CO2 Emissions in Aerobic Wastewater Treatment Process of Potato Processing Industry

Abstract

This paper is about CO2 emissions (CO2e) in Aerobic biological treatment process for wastewater in potato processing industry which include direct emissions (Scope 1-biogenic activity in aerobic biological treatment process) after primary clarifier and indirect emissions (Scope 2-purchased electricity) used by surface aerators, motors and sludge dewatering equipment and electricity consumption in laboratory of effluent treatment plant (ETP) including the ETP office. The study of scope 3 includes use of chemicals in primary and secondary (aerobic) wastewater treatment process in ETP and waste transportation only. This study indicates that CO2e under scope 1 and 2 both can be minimized by reducing the organic load and total nitrogen (TN) load. The organic load is considered in terms of BOD load in kg. This study indicates that CO2e under scope 1, 2, and 3 increase as the organic load and total nitrogen increase and vice versa. CO2e was found in the lower side for the period of Jan to April and increased from April onwards. The CO2e due to N2O emission is found in range of 2.8% to 3.4% of total CO2e (scope1, 2 and 3) and 11% to 14% of Scope 1 emission which found in increasing order as the TN increased in wastewater. CO2e through BOD removal of wastewater (scope 1) was found in range of 22% to 28% of CO2e.  The electricity consumption under scope 2 increased as the organic load increased. CO2e due to electricity consumption was found in range 67.7% to 73.5% of Total CO2e. The CO2e due to electricity consumption is higher in scope 2 as compared to the CO2e in aerobic Biotreatment in scope 1 and chemical consumptions and sludge transportation under scope 3.