反硝化条件下有机碳低丰度河床沉积层中的苯胺降解

Aniline degradation coupled to denitrification in riverbed sediments with lower content of organic carbon

采集渭河河床沉积物,研究了反硝化条件下有机碳低丰度的河床沉积层中苯胺降解。结果表明,反硝化条件下,苯胺在有机碳低丰度的河床沉积层中可生物降解。使该环境中苯胺(约50mg/L)降解近95%,当硝酸盐为30.69、184.16、245.54mg/L时,降解时间分别约为20、45、70d。在上述环境中另加35.98mg/L乙酸盐后,苯胺降解速度在硝酸盐为184.16mg/L时最大,硝酸盐为30.69mg/L时最小。当硝酸盐为30.69mg/L,不加乙酸盐,27d苯胺降解约95%;添加35.98mg/L乙酸盐后,实验进行了47d还仍有近13mg/L苯胺残留,说明外加碳源(乙酸盐)对苯胺降解具有抑制作用。但当硝酸盐为184.16、245.54mg/L时,外加碳源(乙酸盐)则强化苯胺降解。水合金属氧化物对苯胺降解具有促进作用。

A mixturte of modified riverbed sediments （most organics and metals removed）, groundwater and nutrients was prepared to study aniline degradation in riverbed sediments with lower content of organic carbon under denitrification conditions. Aniline was degraded in 1 000 mL brown bottles filled with mixture. 95%degradation of aniline was accomplished in 20, 45 and 70 days in samples with an intinal nitrate concentration of 31, 184 and 246 mg/L, respectively. Adding 36 mg/L of acetate to the 184 mg/L nitrate sample improved its aniline degradation rate substantially; the acetate addition also enhanced biodegradation in the 246 mg/L nitrate sample. However, the same acetate supplement inhibited the aniline degradation in the 31 mg/L nitrate sample. Supplement of essential metal nutrients in hydrous metal oxide forms also enhanced aniline degradation.