Dairy Wastewater Treatment with Rotating Biological Contactor as Secondary unit and use of Treated Effluent for Agriculture

Rotating Biological Contactor (RBC) is a biological fixed film treatment method that can be applied as part of secondary treatment for wastewater treatment. The present investigation was conducted on dairy wastewater treated by employing RBC as a secondary biological unit, which demonstrated encouraging results. Wastewater 3-day BOD was reduced to 85 mg/L from the influent BOD of 995 mg/L and COD from 1220 mg/L to 130 mg/L. Overall efficiency accomplished by RBC was 91.5% for BOD removal and 89.3% for COD reduction. The treated waste was then used for irrigation of soy and corn crops. Results exhibited an increase in organic matter from 0.262% to 0.395% for corn and 0.416 for soya, whereas available total nitrogen, phosphorus, and potassium as nutrients also increased compared to the regular groundwater application for irrigating the crop. Further, crop yield was also higher than normal, exhibiting advantages drawn from the application of treated wastewater for irrigation.