Potential of Vermifiltration Technique to Reduce Chemical Oxygen Demand, Biological Oxygen Demand, and Total Suspended Solid of Farm Dairy Effluent in Developing Countries: Case of Indonesian Farm Dairy Industry

Abstract

Farm dairy effluent (FDE) contains high level of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), and Total Suspended Solids (TSS) which caused river and groundwater pollution. To reduce those parameters, vermifiltration technique was utilized for dairy effluent treatment. It also could reduce greenhouse gasses (GHG) emissions, removing organic and excessive nutrients without odor and recovering manure nutrients in the treated dairy effluent and vermicompost. The objective of this study is to evaluate the potential of Vermifiltration in reducing COD, BOD and TSS of the FDE. Samples of wastewater were collected from dairy farm industry from 3,542 of total cow populations located in Bandung regency, Indonesia. The sample characteristics of COD, BOD, TSS, pH, NH3-N, organic carbon, and macro nutrients (total N, P2O5, and K2O) were measured before and after vermifiltration treatment. Vermifiltration treatment will produce two types of products i.e.: tea water and vermicompost. The result showed that Vermifilter removed the COD, BOD, and TSS of 93%, 95%, and 93% respectively. The organic carbon NH3-N, and total macro nutrients generally decreased after treated by Vermifilter (2.01 to 0.0001% of organic carbon, 718 to 3.75 mg L-1 of NH3-N, 0.2 to 0.02% of total N, 0.19 to 004% P2O5, 0.57 to 0.18% of K2O); however, the pH was not significantly changing (from 8.13 to become 8.05). Vermicompost produced by vermifiltration beds by earthworms consumes sewage solids and excreting them in the vermicast which produces high macronutrients (2.4% of total N, 5.5% of P2O5, and 0.75% of K2O), and organic carbon (15.6%), hence beneficial for soil fertilizer. Vermifilter effectively degrades the organic matter in the dairy effluent. Derivatives produced by the Vermifiltration process, namely tea water and Vermicompost, can be used as substitutes for irrigation materials and organic fertilizers on agricultural land, and act as soil conditioners to improve soil properties.