Research On Urban Domestic Sewage Treatment By Fbbr Packed With The Non-woven Filler

The fixed bed biofilm reactor?FBBR?is a widely used and simple structure sewage treatment equipment.The filler is the core component of the biofilm reactor.Current research directions aim to find suitable filler in the future which will be more conducive for biofilm growth and attachment,has excellent performance,cheap and easy to obtain.Waste non-woven fabrics have the requirements of being biofilm fillers because they are common and easy to obtain,have a rough surface and good chemical stability.In view of the fact that China's solid waste treatment technology is still immature,slow development,and many solid wastes have not been treated with high quality and resource utilization,this study emphasizes on the waste non-woven fabric?NWF0?commonly used in life and waste non-woven fabrics?NWF1 and NWF2?modified by air thermal oxidation and microwave modification as biofilm packing to respectively design and manufacture NWF0-FBBR,NWF1-FBBR and NWF2-FBBR.Through the biofilm formation test,the effect of NWF0,NWF1 and NWF2 fillers on the filming effect and the treatment effect on simulated urban sewage were compared.The effect of NWF0,NWF1and NWF2 fillers on the biofim attachment and the treatment of simulated urban sewage were compared.The NWF2-FBBR with the best comprehensive effect was selected for subsequent tests.The single factor test and orthogonal test were used to analyze the influence of various factors on the pollutant treatment effect of NWF2-FBBR and determine the optimal parameter combination.The NWF2-FBBR was used to treat the actual urban domestic sewage and the feasibility of its practical application was explored.Finally,the mechanism analysis of the waste non-woven filler was carried out.The main conclusions are as follows:?1?The biofilm formation test showed that the biofilm attachment effect and pollutant removal efficiency of NWF1 and NWF2 fillers were better than those of NWF0 fillers.Compared with NWF0 packing,the amount of biofilm attachment on NWF1 and NWF2 packing is larger,and the time required for water outlet stabilization is shorter.NWF2 had the best effect on biofilm attachment and removing contaminants.?2?The single factor test of NWF2-FBBR treatment of simulated domestic sewage showed that the influent COD,HRT,DO,influent pH and filler filling rate all affected the removal efficiency of the reactor by pollutants.Orthogonal tests with organic load,HRT,DO,and filling rate showed that the best sewage treatment effect was achieved when the operating conditions were:influent COD 400 mg/L,HRT 8h,DO 3 mg/L,filler filling rate 6 g/L.?3?The study of NWF2-FBBR in the treatment of practical urban domestic sewage showed that it was feasible to apply NWF2-FBBR in the treatment of municipal waste water.The removal rates of COD,NH₄⁺-N and TP in real domestic sewage by NWF2-FBBR were stable at 92.1%,76.4%and 55.3%respectively.The effluent COD,NH₄⁺-N and TP concentrations were kept below 50 mg/L,5 mg/L and 1.5 mg/L respectively.?4?Non-woven fabric characteristic analysis showed that the specific surface area,contact angle,water absorption and roughness of NWF2 filler were better than that of NWF0 filler.Chemical functional groups such as carbonyl and hydroxyl groups were added to the surface of air thermal oxidation and microwave modification to improve the performance of the package.The NWF1 and NWF2 fillers had shorter biofilm suspension time and biofilm renewal cycle than NWF0 fillers.Also,the amount of biofilm attached to the unit mass of NWF1 and NWF2 fillers were greater than that of NWF0 fillers.The biofilm dehydrogenase activities on the surface of the three kinds of waste nonwoven fabrics were sorted by size:NWF2>NWF1>NWF0.In this paper,the waste non-woven fabric,which is commonly available in daily life,is selected as the biofilm filler to make FBBR for the treatment of municipal domestic sewage,which not only effectively treats urban wastewater and reduces environmental pollution but also solves the disposal problem of waste non-woven fabric.It also realizes the resource utilization of solid waste and improves the economy of the biofilm reactor packing.Therefore,the FBBR packed with the non-woven filler has a large promotion value.