Comparative Study On Organic Carbon Capture Technology Of Effluent In Municipal Sewage Plant

In 2020,China put forward the "dual carbon" strategic goal,and all walks of life began to pay close attention to CO2 emissions.It is estimated that the organic carbon in sewage contains 13-14 kJ/g of energy,which has a broad space to be developed.In the future,if the chemical energy and heat energy in the sewage treatment process of the sewage plant can be effectively used and used as an energy supplement for the operation of the sewage treatment plant,the problem of high energy consumption of the traditional sewage treatment plant can be alleviated.In the long run,the construction of sewage treatment plants as energy plants with "energynutrient-recycled water" as the core can achieve the ambitious goal of carbon neutrality.Carbon capture is a key step and an important part of the transformation from traditional sewage treatment plants to "energy plants".Carbon capture is a general term for organic carbon enrichment technology,which has the advantages of low cost and high efficiency,and can be widely used in the field of sewage treatment.In order to study the feasibility of achieving carbon neutrality in traditional municipal wastewater treatment plants,Yanliang Chengdong Wastewater Treatment Plant,a typical municipal wastewater treatment plant in Northwest China,was selected as the research object.A variety of organic carbon capture technologies were adopted,including chemical primary enhanced treatment activated sludge biofloculation process and typical adsorbent adsorption process.The efficient capture of organic carbon in wastewater treatment plant influent is carried out,and the optimal process and technical parameters are obtained by comparing the effect of carbon capture technology suitable for wastewater treatment plant influent in Northwest China,which provides reference for the transformation of traditional wastewater treatment plant into a structured and low-carbon one.In addition,this paper also carried out the mechanism analysis of different carbon capture technologies,studied the carbon removal mechanism of carbon capture technology,and built carbon capture pilot test equipment to carry out carbon capture pilot test to verify the results of the pilot test.The general conclusions of this study can provide reference for the researchers in this field.The test results show that:The experimental study found that the COD in influent was captured by chemical enhanced primary treatment(CEPT),and cationic polyacrylamide(CPAM)had the best effect of capturing COD in influent,and the COD in water samples could reach 86%.The adsorbent was used to capture SCOD in influent.It was found that clinoptilolite and Australian coal had no effect on SCOD removal in water,and all three biochar had effect on SCOD removal,among which bamboo biochar had the best effect,with a SCOD removal rate of 55%.Using activated sludge from secondary sedimentation tank of sewage plant as raw material,two research methods,namely direct adsorption of high-load sludge and microbial flocculant flocculation,were adopted to remove organic carbon from water.It was found that SCOD,TN and NH 4-N in the removal of high-load activated sludge did not show obvious characteristics.The use of microbial flocculants can remove up to 60%of COD in water.It is found that there is a certain deviation between the pilot test results and the pilot test results,because the operating conditions of the pilot test equipment can not meet the expected requirements.By running carbon capture pilot equipment,only part of the pilot test results can be verified.Under the operation of pilot equipment,PACl can play a good role in carbon capture,stably removing COD in granular and suspended state in water,with a removal rate of 38-42%,while biochar can effectively capture SCOD in water,with a removal rate of 18%.Based on the attribution analysis,it is concluded that the sediment accumulation,inappropriate reaction temperature and pipe blockage of the equipment themselves are the important reasons limiting the long-term,continuous and stable operation of the carbon capture pilot equipment.