太湖流域不同类型区河流水体磷形态分布及矿化速率

DISTRIBUTION AND MINERALIZATION RATE OF PHOSPHORUS IN DIFFERENT POLLUTED RIVERS IN TAIHU BASIN

采用野外采样与室内实验相结合,对种植业(A)、养殖业(B)和生活污水(C)3种影响类型河流水体中磷的形态、矿化速率和周转时间进行分析研究。结果表明,B类型影响的河流水体中总磷(TP)、可溶解性总磷(TDP)和溶解性反应磷(SRP)浓度略高于A类型,却远低于C类型影响的河流水体;但河流水体中可酶解磷(EHP)浓度则相反,以A类型影响的河流水体最高,丰水期最高可达0.11 mg L-1,而C类型影响的河流水体EHP浓度则较低。实验数据显示受农业影响的河流水体磷的矿化速率明显高于C类型影响的河流水体,尤其在丰水期,A类型影响的河流水体中磷的矿化速率最高可达1.437 nmol L-1min-1。研究表明水体中磷的矿化速率与EHP浓度呈正相关关系;受农业影响的河流水体磷的周转时间为3～7 d,低于C类型影响的河流水体的9.1 d。以上结果说明环太湖河流水体磷的形态分布、转化与影响水体的类型密切相关,生活污水对环太湖河流总磷贡献较大,而农业生产所产生的磷其生物可利用性更强。

Water samples were collected for phosphorus （P） analysis in the rivers polluted with farming （Type-A）, fishery （Type-B） and domestic sewage （Type-C） in Taihu Basin, China. The results show that the total phosphorus （TP） , the total dissolved phosphorus （TDP） and the soluble reactive phosphorus （SRP） are slightly higher for Type-B river than Type-A river, but much lower than Type-C river. On the contrary, enzymatically hydrolysable phosphorus （EHP） in Type-A river is the highest with a maximum value of 0.11 mg L^-1 in high-water period, and is the lowest for Type-C. Laboratory analysis reveals that mineralization rate of organophosphorus is significantly higher for Type-A and-B rivers than that for Type-C, especially in high-water period with a maximum value of i. 437 nmol L ^-1 min^ -1 EHP is found to be positively related to mineralization rate, and organo-phosphorus has a regeneration period of 3 - 7 days in Type-A and-B rivers versus the 9.1 days in Type-C river. Overall, the distribution and mineralization rate of P are rivertype dependent. The major TP contributed from domestic sewage, while the phosphorus contributed from farming and fishcry is more readily available to plants in Taihu Lake.