Optimal Synthesis And Operation Of Coking Wastewater Treatment Process

The coking wastewater is characterized as the large amount and highly polluted wastewater,with complex and unstable water quality.Higher efficiency of the coking wastewater treatment process is required to meet the stricter emission standards and reuse requirements.However,simply technical upgrading of the existing process will increase the operation cost of wastewater treatment,and furthermore,the time and financial consumption on the exploratory studies.This thesis focused on the modeling and the synthesis optimization of coking wastewater treatment process,providing references and suggestions to approach the goal of simultaneous optimal flowsheet and operation cost for the wastewater treatment process.The following aspects:are discussed in this thesis.(1)The unit models of coking wastewater treatment processThe modeling of biochemical treatment,coagulation flocculation and advanced oxidation technologies were developed in this thesis,with different unit model types according to the characteristics of technologies.For complex and mutually coupled biochemical reactions,the modified Activated Sludge Model 3(ASM3)was adopted for modeling the biochemical treatment processes.For tertiary treatment technologies,the empirical models were,obtained by correlation analysis of the unit operating data,used as unit models.(2)Superstructure of biochemical treatment process and its optimizationThe superstructure of the biochemical treatment processes was built by the commonly used combinations of biochemical treatment units(A/O,A/A/O,O/A/O,A/O/O)in coking wastewater treatment.The multi-contaminant superstructure model of biochemical treatment processes was constructed and optimized with the goal of annual total cost minimization.In the case of COD concentration of biochemical treatment inlet was 2000 g·m-3,the O/A/O process was presented as the optimized structure for all emission standards.The A/O/O process became to be the optimized structure,in the case of COD concentration of the inlet increases to 3000 g·m-3.(3)Superstructure of coking wastewater treatment network and its optimizationThe superstructure of coking wastewater treatment network was built,including the combinations of biochemical treatment,coagulation flocculation,advanced oxidation and membrane desalination technologies.The superstructure development was based on the unit models by characteristic analysis of the existing wastewater treatment technologies and integration possibilities.The synthesis model of coking wastewater treatment network and its optimization was performed,aiming at the minimization of the annual composite cost of wastewater treatment,and the integration analysis of wastewater treatment networks.