Removal of Antibiotics and Heavy Metal from Water by Electrocoagulation Technology

The release of heavy metals and antibiotics into the environment is a major concern. It affects both human and aquatic lives. A promising cost-effective and high efficiency water treatment process is electrocoagulation (EC). In this study, EC was adopted to treat nickel (Ni) and tetracycline (TC) synthetic wastewater solutions using iron and aluminium electrode materials separately. Two different electrode materials (aluminium and iron) were investigated and compared. The results showed that removal efficiency is favorable at neutral and basic condition with increasing stirring speed and decreasing inter electrode distance. After optimum conditions, removal percentage of Ni solution by iron electrodes reached more than 99% within 60 min with optimum conditions (10 g.L-1 initial concentration, pH 7, 1 cm gap, 1.12 g NaCl, 9 V and 400 rpm mixing speed), while more than 96% removal of TC (15 mg.L-1) with the same electrode within 5 min with pH 9, 1 cm gap, 2.24 g NaCl, 9 V and 250 rpm mixing speed. On the other hand, %removal of TC with Al electrode reached 99.9% within 5 min reaction time (15mg.L-1 initial concentration, pH 7, 1 cm gap, 0.56g NaCl, 4.5 V and 400 rpm mixing speed). The operating costs and electrical energy consumed to remove Ni and TC by Fe were (1.4 $.m-3, 27.9 Kwh) and (0.95 $.m-3, 18.9 Kwh) respectively. In contrast, 0.26 $.m-3 and 5.18 Kwh were the operating cost and electrical energy consumed to remove TC via Al electrode respectively. EC operating parameters in this study at optinium conditions showed that the treatment is extremely effective.