Boron removal from industrial wastewaters by means of optimized sequential chemical precipitation and coagulation processes

In this work, the removal results of the application of sequential chemical precipitation (CP) and coagulation (CC) over boron-containing industrial wastewater were presented. Effect of amount of Ca(OH)2/B2O3concentration ratio, initial pH and Al2(SO4)3∙18H2O concentration on B2O3removal was investigated using Box–Behnken based custom experimental design. Response surface methodology (RSM) was used to evaluate the effect of process variables and their interactions on boron removal. Results show that selected operational parameters and obtained regression model were statistically significant. The coefficient of determination was found as 0.9846, indicating that the model has a good fit with experimental data. Water has been obtained in a dischargeable quality according to Water Pollution Control Regulation of Turkish Authorities with 95% B2O3removal from an initial concentration of 13.23 g/L under optimum operating conditions of 2.01 g Ca(OH)2/1 g/L B2O3ratio, pH 8.12 and 13.5 g/L Al2(SO4)3∙18H2O.