Water Quality Research Journal of Canada

Vol. 42 (1): 63 - 71 (2007). General issue

Pilot Treatment of OCC-based Paper Mill Wastewater Using Pulsed Electrocoagulation

   Yuan-Shing Perng, Eugene I-Chen . Wang, Shih-Tsung Yu, An-Yi Chang, Chi-Yuan Shih

Abstract
There is an increasing trend towards the closure of white water recirculation loops in papermaking, often leading to need for system modification. A pilot-scale study was conducted using pulsed electrocoagulation technology to treat the wastewater of an old corrugated containerboard (OCC)-based paper mill, to evaluate its treatment performance. The operating variables were: a current density of 0 to 240 A/m2, a hydraulic retention time of 8 to 16 min and a coagulant (anionic polyacrylamide) dosage of 0 to 30 mg/L. The water quality indicators investigated were electrical conductivity, suspended solids (SS) and chemical oxygen demand (COD). The results obtained during the pilot-scale studies were favourable. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS and COD were 47.7%, 99.3% and 75%, respectively. The use of coagulant remarkably enhanced the removal of both conductivity and COD. Using a coagulant dosage of 30 mg/L, the highest removal rates achieved for the three water quality indicators were 54.5%, 99.6% and 92.7%, respectively. These water quality levels are adequate to allow for the reuse of at least a part of the treated wastewater as makeup process water in papermaking.

Keywords
pulsed electro-chemical method, electrocoagulation, coagulant, OCC-based paper mill, wastewater, electrochemistry

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