. High particle transfer speed leads fluid to perform various functions (e.g. fluid flow, mixture, re-aeration on water surface), and high MLVSS concentration, dissolved oxygen concentration and pollutant density are simultaneously maintained at the bottom part of the reactor. Thus, stable treatment is feasible even for high-concentration organic wastewater (wastewater from food waste, livestock effluent, sewage sludge) with organic matters, persistent
matters, various pollution sources, solids, and nitrogen and phosphorus of high concentration.


SBR for industrial wastewater treatment

In France, researchers at Veolia Water have developed a process for treating industrial wastewater. The team has reported that aerobic granulation is an attractive process for COD removal from industrial
wastewater, characterized by a high content of soluble organic elements.

Comparative experimental tests were performed on synthetic and industrial wastewater, originating from the pharmaceutical industry. Two pilot plants were operated as sequencing batch bubble columns. More emphasis was placed on the feasibility of the process for high COD removal and its operational procedure. For both wastewater, a rapid formation of aerobic granules was observed along with a high COD removal rate. Granule traits were quite similar with respect to the two types of wastewater. For both wastewater, similar removal performances for dissolved biodegradable COD were observed (>95 per cent). However, a relatively high concentration of suspended solids in the outlet deteriorates performance with regard to complete COD removal. Biomass detachment seemed to play a non-negligible role in the current set-up. After a stable operational phase, variation of pharmaceutical wastewater caused destabilization and loss of granules, despite the control for balanced nutrient supply.

Initial results with real industrial wastewater exhibited the feasibility of this innovative process. However, special attention has to be paid to critical aspects like granule stability and economic competitiveness, both of which need further investigation and evaluation.


Treating nanosized TiO2-containing wastewater

In Taiwan, scientists at the National Sun Yat-Sen University investigated a simultaneous electrocoagulation/electrofiltration (EC/EF) treatment module employed to treat nanosized TiO2-containing wastewater. Nanosized TiO2-containing wastewater was obtained and treated by a self-designed EC/EF treatment module. To evaluate the performance of this novel treatment module, the effects of electric field strength (EFS), transmembrane pressure (TMP) and also cross-flow velocity (CV) on the permeate qualities were studied. Permeate qualities of concern were pH, turbidity, conductivity, chemical oxygen demand (COD) and total organic carbon (TOC).

A full factorial design of experiments was adopted in this study. First, by keeping TMP and CV constant, the effects of EFS on permeate qualities were analysed. In this set of testing, it was noticed that application of electric field greatly increased the filtration rate, which was further
influenced by the magnitude of EFS. In all cases, filtration rate reduced as the treatment time elapsed due mainly to fouling of the membrane. Further trials were conducted to understand the effects of TMP on permeate qualities by keeping EFS and CV constant. Finally, the effects of CV on permeate qualities were assessed by maintaining constant EFS and TMP.

It was observed that the optimal operating conditions would be an electric field strength of 166.7 V/cm, transmembrane pressure of 1 kgf/cm2 and cross-flow velocity of 0.22 cm/s. Under such conditions, permeate would have the following qualities pH of 6.32, turbidity of 2.41 NTU, a conductivity of 15.11 S/cm, COD of 100.0 mg/l and TOC of 512.6 mg/l.


Treating wastewater in thermal power plants

In Japan, Kansai Electric Power Co. Ltd. offers technology for treating wastewater generated in thermal power generation facilities. In thermal power plants, wastewater from all equipment is collected at one place and subjected to treatment by high-performance oil separator and coagulating sedimentation. When
wastewater is known to contain oil, it is sent to high-performance oil separators like the Parallel Plate Interceptor (PPI) and Corrugated Plate Interceptor (CPI). With the oil separated there, water is passed subsequently through a number of filters comprising sand, oil adsorbent and active carbon, so as to remove trace amounts of oil, suspended solids and so on.

Wastewater from the water purifier as well as from the flue gas desulphurizing facility are temporarily held in storage tanks. These are treated in a neutralizing system, coagulating and sedimentation unit to neutralize acids and alkali, and to remove suspended solids and soluble iron.

Contact: Environmental Engineering Group, Kansai Electric Power Co. Inc., Office of Environmental Considerations, 6-16, Nakanoshima, 3-chome, Kita-ku, Osaka 530 8270, Japan. Tel: +81 (6) 6441 8821; Fax: +81 (6) 6441 3549



Oxidation of dye wastewater with gas diffusion cathode

The exorbitant energy costs of an electrochemical method is a major drawback that hinders its large-scale application in wastewater treatment. In a single-chamber electrolysis cell, only direct oxidation at an anode exists. Although a small amount of hydrogen peroxide is produced at the cathode by reduction, it is then transferred to the anode where it is destroyed without providing much benefit to organic decomposition.

A new two-chamber electrolytic cell, connected with an electrolyte bridge, has been developed in China by scientists at Shanghai Jiaotong University. In this reactor, direct oxidation at the anode and indirect oxidation by hydrogen peroxide at cathode can occur simultaneously. As such, dual electrodes oxidation in one electrochemical reactor is achieved. Compared with traditional single cell reactor, this reactor lowers energy costs by 50 per cent and thus might lead to reconsideration of the electrochemical role in wastewater treatment. A Pt/C gas diffusion electrode (GDE) is fabricated and used as a cathode fed with oxygen-containing gases to manufacture hydrogen peroxide. When purified air diffuses through the active layer on the GDE, oxygen is reduced to hydrogen peroxide with a high yield to decompose organics.

Tests have demonstrated that the direct oxidation procedure at an anodic zone is slightly affected by factors such as pH variation, Fe(II) existence and aeration, while indirect oxidation at the cathodic zone is strongly affected. Dye used as a model pollutant was oxidized into small organic acids at both anode and cathode in the electrolytic reactor. GC-MS and IR spectrum were employed to analyse intermediates formed during degradation. Twenty intermediates have been detected, including 14 esters, three acids and three compounds with NO2 or N-OH groups.

Contact: Mr. Zhemin Shen, School of Environmental Science and Engineering, Shanghai Jiaotong University, Dongchuan Rd. 800, Shanghai 200240, China.


Low-cost solution removes colour from wastewater

At Moi University, Prof. Lazano Etiegni has invented and patented a process for tackling waste and industrial effluent. A crucial feature of the method relates to an invention that holds the key to the removal of colour in wastewater, something that has proved to be expensive using conventional techniques. The new process employs electrocoagulation, which has a low power consumption rate, to lower toxicity. It involves mixing coloured wastewater with ash (from wood, coffee husks and leaves) and electrolysing the resulting solution. Tests have shown that the effluent coagulates while the colour disappears within seconds, all this requires only a little amount of electricity. Coagulated matter is allowed to settle at the bottom, before it is drained off.


Treating wastewater from food plants

Matsushita Environmental and Air-conditioning Eng. Co. Ltd., Japan, offers equipment for processing up to 480 m3/d of wastewater generated in potable water production processes. Solids are removed from wastewater having a BOD/COD concentration of about 800 ppm. The volume and quality of wastewater are then regulated in a flow regulating tank at a later stage, while pH of the wastewater is regulated in the neutralizing tank. BOD is removed by biological treatment and the wastewater is treated by a high-grade system utilizing catalytic oxidation. In the final treatment, COD is removed by sand-filtering and active carbon to obtain high-grade treated water.

The treatment procedure involves utilization of prolonged aeration, catalytic oxidation, sand filtering and active carbon methods. Biological treatment component includes an activated sludge system that uses prolonged aeration and a biological membrane unit based on catalytic oxidation for efficient BOD removal.

Contact: Environmental Equipment Engineering Business Unit, The Matsushita Environmental and Air-conditioning Eng. Co. Ltd., 3-28-33, Tarumi-cho, Suita-shi, Osaka, Japan. Tel: +81 (6) 6310 7752; Fax: +81 (6) 6310 7750




Wastewater treatment in electrogalvanizing process

Wastewater discharged from plating processes is broadly classified into continuous wastewater that is discharged continuously and renewal wastewater that is generated when the tanks contents are changed. Matsushita Environmental and Air-conditioning Eng. Co. Ltd., Japan, is offering processing equipment to separate wastewater from the electrogalvanizing industry into chrome wastewater and acidic/alkaline wastewater for collection.

A water tank is provided for the renewal liquid so that wastewater with as stable a quality as possible can be conveyed for the treatment procedure and fixed quantities of wastewater sent to continuous wastewater processes. The equipment, which is based on coagulating sedimentation technology, easily handles up to 64 m3/d of wastewater. In the case of acidic/alkaline wastewater, the pH is regulated to about 9-10.5 in the neutralizing tank and coagulated with Zn extracted. After separation and sedimentation, the pH is regulated again prior to discharging the wastewater.

Chrome containing wastewater is treated by regulating the pH to about 2.5 in the chromium pH regulating tank. After mixing with continuous wastewater, wastewater is then coagulated. Following separation and sedimentation, pH is regulated again before the wastewater is discharged.

Contact: Environmental Equipment Engineering Business Unit, Matsushita Environmental and Air-conditioning Eng. Co. Ltd., 3-28-33, Tarumi-cho, Suita-shi, Osaka, Japan. Tel: +81 (6) 6310 7752; Fax: +81 (6) 6310 7750




Chromium recovery from tannery

Researchers in Iran have studied various processes for the removal and recovery of chromium (III) from tannery wastewater. Analytical reagent grade solutions of lime, NaOH 15 per cent and magnesium oxide (MgO) 10 per cent were utilized in the tests. The team concluded that the optimum pH for precipitating chromium from tannery wastewater is 8-9 and good sludge with high settling rate and low volume is obtained when MgO is used as the precipitating agent. MgO is reported to be much more desirable than lime and NaOH to remove and recover chromium from tannery wastewater.

Contact: Mr. Abass Esmaeili, Dept. of Social Medicine, The Rafsanjan University of Medical Sciences, Rajsanjan, Iran. Tel: +98 (391) 5234 003-5; Fax: +98 (391) 5225 209.



Bioremediating pentachlorophenol

In New Zealand, a team of scientists studied white-rot bioremediation of aged PCP-contaminated soil, from a former timber treatment site, in engineered soil cells to develop proof-of-concept biopiles. The study examined the ability of a white-rot fungus isolate, Trametes versicolor, on PCP degradation, and the effect of fungal inoculum concentration on PCP degradation and reproducibility of the experiments. The soil cells were constructed to allow for forced aeration, irrigation, leachate accrual, and temperature and soil humidity monitoring. The need for irrigation did not arise and there was no proof of leachate. PCP degradation and fungal survival were monitored at regular intervals for 2.5 years. PCP levels decreased from a range of 800-1,000 mg/kg to 0-9.4 mg/kg according to first-order kinetics.


Acid mine drainage treatment system

Linden AMD Bioremediation project is an experimental passive treatment alternative with potential for low
maintenance, high metals reduction and the generation of alkalinity. The system comprises a big limestone-filled bed that has been inoculated with micro-organisms cultured using the Pyrolusite process developed by Allegheny Mineral Abatement Co. (AMA), the United States. This patented process employs highly selected groups of aerobic micro-organisms that grow on limestone while oxidizing iron and manganese into insoluble metal oxides.

The bioremediation process consists of several separate but interrelated systems. Mine drainage passes sequentially through a flow control system, a wetland to lower metals concentrations and provide microbial nutrients and finally through an inoculated limestone treatment bed and/or attendant discharge fixtures and diversion ditches, before being discharged to a receiving stream.


Treating polluted soil/sediment

Adventus Remediation Technologies Inc., Canada, is offering a patented bioremediation technology that uses matrix-specific solid-phase organic amendments to beneficially alter the soil or sediment structure, nutrient profile and water-holding capacity. Following homogenous distribution through the soil or sediment, DaramendTM particles become hydrated and function as aquatic microsites where native micro-organisms can grow, contact contaminants and degrade them. This allows the soil or sediment to be bioremediated more rapidly and thoroughly than would otherwise be possible.

Daramend is designed to enable rapid bioremediation of sediments or soils with high concentrations of creosote, pentachlorophenol (PCP), polycyclic aromatic hydrocarbons (PAHs), heavy oils and petroleum hydrocarbons. Daramend products are matrix-particular solid phase organic particles that are produced from natural botanical materials. Prior to field-scale treatment, the technology is optimized in the lab. Parameters that are optimized are the size, shape, nutrient content, nutrient-release kinetics as well as application rate of the

Daramend particles, running and maintenance conditions like soil water content and aeration status.
Daramend products allow for the treatment of soils with very high PCP concentrations (e.g. 2,000 mg/kg). Large quantities (>10,000 t) of soil or dewatered sediment can be treated at less than US$100/t, which compares favourably with costs of up to US$1,500/t for some alternate methods. Results have shown that after the application of Daramend, degradation of the contaminants carries on even after stoppage of active care.

Contact: Adventus Remediation Technologies Inc., 1345 Fewster Drive, Mississauga, Ontario, L4W 2A5, Canada. Tel: +1 (905) 2735 374; Fax: +1 (905) 2734 367




On-site treatment of sediment

National Water Research Institute, Canada, offers an on-site process for the remediation of contaminated aquatic and marine sediments. Limnofix in situ sediment treatment (LIST) utilizes specially designed equipment for injecting chemicals directly into polluted sediments, thereby enhancing bacterial activity and hence contaminant degradation. The process involves three stages:
  • An investigation to determine the type and concentration of chemicals essential to treat the site pollutants. This is done through bench-scale and pilot-scale tests;
  • A material handling system to prepare the chemical mixtures and deliver them to the injection site; and
  • Patented injection equipment to directly inject treatment chemicals into surface sediments.

Contact: Mr. Tom Murphy, National Water Research Institute (NWRI), 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6, Canada. Tel/Fax: +1 (905) 3196 900/3368 901




UV light helps recover mercury

In the United States, researchers at the National Energy Technology Laboratory (NETL) have developed new technology based on ultraviolet (UV) light to help reclaim mercury from coal-fired power plants. In the photochemical oxidation (PCO) unit, the flue gas stream is irradiated with UV light at 253.7 nm to oxidize elemental mercury into mercuric oxide, mercurous sulphate and
mercurous chloride. Initial results have exhibited that the technology can remove 90 per cent of elemental mercury from simulated flue gas streams, converting it to the oxidized form that can be removed by existing equipment.

The process can easily conform with the most stringent standards that could be proposed for toxic metal. The technology has been licensed to Powerspan Corp.


NOx and SO2 removalNOx and SO2 removal

Cansolv Technologies Inc., Canada, has developed a new method and apparatus to enable the removal of nitrogen oxides (NOx) and sulphur dioxide (SO2). NO is removed from a gas stream by reacting it with an absorbent to form a metal nitrosyl complex. This complex is reacted with sulphite and/or bisulphite to yield recoverable reaction products containing nitrogen and/or sulphur and to regenerate the reagent. The recoverable reaction products are then isolated from the regenerated agent.


Material that soaks up gas

Researchers at the Tokyo University of Agriculture and Technology in Japan have developed an innovative material that efficiently absorbs carbon dioxide (CO2) from thermal energy facility gas emissions. The material is fabricated using lithium silicate particles 3 m across, which have been solidified into granule some 600 m in diameter and coated with aluminium oxide particles of 30 m in diameter.

Lithium silicate easily absorbs CO2 at temperatures of 500C and discharges it at about 800C. As such, it is possible to remove CO2 from the exhaust streams of coal or oil-powered energy production plants if the emissions are cooled slightly and passed through a container filled with the lithium silicate granules. The granules can be reused after heating to release the absorbed CO2. As CO2 concentrations in the discharged gas are as high as 90 per cent, it is easier to dispose of CO2 by burying it in landfills or by dissolving it using sea water. The aluminium oxide surface prevents the granules from becoming sticky even after absorbing CO2, making it easy to move within a plant.


Gas scrubber

X-Tronix AG, Switzerland, offers a fully automatic scrubber to treat toxic gas emissions. Epigress gas scrubber employs combustion in a hydrogen flame as the technique. Capable of achieving 99.99999 per cent efficiency, the scrubber can be controlled using the Epigress process operator interface or a separate control panel. The cost of operation is minimal as there are no consumables or handling of canisters with dry absorbents or toxic waste disposal. Hydrides are oxidized in the hydrogen flame. Waste from the scrubber is water with dissolved oxides. The amount of water depends on the operating conditions.

Hydrogen is supplied by the carrier gas utilized in the process. A fan installed in the cabinet supplies air to the burner. Tuning of the air/hydrogen mixture is achieved by reading the value from the included hydrogen detector, placed in the outlet and manual adjustment of the air flow. The burner has an automatic control with UV flame detector. An alarm network is installed to direct the active gas to a filter in case of malfunction of the burner.

The burner geometry is optimized to offer highly efficient combustion of hydrides (silane, arsine and phosphine). The output is further diluted by cabinet ventilation.

Contact: X-Tronix AG, Corporate Headquarters, Zugerstr. 15/Postfach 168, 6330 Cham, Switzerland. Tel: +41 (41) 7416 320.


Equipment to process waste gases

Central Engineering Co. Ltd., Japan, offers Chemiclean-Z series waste gas processing equipment based on heat plasma, which has been developed for abatement of toxic gases and PFC gases drained from semiconductor and liquid crystal factories. These units allow for the abatement of inflammable gases (e.g. SiH4, NF3, WF6, PFC gases, etc.) and combustion-supporting gases that drain from semiconductor production equipment.

Contact: Central Engineering Co. Ltd., 5727-4 Oaza Okiube, Ube, Yamaguchi 755 0001, Japan.



Wet packed scrubber

Seikow Chemical Engineering and Machinery Ltd., Japan, offers TRS series of scrubbers for processing low concentration exhaust gases. These units allow for energy savings while requiring least maintenance. Key features include:
  • With a natural, drop water spray system, low pump heat pressure suffices and blockages in the water spray pipes are minimized
  • Low static pressure loss allows processing of large volumes
  • The FRP gel coat finish provides the scrubber a pleasing appearance and superior strength; and
  • A compact size saves on space and energy.
    The scrubbers can be employed to process general toxic gases, lab gases produced in the production processes of semiconductors, etc.

Contact: Seikow Chemical Eng. and Machinery Ltd., 1-331, Mizudo-cho, 4-chome, Amagasaki, Hyogo 661 0026, Japan. Tel: +81 (6) 6438 0481; Fax: +81 (6) 6436 1126


Dry flue gas desulphurization

Ducon Technologies Inc., the United States, is offering semi-dry removal (SDR) dry flue gas desulphurization (FGD) equipment as well as dry injection type units. Models in the SDR range are custom designed to absorb gaseous pollutants using a spray dryer and a baghouse filter. The companys specially designed air atomizing nozzles provide the liquid reagent slurry into the spray dryer for high efficiency removal of sulphur dioxide (SO2), HCl, Hg and other hazardous constituents from flue gases.

The dry injection systems utilize lime, trona, activated carbon and other dry reagents to remove SO2, dioxins, Hg, HCl and fumes. The reagent is added in a recirculating type reactor with steam injection for higher absorption. The particulate is then recovered downstream using a bag house filter. These systems can achieve over 90 per cent SO2 removal efficiencies. Ducon dry scrubber generates a dry waste
product that can be disposed of easily with conventional fly-ash handling equipment.

Contact: Ducon Technologies Inc., 19, Engineers Lane, Farmingdale, NY 11735, the United States. Tel: +1 (631) 6941 700; Fax: +1 (631) 4204 985.


Flue gas desulphurization

Chiyoda Corp., Japan, is offering Chiyoda Thoroughbred 121 (CT-121) flue gas desulphurization (FGD)
process that offers ideal conditions for SO2 absorption in flue gas from coal-fired boiler, oil-fired boiler and so on, and for fixation of the removed SO2 from flue gas as gypsum. CT-121 process is an adaptation of Wet Limestone flue gas desulphurization process. The central feature of the CT-121 process is Chiyodas unique absorber, the Jet Bubbling Reactor (JBR), in which the flue gas is blown into water forming a fine bubble bed where SO2 is absorbed, oxidized by injected air and then neutralized by ground limestone slurry. Basically, CT-121 process has the following three main parts:
  • Absorption, oxidation, neutralization and crystallization
  • Limestone slurry preparation
    unit; and
  • Gypsum dewatering unit.

The CT-121 FGD process ensures efficient SO2 removal while lowering .power consumption, owing to a large gas-liquid interfacial area. Also, high particulate removal can be achieved.

Contact: Chiyoda Corp., Energy and Environmental Project Dept., Japan. Tel: +81 (45) 4411 841; Fax: +81 (45) 4411 859



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