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Removal of organic contaminants and recycling of waste water from electroless plating process streams

Objective

Scientific objectives and approach:

Existing methods for removing persistent organic compounds from waste water are end of pipe treatments which create secondary waste streams. The overall objective of the research is to develop advanced oxidation and electrochemical processes to bring about the in situ destruction of persistent and toxic organic compounds as an integral part of PCB manufacturing operations. Both techniques directly oxidise organic components, without the production of by-products and secondary wastes. The advanced oxidation techniques will include synergistic combinations to generate powerfully oxidising radical species capable of converting most organic pollutants into carbon dioxide and water, particularly at very low concentrations in the range 10 ppm to 10 ppb. The electrochemical methods will employ new anode materials, which will enable the direct oxidation of toxic and corrosive organic compounds such as chelating agents, and will be effective at higher concentrations, e.g. up to 10,000 ppm. The two methods are complementary and could be used in novel treatment combinations.

Problems to be solved:

The treatment of organic compounds in waste water is a problem faced throughout the European Community by most printed circuit board (PCB) manufacturers and other surface treatment processors. The removal of these compounds would enable the recycle of large volumes of water within the PCB manufacturing industry in Europe. This would enable European manufacturing organisations to reduce costs and preserve natural resources. In addition to direct pollution from organic compounds, many chelating agents are used which release metals into the environment. It is important that the problem is tackled on a European scale to ensure that the treatment process is compatible with the range of wastes experienced throughout Europe.
There are about 20,000 SMEs throughout Europe involved in PCB manufacture, and more SMEs involved in surface finishing generally. In particular the IPPC (Integrated Pollution Prevention and Control) legislation, which has come into force throughout Europe, has implications for surface finishing companies with a plating bath volume in excess of 30m3 total. The project in this proposal will help many SMEs to cost effectively achieve their environmental targets

Expected Impacts:

The research will devise two processing techniques, which may be used independently or in combination. The project aims to develop robust, economic treatment systems, which can be used by a great number of SMEs and larger companies. The techniques will be directly applicable to the PCB manufacturing industry, and will be transferable to the entire surface-finishing sector. The results of the project will allow end users to improve their competitiveness through the reduction of their costs whilst achieving increasingly stringent discharge limits. Industrial implementation will reduce the volume of waste water and enable water recycle. In addition, the control and recycle of heavy metals used by these sectors will be greatly enhanced.

Funding Scheme

CRS - Cooperative research contracts

Coordinator

P.W.CIRCUITS LTD
Address
Premier Works, Canal Street
LE18 4PN Leicester
United Kingdom

Participants (6)

AB FERRORPRODUKTER
Sweden
Address
Import Gatan 19-21
402 72 Goeteborg
ALCHEMA LIMITED
United Kingdom
Address
King Street 38
CH1 2AH Chester
GRAPHIC PLC
United Kingdom
Address
Down End
EX17 1HN Crediton
METAKEM GESELLSCHAFT FUER SCHICHTCHEMIE DER METALLE GMBH
Germany
Address
Achtzehnmorgenweg 3
61250 Usingen
ROHM AND HAAS ELECTRONIC MATERIALS EUROPE LIMITED
United Kingdom
Address
Herald Way
CV3 2RQ Coventry
WATER TREATMENT COOPERATION AB
Sweden
Address
Unnerstad Gard
585 93 Linkoeping