Remediation Of The Black And Odorous River With Microorganisms

The black color and odor of the river is a biochemistry phenomenon,due to the anaerobic decomposition of organic substances. Rivers are universally black and odorous in the water circumstances of our country,and the trend is increasing. The black color and odor pollution of the river results in the destroying to river ecosystem; seriously influences people's living, shipping and industrial and agricultural production; intersifies the crisis of water resources; and even harms inhabitants'health. So harnessing to the pollution of the black color and odor of river is imminent.Microbial remediation technology is a synthetical technology. It turns organic pollutants of big molecule into inorganic pollutants, making use of metabolic ability and genic diversity of microbes. The outcomes enter natural cycle again. It is not only without second pollution, but also easy to operate, with less remediation cost when compared to traditional methods, etc. In recent years, microbial remediation technology on the aspect of polluted rivers's harnessing is developing constantly. There are successful examples on the harnessing of polluted rivers. This technology has an expansive developing prospect.The research was mainly taking systemic researches to the disposal of the black and odorous river with EM and its directional concentration liquid, the mixed culture effect of high-effective microbes screened from the river, the optimization to inoculating quantity levels of each strain in mixed microbes and reaction conditions of mixed strains. The main content and results are as follows:(1) PO₄^3- degrading rate of EM to the black and odorous river came to the biggest degrading rate 26.4% when the inoculating quantity of EM was 5%, the reaction time was 1d. PO₄^3- degrading rate was degraded when prolonging the reaction time; there was no obvious degrading effect to COD and NH₃-N in the river.(2) Yeast, actinomyceto and lactobacillus directionally concentrated from EM all had degrading effects to COD, COD removal rate of them was 47.2%, 27.3% and 56.9% repectively, when the inoculating quantity of them was 5%, 8%, 2%, and the reaction time of them was 2d, 2d, 6d respectively. Actinomyceto had certain degrading ability to PO₄^3- and NH₃-N in the river, PO₄^3- removal rate came to the highest value 20.6%, when the inoculating quantity was 5%, and the reaction time was 1d, and PO₄^3- removal rate began to degrade when prolonging the reaction time. NH₃-N removal rate came to the highest value 95.3%, when the inoculating quantity was 5%, and the reaction time was 4d, and NH₃-N removal rate began to degrade when prolonging the reaction time. Yeast and lactobacillus directionally concentrated from EM had no degrading ability to PO₄^3- and NH₃-N in the river.(3) Degrading research to the black and odorous river with EM and yeast, actinomyceto, lactobacillus directionally concentrated from EM showed that: COD removal rate of yeast, actinomyceto, lactobacillus directionally concentrated from EM was better than that of EM.(4) Screen 4 strains of actinomyceto numbered with 9#, 11#, 12#, 13# which had the degrading effect to COD, PO₄^3- and NH₃-N in the river, taking the black and odorous wastewater in Qishui river as the origin of microbes, taking the degrading effect of pollutants resulted in the black color and odor of the river as the basis, but the removal rate of them was not ideal enough.(5) The interaction experiment of mixed culture with 9#, 11#, 12#, 13# showed that: most mixed strains had better degrading effect to pollutants than single strain. When the inoculating proportion of 9#, 12# and 13# in the course of degrading pollutants were 0.5%, 2%, 0.5% respectively, the synthetical removal rate of COD, PO₄^3- and NH₃-N was the best. The removal rate of COD, PO₄^3- and NH₃-N was 76.43%, 34.14% and 76.91% respectively.(6) Temperature and pH both had influences to COD , PO₄^3- and NH₃-N removal rate of mixed strains(9#, 12#, 13#), while the influence of T to the removal rate of COD, PO₄^3- and NH₃-N was greater than that of pH. When T=30℃, pH=8, COD, PO₄^3- and NH₃-N removal rate of mixed strains(9#, 12#, 13#)was the best, was 89.2%, 27.2% and 81.5% respectively.