原位化学处理对东湖底泥中磷释放的影响

原位化学处理对东湖底泥中磷释放的影响 Effects of in situ Sediment Treatment on Phosphorus Release in Donghu Lake 刘广容 LIU Guangrong 1 first-author 叶春松 YE Chunsong 1 贺靖皓 HE Jinghao 1 戴文津 DAI Wenjin 1 武汉大学动力与机械学院 武汉大学动力与机械学院 School of Power and Mechanical Engineering,Wuhan University School of Power and Mechanical Engineering,Wuhan University 厌氧条件下对东湖底泥进行了30 d,4种原位化学处理（①Al2（SO4）3,②FeCl3,③CaCl2,④NaNO3）的模拟实验.结果表明,厌氧条件下底泥释放磷的速率大大超过化学处理底泥时释放磷的速率.厌氧条件下用未使用化学处理和分别用上述4种化学处理时磷的平均释放速率分别为7.548,-0.644,0.033,0.174,0.644mg.m-2.d-1;水相中总铁量和总磷量有一定的相关性.底泥中注入上述盐类引起了各形态磷组分的变化:CaCl2使处理后底泥中钙结合态磷PCa含量最高,表明钙盐促进了难溶性的含磷矿物质的生成;FeCl3和NaNO3处理的底泥表面氧化的Fe3+和铁、锰的金属氧化物结合态磷PFe,Mn的含量增加,证实了底泥表面铁氧化物对磷保持力的重要性;Al2（SO4）3处理后铝和铁的金属氧化物结合态磷PAl,Fe含量高,说明磷被吸附在铝氧化物中,因而铝盐具有较强的束缚磷的能力. In situ sediment treatment with several salts is a promising approach to control phosphorus release in Donghu Lake.Under suboxic condition,five treatments were bubbled with N2 by a 30-day experiment with undisturbed sediment cores: ① Al2（SO4）3,② FeCl3,③ CaCl2,④ NaNO3.The results indicate that the amount of sediment phosphorus release under control O2 was much more than the one under adding chemical（Al2（SO4）3,FeCl3,CaCl2,NaNO3）,and the rate of average TP（total phosphorus）effluxes is 7.548 mg·m-2·d-1 under anaerobic condition.Mean accumulated P-release rates for suboxic treatments with Al2（SO4）3,FeCl3,CaCl2,NaNO3 were:-0.644,0.033,0.174,0.644 mg·m-2·d-1,respectively.In order to identify changes in the P binding sites in the sediment as caused by the treatments,a sequential P extraction procedure was applied on the sediment before and after the efflux experiment.Adding CaCl2 can prevent the liberation of phosphate probably as a result of the formation of especially apatite minerals,thus the PCa increasing at the sediment surface.Addition of FeCl3 and NaNO3 to the sediment increased the amounts of oxidized Fe3+ and PFe,Mn,Al2（SO4）3 addition resulted in a higher fraction of PAl,Fe,which shows higher capacity of Al in bound binding P. 底泥 内源磷 Al2（SO4）3 NaNO3 FeCl3 CaCl2 sediment internal phosphorus Al2（SO4）3 NaNO3 FeCl3 CaCl2 X524 国家重点基础研究发展计划（973）项目（2002CB412307） 2008-04-01 2021-04-01 4