| Compared with aluminum and ferric coagulant,titanium coagulant has higher biosafurity and less residual metal.Fast hydrolysis in water,good low temperature resistance;After coagulation,the flocs are large in size and easy to settle.Sol-gel method makes the preparation process of titanium coagulant controllable,but the gelation time is long and the preparation efficiency is low.Based on this,on the basis of sol,iron and aluminum salt coagulant industrial drying process,shorten the subsequent gelation time or save the gelation process,realize the polymerized titanium coagulant(PT)rapid preparation,stability and optimizing production process and production to achieve best kilogram level production,finally choose low temperature and low water as the research object,and evaluate the applicability of PT.Specific contents and conclusions are as follows:(1)The preparation process and condition parameters of PT were optimized in the laboratory to obtain the best scheme.On the basis of sol,PT can be prepared quickly by means of spray drying to eliminate the gelation process or rotary evaporation drying to shorten the gelation time.In appearance,PT in spray drying is a light yellow powder solid,while PT in rotary evaporation drying and natural drying are both dark yellow granular solid.In element composition and functional group structure,the three are similar;Isopropyl titanate is more suitable for titanium source than tetrabutyl titanate.The reduction of solvent can increase the yield of formula.Replacement of ligands and selection of industrial grade reagents did not affect the synthesis and properties of PT.The control range of material synthesis time is large and the solvent can be reused.After optimization,PT materials with turbidity of less than 50 NTU,insoluble mass fraction less than 2% and titanium content of about 35% in reserve solution of 1g Ti/L can be stably prepared.The rapid and stable preparation of PT was realized by optimizing the preparation process and condition parameters.(2)In-plant mass production evaluation PT to open up the industrial production route.Under the condition of industrial production,the solvent in the formula can be further reduced,the waste heat of the reaction can be used to concentrate the material,and the yield of the formula can be increased up to 30%.Spray drying process is the most suitable for the industrial production of PT.According to the cost estimation,the PT of 1 ton of spray drying is RMB 31,664 under the condition of 30% material yield and solvent reuse.After on-site mass production evaluation,it provides guidance for PT’s future industrial production.(3)Combination of PT and aluminum salt coagulant to realize efficient treatment of low temperature and low turbidity water.When PT is mixed with aluminum salt coagulant,it is better than single coagulant in removing turbidity and the content of residual aluminum in the coagulant water can be significantly reduced.The combination effect of PT and aluminum sulfate(AS)was better than that of PT and polyaluminium chloride(PAC).By compound PT,the shortcomings of slow floc settlement and high residual aluminum content when aluminum salt coagulant is used alone can be overcome,which not only provides a simple and effective method for the efficient treatment of low temperature and low turbidity water,but also provides the possibility for the industrial application of PT. |
