To improve the efficiency of petrochemical wastewater purification, the relationship between bacterial community structure and pollutants loading/degrading rates in A/O process for petrochemical wastewater treatment w...To improve the efficiency of petrochemical wastewater purification, the relationship between bacterial community structure and pollutants loading/degrading rates in A/O process for petrochemical wastewater treatment was investigated by denaturing gradient gel eleetrophoresis （DGGE） of the 16S rRNA gene fragments amplified by polymerase chain reaction （PCR）. Results show that while the influent COD and NH4^＋ -N concentrations are 425.92 -560 mg/L and 64 - 100 mg/L respectively, the corresponding average concentrations of the effluent are 160 mg/L and 55 mg/L, which are 1. 6 and 3.6 times more than the national standards respectively. It demonstrates that the performance of pollutants removal process is inefficient. The analysis of PCR-DGGE profile indicates that the bacterial community structure of the activated sludge in A/O system is species-rich but unstable, and the highest and the lowest similarity coefficients are 36% and 6. 25% respectively, which shows that remarkable community structure evolution exists in the system. The variation of bacterial community structure and pollutants loading influences the removal efficiency of pollutants obviously, and relatively stable com- munity structure leads to the stable operational performance of biological wastewater treatment system.展开更多
Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecol...Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecology system over time. It is meaningful to develop a way to identify the microbial diversity related to heavy metal effects in evaluating river pol ution. Water and sediment samples were col ected from eight sections along the Tiaozi River where wastewater and sewage were discharged from Siping City in northeastern China. The main pollutants contents and microbial communities were analyzed. As the primary metal pol utants, zinc （Zn） and arsenic （As） were recorded at the maximum concentrations of 420 and 5.72 μg/L in the water, and 1704 and 1.92 mg/kg in the sediment, re-spectively. These pollutants posed a threat to the microbial community diversity as only a few species of bacteria and eukaryotes with strong resistance were detected through denaturing gradient gel electrophoresis （DGGE）. Acineto-bacter johnsoni , Clostridium cel ulovorans, and Trichococcus pasteuri were the dominant bacteria in the severely pol uted areas. The massive reproduction of Limnodrilus hoffmeisteri almost depleted the dissolved oxygen （DO） and resulted in the decline of the aerobic bacteria. It was noted that the pollution reduced the microbial diversity but the L. hoffmeisteri mass increased as the dominant community, which led to the overconsuming of DO and anaerobic stinking water bodies. Water quality, concentrations of heavy metals, and the spatial distribution of microbial popula-tions have obvious consistencies, which mean that the heavy metals in the river pose a serious stress on the microorganisms.展开更多
基金Sponsored by the National Basic Research and Development (973) Program of China(Grant No.2004CB185050)
文摘To improve the efficiency of petrochemical wastewater purification, the relationship between bacterial community structure and pollutants loading/degrading rates in A/O process for petrochemical wastewater treatment was investigated by denaturing gradient gel eleetrophoresis （DGGE） of the 16S rRNA gene fragments amplified by polymerase chain reaction （PCR）. Results show that while the influent COD and NH4^＋ -N concentrations are 425.92 -560 mg/L and 64 - 100 mg/L respectively, the corresponding average concentrations of the effluent are 160 mg/L and 55 mg/L, which are 1. 6 and 3.6 times more than the national standards respectively. It demonstrates that the performance of pollutants removal process is inefficient. The analysis of PCR-DGGE profile indicates that the bacterial community structure of the activated sludge in A/O system is species-rich but unstable, and the highest and the lowest similarity coefficients are 36% and 6. 25% respectively, which shows that remarkable community structure evolution exists in the system. The variation of bacterial community structure and pollutants loading influences the removal efficiency of pollutants obviously, and relatively stable com- munity structure leads to the stable operational performance of biological wastewater treatment system.
基金Project supported by the National Science and Technology Majo Project of China(Nos.2008ZX07208-005 and 2012ZX07202-003)
文摘Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecology system over time. It is meaningful to develop a way to identify the microbial diversity related to heavy metal effects in evaluating river pol ution. Water and sediment samples were col ected from eight sections along the Tiaozi River where wastewater and sewage were discharged from Siping City in northeastern China. The main pollutants contents and microbial communities were analyzed. As the primary metal pol utants, zinc （Zn） and arsenic （As） were recorded at the maximum concentrations of 420 and 5.72 μg/L in the water, and 1704 and 1.92 mg/kg in the sediment, re-spectively. These pollutants posed a threat to the microbial community diversity as only a few species of bacteria and eukaryotes with strong resistance were detected through denaturing gradient gel electrophoresis （DGGE）. Acineto-bacter johnsoni , Clostridium cel ulovorans, and Trichococcus pasteuri were the dominant bacteria in the severely pol uted areas. The massive reproduction of Limnodrilus hoffmeisteri almost depleted the dissolved oxygen （DO） and resulted in the decline of the aerobic bacteria. It was noted that the pollution reduced the microbial diversity but the L. hoffmeisteri mass increased as the dominant community, which led to the overconsuming of DO and anaerobic stinking water bodies. Water quality, concentrations of heavy metals, and the spatial distribution of microbial popula-tions have obvious consistencies, which mean that the heavy metals in the river pose a serious stress on the microorganisms.
