Abstract: The nano-TiO2 coating was applied to the surface of the fish pond to construct a recirculating aquaculture system consisiting of test group and control group. The effect of nano-TiO2 coating on purification of the wastewater in the water circulation treatment mode was studied. The influences of mass concentration of ammonia nitrogen in the raw water C0, DO and pH value on ammonia nitrogen degradation effiency were investigated. The results showed that after 48h treatment by test group of the recirculating aquaculture system with pH 7.0-7.8, TAN 14.2-15.3 mg/L, NO3--N 20.8-21.9mg/L and colonies number > 106/mL, ammonia nitrogen degradation reaction kinetics accordedwith the first-order kinetic equation. The reaction rate constant was 0.0697h-1, the half-life was 9.92h, and the ammonia nitrogen degradation and bacteriostatic effect were good. The order of the extent of influences of mass concentration of ammonia nitrogen in the raw water C0, DO and pH on ammonia nitrogen degradation in the test group was C0> DO>pH. When the mass concentration of ammonia nitrogen in the raw water C0 was 15 mg/L, DO was 6 mg/L and pH was 7.5, the ammonia nitrogen removal rate reached 41.9% when the test group of the recirculating aquaculture system was operated for 8h. The nano-TiO2 coating applied to the surface of the fish pond has a good purifying effect on the water body of the recirculating aquaculture system, and has a broad application prospect.

Key words: Nano- TiO2, coating, recirculating aquaculture system, water puification

摘要： 将纳米二氧化钛涂料涂覆于鱼池表面，构建循环水养鱼试验组和对照组系统，研究在水循环处理模式下纳米二氧化钛涂料对养鱼污水的净化效果，探讨原水氨氮质量浓度C0、DO及pH对降解氨氮效率的影响。结果显示：pH 7.0~7.8、总氨氮（TAN）14.2~15.3 mg/L、硝酸盐氮（NO3--N ）20.8~21.9 mg/L、菌落总数 >106个／mL的养鱼污水循环水养殖试验组系统处理48 h，氨氮降解反应动力学符合一级动力学方程，反应速率常数为0.0697 h-1，半衰期分别为9.92 h，氨氮降解及抑菌效果好；原水氨氮质量浓度C0、DO、pH对试验组降解氨氮影响大小依次为C0＞DO＞pH。在原水氨氮质量浓度C015 mg/L、DO6 mg/L、pH7.5的条件下，循环水养鱼试验组系统运行8h时，氨氮去除率可达41.9%。涂覆于鱼池表面的纳米二氧化钛涂料对循环水养鱼系统水体具良好的净化效果，应用前景广阔。

关键词: 纳米二氧化钛, 涂料, 循环水养鱼系统, 水净化