In the power plant water purification process of aluminum and aluminum sulfate than the efficiency of water purification plant water purification process of aluminum and aluminum sulfate ratio of industrial comparative test through experiments in both theory and practice proved that the power plant water purification process, Poly aluminum than aluminum sulfate has greater advantages. Pretreatment of water package coagulation, clarification, filtration. Coagulation treatment is the key first process in the water purification process of thermal power plants. The coagulation effect has a direct impact on the quality of water pretreatment and to a certain extent determines and influences the subsequent desalination process. Coagulation treatment need to choose coagulant, the traditional coagulant is mainly aluminum sulfate. Due to its put into the water, the formation of hydrolysis by the water environment and other conditions, can not form the most effective flocs and maximize their performance. With the development of modern industry, polymer coagulants represented by polyaluminum have been widely used in the field of water treatment. Because it is the best prefabricated man-made coagulation control form, put in the water to play the role of electricity and bridging flocculation, so it has more advantages and wider application of aluminum sulfate, the paper through the industrial test , Coagulation effect of aluminum and aluminum were compared. Comparison: Polyaluminum chloride and aluminum sulfate coagulation mechanism According to the information on the introduction: A1 (Ⅲ) polymer morphology can be divided into three categories: (1) A1a: including monomer and primary polymer (A11 -3); ) A1b includes oligomers (such as A16-8) and the intermediate (A113); (3) A1c includes the polymer (A1> 13) and the sol of nA1 (OH) 3. The traditional coagulant aluminum sulfate in the concentrated solution of the main state is A1a, monomer and primary polymer. Into the water, due to dilution and PH value, the rapid hydrolysis, the direction of the formation of primary polymer development, the final formation of precipitate [nA1 (OH) 3], the resulting precipitate with a positive charge, adsorbed negatively charged water Colloids and impurities. During this period, the products of the flocculant mainly play the role of electric neutralization and adhesion bridging or sweeping to remove impurities in the water. During the whole condensation process, the aluminum sulfate undergoes a hydrolysis reaction first, then a suction process, and the coagulation effect is affected by the environment Conditions, water quality, water temperature, PH, particulate matter concentration and disturbance of water flow and other factors. The prefabricated aluminum is mostly active ingredient A113 , that is, [A112  A1O4 (OH) 24] 7 +, which is the best aggregation - flocculation components, they have a higher stability of hydrolysis, In water after a considerable period of time and different PH environment, you can keep its shape unchanged. Because of its high degree of polymerization, its molecular weight and the overall charge higher, into the water preferentially bonded to the particles, showing a strong adsorption force. That is, the polyaluminum is put into water without being hydrolyzed to directly form a polymer and adsorbed onto the surface of the particle, thereby performing electric neutralization and aggregation-flocculation of the bound bridge. Water treatment status and problems A power plant chemical pretreatment system a total of four mechanical stirring clarification tank, a single output of 600 tons / hour. Water uses the river water, pretreatment production process: coagulation - clarification - filtration. The original design of coagulant using aluminum sulfate, after many years of application found that aluminum sulfate in the treatment of low temperature and low turbidity, the effect is not satisfactory, the effluent turbidity easily exceeded, and sometimes the phenomenon of colloidal silicon penetration, (often resulting in furnace water silicon rise , Must be replaced by a large number of boiler water to make it back to normal, resulting in greater loss of steam, power plant safety, economy, and stability of the operation hazards). During the flood season, due to the increase of the turbidity of the river, the dose of aluminum sulfate increased, and the effluent PH in the clarifier decreased drastically (sometimes even below 5.40), causing serious corrosion to the fresh water system. Especially since 96 years, after supplying tap water to the family's residential area, our factory has stricter PH requirements on the treated water quality. In view of the above reasons, we decided to replace the coagulant and replace the aluminum sulfate with polyaluminum to completely solve the above problems . Poly aluminum chloride and aluminum sulfate coagulation effect comparison Small-scale experiments We use the factory production of aluminum and aluminum into the test, small laboratory test to determine the best dosage and turbidity removal effect, provide guidance for industrial test data . Polyaluminum chloride and aluminum sulfate coagulation effect Test method: Polyaluminum chloride and aluminum sulfate each dubbed 5% of the dilute solution, respectively, according to a certain dose by adding 1000 ml test water samples, immediately according to the provisions of time and speed stirring, (( The test using magnetic stirring) and then for a period of time, take the supernatant to determine the residual turbidity. Polyaluminum chloride and aluminum sulfate coagulation effect Conclusion: By contrast, aluminum coagulation better than aluminum sulfate, it has fast coagulation, effluent water quality, suitable for a wide range of changes in water quality and so on. For low temperature and low turbidity water, polyaluminum still has better coagulation effect. Treatment of water with polymeric aluminum, due to its high content of active ingredients, so less dosage, only the amount of aluminum sulfate 1 / 2-1 / 3. Polyaluminum treatment, effluent PH decreased less, reducing the corrosion of the water pipe. Product itself is non-toxic, as the living water in line with national drinking water standards, its indirect economic benefits significantly. Polymeric aluminum for coagulant, the factory can save water costs 380,000 yuan. The information from the filter water purification http://www.gyzhenyu.com/ finishing release, for transfer, please specify the way to the address!