Biological treatment of distillery wastewater by application of the vermifiltration technology

In this study distillery wastewater was treated using the vermifiltration technology in a bid to reduce downstream contamination by the effluent. 10 kg of Eisenia fetida earthworms were used as the vermifiltration media in a 0.5 m × 0.5 m x 0.3 m vermifiltration bed over a 40 h period cycle. The distillery effluent physicochemical parameters which included pH, total Kjeldahl nitrogen (TKN), biological oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS) and the chemical oxygen demand (COD) were measured every 5 days. The vermicompost which was produced as a result of the vermifiltration process's nitrogen, phosphorous and potassium composition was also determined. The distillery effluent pH changed from acidic to neutral whilst a decrease of 94.9% was observed for the TKN, 91.1% for the BOD, 91.9% for the TDS, 92.4% for the TSS and 89.4% for the COD upon treatment with vermifiltration. The vermicompost, a by-product of the vermifiltration process had a nitrogen, phosphorous and potassium composition of 1.87%, 0.87% and 0.66% respectively.