摘要
Since September 2011,A 2/O-MBR wastewater treatment plant in Xi'an Siyuan University has been successfully running without replacing any of membrane modules.A total of 6.661 million m^3 of campus wastewater has been treated,and 4.405 million m^3 of water reaching the national urban miscellaneous water standard has been reclaimed and reused.A total of 25 km pipeline,5 pits,scenery fountains,lakes,and 12 pump stations have been constructed for flushing toilets,irrigating green grass lawn and afforest,and cleaning hardened pavement.The design and construction of 5 pits,scenery fountains,and lakes are important to meet the national urban miscellaneous water standard under occasional phosphorus and/or nitrogen exceed concentration.The unit water cost is 4.19 yuan/m^3,including membrane modules depreciation and amortization.After the A 2/O-MBR system passes the membrane modules depreciation and amortization period,the unit water cost is 2.82 yuan/m^3.The water productivity of the membrane stack rises first at the beginning of operation,reaches the maximum value,and then decreases.The average annual transmembrane pressure difference increases by 1.12 kPa.The average VMD of industrial permeability decreases annually by 0.45 m^3.
