Use of aluminum-based water treatment sludge as coagulant for animal farm wastewater treatment

Abstract

Unlike other studies of artificial wastewater treatment, this study aims to use the aluminum-based water treatment sludge (Al-WTS) as a substitute for traditional chemicals as coagulant in the coagulation-flocculation process for a real animal farm wastewater treatment. The study was designed for a lab-scale trial to explore the optimum conditions of coagulation and flocculation process so that the removal efficiencies of the total suspended solids (TSS), total organic carbon (TOC) and PO43− concentration of the wastewater can be maximized. The experiments were conducted in a series jar-test apparatus to simulate the coagulation-flocculation process. The effects of initial pH and the dosage of liquid Al-WTS on the removal efficiencies of the animal farm wastewater were examined and discussed. Moreover, a Box-Behnken statistical experimental design (BBD) by Design expert 8.0 was used to optimize the experimental conditions. At the optimum initial pH value of 7.0 and Al-WTS dosage of 1588 mg/L, the removal efficiencies of TSS, PO43−, and TOC were 87.8 ± 2.2%, 96.9 ± 2.9%, and 62.1 ± 1.8%, respectively. It is concluded that the Al-WTS could be used for the treatment of animal farm wastewater with considerable removal efficiencies, thus opening a cost-effective way for using a “waste” for wastewater treatment.