Design For Reform Project Of Tianjin Lingzhuang Water Plant

Through the analysis of water quality survey, this paper concludes the characteristics of quality of various source water in Lingzhuang Water Plant: (1) water from Luanhe River is a slightly polluted source and is low temperature and low turbidity water in winter while high temperature and high algae water in summer; (2) quality of south-north transferred water always changes. (3) there are no obviously regular seasonal changes in water from Huanghe River; quality of water is unstable and fluctuates with the change of water quantity; sudden pollution occurs from time to time. Target for quality of ex-plant water after the reform of the plant is determined according to the Standard for Quality of Drinking Water newly issued by China.Through on-site survey, it is found that there are problems in Lingzhuang Water Plant. It is imperative to upgrade and reform the process of Lingzhuang Water Plant. Through analysis of such aspects as structural stability and process planning design of existing major water purification structures, it has been confirmed that all the existing water purification structures of Lingzhuang Water Plant can not meet the future demand for water supply thus will be removed one by one. Guiding ideology and implementation measures for the reform of Lingzhuang Water Plant are determined after analyzing the current situation and the demand of development. That is, after building a new conventional treatment system on a vacant lot in apple orchard in the north, existing system will be reformed.Through analysis and comparison of technical and economic performances of various pre-treatment processes, conventional treatment processes and advanced treatment processes, this paper recommends pre-oxidation with chemical agents in pre-treatment, namely, ozone and permanganate PPC are used jointly as pre-oxidant. In conventional treatment process, mechanical mixing, grid reaction, horizontal flow sedimentation tank and type V filtering tank are adopted. In advanced treatment process, post-ozone-activated carbon technique is adopted. The reform project will be carried out in three phases, among which phase I and phase II are for conventional treatment system with construction scale of 250 thousand m3/d; phase III is for advanced treatment system with construction scale of 500 thousand m3/d. Meanwhile, main design parameters for structures are determined in design and calculation and project design is completed. Lingzhuang Water Plant after reform will become an advanced water treatment plant with a combination of conventional treatment process and advanced treatment process.