Study On Emergency Water Supply Technology Of A Water Plant Due To Sudden Pollution Of Water Source

Because the water source of a surface water plant is seriously polluted,it needs to replace a new underground water source.Because the underground well source of emergency water source is shallow,surface water is mixed with groundwater,and the new water source presents the compound pollution property of groundwater and surface water.The turbidity,chroma,iron,manganese,ammonia nitrogen are far beyond the national standard,and the conventional two-stage filtration technology is difficult to make the water treatment of the water source reach the standard.According to the characteristics of the water source,the process of removing manganese and ammonia nitrogen by coagulation and two-stage bio-enhanced filtration is studied in this paper,so that the water of the water source can reach the national standard after treatment.First of all,in the field experiment,the operation effect of conventional two-stage filtration process is not good,except iron can reach the standard in a short time,other pollutants are difficult to reach the national standard.The water quality of the new source water was analyzed to determine the process modification scheme.Through the analysis of the contaminants,combined with the actual situation of the field,the process of removing manganese and removing ammonia nitrogen by coagulation and two-stage bio-enhanced filtration was adopted.The turbidity,chroma and iron were removed by coagulation strengthening process,and the removal effect of manganese and ammonia nitrogen was improved by biological strengthening process.Secondly,the initial dosage of coagulant and coagulant aid was determined by small test.The coagulant was polyaluminum chloride,and the coagulant was polyacrylamide.More than 90% turbidity and chromaticity could be removed by coagulation,about 70% of iron could be removed,and about 30% permanganate index could be removed by coagulation.In the actual engineering debugging,the dosage of coagulant and coagulant aid was gradually reduced,and the dosage of coagulant was determined to be 3mg/L polyaluminum chloride.The turbidity,chromaticity,iron and permanganate index of the effluent of the filter can reach the national standard stably.Finally,the biological enhancement process was used to improve the ability of removing manganese and ammonia nitrogen from the filter tank,and the manganese and ammonia nitrogen from the effluent of the process were successfully reduced to below the national standard,indicating that the biological enhancement can effectively improve the ability of removing manganese and ammonia nitrogen from the filter tank,and can resist the impact load to a certain extent.So far,all the indicators of effluent water have reached the national standard and run stably.In order to understand the surface structure,element composition and community structure of the filter material,scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and high-throughput sequencing were performed on the filter material.The results showed that there were a large number of iron bacteria on the surface of the primary iron removal filter,which occupied the absolute dominance in the community.After the secondary bioenhancement,the surface of the filter will show a loose and porous honeycomb structure,and there will be a large number of microorganisms attached,and the dominant bacteria is nitrifying bacteria.The analysis of its elements and flora shows that the removal of manganese is the result of the combined action of biological oxidation and chemical contact oxidation.