Removal of color and chemical oxygen demand from sugar industry wastewater using thermolysis processes

Abstract

In the present study, treatment of sugar industry wastewater (SIWW) was investigated for the reduction of chemical oxygen demand (COD) and color using catalytic thermal treatment (thermolysis). Effect of various parameters such as pH 2–10, temperature 55–95°C, catalyst mass loading (C_w) 2–5 kg/m³, and types of catalysts was studied on COD and color reductions of the effluent. Among various catalysts used, copper oxide was found to be the best catalyst giving 74% COD and 80% color reductions with a catalyst concentration of 4 g/dm³ at pH 10 and 75°C temperature. Order of COD degradation rate was found to be 1.5 with respect to COD and 0.805 with respect to catalyst mass loading. Settling rate of the treated effluent was good and was found to be affected by the treatment temperature. The initial pH (pH_i) of the effluent played an important role in the treatment process, and optimum value was found to be different for different catalysts. Results show that the process can be applied for the treatment of SIWW.

Keywords:

• Catalyst
• COD reduction
• Filtration
• Sugar industry wastewater
• Settling
• Thermolysis