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) in different breeding pond and its influence factors

To understand the variations of chemical oxygen demand (COD) in culturing ponds, water samples were collected from four different breeding species(Oxyeleotris marmoratus, Mylopharyngodon piceus, Micropterus salmoides, Channa argus) ponds of Shunde District, Foshan City in 2012. The results indicated that CODMn content of the four breeding ponds ranged from 3.71 to 50.76 mg/L, and there existed significant seasonal differences in CODMn content for M. salmoides and C.argus ponds, but no seasonal difference in O. marmoratus and M. piceus ponds. The sequence from low to high for breeding pond CODMn content was O.marmoratus >M. salmoides> M. piceus >C. argus. CODMn pollution index (Pi) ranged from 0.67 to 8.46, and the over standard rate reached 92.9%. Atlas analysis showed that from May to August, CODMn in ponds of O. marmoratu and M. salmoides had relatively similar characteristics. However, ponds of M.piceus and C.argus featured a larger difference from other ponds. From September to December, CODMn in ponds of O.marmoratus, M.piceus and M.salmoides had relatively similar characteristics, while pond of C.argus differed from other ponds. The relationship between Permanganate index (CODMn) and 14 water quality factors showed that potassium permanganate (CODMn) was negatively correlated 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.