VATIS Update Waste Management . Jan-Feb 2006

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Waste Management Jan-Feb 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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Low-cost solution to track POPs globally

Research undertaken by Ms. Karla Pozo of Environment Canada has revealed that low-cost passive air samplers could be used to ensure compliance with the United Nations pact on persistent organic pollutants (POPs). Pilot testing for the study involved 50 sites on all the seven continents. Results from the first three months of testing for PCBs and organochlorine pesticides with polyurethane foam (PUF) samplers at 29 sites reveal that PCB levels vary from 2 to 1,000 pg/m3, with the highest in urban areas of Turkey and the Philippines. Chlordane levels were low overall, with the exception of the Philippines. Chlordane and PCBs are among the 12 chemicals covered by the POPs treaty.

Some of the most noteworthy data collected so far were for pesticides that are not yet on the list of banned chemicals, reports Ms. Pozos team. For example, of all the pesticides analysed, levels of Endosulphan I varied most widely. Highest levels were recorded in rural Argentina (11,200 pg/m3) and Canary Islands (4,700 pg/m3). The levels of gamma hexachlorohexane, included in the pesticide lindane, were elevated in rural Finland (114 pg/m3), where the compound has been banned since 1988. South Africa also registered high levels of gHCH (74 pg/m3).


Regional accord aims at sound recycling society

A joint declaration by environment officials from China, the Republic of Korea and Japan seeks to build a sound material-cycle society in Northeast Asia. This goal is deemed to be crucial to achieve sustainable development in the region. The statement was released at the end of the 7th Tripartite Environment Ministers Meeting (TEMM) held in Seoul. The three ministers concurred that the three countries take turns holding joint seminars/workshops on sound material-cycle society and circular economy and 3R (waste reduction, recycle and reuse) activities for the next three years as important TEMM activities to strengthen trilateral cooperation on this issue, the statement said. Officials also welcomed the Kyoto Protocol, evaluating its enforcement as a first step towards achieving the ultimate objective of the United Nations Framework Convention on Climate Change.


Indian state cracks whip on hospitals

The government of the Indian state of Uttar Pradesh has embarked on a strict drive to ensure that private nursing homes and hospitals make proper arrangements for disposing medical wastes. The government had to initiate this measure following reports of large-scale recycling of untreated medical waste. According to Environment Minister Mr. Ujjwal Raman Singh, the government has fixed 10 parameters to dispose off biomedical wastes and stipulated guidelines for hospitals to comply with. The government also mooted the idea of common treatment plants in several cities set up by private nursing home owners, he said.

According to a recent World Bank report, an average of 20.7 t/d of biomedical wastes is generated in the state. A World Health Organization study has shown that of the total biomedical wastes, about 85 per cent is non-infectious, 10 per cent infectious but non-hazardous, and 5 per cent both infectious as well as hazardous in nature. The report also stated that of the 1,624 hospitals identified in the state, only 344 (about 21 per cent) either own or use common incineration facilities for disposal of biomedical wastes.


Wastewater project in the Philippines

Manila Water Company Inc., the Philippines, has launched a US$85 million dollar wastewater project that is expected to serve about 3.3 million people within its concession area in eastern Metropolitan Manila by the year 2010. The company will finance the Manila Third Sewerage Project (MTSP) through a US$64 million loan obtained from the World Bank through the state-owned Land Bank of the Philippines, plus US$21 million in direct equity.

MTSP is believed to be the biggest wastewater project in the country. This project is intended to increase sewerage coverage and sanitation services in the eastern portion of Metropolitan Manila to 30 per cent from the current 10 per cent over the next five years. Manila Water, a unit of Ayala Corporation, supplies potable water to about 5 million residents under a 25-year concession agreement with the government.


Private sector in Sri Lanka takes lead in waste recycling

In Sri Lanka, efforts initiated by the government and its agencies for recycling wastes have not been up to the desired level. On the other hand, the private sector, which plays a leading role in the economy, is learning to cut down on wastes. Cleaner Production, an international organization, is helping the private sector in its endeavour. While many companies are striving to recycle wastes, a few are coming up with useful ways to dispose them.

Lion Brewery Ceylon Ltd. converts waste yeast sludge generated at its factory into a feed supplement for animals. According to Dr. K. Chad Kanagachandran, Special Projects Manager at Lion Brewery Ltd., tests have shown that the supplementary animal food has high protein content (40-50 per cent) and is rich in vitamin B and minerals. Also, spent grain from the brewery has a ready market as animal feed and each day about 20 t are sold. Furthermore, wastewater generated at the factory is purified at two large treatment plants and a part of the treated water is used to irrigate the garden on the factory premises and the balance discharged into the river. Even the sludge obtained after wastewater purification can be sold for use as a fertilizer.


Philippine hazardous waste treatment plant

In the Philippines, the Department of Environment and Natural Resources (DENR) reports to have identified a financier to provide a loan as the governments counterpart fund for a hazardous waste treatment plant in Batangas. Mr. Angelico Salud, President of the Natural Resources Development Corp. (NRDC), said the Development Bank of the Philippines is considering DENRs loan application. NRDC may look to two other financial institutions in case things do not work out with the Development Bank of the Philippines.

Mr. Salud informed that the Japan International Cooperation Agency, involved in the construction of the plant, is updating a 2001 study on the project. The project, which will be located on a 10 ha property in Malvar, Batangas, is the first of its kind in the country. According to the environment department, with the completion of the plant, major industries could do away with the practice of shipping wastes abroad for treatment.


Germany to fund Viet Nams wastewater projects

Viet Nams Ministry of Finance and the German Reconstruction Bank (KfW) have entered into two financial agreements for a similar number of projects on water treatment and healthcare. About US$6.75 million has been earmarked for a project aimed at improving the wastewater treatment system in the southern province of Tra Vinh. The remaining US$12.27 million, of which US$1.84 million is non-refundable aid, is for a programme on family planning. To date, the German government has committed about US$28.21 million for wastewater treatment projects in five cities and provinces in Viet Nam. Since 1995, Germany has provided US$55.20 million for family planning projects. Viet Nam has so far received US$515.34 million in ODA loans and non-refundable aid from the German government.


Thailand and the Philippines staring at e-waste problems

Greenpeace has warned Thailand and the Philippines of an imminent electronic waste crisis. According to a new report Toxic Tech: Pulling the Plug on Dirty Electronics in Southeast Asia, the hassle is intensified by the lack of international legal protection since both countries have not ratified the Basel Convention, which bans industrialized countries from dumping hazardous materials in the third world. Also, the booming usage of electronic and electrical goods particularly PCs and cell phones in these countries has created a corresponding explosion in electronic scrap containing heavy metals and toxic constituents. The report details as to how the growing volume of e-waste is affecting the region and the environmental and health consequences from toxic electronic components to which its workers are being exposed to.

Greenpeace is campaigning for the major mobile phone and computer companies worldwide to clean up their act. Companies like Samsung, Nokia, LG Electronics, Sony and Sony Ericsson have pledged to do away with the use of toxic chemicals such as PVC and brominated flame retardants in their products. Latest to join this list is Motorola. However, other companies like IBM/Lenovo, Dell, HP, Siemens, Acer, Toshiba, Panasonic, Fujitsu-Siemens and Apple have, so far, failed to commit.

Contact: Mr. B. Baconguis, Toxics Campaigner, the Philippines. Tel: +63 (917) 8036 077; Or Mr. Kittikhun Kittiaram, Thailand. Tel: +66 (1) 3721 149; Or Mr. Arthur Dionio, Thailand. Tel: +66 (1) 9254 835.


Biological entity to remove arsenic

In China, a programme involving so-called hyper-accumulators, poison accumulating plants, aims to suck out poisonous arsenic from the soil. A team led by Mr. Chen Tongbin, well known for their technology in collecting arsenic from soil, has uncovered more than a dozen hyper-accumulators. At present, Pteris vittata L., a brake fern widely found in southern China, has been planted at three sites in Hunan, Zhejiang and Guangdong provinces. Pteris vittata is estimated to remove 10 per cent of arsenic in a year. About 20 per cent of farmlands in China is estimated to be polluted by heavy metals, causing 10 million tonnes of crop losses annually.


India decides to ratify POPs treaty

The Indian union cabinet is set to ratify and accede to the Stockholm Convention on Persistent Organic Pollutants (POPs). This decision will enable India to be a part of the first-ever concerted global effort to save humans from the adverse impact of POPs. As such, India will be eligible for technical and financial aid for implementing measures to meet the treatys obligations. The treaty aims to eliminate or restrict the use and production of all intentionally produced POPs. Chemicals slated for elimination include aldrin, chlordane, dieldrin, endrin, heptachlor, hexachlorobenzene, polychlorinated biphenyls (PCBs), toxaphene and mirex. Countries are required to make efforts to identify, label and remove PCB-containing equipment by the year 2025, and manage the wastes in an environmentally sound manner, not later than 2028. Each party is required to develop a plan for carrying out its obligations.


Pollution control gains momentum

The Communist Party of China has called for more efforts to prevent and control pollution. The Proposal for Formulating the 11th Five Year Programme (2006-10) for the National Economic and Social Development, recommends that local governments at all levels should initiate effective measures to decrease discharge of pollutants. Efforts in safeguarding the sources of potable water must be intensified, says the document. It stresses on the comprehensive treatment of the urban environment by strengthening control of industrial pollution, raising sulphur dioxide treatment produced by power facilities, reducing greenhouse gases and proper disposal of urban garbage and toxic wastes. In addition, the environmental monitoring and supervision system should be improved while strengthening all the relevant laws and their enforcement.


Chinese efforts to control POPs

Mr. Zhang Lijun, Deputy Director of the State Environmental Protection Administration (SEPA) of China, has stated that the nations efforts to implement the international treaty on Persistent Organic Pollutants (POPs) would be strengthened. Mr. Lijun stated that even in the face of tough challenges, China adopted a series of measures to phase out and control existing POPs and prevent pollution through production of new POPs. Commendable results have been achieved through efforts that targeted supervised production, circulation, storage and disposal of these toxic chemicals, and through research conducted to map out a strategic programme to control POP.

China has set up a national work group to coordinate the countrys efforts to implement the Stockholm Convention. The onus will be on this group for examining policies, laws, standards and regulations governing POPs control in the country. Mr. Lijun appreciated the international community for its support, pledging that the Chinese government would work more closely with other nations as well as international institutions for better implementation of the pact.


Korea plans to halve sewage discharged to sea by 2011

According to the Ministry of Maritime Affairs Fisheries, Republic of Korea, a telemetering system (TMS) will be installed by 2007 for enterprises discharging effluents, in order to prevent dumping-related accidents. Testers will be established in 2,443 workplaces associated with wastewater and will be connected to a control centre to be set up at the Environmental Management Corp. (EMC) for surveillance. According to the Ministry, this step would allow for the management of about 86.7 per cent of the total effluent generated each year.

Testers will be set up at factories and workplaces for the TMS to make it possible to check and gauge a variety of hazardous components. Testers will vary according to the workplace and ingredients in the effluent discharged. The government plans to extend up to US$200,000 in financial support to companies installing testers. If companies are found to have discharged hazardous effluent more than allowed, a penalty will be levied or technical aid provided by EMC, depending on the cause. The Ministry is also planning to crack down on those who illegally dump waste into the sea. Aircrafts and patrol ships will watch Korean coastline to prevent such dumping, while mapping out steps to support fishermen suffering from the effects of waste being dumped. The Ministry will also work with the Korean Food and Drug Administration to check contamination of food products from those areas.



Products from automotive wastes

Shredder residue (SR) or fluff, left behind after metallic constituents have been extracted from discarded automobiles, can yield economically valuable products. Polyurethane foams and rubber constitute the major portion of this SR. Changing World Technologies in the United States has transformed two different SR mixtures into a variety of products, including light hydrocarbon oil. The SR mixtures differed in both their composition of solids and moisture content. The bench-scale reactor is capable of operating at pressures above 138 atm and over 900C.

In SR #1, the polymers constituting rubber and plastics were converted mostly into hydrocarbon oil similar to diesel, with a small fraction going to the second stage gas. The first stage gas was primarily carbon dioxide while the second stage was rich in hydrocarbons and supported combustion. The latter had a heating value approximately 80 per cent that of natural gas. Hydrocarbon oil yield was 41.9 per cent of the total input mass or 65 per cent of the initial weight of solids. Less than 20 per cent of solids went into the carbon matrix. For SR #2, which had more water, oil yield was 29.8 per cent of overall mass, or 52.7 per cent of the initial solid matter. The carbon matrix yield was 32 per cent of the solids. The two samples of fuel gas were quite similar, as were the diesel oil obtained.


Polymers yield fuel

Ozmo Energy Ltd., Hungary, has developed a system for obtaining energy from waste plastics. In this plant, waste plastics are loaded into a pyrolysis chamber and converted into pyrolysis gas. The gas is then passed through a patented catalytic converter and transformed into a distillate fraction by the catalytic cracking process. Next, the distillate is sent to the recovery tank after cooling in a condenser. From the recovery tank, the product is sent to a centrifuge to isolate pollutants like water or carbon.

Cleaned distillate is later pumped to the reserve tank where a small quantity is drawn off as fuel for the system itself. The remaining product is pumped into the storage tanks. Recovery ratio and characteristics of the product distillate depends on the types of plastic or decomposing temperature. Approximately 950 ml of oil can be recovered from 1 kg of plastics such as olefins, including polyethylene and polypropylene or polystyrene.
Generally, input feedstock plastics do not require washing or sorting. The fully computer-controlled plant operates under normal pressure and has numerous safety features built in as part of the design.

Contact: OZMO Energy Ltd., H-1125 Budapest, Mtys kirly t 23., Hungary. Tel/Fax: +36 (1) 3917 490/491



New plant to recycle carton packagings

Alcoa has stated that its Brazilian affiliate, Alcoa Aluminio, has teamed up with Tetra Pak, Klabin and TSL Ambiental to launch the worlds first carton packagings recycling facility at Piracicaba, Brazil. The new plant employs ground-breaking plasma technology, which allows for total separation of aluminium and plastic components from the cartons. This process constitutes a significant enhancement to current recycling methods, which, up to now, removed paper but kept aluminium and plastic together. The new technique allows for the return of all three components of the package to the productive chain as raw material.

The plasma technology employs electrical energy to produce a jet of plasma at 15,000C to heat the plastic and aluminium mixture. As such, plastic gets transformed into paraffin while aluminium is recovered as high-purity ingot.

Contact: Alcoa Corporate Centre, 201, Isabella St., Pittsburgh, PA 15212 5858, United States of America. Tel: +1 (412) 5534 545; Fax: +1 (412) 5534 498.


Profit from recycling automotive plastics

Researchers at Argonne National Laboratory, the United States, are developing a new technology that allows for successful reclamation of plastics from used automobiles. According to the Director of Energy Systems Division, Mr. Ed Daniels, about 75 per cent of the weight of an obsolete car is presently recycled profitably. Current investigations at Argonne is focused on mechanical recycling recovery of materials like plastics from shredder residue for reuse in automotive and other applications.

Argonnes technology involves two major processes. The first is a bulk separation technique to segregate shredder residue into constituent fractions, followed by the second method that recovers specific plastics from a polymer concentrate. A large-scale pilot plant designed and installed at Argonne processes 1 tph of shredder residue. One-third of the shredder residue the plastic-intensive part is recovered as a polymer concentrate. High-quality plastic is then reclaimed from this concentrate by using a wet density/froth floatation process.

Contact: Energy Systems Division, Argonne National Laboratory, 9700 South Cass Ave., Building 36, Argonne, IL 60439 4844, United States of America. Tel: +1 (630) 2526 230; Fax: +1 (630) 2525 132



Fuel gas obtained from plastic wastes

In Japan, a team of researchers from the National Institute of Advanced Industrial Science and Technology, and the Polymer Decomposition Laboratory Inc. have successfully converted waste plastics into fuel gas. The thermal process allows for improved economics in recycling waste plastics. Considering the role of sand as a heating medium and by using a reactor structure for suitably controlling the reaction time and temperature, a new type of reactor was developed. The moving-bed reactor is fitted with a screw conveyor. Formation of gaseous hydrocarbons was achieved at 82 wt% (pyrolysis) and 94 wt% (catalysis) using polypropylene as the feed.

The plant comprises a feed hopper, tubular reactor with screw conveyor, electric heater and an oil/residue receiver. The rotation rate of the screw conveyor is controlled by an inverter motor. The tubular reactor is made of stainless steel. Internal diameter and length of the tubular reactor are 70 mm and 1,200 mm, respectively.

Contact: The National Institute of Advanced Industrial
Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan; Or The Polymer Decomposition Laboratory Inc., 2-12-7 Aoshima, Miyazaki City, Miyazaki 889-2162, Japan.


Automated sorting

SINTEF, Norway, has developed a machine to sort drink cartons and plastic bottles. Based on infrared spectroscopy, the new system uses ordinary halogen lamps as the light source. A computer differentiates between plastic-coated cardboard, ordinary cardboard and the various kinds of plastic by small variations in the colour of the reflected infrared light.

Reflections at various infrared wavelengths are recorded continuously as the waste crosses a transverse sensing line of the conveyor belt. The data are passed to a computer, which analyses the readings and constructs a two-dimensional image of the debris. Based on this analysis, the computer identifies the location of the desired element in the waste on the conveyor and directs jets of pressurized air, e.g. to blow beverage cartons into a container while the rest of the waste proceeds on to another conveyor. The system sorts any combination of domestic waste plastic and beverage cartons. The largest machine can handle 10 t/h of waste on a conveyor belt that is 2.8 m wide and moving at a speed of 2.5 m/s. When sorting bottles, the selected plastic fraction is 97 per cent pure and 95 per cent of the desired packaging type is picked up from the conveyor.

Contact: Mr. Jon Tschudi, SINTEF, No. 7465 Trondheim, Norway. Tel: +47 7359 3000; Fax: +47 7359 3350



Go shopping with recycled bags

Conserve, an NGO based in India, has achieved commendable results in its efforts to recycle discarded plastics. Conserve transforms waste plastic bags into rather uncommon items handbags, shopping bags, wallets, notepad covers, etc.

First, waste plastic bags are washed meticulously, dried, separated by colour and arranged in trays. The plastic then goes into a proprietary machine, designed by Conserve, which compresses them into thick sheets. The sheet is then cut, lined with cloth and stitched or made into various products. About 60 plastic bags go into making one sheet.


Waste plastics in new mould

Expedient Trading, Malaysia, offers plastic products manufactured using resins reclaimed from waste plastic, even film-grade ones. According to Mr. Kent Chin, the company director, all types of plastic can be easily recycled. However, soiled waste is not preferred at the factory as the additional cost of cleaning makes the recycling process economically non-viable. The facility transforms around 100 t of plastic scraps into an almost equivalent quantity of recycled resin each month.
The recycling procedure is quite straightforward. Waste is shredded, melted, pressed into strings and finally, cut into pellets or granules. Various types of plastics are blended in the recycling process, but this must be at the right ratio so as to obtain a useable material.

Contact: Expedient Trading, Malaysia. Tel: +60 (3) 5162 1079.



New recycling process in the offing

The United States-based Electronic Scrap Recycling Corp. (ESRC) is offering full e-waste recycling, logistics and certified data destruction services to public and private sector clients. The company is developing a new ferrofluid process capable of preferentially separating targeted compounds from a mixed solid waste stream. Ferrofluid has nano-scale magnetic particles suspended in a carrier fluid, and exhibits novel properties when exposed to specific magnetic fields. Conductivity, viscosity, volatility etc. can be manipulated through the selection and sizing of particles and by applying specific magnetic fields.

The proprietary ferrofluid method allows for preferential separation of the targeted compounds out of a mixed micron-sized powder. This could be important as the Tornado GeneratorTM technology from Green Shift, which has gained 80 per cent stake in ESRC, can grind, desiccate and atomize solid and liquid wastes as well as other materials into micron-sized powders. ESRC plans to use its ferrofluid process, GreenShifts Tornado Generator and existing plastics and metal separation and other technologies, along with some traditional process technologies to dramatically lower capital costs while raising operating efficiencies for processing e-wastes.


Recycling CRTs

A Finnish firm CRT-Finland Oy specializes in recycling TVs and PC monitors, converting them into high-quality raw material for use in the manufacture of cathode ray tubes (CRTs). At the core of the recycling process is a fully automatic laser technique that fragments the CRTs. Laser cutting separates the panel glass from leaded funnel glass. The equipment automatically produces statistical data on the number, mass and measurement of CRTs for the benefit of customers and production development.

Following separation, the glass is crushed and purified to ensure its use in the production of CRTs. Other materials separated from TVs and monitors are sorted and recovered as industrial raw material. A 40 kg TV set yields about 35-38 kg of reclaimable raw material.

Contact: CRT-Finland Oy, Kiimassuontie 127, FIN 30420 Forssa, Finland. Tel: +358 (3) 4343 440; Fax: +358 (3) 4242 630



New electronics recycling plant, a part of Recycling., has opened a new recycling facility in the United Kingdom. Spread over 50,000 ft2, the site has several buildings, each containing different recycling equipment, including a new cathode ray tube recycling plant capable of processing around 50 computers and television monitors in an hour. The company has its line set up to test the monitors before proceeding to the dismantling stage. Monitors that are in working order are segregated for reuse. A WEEE shredder, which deals with general household electrical items, is also installed. About 4 tph of these wastes are broken into small pieces and the metals copper, aluminium, stainless steel and ferrous segregated through a combination of magnetic and eddy-current processes. Plastic waste is also sent for recycling.

According to the firms Managing Director, Mr. Charles Jackson, the centre can offer a comprehensive recycling facility that complies with all current legal requirements and industry standards. Mr. Jackson added that We have undergone rigorous assessment by the Environment Agency and are known as a fully licensed handler of hazardous waste electronic and electrical equipment. Also, we are registered an authorized treatment facility, as a waste transfer station and as a licensed waste carrier.


Recycling printed circuit boards

NEC Corp., Japan, has developed a new recycling system for printed circuit boards (PCBs) that allows for reclamation of value through stepwise segregation of the resources. First, PCB components are isolated through the application of heat and external forces. Next, solder on the board surface is removed using surface polishing and heat shock process. Then, copper and a mixed powder of glass fibres and resins are separated from the remaining part of the board in the pulverizing and separating processes. The unit is designed to recover all the PCB components as high-grade valuable resources and recycle them for use in high value-added applications.

Notable features and advantages of the patented technology include:
  • The equipment can be utilized as a small-scale on-site system at manufacturing plants or recovery bases. It can be applied to lead-free solder. Numerous units allow for a system amenable to large-scale processing; and
  • The unit has a simple structure, is easy to manufacture and has a throughput of 50 boards/h, roughly 1,000 mm 500 mm 500 cm and is easy to maintain.

Contact: NEC Corp., Intellectual Assets Sales Dept., NEC Headquarters Bldg., 7-1, Shiba 5-chome, Minato-ku, Tokyo 108 8001, Japan.



Recycling electronic scrap

Blue Star Electronics LLC of the United States, recycles electronic scrap by employing processes such as melting, smelting, refining and grinding. First, the material to be recycled is sorted into base metals, printed circuit boards (PCBs) and non-metallic (plastics) fractions. Base and non-metallic metals are melted, refined and upgraded for reuse as raw material. Metals like aluminium, copper, brass and other metals are smelted into ingots, rods, wire and coils for reuse. Integrated circuits, PCBs and other such components are melted to recover trace amounts of precious metals (gold, silver, palladium). The non-metallic fraction is grinded and palletized for reuse.

Overall, new metals and plastics are produced from waste electronics.

Contact: Blue Star Electronics LLC, 460, Nelo Street, Santa Clara, CA 95054, United States of America. Tel/Fax: +1 (408) 3270 901/907



New shredding technology

Erdwich Zerkleinerungs-Systeme GmbH, Germany, offers shredding equipment that allow manufacturers to comply with the Waste Electrical and Electronic Equipment (WEEE) legislation. The company provides process technology for recycling refrigerating devices, tumble dryers, washing machines, printed circuit boards, dishwashers, etc. Benefits of Erdwichs technology include:
  • No inertization while treating CFC-foamed refrigerating devices;
  • Multiple-sensor monitoring in the event of an increased proportion of pentane, for protecting the system;
  • Completely automatic shredding and separation;
  • Nitrogen-free reclamation of the refrigerating agent;
  • High level of purity and maximum recovery rates;
  • Watertight long-term archiving of important operating parameters;
  • Innovative special solutions for brown goods; and
  • Proven solution for white goods.

Contact: Erdwich Zerkleinerungs-Systeme GmbH, Postfach 65, D-86912 Kaufering, Germany. Tel: +49 (8191) 8652-0; Fax: +49 (8191) 9653-16



Higher efficiency recovery system

In Canada, Materials Separation and Recovery Corp.s (MaSeR) recycling and segregation facility at Barrie employs delamination technology, developed in Europe, for the first time in the North American electronics recycling industry. Application of the new technology results in improved recovery efficiency for electronics component material, including steel, copper, precious metals, aluminium and plastics.

The front end of the plant comprises a series of shredding and preliminary sorting apparatus that liberate and remove ferrous materials and some plastics while concurrently downsizing the remaining materials. At this point, the MaSeR procedure departs from traditional recycling technology. After the preparation phase, the fragmented material (this portion of the stream can include pieces of circuit boards, hard drives and miscellaneous fastened pieces) head to MaSeRs FractionaterTM for delamination. In this stage, materials bound together during manufacturing by lamination and with fasteners are physically separated, allowing for higher value recycling. Next, the mixture of un-bonded constituent material is segregated by size and recovered through a series of sieves and fluid-bed separators that yield three desirable, recyclable items aluminium choppings and powder, mixed copper and precious metals choppings and powder, and mixed plastics.

MaSeRs process ensures secure data destruction. By delaminating the cobalt-chromium plating from the aluminium platters in hard drives, the data-bearing medium is isolated from the platter and all information stored on the drives is eliminated. This destruction process exceeds the capabilities of traditional data security techniques, including hard drive overwriting, degaussing and shredding, while ensuring, on the environmental front, that the process does not involve burning, exporting or landfilling residual materials.



Remediating soils contaminated with hydrocarbons

An ex situ solvent extraction method for remediating soils contaminated with semi-volatile petroleum hydrocarbons has been investigated by a team of researchers in Portugal. Composition of the organic phase included ethyl acetate, acetone and water. This composition satisfied the requirement for the formation of a single liquid-phase mixture within a large spectrum of compositions and allowed intimate contact with the soil. Contaminants in the diesel range xylene, naphthalene, and hexadecane within a variety of functional groups were selected. Fast extraction kinetics produced equilibrium after 10 minutes. Lower solid-to-liquid ratios (1:8 w/v) were more efficient, with recoveries in the order of 95 per cent. Extraction in multiple contacts did not improve recovery significantly in relation to a single contact.

The solvent can be regenerated by distillation, albeit with about 10 per cent loss. The contaminants are not evaporated and remain non-volatile. The team found that ex situ solvent extraction provides a technically feasible option for remediating semi-volatile aromatic, polyaromatic and linear hydrocarbons.

Contact: Mr. Silva A, REQUIMTE Inst. Superior de Engenharia Do Porto, Portugal.


Electrons and UV aid detoxification

In the United States, researchers from the University of Maryland and the National Institute of Standards and Technology (NIST) report that the concentration of certain toxic organic constituents in waterway sediments could be reduced by up to 83 per cent using electron beams. Ultraviolet (UV) light can also lower the concentration of these chemicalswhile, electron beams and UV light can effectively detoxify the banned polychlorinated biphenyls.

The results are significant because sediments, soupy mixtures of water and particles of various sizes, are notoriously difficult and expensive to decontaminate. However, whether electron beams and UV light are practical decontamination methods will depend on cost-effectiveness comparisons with existing methods.


Photothermal destruction of toxic organic compounds

In the United States, researchers at the University of Dayton Research Institute have developed an efficient and extremely clean photolytic detoxification process that offers the speed and general applicability of combustion technologies. The new photothermal detoxification unit, or PDU, utilizes photothermal reactions carried out at temperatures higher than in conventional photochemical processes (200-500C vs. 20C), but less than combustion temperatures (typically >1,000C).

The PDU comprises an insulated reactor vessel illuminated with high-intensity ultraviolet (UV) lamps. Site remediation methods that generate high-temperature gas streams (e.g. thermal desorption, in situ steam stripping, etc.) can incorporate the PDU with only slight modifications to their equipment. Other processes (soil vapour extraction, air stripping, etc.) could easily integrate a PDU fitted with a preheater to precondition the process stream. Furthermore, the PDU can be fitted with air pollution control devices to remove acids and suspended particulate from the treated process stream.

The PDU is extremely effective in destroying polychlorinated dibenzodioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, aromatic and chlorinated solvents, as well as brominated and nitrous wastes found in soil, sludges and aqueous streams.

Contact: Office for Technology Partnerships, 300, College Park, Dayton, Ohio 45469 0102, United States of America. Tel: +1 (937) 2293 515; Fax: +1 (937) 2293 873.


New method to treat contaminated soils and sediments

In the United States, Environmental Technology Unlimited has designed and tested an ex situ process for removing PCBs and other targeted contaminants from sediments and soils through solvent extraction. In this process, the contaminated soil is mechanically blended with clean solvent in a suitable receptacle. The organic solvent and co-solvents effectively mobilize the pollutant and the contaminated solvent is then extracted from the soil matrix. The process is repeated in an iterative fashion since all the contaminant cannot be removed during the initial cycle itself.

The primary solvent is reclaimed through distillation while co-solvents and contaminant compounds are concentrated in still bottoms for disposal.

Contact: Environmental Technology Unlimited, Research and Field Operations, P.O Box 7750, Wilmington, North Carolina 28403, United States of America. Tel: +1 (910) 2626 007; Fax: +1 (910) 7912 143



POPs removal

Researchers at Fiskeriforskning, Norway, report that it is possible to remove virtually all of the persistent organic pollutants (POPs) that may be present in fish oil and fishmeal. Fiskeriforsknings method replaces hexane, the solvent conventionally utilized to decontaminate fishmeal, with fish oil and incorporates the decontamination stage in the fishmeal production process itself. This results in over 90 per cent of POPs being removed, and that too at lower costs. Fishmeal thus obtained has a lower level of POPs than meal decontaminated with hexane. Moreover, the product also contains more polyunsaturated fat, which makes it nutrient-rich. Otherwise, the meal exhibits the same characteristics as regular fishmeal.

Contact: Mr. ge Oterhals, Senior Researcher, Fiskeriforskning, Troms, Norway. Tel: +47 5550 1274, 5511 2168; Fax: +47 5550 1299


Soil washing system

BioTrol Inc. in the United States, is offering a patented water-based volume reduction process for treating excavated soil contaminated with wood preserving wastes, such as polynuclear aromatic hydrocarbons (PAH) and pentachlorophenol (PCP). At the core of this process is a multi-stage, counter-current, intensive-scrubbing circuit having inter-stage classification. The scrubbing action disintegrates soil aggregates, freeing contaminated fine particles from the coarser material. In addition, the abrasive scouring action of the particles themselves removes surface contamination from the coarse portion. Contaminants may be made soluble, as determined by solubility traits or partition coefficients. The polluted residual products can be treated by other methods while process water is normally recycled after biological or physical treatment.

BioTrol process can be applied to contaminants concentrated in the fine soil fraction (silt, clay, and soil organic matter) or contamination associated with the coarse (sand and gravel) soil fraction. It can even be applied to soils tainted with polychlorinated biphenyls, petroleum hydrocarbons, pesticides, various industrial chemicals and metals.

Contact: BioTrol Inc., 10300, Valley View Road, Suite 107, Eden Prairie, MN 55344 3456, United States of America. Tel: +1 (612) 9428 032; Fax: +1 (612) 9428 526.


Eliminating PCBs

Powertech Labs Inc., Canada, is offering an effective and economical method for destroying liquids and solids tainted with polychlorinated biphenyls (PCBs). Presently available destruction methods produce atmospheric emissions and could potentially contaminate a wide area around the treatment site. The new chemical technique is based on a patented sodium process that has been used to decontaminate over 12 million litres of PCB-polluted oil from transformers. The procedure uses a finely dispersed suspension of metallic sodium to dechlorinate PCBs. Sodium also reacts with the chlorobenzenes, organic acids and other such oxidation products found in the oil.

A plant offered by the company is designed to reclaim oils containing less than 5,000 ppm PCB. Also, the process can be scaled and altered for different feed materials as well as to treat liquids containing up to 100 per cent PCB. The other 3,300 kg/shift plant, designed and built to decontaminate fluorescent ballast wastes like potting compound and capacitor windings, can operate continuously on three shifts per day basis. Both plants are capable of destroying PCBs to well below 2 ppm and do not produce any hazardous effluents.

Contact: Powertech Labs Inc., 12388-88 Avenue, British Co-lumbia, V3W 7R7, Canada. Tel: +1 (604) 5907 500; Fax: +1 (604) 5905 347




Disposing asbestos containing material

Asbestos Conversion Systems Inc. in the United States is offering two methods for permanently eliminating asbestos containing material (ACM). In the first technique, asbestos is rendered inert through the action of thermodynamic and chemical de- mineralization mechanisms. The demineralizing agent used in the process is not influenced by the presence of organic and inorganic components. The quantity of agent added is typically 2-4 per cent of the ACM weight and applied in an aqueous form to ACM, consistent with ACM wetting for purposes of dust suppression.

Equipment for the second process comprises a materials handling unit, shredder, mixing bath, dewatering screw, rotary hearth and quench tank. All these can be mounted in a large trailer, enabling the process to be undertaken on-site, or set up in a central location. The whole process is controlled by computer and eliminates the need for dedicated labour to operate. ACM is loaded into the machinery manually or by vacuuming directly into hoppers, which will automatically feed into the system. The waste then passes through a shredder to the chemical bath, then via the dewatering screw (to remove excess moisture) to the furnace. It is preheated to remove the rest of the moisture and then passed to the rotary hearth where it is heated to 1,200C for about an hour before being ejected into the quench tank and from there into a sealed skip.


Flue gas cleaning with catalytic dioxin removal

Keppel Seghers, Belgium, offers an integrated solution to solve the problems of both gaseous and particulate dioxins, as well as dust. Other benefits include minimized footprint, minimal pressure drop and very low operational costs. The CATFILTER concept is based on the synergy between a high-efficiency fabric filter and a honeycomb catalyst bed; both proven, simple and efficient technologies. Honeycomb catalyst modules are added as a layer above each compartment of the fabric filter. The perfect laminar flow and low face velocity (around three times lower than the typical face velocities in a traditional SCR reactor) at the outlet of the bags sealing plate guarantees high dioxin destruction efficiency (up to 99 per cent) with low pressure drop.

The simplicity of the CATFILTER concept (no moving parts, no fluid or gas injection, etc.) guarantees trouble-free operation to:
  • Avoid plugging of the catalyst and improving the filtration;
  • Avoid the risk of ammonium bisulphate (ABS) formation;
  • Increase plant availability;
  • Limited additional footprint; and
  • Minimize the exploitation cost.

CATFILTER can be employed with high-temperature ammonia injection (in the post-combustion chamber) for preliminary removal of nitrogen oxides step.

Contact: Mr. Ivan Christiaens, Global Head of Sales and Marketing, Keppel Seghers, Belgium. Tel: +32 (3) 8807 704; Fax: +32 (3) 8807 749.


Eliminating chlorinated phenols

Researchers from China and the United States have identified an economically viable oxidant-catalyst system that destroys up to 99 per cent of trichlorophenol, or TCP, in aqueous solution. Polychlorinated phenols (PCPs) are a persistent and hazardous class of environmental pollutants. This remediation process uses simple and inexpensive reactants efficiently to convert PCPs to environmentally safe products.

The TCP solution was treated with a stoichiometric amount of NaNO2 at about 150C for 8 h under 0.5 MPa pressure. About 91 per cent of the chlorine was released as innocuous inorganic chloride. The degradation products from the process include various mono-, di- and tricarboxylic acids; succinic acid was the main product. The team then scaled up the process using a 5 litre Hastelloy autoclave. The slightly decreased degradation at this scale was easily compensated for by increasing the reactor temperature to 170-210C. Most of the degradation products identified did not contain chlorine. This is consistent with the high conversion to inorganic chloride.


Polycyclic aromatic hydrocarbon removal from soil

Polycyclic aromatic hydrocarbons (PAHs) are potentially hazardous compounds with the ability to induce both carcinogenic and mutagenic effects in living organisms. At the National University of Singapore, researchers have developed a rapid clean-up technology based on a combination of non-ionic surfactant soil washing and subsequent PAH removal from the wash water in a rotating biological contactor (RBC) reactor using the white rot fungus, Phanerochaete chrysosporium.

Experiments have shown that the process can remove more than 90 per cent of PAH from the soil to the aqueous phase using a low concentration of 0.5 per cent (w/v) Tween 80 surfactant with a soil/water ratio of 1:10 (w/v). Subsequent treatment in the RBC reactor results in more than 90 per cent removal for any of nine PAHs by the immobilized fungus P. chrysosporium with the reactor in batch mode. Overall, the treatment of PAH contaminated soil using a combination of soil washing and subsequent PAH removal in a RBC reactor, in the presence of white rot fungus, is an effective remediation technology for contaminated soil.

Contact: Faculty of Engineering, National University of Singapore, Deans Office, Block EA, # 07-26, 9 Engineering Drive 1, Singapore 117576.



Process to efficiently recover chrome

The conventional method of chrome tanning, used in the leather industry, results in very poor exhaustion of chrome, which adds to the toxicity of the effluent. The Central Leather Research Institute, India, has developed a process in which chrome let out in the effluent is recovered for reuse, thereby ensuring economical usage of chrome while allowing for effective management of this toxic substance. The method involves precipitation of chrome with an alkali, whereby the supernatant liquor is segregated, allowing the resulting precipitate to settle down. The pre-cipitate is treated with sulphuric acid to get the BCS, which can be reused. To enable more chrome pre- cipitation, polyelectrolytes are used.

About 98-99 per cent of chrome can be reclaimed by this method. The cost of installation of the plant can be recovered within 12-24 months, depending on the scale of operation.

Contact: Head, Business Processes Division, Central Leather Research Institute, Adyar, Chennai 600 020, Tamil Nadu, India. Tel: +91 (44) 2491 5238/2491 1386; Fax: +91 (44) 24 915238, 24911589

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New system to treat wastewater

Researchers at the Central Leather Research Institute, India, offers an integrated biological and chemical oxidation system to treat wastewater. In the Chemo Autotrophic Activated Carbon (CAACO) system, biological and chemical oxidation processes are carried out in a single hybrid reactor packed with activated carbon-based redox resin. The tech- nology involves anaerobic treatment of the wastewater followed by wet air oxidation using activated carbon, which contains chemo autotrophic bacteria in an immobilized state. As only the stoichiometric quantity of oxygen is supplied for oxidation, utilization of electrical energy is minimized, leading to nearly 75 per cent savings in electricity usage, compared with aerobic systems.

The treatment eliminates about 92 per cent of suspended solids, 98 per cent BOD, 85 per cent COD, 100 per cent sulphide and 100 per cent odour with a very high degree of performance consistency. One major advantage of the system is that the pH of the processed liquor is very close to the neutral range, which facilitates easy disposal of the processed water.

Contact: Head, Business Process Division, Central Leather Research Institute, Adyar, Chennai 600020, Tamil Nadu, India. Tel: +91 (44) 2491 5238, 2491 13 86; Fax: +91 (44) 2491 5238, 2491 1589



Effluent treatment and recycling

The United Kingdom-based W2O Environment offers a relatively low-cost and compact membrane bioreactor (MBR) that has been used for treating tannery effluents successfully. With proven economical and technical feasibility, this novel technology has expected reductions of 95 per cent in COD, 100 per cent in BOD and complete removal of suspended solids. The effluent left over after MBR treatment is high-quality, allowing for cost-effective polishing through reverse osmosis (RO) treatment, which enables salt-free water recycling.

Full-scale application of MBR and RO treatment has demonstrated up to 80 per cent recovery of water.

Contact: Dr. Wolfram Scholz, W2O Environment, 58 Cecil Road, Northampton NN2 6PQ, United Kingdom. Tel: +44 (1604) 478 415; Fax: +44 (1604) 478 415



New textile effluent treatment method

Researchers at Sucher and Holzer GmbH, Austria, have developed a process for continuous treatment of textile bleaching effluents using immobilized enzymes. This method allows for reuse of the water in other processing steps, such as dyeing. Catalases were locked on alumina to increase their stability. A vertical and horizontal packed-bed enzyme reactors were constructed for the continuous degradation of hydrogen peroxide. An alumina-based carrier material was developed with special shapes, in order to ensure oxygen release from the reactor. Catalase-treated bleaching pollutants were used for lab-scale dyeing and it was exhibited (evaluation based on dE values) that satisfactory staining levels could be obtained provided that the dyeing protocols are altered accordingly.

Contact: Dr. Georg, Sucher and Holzer GmbH, Department of Research & Development, Alberstrasse 4, Sudosterreich Stei-ermark, Graz 8010, Austria. Tel: +43 (316) 327 071; Fax: +43 (316) 383 703.


Sludge-free treatment of textile effluents

Conventional processes of treating textile effluents use lime and ferrous sulphate in large quantities to isolate colour and odour, thus generating hazardous sludge. As such, it is imperative to invest in reverse osmosis facilities, which treat the hazardous sludge. AuroZon, India, has developed an Ozonator that eliminates the use of lime, ferrous sulphate and various other chemicals that are traditionally employed in effluent treatment plants in the primary treatment stage. The new cost-effective technology does not produce any toxic sludge. Ozone, being a strong oxidant, oxidizes all the colouring dye molecules and organic pollutants in the effluent. The bio-friendly ozone treatment technology also enhances the life of reverse osmosis plants.


Biological systems for industrial effluent

Pollution Control Systems Inc., the United States, offers a range of solutions to treat industrial wastewater. The Variable Depth Reactor (VDR) system combines functions of an equalization tank with that of secondary biotreatment. It achieves equalization of the effluent inflow while using a portion of the aeration tank, allowing biological reduction to take place during the equalization process. The VDR system was dev-eloped as an efficient method for treating food and chemical plant process wastewater. It is also a cost-effective alternative to other forms of biological wastewater treatment including SBRs, RBCs and conventional activated sludge processes.

The company also offers Dissolved Air Flotation (DAF) technology to float contaminates from wastewater. Its flotation systems are well-suited for the removal of light solids such as oils, fibres, proteins, blood, inks starches and other substances that do not settle well by gravity. Enhanced removal by flotation is available using a three-stage DAF system with recycled water mixed individually into the flow at each of the three stages of the system.

Typical applications for DAF units are found in the food and chemical processing facilities, pulp and paper processing, and any facility that requires reduction of oils, fibres and other light solids.

Contact: Pollution Control Systems Inc., 5827, Happy Hollow Road, Suite 1-B, Milford, Ohio 45150, the United States. Tel/Fax: +1 (513) 8311 165, 9654 812



Wastewater through the recycling glass

In the United Kingdom, results from a series of trials funded by WRAP and conducted by Aqua-Enviro has found that Recycled Glass Filtration Media (RGFM) improves the quality of effluent compared with traditional sand media. Full-scale trials employing the RGFM have been carried out since November 2004, with the end-users including vegetable processor JE Hartley, packaging giant Georgia Pacific, Croda Chemicals Europe, and Yorkshire Water at its wastewater treatment plant.

Mr. Mark Lowe, consultant at Aqua Enviro, stated that Tests have shown that RGFM delivers more efficient backwash performance than sand with backwash being required less often and less energy usage in the backwash due to the lower specific density of glass. Also, unlike sand, RGFM does not have a marked tendency to clog up or bind when high loadings of suspended material are effected. Moreover, as glass is a processed product, it can be sized to treat specific solid types.


Optimization of plants treating wastewater

Bayer Technology Services GmbH (BTS), Germany, has introduced its trademarked process for optimizing wastewater treatment plants. The new pressure relief flotation method improves separation of suspended matter in process water and wastewater while concurrently reducing operating expenses. The patented method for dissolving air in a very narrow bubble range (30 to 80 m) enables optimal use of flocculation aids and results in maximum solids separation.

BayFlotechTM is ideal for secondary clarification and pre-clarification, solids separation after precipitation as a third stage in wastewater treatment facilities as well as sludge concentration. BayFlotech provides an elegant means to treatment plants for preventing loss of biomass and lowering the formation of bulking sludge and skimmings. BTS offers integral solutions for the entire life cycle of chemical/pharmaceutical plants from product and process development to unit engineering and construction, through to plant and process automation/optimization.

Contact: Dr. Markus Gerigk, Bayer Technology Services, Germany. Tel: +49 (214) 3080 048; Fax: +49 (214) 3096 80048




Wet scrubber

Tri-Mer Corp., the United States, is offering Cloud Chamber Scrubber (CCS) system as a better alternative to ESPs. In a CCS, which requires just 600 W of power, billions of droplets and particles move continuously in relation to each other. As they reach 10 m of separation, electrical attraction causes the particulate to enter the droplets.

CCS offers significant performance advantages over ESP emissions equipment and other devices for controlling sub-micron particulate. Notable among them is the need for less than one inch of pressure drop per phase under full load operation. This factor is a major contributor to the CCS systems low operating costs. CCS also removes fumes and gases, including HCl, HF, H2SO4, SO2, Cl2 and NH3, simultaneously with particulate. More than 99.99 per cent of particulates, from 0.1-300+ m, can be removed. These systems are manufactured in UV-stabilized polypropylene, FRP, PVC, 304 and 316 stainless steel, as well as higher alloy materials.

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



High-temperature dust collector

Biothermica Technologies Inc. of Canada offers Clinox dust collector to filter high-temperature gaseous effluents containing incandescent particles. This technology is based on the same principle as traditional sleeve filter systems, though it uses stainless steel filter bags that can withstand temperatures lower than 600C. Clinox is suitable for treating gaseous effluents from bark-boilers, cement and metallurgical factories, etc. The system lowers dust levels to under 50 mg/Nm3 at the stack outlet (dry concentration corrected to 8 per cent oxygen).

Gaseous effluents to be treated are introduced into an enclosed space where a deflector is used for the first phase of filtration. Large particles are intercepted and directed to an ash evacuation hopper at the base of the deflector. Air then passes through the stainless steel mesh filter bags, which recover the fine particles. A pulse-jet unplugging system allows for periodic cleaning of the bags. Clean air is blown in the opposite direction to the flow of gaseous effluents being treated, dislodging particles that then fall into a hopper. A horn that can generate low-frequency sound waves may also be used to clean the filter bags. An access door permits system maintenance and a monitoring system ensures automatic control of the filtration procedure.

Contact: Mr. Jacques Dubois, Biothermica Technologies Inc., 426, Sherbrooke Street East, Montral, Qubec H2L 1J6, Canada. Tel/Fax: +1 (514) 48 83 881, 4883 125



Gaseous effluent treatment system

Mesar/Environair, Canada, offers wet scrubbing technology for treating pollutants in gaseous emissions. The system consists of two main components: a reagent-effluent control system unit and an absorption tower purification system. The latter includes a gas diffuser, packing or absorption zone, a purification liquid diffuser, mist eliminator and a purification liquid sump. This arrangement ensures constant control over the purification liquid being injected into the tower.

The system self-adjusts to variations in the concentration of contaminants in gaseous emissions undergoing treatment and the response time is less than 2.5 seconds. A removal rate of 99 per cent of the purification droplets (<5 m) is achieved, thus minimizing the quantity of liquid that may need additional treatment in certain cases or may escape into the atmosphere. Furthermore, 98 per cent of the chemical reagents used are recovered. The gaseous effluent treatment system can cope with flow rates of 1,700-85,000 m3/h and can treat acidic emissions, VOCs, combustion emissions and odours.

Contact: Mr. Yvan Masse, Mesar/Environair Inc., 410 Charest East, Office 550, Quebec, QC, G1K 8G3, Canada. Tel: +1 (418) 6887 475; Fax: +1 (418) 6880 482




Technology to lower GHG emissions

GreenShift Corp., the United States, is offering a patented bioreactor process for lowering greenhouse gas (GHG) emissions produced by fossil-fuelled combustion processes. Originally devised by Ohio University, the bioreactor removes carbon dioxide (CO2), a primary GHG, from the smokestacks of fossil-fuelled power plants in a way that leverages natures own mechanism photosynthesis. At the heart of the bioreactor is Chroogloeocystis siderophila, a newly discovered iron-loving cyanobacterium (blue-green algae).

In the bioreactor, the algae grows on membranes of woven fibres that are akin to window screens interspersed between Oak Ridge glow plates a unique arrangement of parabolic mirrors, fibre optic cables and slabs of acrylic plastic. Capillary action takes water to the algae and fibre optic cables channel sunlight into the glow plates while ducts bring in the hot flue gas. The algae utilize the available CO2 and water to grow new algae, giving off pure oxygen and water vapour in the process. The organisms also absorb nitrogen oxide and sulphur dioxide, which contribute to acid rain. Once the algae grow to maturity, they fall to the bottom of the bioreactor and may be harvested for other uses. A prototype of the technology develeoped is capable of handling 140 m3/min of flue gas, an amount equal to the exhaust from 50 cars or a 3 MW power facility.

Contact: Mr. Jim Grainer, GreenShift Corporation, United States of America. Tel/Fax: +1 (973) 3988 183/037.


NOx stripper

Seikow Chemical Engineering and Machinery Limited, Japan, is offering oxidation reduction type NOx stripper that provides excellent stripping results regardless of variations in the ratio of concentration between NO and NOx. A main obstacle in the denitrification method is the presence of NO. Key features include:
  • The system enhances stripping effects through two separate towers, which use an oxidizing agent and reducing agent, respectively;
  • Adapts to changes in NO and NOx concentrations; and
  • Appropriate for main processing equipment under 2,000 ppm.

The equipment permits over 99 per cent stripping efficiency.

Contact: Seikow Chemical Engineering and Machinery Ltd., 1-331, Mizudo-cho, 4-chome, Amagasaki, Hyogo 661-0026 Japan. Tel: +81 (6) 6438 08 41; Fax: +81 (6) 6436 1126



New scrubber

Hi-Tech Furnace Systems Inc., the United States, offers wet scrubbers for HF and HCl neutralization. All scrubbers feature high-efficiency packed columns with high surface area packing to ensure maximum surface contact between the gas and scrubbing liquid.

Typical components of a scrubber include a Venturi, recirculation tank, recirculation pump, packed column, pH controller and a caustic supply pump. Venturi creates gas movement, cools the incoming gas and impinges solid particles carrying the pollutants into the recirculation tank. The particulate-free gas travels to the packed column where it flows counter-current to a liquid stream of caustic solution, which cascades over a high surface area media in the packed column. Absorption is affected by various chemical and mechanical principles, which are considered when the column design is established. Among these tenets are the liquid-to-gas ratio, the type and amount of packing, and make-up of the scrubbing solution. Above the packed column a second section of media is kept to condense visible traces of water vapour in the exhaust gas stream. Any condensation will return to the recirculation tank via the packed column.

Caustic water solution is supplied to the Venturi and packed column by a vertically mounted high-pressure centrifugal pump. Caustic solution is routed through a filtering system for removing large particulates and a liquid-liquid heat exchanger to remove heat. The caustic solution is balanced to a pH of 8-10 using a concentrated solution of KOH or NaOH. This balance is maintained automatically by additions of NaOH or KOH using a chemical feed pump controlled by a pH control system whose sensor is mounted in the recirculation tank.

Contact: Hi-Tech Furnace Systems Inc., 50685 Wing Drive, Shelby Township, MI 48315, United States of America. Tel/Fax: +1 (586) 5660 600, 5669 253



Removal of hydrogen sulphide

ADI Ltd., Canada, has introduced a new hydrogen sulphide (H2S) gas stripping procedure to remove this highly corrosive component present in gaseous emissions from wastewater treatment plant off-gases as well as from a couple of industrial methods. The patented Sulfa-Bind process allows for efficient and cost-effective removal of H2S from biogas. A bench-scale version of the Sulfa-BindTM filter has demonstrated its ability in treating gases with H2S concentrations as high as 30,000 ppm, and reducing it to less than 1 ppm. An on-site pilot-scale filter was able to reduce H2S from 60-100 ppm down to less than 0.2 ppm on digester gas at a wastewater treatment plant. H2S saturated Sulfa-Bind was also subjected to leachate testing, utilizing both the Canadian and US protocols with the results considered non-hazardous waste.

Sulfa-Bind comprises an inorganic, natural material, calcined to raise hardness, porosity and surface area and coated with iron oxide. Based on performance evaluation and the economic comparison with existing technologies, H2S removal through Sulfa-Bind filter media is found to be a practical and viable choice.

Contact: Mr. Paul Morrison, ADI Limited, No. 1133, Regent Street, Suite 300, Fredericton, NB E3B 3Z2, Canada. Tel: +1 (506) 4529 000; Fax: +1 (506) 4593 954




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