Study On The Intensive Treatment Of Black-odor Sewage And River Sediment By Biological Agent

With the acceleration of the urban construction,the pollution of urban rivers is becoming more and more serious.The number of black-odor rivers in the country is increasing day by day.The problem of black-odor pollution is becoming increasingly prominent.Pollutants are concentrated in the sediments of river channels.The phenomenon of floating sediment frequently occurs,which aggravates the current situation of black-odor rivers.As a result,solving the problem of black-odor rivers has become a heated focus.In this paper,the control of floating sediment in some sections of the Liangshui River was studied,and the black-odor water was controlled in two ways:enhanced treatment of the outlets and in situ treatment of sediment.In this study,the CMPA-5 bacteria was used for microbiological enhancement in contact oxidation pond to analyze the water quality,the sediment and the microbial community structure attached to the filler;The properties of floating sedimentwere studiedby the ignition method,immersion extraction method,scanning electron microscope,and Illumina high-throughput sequencing method.The reduction effects of floating sediment by using single bacteria and a mixture of various bacteria were analyzed through the static research of the compound microbial enhancement technology on the bottom sludge;the field experiments were conducted to study the degradation effect of bacteria on organic matter,total nitrogen,total phosphorus and available phosphorus.In the condition of HRT=24 h and DO=4?5 mg/L,the removal rate of COD,TN,NH3-N and TN were increased gradually with the increase of CMPA-5 dosage,and the oxidation-reduction potential of effluent increased gradually.The total treatment effect was the best when the dosage of bacteriawas 250 mg/L.At this time,the average removal rates of the indicators were 97.0%,50.0%,85.0%and 60.0%,respectively.The ORP of the outlet water was 233 mV.The addition of CMPA-5 can significantly increase the removal efficiency of various pollutants in the reactor,especially the removal of total phosphorus.Twelve phyla the microbial community structure of biofilm samples were detected in twelve fungi,among which the dominant phylums were Proteobacteria,Acidobacteria,and Nitrospirae.The detected dominant bacteria were Holophaga,Ideonella and Nitrospira.Among the dominant bacteria,Nitrospira was a nitrifying bacterium,and Rhodanobacter as a denitrifying bacterium was found in the system,indicated that the nitrification and denitrification system in the reactor was in good condition.The properties of floating sediment were studied.The contents of organic matter and chlorophyll in the floating sediment were very high.The values were 270.40 g/kg and 52.43 ?g/kg,respectively.The results of scanning electron microscopy showed that the floating sediment was mainly composed of bacterial micelles,which contained protozoa,algae,bacilli,inorganic substances,etc.Microbial community structure analysis showed that the dominant bacteria in the floating sediment was Proteobacteria,Bacteroidetes,Bacillariophyta and Euryarchaeota.It can be seen that the high content of organic matter and the richness of algae substances were the main reasons for sediment floating.The CMPA-3 inoculum contributedto the best removal effect on organic matter and total nitrogen,and the effect was enhanced with the increase of dosage in a certain range.CMPA-5 contributed to the best effect on total phosphorus and effective treatment.The study of dosing methods with the mixed use of various bacteria.The results showed that the dosing method with a high quantity of single shot and the high frequency of dosing was the best.The removal effects were good on organic matter,total nitrogen,total phosphorus and available phosphorus in the sediment when added CMPA-3,CMPA-5 and biological enzyme preparations simultaneously.The values were 67.18 g/kg and 2.04 g/kg,2.04 g/kg and 1.49 g/kg,respectively.Among them,the dominant bacteria were Ochrobactrum(8.51%)and Desulfuromonas(7.32%).It was found that in field experimental the contents of organic matter,total nitrogen,total phosphorus,and available phosphorus in the sediment were significantly reduce with the addition of inoculant alone,and the values were 66.56 g/kg,6.49 g/kg,2.48 g/kg and 1.87 g/kg,respectively.When planting the plants and the addition of inoculant were at the same time,the indicators in the sedimentwere decreased to 54.64 g/kg,4.54 g/kg,2.19 g/kg and 1.24 g/kg respectively.It was indicated that the plants could enhance the reduction effect.The dominant genus was Dechloromonas(3.67%)and Longilinea(2.50%),which had significant effects on the removal of total nitrogen and organic matter,respectively.After the restoration,the sediment turned black to yellow,and had an oxidation state,the black-odor phenomenon was disappeared.