Study On The Transformation And Transformation Of Pollutants In Sewage Network Between Sewage And Sediment

In order to solve the problem of pollutant deposition and scouring in urban sewage pipelines,through the establishment of the pilot plant of sewage pipe line simulation and the actual sewage pipe network monitoring,the pollutant migration and transformation characteristics of sewage-sediments,and the scouring and sedimentation rules under different hydraulic conditions,and then evaluated the impact on the influent water quality of the wastewater treatment plant.The study on the stable operation of the sewage pipeline and the impact on the impact of the sewage plant is of great importance.The results show that the concentration of pollutants of carbon,nitrogen and phosphorus in wastewater drops in the sedimentation and sedimentation of particulate matter in the slow flow regime.The concentration of TCOD,TN and TP in sediments increased gradually in the monitoring of 61 days,which increased by 8532mg/L,111.95mg/L and 89.78mg/L respectively,and the pollutants were mainly enriched at the end of the pipeline system.The quantitative analysis model of the four pollutant transformation pathways of pollutant physical deposition,pollutant suspension,microbial adsorption and sediment release was established by controlling the nature of sewage and sediments in the pipeline.The results showed that the transformation amount of the physical deposition route was the highest(TN 5.15mg/L;TP 3.80mg/L),indicating that the physical sedimentation of contaminants carried by the particles in the effluent is the decisive factor in the change of the concentration of pollutants between the two phases,and the transformation of sediments was higher than that of microbial adsorption,which indicated that the metabolic activities of microorganisms in sediments were more significant,and the concentration of dissolved and small molecule pollutants in sewage could be improved.In order to clarify the relationship between the concentration of pollutant and the flow velocity,a pilot sewer system was established.The effects under different flow rates on the content of carbon(organic),nitrogen and phosphorus in the pipeline were studied.The results show that with the increase of the flow rate and the scouring intensity increases,the concentration of pollutants in the pipeline increases sharply.The results show that the organic pollutants in the pipeline are easy to exist on the particles with large particle size,when the flow rate is less than 0.6m/s,the deposition of particulate pollutants in sewage is greater than that of scouring,and physical deposition occurs,resulting in insufficient carbon source in the effluent.When the flow rate is less than 0.6m/s,when the flow rate is larger than 0.6 m/s,the erosion intensity of the water is increased and the sediment is carried by the water flow.However,the increase of the carbon pollutants in the sewage is larger than that of the nitrogen and phosphorus pollutants,so that the existing carbon source of the sewage is improved.Carbon source demand for biological nitrogen and phosphorus removal from subsequent wastewater treatment plants.