Research On Process Optimization Of "Zero Emission" Of Coal-to-Gas Wastewater

This paper takes a coal-to-gas wastewater treatment process in China as the research object,and compares various technologies by means of enterprise research,literature review,data collection,water quality and quantity analysis,etc.,combined with the operation of domestic coal-to-gas wastewater treatment technology.And process optimization,for the enterprise to develop a set of economical and practical technology advanced coal gasification wastewater "zero emission" process plan.The design is analyzed from five key processes: phenol ammonia treatment,sewage treatment,water reuse,high brine and evaporation crystallization.By comparison,because the removal rate of polyphenols in wastewater is high,and the effluent COD and ammonia nitrogen are well controlled,the domestically improved deacidification and deamination extraction and dephenolization process technology is selected for the phenol ammonia recovery section of the project;the sewage treatment adopts the application effect.Good EBA domestic independent intellectual property technology;the process of "softening +filtration + ultrafiltration + first-order reverse osmosis" is the process of reusing water and concentrated brine;considering multi-effect evaporation crystallizationtechnology,simple and mature operation is stable and easy to operate The "purification + four-effect evaporation + crystallization" process is used to concentrate and crystallize the concentrated brine,and the by-products NaCl and Na2SO4 are sold as industrial raw materials to realize "zero discharge" of the wastewater."Zero Emission" of coal chemical wastewater No matter what kind of process is adopted,the wastewater is finally converted into solid salt and then treated.The complex salt components produced are complex and can only be piled up,landfilled or treated as hazardous waste,and the risk of secondary pollution is high.According to the cost of hazardous waste treatment,how to reduce the processing cost,reduce the economic burden of the enterprise,minimize the environmental hazards,and utilize the resources is a problem that enterprises and researchers need to solve urgently.It is also the research focus of this paper.In the process of returning water,concentrated brine and crystallization evaporation,the optimization process uses splitting and mass separation to treat biochemical effluent from different sources,desalination station drainage,circulating water station and other clean wastewater.After the optimized process,the amount of hazardous waste generated is reduced by about 60% compared to the conventional process.Because the disposal costs of solid waste and hazardous waste vary greatly,the economic advantage is obvious.Applying the optimization process,part of the solid waste is changed from dangerous solid waste to general solid waste,which realizes the reduction of hazardous waste discharge,effectively reducing the problem of large-scale hazardous waste production and high treatment cost.The design plan of this coal-to-gas project saves water resources,clean production and recycling throughout.After a series of optimized processtreatments,the project realizes "zero discharge" of the project wastewater,and the optimization process can provide reference and reference for other coal gasification projects to be built.