Biofiltration as an Advanced Primary Treatment Method to Achieve Substantial Energy Savings
Energy Savings and Other Benefits of Biofiltration for Wastewater Treatment
Biofiltration generates energy savings by removing more organic load, which in turn reduces aeration electricity consumption in the downstream biological treatment and increases digester gas energy production from the diverted organic material. This project quantified a electrical energy reduction between 15 to 20 percent achieved by biofiltration based on demonstration results at the Linda County Water District plant. The biofiltration demonstration proved the technology to be a feasible alternative to conventional primary wastewater treatment processes.
Conventional wastewater primary treatment uses clarification for solids removal and activated sludge treatment for secondary treatment to remove organics. Biofiltration is an emerging advanced primary-treatment technology that more efficiently and economically removes particulate and soluble material than the conventional primary method of clarification that removes only particulate material. In a biofiltration system, particulate material is removed mainly through filtering, and soluble organic material is removed by using microorganisms to capture and biologically degrade the pollutants. This project demonstrated that biofiltration is a technically viable and commercially attractive approach to achieve significant electrical energy savings at wastewater treatment plants with a full scale demonstration at Linda County Water District plant.
Aeration power requirements are estimated to decrease by approximately 45 to 60 percent compared to conventional treatment methods. Assuming 25% implementation of the technology, it is estimated that the annual electrical energy and cost savings for the wastewater treatment plant operators in California will be 110,000,000 kWh and $12,900,000 per year, respectively.