Quality Assessment of Effluent Discharges from Vegetable oil Plant

Abstract

The quality of effluent discharges from a vegetable oil processing company, located in Anambra State – South east Nigeria, was evaluated relative to regulatory body – Federal Environmental Protection Agency (FEPA) standard. Wastewater quality parameters namely; biochemical oxygen demand (BOD), dissolved oxygen (DO), total hydrocarbon content (THC), oil and grease, total dissolved solids (TDS), pH, and temperature were determined weekly on effluent samples, for a period of 12 weeks, using standard methods. The effluent data were subjected to statistical correlation. BOD values ranged from 10.80 – 94.20 mg/L, with 90% occurrence value of 81.20 mg/L, which exceeded FEPA set limit of 50mgLl by 62.40% for about 14% of the time. DO level ranged from 2.70 – 4.60 mg/L which was below the saturation point of 7.5mg/L at 30⁰C. THC, Oil and Grease consistently exceeded the set limit of 10 mg/L. Effluent pH range of 4.60 - 9.60 was outside FEPA range of 6-9. However, TDS and temperature levels were consistently within permissible limits through out the period under investigation. There is need for proper treatment and monitoring of effluent to ensure consistent quality that meets  environmental standard.

Keywords: Quality parameters, set limits, percent occurrence value, period, regulatory