牙鲆养殖循环系统中3种硝化作用滤器性能的比较

The comparison of three nitrification filters in a recirculating system for Japanese flounder Paralichthys olivaceus culture

通过测定牙鲆Paralichthys olivaceus养殖循环水中总氨氮、亚硝酸态氮和硝酸态氮的含量，了解以塑料环、火山石和牡蛎壳为载体的3种硝化滤器生物膜的熟化情况；调节循环水流量，使硝化滤器水力停留时间分别为5、15、20、30、60min，比较氨氮去除率，得到实验条件下3种载体硝化滤器的最佳水力停留时间，并在此条件下，投加NH4Cl，使循环养殖水中总氨氮浓度分别为1、3、5mgCL，测定水中总氨氮随时间的变化，研究氨氮去除动力学规律，计算硝化滤器的去除效率。结果表明：附着于3种载体上生物膜的熟化时间约为25d；塑料环上异养菌和硝化菌数量均为最高，氧化还原反应最活跃，火山石次之，牡蛎壳最低；3种载体硝化滤器的最佳水力停留时间为20～30min。氨氮负载为1mg／L时，12h内氨氮去除为0级反应；氨氮负载分别为3mg／L和5mg／L条件下，24h内氨氮去除为0级反应。氨氮负载越大，氨氮去除速率就越大。在氨氮负载为1、3、5mg／L时，5种载体的氨氮去除效率分别为17．5l～16．39、36．39～33．04、58．96—53．25g／（m^3·d）。

The growth and nitrification performances of plastic ring, volcano stone and oyster shell biofiher media were studied in a water recirculation system for Japanese flounder Paralichthys olivaceus culture by determination of the nitrogen concentrations of ammonia, nitrite and nitrate. Ammonia removal was compared in the same filter media 5, 15, 20, 30, and 60 min after hydraulic retention. The nitrification kinetics and ammonia removal rate were studied by ammonia concentrations decreasing with time at different initial ammonia - N concentrations of 1, 3, and 5 mg/L. The maturation time of the three types of filter media was found to be about 25 d. The maximal heerotrophic bacteria and the nitrite bacteria and the maximal active oxidation -reduction reaction were observed on the plastic ring among three types filter media, fowlled by on the volcano stone, then on the oyster shell. The optimum hydraulic retention period of the three types of filter media was found to be 20 - 30 rain. The biodegradation of ammonia - N followed the zero - order kinetics in 12 h at the nitrogen load of 1 mg/L, and in 24 h at the nitrogen load of 3 mg/L or 5 mg/L. The ammonia removal rate by the three types of nitrification filter was 17.51 - 16.39, 36.39 - 33.04,and 58.96 -53.25 g/（m3 · d） at nitrogen load of 1,3,5 mg/L.