Treatability Studies of Dairy Wastewater by Electrocoagulation Process

Abstract

The dairy industry generates wastewater with high levels of pollution, including Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS). This study aimed to assess the impact of various operational parameters, such as voltage, pH, and reaction time, on treating real dairy wastewater using the electro-coagulation process. Stainless Steel electrodes were employed with Sodium chloride as an electrolyte. The research focused on removing COD, BOD5, and TSS. Initially, experiments were conducted with different voltages (10V, 20V, and 30V) while keeping the electrode distance constant and using 0.5gms of NaCl. In the second stage, experiments varied the initial pH (4, 6, 8, and 10) under optimal contact time, maintaining 1.5cm electrode spacing. Initially, a 2mm electrode thickness was tested but resulted in high energy consumption, so subsequent experiments used a 0.5mm electrode thickness. The electrode dimensions remained consistent at 150mm X 250mm X 10mm. The highest removal efficiencies for COD, BOD5, and TSS were achieved with a 30V applied voltage and SS-SS electrode combination, reaching 96%, 93%, and 94%, respectively. This study concludes that the SS-SS electrode combination with a 0.5mm thickness was the most effective in reducing COD, BOD5, and TSS, while also generating comparatively less sludge.