Clean production and recycling in PCB industry

摘要

Printed circuit boards (PCBs) manufacturing is a series of sophisticated industrial processes, which involve the use of numbers of consumables and chemical additives. Those Chemicals, with their high chemical oxygen demand (COD) content and in the form of waste concentrates, exist as pollutants that increase the difficulties in wastewater treatment. This paper aims to demonstrate a successful case done by cooperation between DaLian Pacific Electronics Co. Ltd. (DPEC) and C&G Environmental Technology Ltd. (C&G), in which the pollution source control, waste segregation, sorting, batchwise and continuous treatment processes are highly integrated. By introducing an advanced biological treatment, the COD level was reduced and fulfilled the legal requirement. Water collected after the biological treatment was reused, either as grey water or in the production line. Resources recycling were achieved in copper and gold recovery from waste concentrates. Secondary wastewater generated in the recycling processes was reused in the production line or for the preparation of coagulant. Solid wastes, including spent PCBs and dusts, were undergone non-toxic treatment. Clean production was achieved by incorporating the waste treatment and recycling technologies.