底泥原地稳定化过程中药剂对上覆水体的影响

Effects of chemical agents on the overlying water during in-situ sediment treatment

摘要: 采用底泥原地稳定化处理技术中的药剂投加方法,对苏州河底泥中投加零价铁(Fe⁰)、硝酸钙的上覆水体进行为期80 d研究比较.结果表明:投加Fe⁰后上覆水体的溶解氧(DO)被迅速消耗,体系易形成厌氧环境,而硝酸钙则减缓了上覆水体DO的消耗;投加零价铁或硝酸钙后都会使上覆水体的pH升高,Eh下降;投加Fe⁰后对上覆水体COD_Cr或TOC的影响较硝酸钙小;此外,两者上覆水体DO、pH和Eh与COD_Cr和TOC之间均具有一定的相关性.

Abstract: The zero valent iron(Fe⁰) or calcium nitrate was added into the sediment of Suzhou creck for 80 days in the anaer obic environment for in-situ sediment treatment.The effects of chemical agents on the overlying water were studied by DO,pH,Eh,COD_Cr and TOC measurements.The results show that DO is depleted dramatically by Fe⁰ added,resulting in anaero bic environment easily,whereas the consumption of DO is delayed by the added calcium nitrate.And Fe⁰ or calcium nitrate added will raise pH value and descend Eh value.Meanwhile,the effect on COD_Cr or TOC in overlying water by Fe⁰ added is lower than that of the calcium nitrate added.In addition,there are certain relations among DO,pH and Eh or between COD_Cr and TOC in overlying water as Fe⁰ or calcium nitrate is added respectively.