Aniline biodegradation in riverbed sediments with low concent of organic carbon under denitrification conditions

摘要

The riverbed sediments (collected from Weihe River, close to Xi'an, China) treated with chemical sequential extraction procedures, and as well as groundwater (from a 20m-depth well in Xi'an) are used in the microcosms tests to research the characteristics of aniline biodegradation in the riverbed sediments with low content of organic carbons (SLC) under denitrification conditions. The results show that aniline can be degraded in SLC under denitrification conditions. It takes about 20d, 45d and 70d to degrade (about 50mg/L) aniline 95%, when the intinal concentration of nitrate is 30.69 mg/L, 184.16 mg/L and 245.54 mg/L respectively. But, when 35.98 mg/L acetate is added as external organic matters to the microcosm, and the intinal concentration of nitrate is 184.16 mg/L, aniline is degraded quicker than that when nitrate is 30.69 mg/L or 245.54 mg/L. Compared the rates of aniline degradation in the microcosms without and with (35.98 mg/L) acetate added, aniline is degraded faster in the microcosms without acetate than that in the microcosms with acetate added. So the external matters have a potential to inhibite the degradation of aniline under this studied conditions. However, when the concentration of nitrate is 184.16 mg/L or 245.54 mg/L, the external matters have a potential to enhance the degradation. Hydrous metal oxides accelerate the degradation of aniline in SLC under denitrification conditions.