Batch Electrocoagulation Treatment of Peat Water in Sarawak with Galvanized Iron Electrodes

Abstract

Peat water is an abundant water resource in Sarawak where some of the coastal areas in Sarawak still utilize peat water for domestic usage. Peat water contains natural organic matters especially humic substances which include humic acids. Humic acids contribute to the brown color of peat water and can cause diseases such as stomach cancer, blackfoot disease and etc. if consumed by human. Electrocoagulation is an alternative to conventional water treatment methods which have the advantages of being environmental friendly, minimal sludge production and no addition of chemical substances. The aims of this study are to fabricate a desktop scale electrocoagulation system with galvanised iron electrodes and to investigate the effects of the operating parameters such as inter-electrode distance, applied current density, number of electrodes, and treatment time on peat water in the system. The performance of batch electrocoagulation system in term of their removal efficiency of several parameters such as total organic carbon (TOC), chemical oxygen demand (COD), color and turbidity are evaluated. Through experimental tests conducted, this system successfully removes 98.44% of COD, 92.02% of TOC, 97.92% of turbidity and 99.91% of color by using galvanized iron as an electrode at current density of 25 A/m2in 30 minutes with 10 galvanized iron electrodes. Despite the fact that there is a small amount of iron ions and zinc ions remained in the treated peat water which are 0.001mg/l and 0.0442mg/l respectively, these concentrations are far below the standard limits imposed by Malaysia Ministry of Health (MOH). Generally, all the parameters studied meet the standard limit imposed by MOH except for total organic carbon. This is particularly due to the improper filtration system adopted in this study. The total operating costs for 252 in 30 minutes treatment time of 10 electrode plates is RM 8.75 per . Overall, the study have successfully designed a batch electrocoagulation system to treat peat water by using galvanized iron for domestic usage.