鲢鳙鱼原位修复水库水质的试验

Experiment of Reservoir Water Quality In-Situ Remediation with Silver and Bighead Carps

为解决辛安水库水体富营养化影响供水水质的问题,进行了鲢鱼、鳙鱼改善水库水质的试验研究。试验采用4个4 m×1.5 m×2.5 m的围隔生态塘,鲢鱼、鳙鱼的投放比例为3:1,鱼类总密度分别为15、20、35 g/m^3和50 g/m^3,试验期间水温维持在17.5~23.8℃。试验结果表明,投放鱼类对溶解氧浓度影响不大,溶解氧在8.72~9.28mg/L;鲢鱼、鳙鱼对COD_(Mn)、NH_3-N、TN、TP、藻类等指标有一定的去除效果,投放鱼类密度越高,去除效果越好。在试验条件下,COD_(Mn)、NH_3-N、TN、TP和藻类的去除率分别为6.9%~22.4%、11.6%~25.1%、8.9%~32.1%、14.6%~29.7%和48.4%~69.3%。综合考虑经济投入和处理效果,建议选择35 g/m^3的鱼类投放密度。

To solve the problem of eutrophication in Xin,an Reservoir that has resulted in the deterioration of water supply qual i ty, si lver and bighead carps were introduced to remediate the water qual ity. 4 ecological ponds （4 mx1.5 mx2.5 m） were adopted in the study. Si lver and bighead carps were put into every pond at a population ratio of 3 ： 1, and total fish densities of the 4 ponds were 15, 20, 35 g/m 3 and 50 g/m 3,respectively. Water temperature in the 4 ponds was maintained at 17.5 ？23.8 丈.According to the re sults, introduction of fish into the ponds was not an effective way to change the amount of dissolved oxygen. The dissolved oxygen was between 8.72 mg/L to 9.28 mg/L. However,si lver and bighead carps could lower some other water qual ity indexes,such as C0DMn,N H 3-N , TN and TP. A higher fish density could result in better removal efficiency of the contaminants. Under the experimental conditions, removal efficiency of C0 D mh , NH^N ,TN,TP and algae was attained to 6.9%~22 .4 %, 1 1 .6% ~ 2 5 .1% , 8 .9% ~ 3 2 .1 %, 1 4 .6% ~ 29.7% and 48.4% ？69.3% ,respectively. Considering the economic investment and treatment performance comprehensively, the suggested fish density was 35 g/m3.