Coagulation-Flocculation Sequential with Solar Photo-Fenton Process for The Dairy Wastewater Treatment

Abstract

Dairy industry wastewater with high chemical oxygen demand (COD), total solids and concentrated colour. Direct disposal of untreated dairy wastewater into water bodies can pose a serious risk to human health and environment. This study presents combined coagulation and solar photo Fenton process of dairy wastewater was investigated. The efficiency of two alternative combined treatments for the reduction of chemical oxygen demand in dairy wastewater was evaluated, coagulation with poly-aluminium chloride and Ferric chloride hexahydrate followed by solar photo-Fenton process. In order to minimize operating cost, the effects of operating parameters were determined, and central composite deign was used to optimize the operating parameters. The operating parameters were, chemical oxygen demand (COD) removal were obtained under optimal conditions, pH= 4, Fe ²⁺ = 1g/L, H₂O₂ = 5 g/L and contact time = 90 min. Also it enhances the biodegradability of wastewater and the biochemical oxygen demand (BOD)/COD ratio was found to increase from 0.025 to 0.84. The wastewater BOD and total suspended solids concentrations were found to be 0 and 45 mg/L, respectively, which meets the requirements of the discharge standard. The combined treatment could be a promising alternative treatment for dairy wastewater and the potential of solar radiation as a sustainable and renewable energy resource could be exploited.