Degradation of aniline in Weihe riverbed sediments under denitrification conditions.
Three groups of microcosm tests were conducted to study the possibility of aniline degradation and the effects of organic matter and hydrous metal oxides on the degradation in Weihe riverbed sediments under denitrification conditions. After the riverbed sediments (20 g) and groundwater (800 ml) were put into bottles, aniline, nitrate and other reagents were added, and then the bottles were flushed with N2 for 30 minutes to create microcosms. Samples from the microcosms were employed for the analysis of aniline, nitrate, and chemical oxygen demand (COD). In the first test group, the concentration of aniline remained unchanged when NaN3 (500 mg/L) was added. When there was no nitrate or NaN3, the concentration of aniline also remained unchanged, although COD declined. However, the concentration decreased when nitrate (50 mg/L) was added. Therefore, aniline can be biodegraded under denitrification conditions. In the second test group, when the concentration of nitrate reached 50 mg/L, 300 mg/L or 400 mg/L, either the external or internal organic matter or both of them in Weihe raw sediments inhibited aniline degradation. In the sediments where organic matter alone or organic matter plus hydrous metal oxides were removed, the organic matter still inhibited the degradation when the concentration of nitrate reached 300 mg/L or 400 mg/L, but the external organic matter could accelerate the degradation when the concentration of nitrate was 50 mg/L. The result of the third test group showed that hydrous metal oxides can accelerate degradation. By analyzing the mechanism of the aniline degradation, we conclude that aniline is degradable by microbes in their growth metabolism, in which deamination is involved.
Wu
Yao-Guo
YG
Department of Applied Chemistry, Northwestern Polytechnical University, Xi'an, Shaanxi, China. wuygal@hotmail.com
Hui
Lin
L
Li
Xiang
X
Zhang
Yue-Zhou
YZ
Zhang
Wen-Cun
WC
D000537:Aluminum Oxide / Q000032:analysis; D000814:Aniline Compounds / Q000032:analysis / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002681:China; D005290:Ferric Compounds / Q000032:analysis; D019015:Geologic Sediments / Q000032:analysis / Q000382:microbiology; D017895:Manganese Compounds / Q000032:analysis; D009566:Nitrates / Q000032:analysis / Q000378:metabolism; D010087:Oxides / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D014881:Water Supply
D000814:Aniline Compounds; D005290:Ferric Compounds; D017895:Manganese Compounds; D009566:Nitrates; D010087:Oxides; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C000499:ferric oxide; C027424:manganese oxide; D000537:Aluminum Oxide; C023650:aniline