不同养殖品种池塘化学耗氧量(CODMn)变化趋势及环境影响因素

为了解养殖池塘水体化学耗氧量的变化特征，于2012 年在佛山市顺德区内4 种不同养殖品种(云斑尖塘鳢、草鱼、大口黑鲈、乌鳢）池塘采集样品进行分析。结果显示院不同时期4 个品种养殖池塘CODMn含量在3.71~50.76 mg/L 之间，其中大口黑鲈、乌鳢两个品种养殖池塘季节的变化有显著差异；云斑尖塘鳢、草鱼池塘的CODMn 含量没有明显的季节性变化。不同品种养殖池塘CODMn含量从低到高依次为云斑尖塘鳢、大口黑鲈、草鱼、乌鳢。养殖池塘水体CODMn污染指数（Pi）范围在0.67~8.46 之间，超标率为92.9%。图谱分析结果显示，5~8 月间不同养殖池塘水体中云斑尖塘鳢、大口黑鲈养殖池塘CODMn有比较相近特征，而草鱼、乌鳢养殖池塘与其他池塘特征相差较大。9~12 月间不同养殖池塘水体中CODMn 云斑尖塘鳢、草鱼、大口黑鲈养殖池塘有比较相近特征，而乌鳢养殖池塘与其他池塘特征相差较大。对CODMn 与14 个水质因子进行相关分析发现，CODMn 与透明度、pH 值及硅酸盐存在负相关关系，与盐度、电导率、叶绿素、磷酸盐、硝酸盐、氨氮等存在正相关关系，而与溶解氧及非离子铵不相关。

Changing trend of chemical oxygen demand (CODMn) indifferent breeding pond and its influence factors

To understand the variations of chemical oxygen demand (COD) in culturing ponds, water samples werecollected from four different breeding species(Oxyeleotris marmoratus, Mylopharyngodon piceus, Micropterus salmoides, Channaargus) ponds of Shunde District, Foshan City in 2012. The results indicated that CODMn content of the four breeding pondsranged from 3.71 to 50.76 mg/L, and there existed significant seasonal differences in CODMn content for M. salmoides andC.argus ponds, but no seasonal difference in O. marmoratus and M. piceus ponds. The sequence from low to high forbreeding pond CODMn content was O.marmoratus >M. salmoides> M. piceus >C. argus. CODMn pollution index (Pi) rangedfrom 0.67 to 8.46, and the over standard rate reached 92.9%. Atlas analysis showed that from May to August, CODMn inponds of O. marmoratu and M. salmoides had relatively similar characteristics. However, ponds of M.piceus and C.argusfeatured a larger difference from other ponds. From September to December, CODMn in ponds of O.marmoratus, M.piceusand M.salmoides had relatively similar characteristics, while pond of C.argus differed from other ponds. The relationshipbetween Permanganate index (CODMn) and 14 water quality factors showed that potassium permanganate (CODMn) was negativelycorrelated with transparency, pH and silicate, and was positively correlated with salinity, conductivity, chlorophyll,phosphate, nitrate, ammonia nitrogen, but not related with dissolved oxygen and non ion ammonia.