Study On Biological Treatment Of Recycled Water In Medium And Small Towns Of China

China is developing rapidly in recent years with more and more towns are being built. However, water resource is becoming a bottleneck of sustainable economic development of many areas in the country, particularly in medium to small towns. These towns normally have issues like lagging on environment protection, lack of measures to prevent and control pollution, weak awareness of environmental protection, etc. To make the situation worse, urban wastewater treatment technology in medium to small towns is relatively weak, designed waste water process cannot reach the desired effect. All the above are heavily threatening the water quality. So studying waste water reuse technology not only can benefit the waste water reuse efficiency but also can help cut the cost of industrial production and maintain the sustainable development of these towns.During the study we take into account the characteristics of waste water in medium to small town and the common problem in the biological treatment process adopted in most of the waste water station and make the following achievements by analyzing "hydrolytic acidification + MSBR + flocculation reaction + active sand filter” water reuse treatment technology:(1) By analyzing the polluted water characteristics from medium to small towns in China and comparing different waste water recycling technology we find out that the that using MSBR as a core waste water processing technology along with “hydrolytic acidification” as a pre process methodology and “flocculation reaction” +“active sand filter” as post process methodology is the most suitable option to the medium to small towns. As it has the advantage of small land usage, strong ability to remove Nitrogen and phosphorus and it is also very economic in terms of the waste water volume it can handle every day.(2) We demonstrate the feasibility of "hydrolytic acidification + MSBR + flocculation reaction + active sand filter” water recycles technology by analyze the Qinhuangdao QingLong County sewage treatment plant process. Our analysis is supported by a large number of monitoring data at the inlet and outlet of the sewage. On top of technical feasibility we also assess the economic impact of investing in this technology by estimating the cost, profit, social impact, etc and our assessment shows very positive result regarding adopt this technology in the country.This research provides sound and solid technical support for plan and design of medium and small town sewage treatment. More over it is a good template for medium to small towns near Qinhuangdao to develop their waste water reuse technology. It also brings far-reaching influence to the followings: construction of new water recycling technology, promote the small and medium-sized towns on their water recycling appliance and improve urban water quality.