The Design And Feasibility Of Facilities Reform Project Of A Company’s Sewage Treatment And Resources Recycling In Jilin

With the rapid development of China’s economy in the past 30 years, people’s life has been greatly improved and ice-cream has become a kind of summer food. China’s ice-cream sales have exceeded 2.8 million tons since the market experienced an average annual growth rate of 10% in the past 20 years. Accompanied with the large production of ice-cream, ice-cream wastewater has also been sharply generated. Due to the dairy products used as raw materials for ice-cream production, ice-cream wastewater consisted of organic suspended solids(SS), lipids and high COD and BOD. Generally, ice-cream wastewater can be effectively treated by coupling of physical, chemical and biological methods to meet effluent discharge standards, instead of anyone of the methods alone. If ice-cream wastewater was directly discharged into ambient environment without any treatment, it would deteriorate the environment and even break ecological balance.The beverage company in Jilin constructed a physical-chemical sewage plant at 2006. However, the original design has been unable to meet the requirement of ice-cream wastewater treatment. In addition, the heavy corrosion of aged facilities has seriously affected the treatment performance. Therefore, the company decided to reform the existing sewage treatment facilities so that ice-cream wastewater can be effectively treated.In this paper, the feasibility and design of the new sewage treatment plant has been analyzed according to the wastewater effluent of the company. Through the investigation of similar wastewater quality and mature process, we systematically summarized and analyzed the running process and corresponding design of the reformed sewage plant. Then, a coupling process of air floatation, hydrolytic acidification, biological contact oxidation and chlorine dioxide disinfection was selected. Main theoretical basis as following:(1) air flotation method can remove lipids which are refractory to microorganisms, the removal of lipid benefits oxygen transmitting to biofilm in the following aerobic process;(2) hydrolysis acidification can decompose macromolecular organic matters into small molecule organic matters and thus improve the wastewater biodegradability;(3) biological contact oxidation combines the advantages of activated sludge and biofilm methods. Based on the design principle, this paper completed the sewage and sludge treatment process design, analyzed social, economic and environmental benefits of the reform project, analyzed the environmental influence and the identified countermeasures during the project’s construction and running, assessed risks and the corresponding preventive measures of the new plant. The reform project will be a reference for other similar projects and design.