Study On Treatment Of Rural Domestic Sewage By Elastic Filler Coupled With ABR

In order to solve the problem of unreasonable discharge of rural domestic sewage in arid and semi-arid areas and improve the current status of water pollution,this article explores the process of turning rural domestic sewage into resources after treatment.The anti-aging,temperature-resistant and corrosion-resistant high-quality materials selected from polyamides and polyolefins are used as elastic fillers.Comparative study of ABR with elastic filler and ABR without elastic filler to treat rural domestic sewage.Through the "simultaneous" comparative experimental of two sets of ABR devices,analyzed of the intermittent start-up,the removal effect of conventional pollutants under different working conditions,the change of the pollutant concentration of each agricultural irrigation index and transformation of nutrients in each compartment,as well as changes in DOM and the sludge performance under stable operation,study the impact of elastic fillers on ABR,the main conclusions are as follows:Two sets of ABR devices were started by reducing the hydraulic retention time(HRT)to24 h,18 h,and 12 h,respectively.The start-up time of ABR equipped with elastic filler was 7days shorter than that of ABR without filler.The elastic filler is beneficial to improve the removal rate of COD by ABR and shorten the start-up time of ABR;The elastic filler is helpful to reduce the ORP of each compartment of the ABR,and is conducive to forming a growth environment for anaerobic microorganisms;the elastic filler can also slightly increase the pH and alkalinity of each compartment of the ABR,so the anaerobic environment remains suitable pH range,but has little effect on the VFA concentration in each compartment.The research on the operation stage of different working conditions shows that during the process of HRT gradually shortening from 24 h,18 h,12h.The removal rates of TP and TN are both low and not much different.The elastic filler is beneficial to improve The removal rate of COD and SS and the ability of ABR to resist hydraulic impact.As the temperature decreases from 35?,25? to 16?,the average removal rates of COD,SS,TP and TN of the two groups of ABR devices have all declined.But the removal rate of COD and SS with ABR with elastic filler is higher than that of ABR without elastic filler,so the elastic filler is beneficial to the ABR device to improve the removal rate of COD and SS and the performance of resisting low temperature.However,the elastic filler has little effect on the removal of nitrogen and phosphorus in the ABR device.In the process of increasing organic load from 0.25 kg/(m3·d)and 0.33kg/(m3·d)to 0.42 kg/(m3·d),the average removal rate of COD in two groups of ABR devices increased,the average removal rate of SS decreased,and the removal rate of TP and TN increased slightly,indicating that the elastic filler is beneficial to improve the COD and SS removal rate of ABR,and it can also improve the ability to resistorganic load impact.In the stage of stable operation,under the condition of controlling HRT=24h.When the concentration of COD in the influent is between 100.89~310.03 mg/L,the removal rates of COD by the two groups of ABR devices are 58.70%(with elastic filler),55.77%(without elastic filler);When the concentration of SS in the influent is between 71.99~8.74 mg/L,the removal rates of SS by the two groups of ABR devices are 88.42%(with elastic filler)and83.65%(without filler);Compared with the back two compartments,the ammonia nitrogen concentration in the front two compartments of the ABR with elastic fillers increased significantly.The changes of TN,nitrate nitrogen,nitrite nitrogen and TP in each compartment of the two groups of ABR Very small,It has better retention effect on nitrogen and phosphorus.It shows that the elastic filler helps to improve the removal rate of COD and SS by ABR.The effluent concentration reached "Standards for irrigation water puality"(GB5084-2005).In the stable operation stage,the removal rates of LAS by the two groups of ABR devices are 40.96%(with elastic filler)and 39.16%(without elastic filler);The removal rates of the total salt content of the two groups of ABR devices are 10.97%(with elastic filler)and6.38%(without elastic filler);In terms of the removal of heavy metals,the concentration of most heavy metals in the ABR effluent(total arsenic,lead,chromium,and barriers)is lower than the "Standards for irrigation water puality" GB 5084-2005,The elastic filler can improve the removal rate of LAS,total salt content and heavy metals in the ABR device,but has little effect on the removal of fecal coliform.The Ion Chromatography and Excitation-Emission-Matrix Spectra analysis of each compartment of the two groups of ABR devices in the stable operation stage showed that the elastic filler can increase the concentration of formic acid,acetic acid and propionic acid in the first compartment of the ABR device.The influence of the DOM composition in each compartment of the ABR device is very small,but it can promote the removal of humic acids and dissolved microbial metabolites.The results of the research on the granular sludge in the two groups of ABR devices during the stable operation stage show that the elastic filler does not significantly change the particle size of the anaerobic granular sludge in each compartment of the ABR device.Through scanning electron microscopy,it can be observed that there are a large number of filamentous bacteria on the surface of the granular sludge in the first compartment of the two groups of ABR devices,which are reduced in the subsequent compartments,but the extracellular polymer is increased.In the Energy Dispersive Spectrometer analysis,it was found that Al,Na,P,Ca,As,Fe,Pb,Hg and C,N,O elements can be detected on the surface of the particulate sludge in the two groups of ABR devices,among which C,N,O elementsAccounted for relatively large.Compared with the ABR device without elastic filler,the heavy metal elements on the surface of the granular sludge in the ABR device with elastic filler account for a relatively low amount.The FTIR spectrum analysis of the biofilm on the elastic filler showed that the sludge attached to the elastic filler contained organic substances such as lipids,sugars and aromatics.The types of organic matter in the granular sludge of the sludge bed in the two groups of ABR devices are similar to those in the biofilm.The elastic filler can increase the biomass in the ABR device,but the increase in the types of microorganisms is not obvious.