沈抚灌区含油污水灌溉对稻田土壤微生物种群及土壤酶活性的影响

Impacts of petroleum-containing wastewater irrigation on microbial population and enzyme activities in paddy soil of Shenfu irrigation area.

通过对沈抚灌区长期污水灌溉造成的石油污染状况的调查,从土壤微生物种群数量和土壤酶活性的角度评价了含油污水灌溉对土壤生态系统的影响.结果表明,石油污染物在灌区干渠和支渠中的积累和分布趋势大体上是上游地区较严重,下游地区较轻.干渠上游污染最严重的样点总石油烃(TPH)含量高达5213.37mg·kg-1.在目前污染程度下,含油污水灌溉刺激了土壤中好氧异养细菌(AHB)和真菌的生长,土壤中总石油烃(TPH)含量与AHB和真菌数量的相关系数分别为0.928(P<0.001)和0.772(P<0.05).土壤脱氢酶、过氧化氢酶、多酚氧化酶活性与土壤中TPH含量呈显著正相关,相关系数分别为0.974(P<0.001),0.957(P<0.001)和0.886(P<0.001).而土壤脲酶活性与土壤中TPH含量呈显著负相关,相关系数为-0.814(P<0.05),可作为石油污染的敏感生化指标.各样点土壤的底物诱导呼吸(substrateinducedrespiration/SIR)率与土壤中TPH含量、细菌数量及土壤脱氢酶活性密切相关,统计表明,相关系数分别为0.916(P<0.001)、0.770(P<0.001)和0.903(P<0.001).

The study showed that the upper reaches of main petroleum-containing wastewater irrigation channels had the highest accumulation and distribution of total petroleum hydrocarbon (TPH) (5 213.37 mg·kg^(-1) dry soil),and the CFU of soil bacteria and fungi was increased with increasing soil TPH concentration,the correlation coefficient being 0.928 (P<0.001) and 0.772 (P<0.05),respectively.The activities of soil dehydrogenase,catalase and polyphenoloxidase had a significantly positive correlation with soil TPH concentration,their correlation coefficient being 0.974 (P<0.001),0.957 (P<0.001) and 0.886 (P<0.001),respectively,while soil urease activity showed a significantly negative correlation (P=0.002),which could be used as the most sensitive indicator of petroleum contamination.The substrate-induced respiration (SIR) of polluted soil was significantly correlated with soil TPH concentration (P<0.001),dehydrogenase activity (P<0.001),and heterotrophic bacterial CFU (P=0.006).