| The worm bed process is a process that uses aquatic worms to prey on the remaining sludge generated by the sewage treatment system,so as to reduce the output of the system sludge and adjust the properties of the activated sludge.The worm predation sludge reduction process has been proven to have good sludge reduction at the laboratory scale,to optimize the treatment water quality,and to reduce the membrane pollution characteristics of the coupled MBR system.Through the pilot scale sewage treatment system coupled with the operation of the worm bed process,the technical advantages of the worm bed process at the pilot level are discussed,and the environmental impact assessment of the pilot worm bed system is discussed.The environmental benefits of the worm bed process are discussed.The plant-scale sewage treatment process of the plant's BNR-MBR is an example of the coupling of worm-prediction sludge reduction with worm simulation,and life cycle assessment to explore the application prospects of the worm bed process in actual projects.The three sets of control systems A/O-MBR,A/O-MBR-blank bed and A/OMBR-worm bed were operated,and the A/O-MBR-blank bed and A/O-MBR-worm bed existed.Sludge reduction effect,the sludge reduction effect of A/O-MBRblank worm bed was 26.4%,and the sludge reduction of A/O-MBR-worm bed system reached 82.1%.A/O-MBR-worm bed effluent water quality improvement,COD removal rate 98.57%,ammonia nitrogen removal rate 99.19%,TN removal rate 60.8%,TP removal rate 83.38%,with the help of chemical phosphorus removal effluent TP is less than 0.3mg/L,Except for TN,the preset surface water class IV standard was reached,and the TMP growth rate decreased by 79.5%.Conduct LCA research on the operation phase and inventory type of the two groups of pilot systems,select seven representative environmental impact categories,analyze and study the four operation sub-stages and three types of input and output inventory types of the system,and conduct biochemical treatment in the pilot system The sub-stage occupies the largest contribution to environmental impact,the use of chemicals mainly contributes to ADP,and the disposal of waste mainly contributes to GWP,EP,FAETP.Among the seven environmental impact categories,A/O-MBR-worm bed increased by 14.78%,3.38%,0.74%,10%,16.78% in terms of GWP,EP,HTP,AP,ODP compared to A/O-MBR In the ADP and FAETP categories,it decreased by 1.17% and 45.67%.After the weight is given to the comprehensive environmental impact value,the A/O-MBR-worm bed is slightly smaller than the A/O-MBR system.Taking the current BNR-MBR process of Shenzhen Luofang Sewage Treatment Plant as the research object,and relying on the operating data obtained from the pilot test,the project-scale BNR-MBR system and BNR-MBR-worm bed process LCA study were obtained,and Contributions of similar operation substages and inventory division were tested,and the environmental impact values of BNR-MBR-worm bed were reduced by 1.17%,12.54%,5.75%,21.58%,23.38% among the seven environmental impact categories within the scope of the study,29.72%,6.89%,comprehensive environmental impact values LCAIs=3.18E-09,LCAIc=2.68E-09,BNR-MBR-worm bed reduced 15.63% compared to BNR-MBR.The sensitivity analysis and robustness analysis of the LCA results under different scenarios of weight distribution and changes in the main parameters of the worm bed process were conducted,and it was concluded that the worm bed coupled wastewater treatment process has a stable and lower environmental impact. |
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