中文摘要：

运用水溞趋光行为的抑制试验研究了水体中不同磷形态和重金属（Cu、Zn、Cd）共同存在时的联合生物毒性效应．结果表明，水体中重金属的生物毒性不仅取决于它们的种类和浓度，也与溶液中共存的P形态有关．重金属对水溞的生物毒性由强至弱依次为Cu^2＋＞Zn^2＋＞Cd^2＋；当溶液中存在不同形态的P时，重金属的生物毒性发生了改变．中等P营养水平（TP为0．05mg·L^-1）时，不同形态P的存在可显著降低Cu、Zn、Cd的生物毒性，在某种程度上减轻重金属对生物的伤害．不同形态P对重金属生物毒性的拮抗作用顺序为H2PO4^-≈HPO4^2-＞PO4^3＋．因此，重金属污染与富营养化双重胁迫水体的生物毒性，将可能因水体中P形态的不同而产生差异．

英文摘要：

The effects of the different forms of phosphorus on heavy metal （ Cu^2＋ , Zn^2＋ and Cd^2＋ ） joint-biotoxicity were studied by the phototactic behaviour of Daphnia carinata. The results showed that the toxicity of heavy metals was mainly related to their concentrations, which was also influenced significantly by the forms of phosphorus coexisted in eutrophication waters. The toxicity of heavy metals on Daphnia in the sequence was Cu^2＋ 〉 Zn^2＋ 〉 Cd^2 ＋. The same heavy metal had different inhibition on Daphnia ＇s phototaxis when the different forms of phosphorus coexisted in waters. The results indicated that the toxicity of Cu^2＋ , Cd^2 ＋ or Zn^2＋ to D. carinata was reduced in the presence of moderate level of phosphorus（ TP = 0.05mg·L^-1 ）, and thus somewhat reduced the harmness of heavy metals to aquatic organisms. The antagonism of phosphorus on heavy metal in the sequence was H2PO4^- ≥HPO4^2- 〉PO4^3-. It seems reasonable to suggest that the biological harmness caused by heavy metals and eutrophication varied with phosphorus forms.