期刊名称：Journal of Environmental Science and Technology
印刷版ISSN：1994-7887
电子版ISSN：2077-2181
出版年度：2011
卷号：4
期号：6
页码：590-600
DOI：10.3923/jest.2011.590.600
出版社：Asian Network for Scientific Information
摘要：Despite the attendant environmental consequences, direct discharge of untreated waste water from industries into water bodies is common in many developing countries . This study evaluates the impact of abattoir wastes on microbial ammonium and nitrite consumptions in a tropical fresh water ecosystem. Samples were collected from points (source point, upstream and downstream) about 300 m apart. Autotrophic and heterotrophic ammonium and nitrite consumptions were estimated by incorporation of allyl thiourea and sodium chlorate, inhibitors of autotrophic ammonium and nitrite oxidations, respectively. Source point sample was the most turbid, richer in nutrients and microbial populations than the upstream and downstream samples. Ammonium and nitrite consumption patterns were active at the upstream and downstream stations. Autotrophic ammonium consumption was completely repressed while autotrophic and heterotrophic nitrite consumptions were very active at the source point. Correlations between ammonium and nitrite consumptions at the various sampling points were negative (r = -0.96) for autotrophs at the source point, and positive (0.96<r<1.0) for autotrophs and heterotrophs at the other stations. Nitrite consumption rates were greater for heterotrophs than autotrophs. The highest rate of autotrophic ammonium consumption was 14.254 μg NH4+-N h-1, observed upstream while the highest rate of heterotrophic nitrite consumption was 122.917 μg NO2¯ -N h-1, observed at the source point. The adverse effect of abattoir wastes on nitrification in the tropical fresh water ecosystem was through repression of autotrophic ammonium oxidation. This could change composition of available nutrients and is capable of causing shifts in microbial community structure and altering aquatic nitrogen cycle.
