Narinder Bains, Martin Goosey and Runveer Hayer
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…
Abstract
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.