Research On The Wastewater Treatment Effect And Denitrification Mechanism Of Composite Filler Infiltration System

In order to improve the effect of nitrogen pollutants on the traditional surface wastewater infiltration system(SWIS,??????),three sets of devices were constructed using soil,cinder and biological matrix as fillers.Thwas study constructed 1#(cinder-biomatrix),2#(cinder-biomatrix)and 3#with coal slag and dry sludge as filler.Among them,the particle size range of 1#,2#and 3#devices were d<3 mm,d<2 mm and d<3 mm,respectively,which was intended to change the slag particle gradation and add biological matrix to strengthen the nitrogen removal effect of the systems.And analyze the denitrification mechanwasm of the composite filler percolation system.The main findings are as follows:(1)Four different fillers were screened out,which were soil,cinder(d<2 mm),cinder(d<3mm),and biological matrix(d<3 mm).The permeability coefficients were 0.87,115.68,62.86,respectively.44.61 cm/h,the organic matter content was 0.50%,0.85%,0.95%,4.50%,the main particle size dwastribution was 1.000~3.000 mm,0.075~1.430 mm,0.075~1.430mm,0.150~3.000 mm,respectively.The ammonia nitrogen adsorption amounts were 0.097,0.156,0.145,and 0.082 mg/g,respectively.(2)When the hydraulic load was 10 cm/d,sodium acetate and glucose were used as carbon sources to study the effects of different carbon sources on the nitrogen removal of the three devices.When sodium acetate was used as the carbon source,the average removal rates of NH4~+-N in the three sets of 1#,2#,and 3#are 96.54%,97.86%,and 93.68%,respectively,and the average removal rates of TN are 35.35%and 31.40%,35.56%respectively;when the carbon source was glucose,the average removal rates of NH4~+-N in the three sets of 1#,2#,and 3#were94.25%,94.85%,and 94.66%,respectively.The average removal rates of TN were 54.47%and50.42%,53.21%,respectively.(3)The hydraulic load was applied at 10 cm/d and 15 cm/d to study the effect of hydraulic loading on the removal of nitrogen pollutants from the three sets.When the hydraulic load was 10cm/d,the average removal rates of NH4~+-N for the three sets of 1#,2#,and 3#were 94.25%,94.85%,and 94.66%,respectively.The average removal rates of TN were 54.47%and 50.42%,53.21%,respectively.When the hydraulic load was 15 cm/d,the average removal rates of ammonia nitrogen in the 1#,2#and 3#devices were 92.29%,90.45%and 93.45%,respectively,and the average removal rates for TN were 72.49%,59.88%and 42.77%.The denitrification effect of the three sets of devices at a hydraulic load of 15 cm/d was significantly different,confirming that 15 cm/d was the hydraulic load for subsequent mechanwasm studies.(4)Three sets of 1~#,2~#,and 3~#mainly remove ammonia nitrogen at 20-60cm,and remove TN at 60-80cm.The 2~#device was evenly dwastributed and added with biological matrix.The activity of NAR and NIR was better,and the strength of nitrification-denitrification was higher,which maked the system had the best nitrogen removal effect.In addition,the correlation between NIR activity and TN removal rate was significant and positively correlated,and therefore,NIR activity can evaluate the removal effect of TN.