Neutralization/purification of the wastewaters from printed circuit boards production using waste by-products.

The purpose of this work was development of a new method for the neutralization/purification of printed circuit boards wastewater (PCBW) originating from Zagreb, Croatia, using two industrial by-products. PCBW was characterized with low pH value (2.11) and high concentration of TDS (50190 mg L−1), copper (4190 mg L−1) and iron (2660 mg L−1). Waste base (WB), by-product of the alumina production, and waste sludge, by-product of the electrochemical treatment of groundwater, were employed as neutralization/adsorption agents. Due to its high neutralization capacity WB was used for pH adjustment to pH 8 and heavy metals removal from both effluents, yet the final removal of the contaminants down to the regulated values was assessed by adsorption/coagulation with the iron and aluminum rich waste sludge. Following the combined treatment the removal efficiency of iron and copper was higher than 99.99% with their final concentration in the treated water of 0.151 mg L−1 and 0.129 mg L−1, respectively. Following the ...