Traditional Coal Chemical Enterprise-Weihua Group Wastewater Treatment Device Research On Capacity Expansion And Transformation Technology

Coal is the most important energy source in China.There are many coal chemical enterprises in China,and if a large amount of coalification wastewater generated can be treated and recycled,it is of great significance for ensuring China's energy security and promoting the sustainable development of regional economy,society and ecological environment.This paper analyzes the existing problems of wastewater treatment system of Shaanxi Weihua Coal Chemical Industry Group Co.,Ltd.(referred to as Wuihua),and proposes a whole process wastewater treatment quality improvement and treatment plan for wastewater treatment system,dosing system,sludge discharge system and ancillary facilities.Based on the scheme,the design of wastewater treatment process transformation was completed,and the engineering operation and economy after upgrading and transformation were analyzed.It provides an important theoretical and engineering basis for the expansion and upgrading of the wastewater treatment system of coal chemical enterprises in China.The existing wastewater treatment process of Weihua Group is mainly composed of the first-stage anaerobic internal circulation process(IC system)constructed in1995 and the two sets of sequential batch activated sludge process(SBR system)in the second and third phases.At present,the enterprise wastewater load is about 350m3/h,while the existing wastewater treatment system has a total treatment capacity of only 135 m3/h,and the wastewater treatment capacity is seriously insufficient,with a gap of 215 m~3/h.The pretreatment facilities of the second-stage SBR system lack the necessary degreasing process,which makes the intrinsic methanol in the water difficult to be an effective carbon source,providing energy and nutrients for the microorganisms,and the ammonia nitrogen and COD of the effluent are difficult to reach the standard.In addition,the auxiliary facilities such as the dosing device,the mud discharging device,the automatic control device and the online monitoring device of the three systems all have different degrees of equipment,and the original design is difficult to meet the problems of wastewater quality and emission status,and further increased.Existing wastewater treatment system pressure.In response to the above problems,through the transformation of wastewater pipelines,rationally distribute the wastewater load,optimize the carbon source configuration,update the auxiliary equipment,stimulate the potential of the second and third phase wastewater treatment systems,and achieve efficient use of existing wastewater treatment processes.Based on the characteristics of enterprise wastewater,a new wastewater expansion system was established.Through the comparison of the schemes,a secondary treatment process with“coagulation,sedimentation+SBR”as the core was proposed to replace the first phase of early construction.The system is processed to ensure the wastewater treatment capacity and energy saving of the enterprise.The upgraded wastewater treatment system has significantly improved treatment capacity and impact resistance.The biochemical system has stable effluent,COD removal rate of 95%,BOD removal rate of about 97%,ammonia nitrogen removal rate of 99%,and various water quality.It meets the Class B emission standard of the Integrated Wastewater Discharge Standard of the Yellow River Basin(Shaanxi Section)(DB61/224-2018),and the treatment cost per ton of water is 6.55 yuan.