A pilot study on the dual membrane process of ultrafiltration and nanofiltration to treat algae-laden raw water compared to O3-BAC

Abstract In this study, a dual membrane process that combines seven-hole ultrafiltration and nanofiltration was designed and compared to O3-biological activated carbon (O3-BAC) for high-quality drinking water production. The pollutant removal, membrane fouling, long-term operational characteristics, and technical economy were systematically investigated using raw water from Tai Lake, which has a high algae content. The results elucidate that the dual membrane process has superb decontamination. This method has much better removal of turbidity, CODMn, UV254, and algae than O3-BAC. Its removal of ammonia nitrogen and fluorescent substances is slightly lower than that of O3-BAC, but the effluent still satisfies the drinking water standard. The dual membrane process is also much more capable of dealing with high algae-laden raw water. Compared to O3-BAC, the cost of the dual membrane process is 46.4% higher per ton without consuming chemicals, so it is more environmentally friendly. In summary, the dual membrane process offers a promising and effective technology to treat high algae-laden water with the advantages of high stability, reliable effluent, and zero emissions.