1Centre for Environment, Institute of Science & Technology, Jawaharlal Nehru Technological University, Hyderabad- 500 080, India
2Centre for Environment, Institute of Science & Technology, Jawaharlal Nehru Technological University, Hyderabad- 500 080, India. Department of Civil Engineering, Indian Institute of Technology (IIT), Kanpur,India
This paper is a preliminary communication of a study on removal and recovery of heavy metals from industrial waste waters using electro-coagulation (EC) technique. The larger study envisages use of solar energy for producing the D.C. current, and simple chemical methods of standard methods in chemistry like use of hydrochloric acid, hydrogen sulfide, collection of precipitate, incineration and getting metal oxides in the most economical way of metal recovery. However, this paper reports on the removal of Arsenic (As) from industrial effluent using electro-coagulation (EC) technique. The optimization has been performed to increase the removal efficiency of As by varying initial pH (2-10), time of electrolysis (5-30min) and current density (0.8-4.8 A/dm2). For the first time, we notice that the current density 4.8 A/dm2 has been observed to produce the quickest removal (99.9%) within 10min. The phenomenal COD reduction from 400mg/l to 30mg/l with electrolysis time of 15min is a significant finding, to achieve this type of COD reduction by the existing methods generate huge quantities of sludge. The sludge formed in the reaction vessel also have been Investigated.