Cost-effective removal of COD in the pre-treatment of wastewater from the paper industry

NADDEO, VINCENZO; KLOSOK-BAZAN, IWONA; BOGUNIEWICZ-ZABLOCKA, JOANNA; MOZEJKO, CLARA A.

WATER SCIENCE AND TECHNOLOGY

I W A PUBLISHING

Año: 2019

0273-1223

The present paper reveals results of research for cost-effective removal of chemical oxygen demand(COD) contained in industrial paper mill effluent. Not only process efficiency but also wastewatertreatment costs are discussed. Different pre-treatment processes are applied aiming to investigate theCOD removal before discharge to the municipal sewage network. The objective of this paper is to find theoptimal operating conditions for the coagulation process. The effects of key operational parameters,including the type of coagulant, initial pH, temperature and coagulant dose, on COD percentage removalwere investigated. The laboratory experiments confirmed the high efficiency of chemically enhancedmechanical treatment towards COD. The data obtained shows that even low dose of chemicals providessufficient COD reduction. The initial pH of the wastewater had a significant impact on the COD removal.Under the optimal operational conditions (pH ¼ 7.5, T ¼ 18 C) the treatment of wastewater from paperindustries by coagulation has led to a reduction of 70% COD for wastewater discharged. In terms of theinvestigated paper industry wastewater. Polyaluminium chloride appears to be most suitable fortreatment of high COD concentration. However, in an economic evaluation of requirements forwastewater treatment, operating costs and associated saving were such that PAX was more favourable