Study On Functional Microbe Of Typical Rural Domestic Sewage Treatment Systems In Ningxia

With the development and the constantly advancing synthesized management of country environment, the work of treatment of domestic wastewater has already developed widely and made some progress in Ningxia Hui Automous Region. But the work still faces lots of difficulties and problems, especially the lower removal efficiency of wastewater treatment processes. As the microbes are important to remove contaminants of sewage, in this study, based on the surveys of the centralized domestic sewage treatment systems of the rural in Ningxia, two kinds of typical rural domestic sewage treatment systems are selected, and according to the bio-augmentation technique, the effect research of the removal efficiency of wastewater treatment is conducted.Bio-augmentation is to add the Functional microbial flora chosen from the rural domestic wastewater, and then to make it grow in exponential rate to strengthen the purification effect of the rural domestic sewage treatment system and to improve the efficiency of purification. The successful application of this technique would greatly help improve the degradation of Ningxia rural sewage system and the effect of pollutant removal, and achieve the realization of the rural sewage discharge, and at the meantime can effectively save water resources that is of the increasingly shortage to recycle the rural water use, and finally all of that significances would play a strategic role in the goals of building a new socialist countryside and promotinge the sustainable development of environmental resources in the northwest region. The main conclusions are as follows:(1)There is a certain correlation between the number of the three major microbial groups and the pollutant removal efficiency in the sewage treatment system of the typical rural sewage treatment system in Ningxia. The pollutant concentration and the quantity of microbe along the process in Ningxia’s two kinds of typical rural sewage treatment sewage system presents decreasing trend; In August the numbers of the sewage microorganisms and the pollutants removal rate reached the maximum value, and in January the minimum value; An obvious positive correlation between the quantity of the three microbial species in the polluted water and theNH4+-N, CODcr removal rate was apparently transparent, indicating the important effect of the microbial removal of the ammonia nitrogen, organic pollutants; But the uncorrelation between microbial quantity and TP removal rate showed that there exist some other ways to remove TP. From the water and artificial wetland, separated and purified, 54 strains of microorganisms were obtained, including 20 strains for bacteria,19 strains of fungi,15 strains of actinomycetes and this helps build a foundation for further screening the local advantages of the functional microbial strains.(2)In the simulation experiment of a single strain water purification capacity,3 strains with high efficiency of sewage purification capacity of degradation bacteria were screened out the 54 strains obtained by Separation and purification were added to the purifying tank filled with sterilized homemade domestic sewage, and observed and analyzed its sewage purification capacity and characteristic. The study found that 20 strains in 54 strains of single strain have the ability of water purification, of which three strains (B2-10X, B2-19Z, C2-1Z) have a high purification ability of nitrogen, phosphorus and organic matter. Through comprehensive morphological characteristics and physiological and biochemical characteristics and the 16S rRNA gene sequence anafyzed, strain B2-10X is identified as Bacillus sp., and strain B2-19Z as Bacillus subtillis., strains C2-1Z as Bacillus megaterium.(3)The concentration of composite microbial inoculum 5% and 10% have a higher degradation ability of sewage. Under the same condition of various pollutants initial concentration, temperature and hydraulic retention time, pH conditions in each treatment pool,3 or 2 strains with the same concentration selected from the 3 degrading bacteria were mixed up and then the compounds with different concentrations were added to the domestic sewage. Studies have shown that the compound with three strains of bacteria, B2-10X, B2-19Z, C2-1Z, has a higher efficiency, and when the concentration of bacteria is between 5%-10%, composite microbial inoculum of pollutants actual removal rate is the highest,25%-35% or so higher than any single strain removal rate.