This project belongs to the technical field of urban water supply engineering.  Drinking water safety is related to public health and social stability. In response to problems such as excessive ammonia nitrogen and CODMn during low-temperature periods, sludge accumulation in biological pretreatment fillers and the growth of aquatic animals, year-round operation management and biological leakage of carbon ponds, and the impact of chemical pre-oxidation on biological pretreatment, relying on the first project, the project was launched in the national major water project Under the funding, through 7 years of joint technology research, the main innovations are: 1. Integrated technology for post-sinking aquatic organism contact oxidation and ceramsite biological filtration. Innovatively formed the ldquo; turbidity removal first and biological rdquo; process, and proposed to strengthen routine pretreatment as biological treatment to effectively remove suspended solids and aquatic animals, reduce the load on the biological filter, and solve the long-standing problems of biological pretreatment. Problems such as sludge accumulation, accumulation, red bean snail water earthworms and gnawing on biomembrane, avoid the impact of preoxidants on biomembrane. It took the lead in proposing biological contact oxidation technology in the outlet channel of sedimentation tanks, adding fillers and aeration to play multiple roles such as biodegradation, inoculation and oxygenation. Innovatively developed ceramsite biofiltration enhanced technology for treating post-sedimentation water, proposing parameters such as large particle size, low flushing and long period to achieve the ratio of ammonia nitrogen in filtered water to the same raw water during low temperature period. Traditional process increased by 27%. 2. Integrated technology of ozone upflow biological activated carbon and fine sand filter. The expansion rate and head loss laws of the upflowing activated carbon layer with different water temperatures, particle sizes, rising flow rates and the decline laws of the expansion rate of old carbon are revealed. The rising flow rates and backwash intensity and cycle in different seasons are proposed, and the surface of the carbon layer to the finger-shaped groove are established. The safe height of the bottom weakens the turbidity removal function, gives full play to the adsorption and biodegradation of activated carbon, achieves uniform upward water distribution, reasonable suspension expansion, and timely renewal of biomembrane, solving the year-round operation and management problems. For treating the same raw water, the CODMn removal effect of the upward-flowing carbon tank is better than that of the downward-flowing carbon tank, and the construction of intermediate lifting pump rooms is eliminated, reducing project investment and maintenance management. Based on the low turbidity of post-carbon water, biological leakage, etc., small particle diameter fine sand filtration technology has been created to ensure the turbidity of factory water and solve biosafety problems such as 16S rRNA (a).  3. Integrated technology for the full process of biological filtration-granular carbon filtration-sand filtration. Based on the synergistic effects of the three types of filtration, such as biological oxidation, physicochemical adsorption and safe interception, ldquo; chemical pre-oxidation-coagulation sedimentation-biological contact oxidation-ceramsite biological filtration-ozone-upflow biological activated carbon-small particle size sand filtrationrdquo; The new full-process integrated process reveals the changes and composition evolution laws of various organic compounds such as heptanaldehyde, and proposes technologies such as mixed zone aeration, biological filter aid filtration, biological powder carbon reflux, and multi-mode disinfection, which have improved the overall treatment efficiency of the water purification process, achieving that the concentration of ammonia nitrogen, CODMn and heptanaldehyde in factory water during the low-temperature period is significantly better than the national standard, modern water plant standards and smell threshold, solving the outstanding problem of exceeding the standard in winter.  According to novelty search and consultation, the comprehensive technology has reached the international advanced level. Authorizes and applies for 19 patents (6 invention authorizations and 8 acceptances), publishes 21 papers (2 papers included in SCI/EI), and editor-in-chief 1 industry technical regulation. The results have been applied to the first domestic ldquo; Chemical preoxidation-Strengthening conventional-biological treatment-ozone upflow activated carbon-small particle sand filter rdquo; National Water Special Demonstration Project mdash; mdash; The second phase of the Guanjinggang Water Plant in the southern suburbs of Jiaxing City. The stability of the factory water during the low temperature period is better than that of the national standard and modern water plant standards, solving the outstanding problem of excessive ammonia nitrogen, CODMn and heptanal in winter. It has been promoted in Jiangsu, Shanghai, Henan, Zhejiang, Shandong, etc., involving raw water in 7 river basins, with a total scale of more than 2.3 million m3/d. The project investment has been saved by 90 million yuan, and the electricity bill has been reduced by 6.5 million yuan/year, which has effectively improved the biological treatment of water supply. and low-temperature water purification technical level.