Experimental Study On Wastewater Treatment By Biofilm Reactor Filled With Modified Combined Carrier

With the development of economy,the problem of water pollution control has become one of the important topics that people generally pay attention to.Biofilm reactor is an important technology for sewage treatment and has been widely used.However,the biofilm reactor carrier also has the disadvantages of higher cost,poor film hanging effect,and uneven removal of pollutants in sewage.At the same time,a large amount of waste plastics and waste non-woven fabrics are produced in industrial production and people's lives,and their conventional treatment methods often have problems such as waste of resources and secondary pollution.Based on the above background,this paper used common waste plastics and waste non-woven fabrics as raw materials to prepare biofilm reactor combination carrier?ZH0?,and used chemical oxidation-iron ion covering method to face multiple hollow balls?prepared from waste plastics?Modified with waste non-woven fabric to produce modified combined carrier?ZH1?;Two sets of carriers were used to treat simulated urban domestic sewage,comparative study of ZH0,ZH1membrane performance and unmodified combined carrier biofilm reactor?ZH0-BR?,modified combined carrier biofilm reactor?ZH1-BR?Treatment effect on simulated urban domestic sewage;Used ZH1-BR to carry out single-factor test and orthogonal test to explore the best operating parameters of ZH1-BR for sewage treatment;Under the best operating parameters,explored the treatment effect of ZH1-BR on actual urban domestic sewage;Finally,the mechanism analysis were carried out.The main conclusions are as follows:?1?The results of the continuous flow film test showed that:compared with ZH0,ZH1 had a shorter film hanging time and more biofilm attached to the unit mass of carrier;During the stable operation of ZH0-BR and ZH1-BR,the removal rate of COD,NH₄⁺-N and TP in simulated urban domestic sewage by ZH1-BR could be stabilized at 93.7%,86.1%and 61.0%,respectively,the removal rate was significantly better than ZH0-BR.?2?The single factor test results showed that dissolved oxygen concentration?DO?,hydraulic retention time?HRT?,carrier filling rate,pH value and carrier mixing ratio all had certain effects on the removal effect of pollutants in simulated urban domestic sewage.Orthogonal test results showed that when DO was 3 mg/L,HRT was 10 h,carrier filling rate was 60%,and carrier mixing ratio was 3:2,ZH1-BR had the best removal effect on pollutants in simulated urban domestic sewage.?3?ZH1-BR had a good treatment effect on actual urban domestic sewage,and the removal rates of COD,NH₄⁺-N and TP in actual urban domestic sewage could be stabilized at 91.5%,80.6%and 52.0%,respectively.?4?The mechanism analysis showed that the hydrophilicity of the modified combination carrier was obviously superior to that of the unmodified combination carrier;After chemical oxidation and iron ion coverage modification,hydrophilic active groups such as carbonyl and hydroxyl groups on the surface of multi-faced hollow spheres and non-woven fabrics increased significantly,improving the hydrophilicity and biological affinity of the carrier surface;The roughness of the carrier surface was significantly increased after modification;The dehydrogenase activity of the biofilm on the surface of the modified carrier was significantly greater than that of the unmodified filler;The analysis of biofilm characteristics showed that the modified combination carrier was easier to enrich,grow and reproduce microorganisms;The amount of biofilm and the update rate of biofilm on the surface of modified combined carrier were better than those of unmodified combined carrier.In this paper,waste plastics and waste non-woven fabrics that are common in life were used as carriers in biofilm reactors for sewage treatment.The cost is low.While effectively treating sewage,it realized the recycling of solid wastes and had practical value.It is innovative in the selection and treatment of carriers and the design of internal structure of the reactor..