Narinder Bains

An integrated approach to electronic waste (WEEE) recycling

Purpose – This paper aims to present a review carried out under DEFRA‐funded project WRT208, describing: the composition of WEEE, current treatment technologies, emerging technologies and research.Design/methodology/approach – This paper summarises the output from the first part of the project. It provides information on the composition of WEEE and an extensive survey of technologies relevant to materials recycling from WEEE. A series of further papers will be published from this research project.Findings – WEEE has been identified as one of the fastest growing sources of waste in the EU, and is estimated to be increasing by 16‐28 per cent every five years. Within each sector a complex set of heterogeneous secondary wastes is created. Although treatment requirements are complicated, the sources from any one sector possess many common characteristics. However, there exist huge variations in the nature of electronic wastes between sectors, and treatment regimes appropriate for one cannot be readily transfer...

Evaluation of an enhanced oxidation method for the destruction of ethylene diamine tetra‐acetic acid (EDTA) and related compounds in aqueous solution

Ethylene diamine tetra‐acetic acid (EDTA) and other chelates are widely employed in the electroless copper plating solutions and related chemistries used in printed circuit board (PCB) manufacturing. EDTA in particular, imparts many benefits to these processes but it is also becoming increasingly undesirable from an effluent treatment and environmental perspective. Consequently, there is a need to remove EDTA and similar compounds from effluent produced during the PCB manufacturing process. In this paper, the effectiveness of hydroxyl radicals, generated by a UV/ozone based enhanced oxidation process, in destroying relatively low levels of EDTA and other chelates has been evaluated. The influence of temperature, operating pH and chelate concentration has been investigated. Initial results indicate that a combined UV/ozone based process provides a useful and effective method for conveniently destroying EDTA, its hydroxy ethyl analogue and ethanolamine in aqueous solution.

A new method for destroying organic contaminants and recycling waste water from printed circuit board manufacturing process effluent streams

Ethylenediaminetetraacetic acid and other organic chelates are widely employed in electroless plating processes used by the printed circuit board and metal finishing industries. These chelating agents can pose problems with downstream waste water treatment, and metals and water recycling processes, due to their ability to complex heavy metal ions and their low biodegradabilities. Conventional treatment methods, such as carbon adsorption, air stripping and reverse osmosis can create secondary waste problems and are normally applied as “end of pipe” treatments. The development of new technology to address these problems would be welcomed. The ROCWAT project, funded by the EC under the “CRAFT” programme, detailed in this paper was undertaken to develop and deliver innovative techniques for the in situ destruction of chelates and other organics found in manufacturing process chemistries and effluent streams.

Development of a new, more efficient and environmentally friendly method of producing high density interconnects – the “PRIME” process

In September 1998 six European companies involved in PCB manufacturing and electronic packaging started collaborating in a development project known as “PRIME”. The “Program for Re‐engineering and Innovating (PCB) Manufacturing and Equipment” project lost one of its original members in late 1999, and Coates Circuit Products joined as the dielectric supplier. The project is now approaching the mid‐term assessment (MTA), where alternative production scenarios will be discussed and the most attractive carried forward to fabricate test vehicles and ultimately demonstrator patterns. Some essential features of the project have already been demonstrated and these initial results will be presented.

New technologies for a sustainable printed circuit board manufacturing process: further results

Purpose – To present the initial results from a project recently undertaken by Rohm and Haas Electronic Materials Europe Ltd, in collaboration with a number of European partners, to develop individual elements of the traditional PCB manufacturing process towards a sustainable and zero‐discharge alternative.Design/methodology/approach – This paper presents initial results from work aimed at enabling PCB manufacturing to become more sustainable. Novel processes evaluated include special electroplating techniques, advanced oxidation methods to remove organic contaminants, and new ion exchange systems. Work has been carried out to develop these processes into viable demonstrators and the results of progress to date are reported. Descriptions of how these individual technologies may be combined to provide an integrated approach to a more sustainable PCB manufacturing methodology are also given.Findings – Initial results indicate that a more sustainable PCB manufacturing process may be achieved by combining the...

New Method for Destroying Organic Contaminants and Recycling Wastewater from PCB and MF Manufacturing Process Effluent Streams

This paper was recently published in the January edition of Industrial Environmental Management and is a modified version of an article published previously in Circuit World Vol.9 No. 4, 2003. The work was carried out as a CRAFT Project (ROCWAT-Thematic Priority F5 (Project number EEVK1-2001-30014). Part of the process involves dissemination to as wide an audience as possible through appropriate journals.