【摘要】 对硬头鳟（Oncorhynchus mykiss）和虹鳟（O. mykiss）鱼苗循环水养殖系统生物滤池运行效率以及其不同部位主要功能进行比较。于2017年5—11月,测定了六级生物滤池的基本水质指标（TAN、NO₂^--N和NO₃^--N等）,并计算了六级生物滤池对TAN、NO₂^--N和NO₃^--N的去除率。于养殖中期,测定了六级生物滤池不同部位（BF1～BF6）的硝化速率、亚硝氮氧化速率和反硝化速率。结果表明:六级生物滤池对TAN、NO₂^--N和NO₃^--N的平均去除率分别为75.00%、44.00%和17.70%,其主要去除效果发生在BF1～BF3;六级生物滤池中BF1的硝化速率最高,与BF1较高的初始TAN浓度、充足的溶氧和最适pH有关;BF3的亚硝氮氧化速率最高,与BF3较高的初始NO₂^--N浓度有关;BF5的反硝化速率最高,与BF5较低的pH和较高NO₃^--N浓度有关。结果表明适当缩减生物滤池级数,并在循环水养殖系统中加入反硝化反应器,有利于提高系统运行效率。更多还原

【Abstract】 In this study, the performance and main functions of different part locations in the six-stage biofilters used in the recirculating aquaculture systems of Oncorhynchus mykiss and O. mykiss were compared. From May to November of 2017, the water quality parameters of the six-stage bio-filters, such as TAN, NO₂^--N and NO₃^--N, etc., were tested, and the removal efficiencies for these parameters were calculated accordingly. During the mid-period of culture, the nitrification rate, nitrite nitrogen oxidation rate, and denitrification rate at different locations of the six-stage bio-filters（BF1～BF6） were measured. The experimental results showed that the average removal rates of TAN, NO₂^--N and NO₃^--N by the bio-filter were 75.00%, 44.00% and 17.70%, respectively,which mainly occurred at BF1～BF3 locations. The highest nitrification rate happened at BF1 which was associated with high TAN, enough DO and feasible pH value at this location. The nitrite nitrogen oxidation rate of BF3 was the highest due to the higher initial NO₂^--N concentration. And the highest denitrification rate appeared at BF5, it was related to low pH and high NO₃^--N concentrations. The study indicated that proper reduction of the bio-filter stages and addition of denitrification reactor in the recirculating aquaculture systems could improve the operation efficiency of the system.更多还原