微囊藻毒素含量与自然水体环境影响因子的相关性

研究了太湖流域湖州段、杭州市贴沙河和某水华池塘等自然水体的微囊藻毒素水平,利用相关性分析、主成分分析、聚类分析等统计方法,探讨了自然水体中微囊藻毒素MCLR和MCRR与环境影响因子的相关性.结果表明,3处水体的微囊藻毒素MCLR水平为0.049～12.30μg/L,MCRR为0.032～7.90μg/L,底层水中微囊藻毒素的含量显著高于表层水;水体中MCLR的平均浓度与TN、NH₄⁺-N、NO₂^--N和TP呈显著正相关(p<0.01),与水温、DO和氮磷比呈显著负相关(p<0.01),MCRR的平均浓度与NO₃^--N和氮磷比呈显著正相关(p<0.01),与pH、DOC、高锰酸盐指数、光密度呈显著负相关(p<0.01);TP和NO₂^--N是影响MCLR生物合成的主导因子,NO₃^--N和氮磷比是影响MCRR生物合成的重要因子;NO₂^--N和NO₃^--N可能分别是MCLR和MCRR生物合成中利用的主要无机氮源.

Research on Microcystins in Freshwaters of Zhejiang with relation to Environmental Factors

This research investigated the concentrations of microcystins and environmental factors in three freshwaters of Zhejiang such as Taihu Lake (Huzhou section), Tiesha River and a blooming lagoon. The relativities between microcystins and environmental factors were studied by the methods of correlation analysis, principal components analysis, cluster analysis and stepwise multiple linear regression. The results show that the concentrations of MCLR and MCRR range from 0.049 microg/L. to 12.30 microg/L and from 0.032 microg/L to 7.90 microg/L, respectively, and the concentrations of microcystins at the bottom of the waters are higher than the aquatic surface. Significant positive relationships (p < 0.01) were observed between MCLR and TN, NH4+ -N, NO21- -N and TP, and also between MCRR and NO3- -N, N:P ratio; Significant negative relationships (p < 0.01) were observed between MCLR and water temperature, DO and N: P ratio (p < 0.01), and between MCRR and pH, DOC, permanganate index and optical density. Our research indicated TP and NO2- -N possibly be the main factors for the biosynthesis of MCLR, while NO3- -N and N:P ratio would be important for MCRR. NO2- -N and NO3- -N are possible the mainnitrogen resources for the biosynthesis of MCLR and MCRR, respectively.