Effect of recycling of elemental chlorine free bleaching effluent treated by electrocoagulation on paper properties

Abstract

This study aimed to determine the effect of recycling elemental chlorine free (ECF) bleaching effluent (D0 Ep D1 and OD0 Ep D1) after treatment through electrocoagulation under optimum conditions on paper properties. The effect of pH, current density, time and dose of electrolyte on the reduction of chemical oxygen demand (COD) and color was studied. Maximum decrease in COD and color was found under optimum conditions (i.e., pH 7, treatment time of 30 min, current density of 29.16 mA/cm2, and 1 g/L NaCl). Under these optimum conditions, the reduction in COD and color was of 79.9% and 99.10%, respectively. The reduction in the strength properties of paper, caused by recycling, was found to be insignificant, but a decline of 2.11% for D0 Ep D1 and of 1.43% for OD0 Ep D1 in brightness was found. Using the electrocoagulation method to treat the bleaching effluent can prove to have valuable potential towards wastewater utilization, pollution control, and sustainable development of the industry.