Characterization and treatability of latex and PVA based paint production wastewaters

In this paper, characterization and treatability of water-based paint manufacture wastewaters were assessed. The aim of the study was to comparatively evaluate the effect of replacement of the conventional binder PVA with latex. Binder is an important component of paint production and one of the determining elements of wastewater characteristics. Wastewater characterization studies indicated that latex-based production wastewaters were several fold diluted with respect to PVA-based paint wastewaters while they were still strong having COD values in the order of 16 g/L. Pre-aeration of both wastewaters yielded COD removals 20-26%, however this application resulted in reduction in coagulation efficiency. Coagulation of PVAbased wastewaters with alum and FeCl₃ provided 80% COD removal at 2000 mg/L doses. Lime was also effective at high pH as it was combined with FeCl₃. Coagulation of latex-based production wastewaters with the same doses of alum and FeCl₃ was more effective providing over 90% COD removals.