Application Of SBBR Process In Detergents Wastewater Treatment And Its Impact Resistance Research

With the acceleration of industrialization in China,a large number of detergents are used in industrial production,resulting in an increase in the discharge of detergent wastewater and environmental pollution.Nonionic surfactant polyoxyethylene lauryl ether?Brij35?and detergent auxiliary tetrasodium ethylenediamine tetraacetate?Na₄EDTA,abbreviated as EDTA?are the common components of detergent wastewater,which are harmful to human,mammals and aquatic animals.Biological treatment of wastewater is considered as a lower cost,higher efficiency,lower energy consumption,easier operation and no secondary pollution option.Sequencing Biofilm Batch Reactor?SBBR?is a kind of biological process for wastewater treatment.It has many advantages,such as saving land occupation and construction cost,abundant microorganism species and quantity,saving energy consumption and low sludge production,and is widely used in wastewater treatment.In this study,two SBBR devices,namely reactor A and reactor B,are used to treat simulated detergent wastewater.The purpose of this study is to investigate the degradation rate of Brij35,EDTA and COD,the microbial community structure in the start-up stage of different filling modes,and to explore the effects of influent changes[including organic loading rate and biodegradability variation]on the performance of Brij35,EDTA and COD removal and the dynamics of microbial community structure.The purpose is to find the dominant bacterias in response to impact load,and to provide data support for controlling the structure of microbial population and stabilizing the operation of wastewater treatment equipment under the fluctuation of water quality in the actual detergents wastewater.At the same time,it also provides support for the research and development of process stable operation control technology under the impact of water quality load.The main research results are as follows:1.In the start-up stage of soft filler,the influent organic loads of reactor A and B were 0.073and 0.074 kgCOD/kgMLSS/d,on 1-51d respectively.The average influent concentrations were:COD=582.8 and 593.8 mg/L,EDTA=195.8 and 188.9 mg/L,Brij35=205.3 and 213.8mg/L.The average removal rates of effluent at 48h were:COD=84.0 and 82.5%,EDTA=36.3 and 40.1%,Brij35=87.3 and 85.6%,respectively.During 52-95d the organic loads of reactor A and B were 0.096 and 0.093 kgCOD/kgMLSS/d,respectively.The average influent concentrations were:COD=1009.3 and 980.1 mg/L,EDTA=171.8 and 164.6mg/L,Brij35=466.8 and 450.9 mg/L.The removal rates at 72h were COD=93.0 and93.3%,EDTA=61.2 and 65.2%,Brij35=95.8 and 96.5%,respectively.The results show that the prolongation of HRT?HRT increased from 48 h to 72 h?improves the removal efficiency of detergent wastewater by SBBR with soft fillers.2.In the start-up stage of combined fillers,the influent organic loads of reactor A and B were 0.109 and 0.11kgCOD/kgMLSS/d during 96-143d,respectively.The average influent concentrations were:COD=979.0 and 992.4mg/L,EDTA=156.6 and 153.6mg/L,Brij35=415.3 and 472.1mg/L.The removal rates at 72h were:COD=96.8 and 97.8%,EDTA=80.7 and 83.4%,Brij35=97.4 and 97.7%,respectively.The results show that the SBBR device of combined fillers is better than the SBBR device of soft fillers in the treatment of detergent wastewater.In addition,the effluent removal rates of COD and Brij35during 96-143d were above 95%,EDTA removal rates were above 80%,and the device was successfully started.3.The effect of the increase of Brij35 and EDTA concentration?load?on the treatment effect was investigated.The results show that the organic loads of the control group?reactor A?and the experimental group?reactor B?were 0.105 and 0.181 kgCOD/kgMLSS/d during144-183d,respectively.The average influent concentrations were:COD=943.6 and 1631.2mg/L,EDTA=162.0 and 262.0 mg/L,Brij35=474.9 and 825.8 mg/L,respectively.The average removal rates at 72h were COD=98.7 and 98.8%,EDTA=95.2 and 96.1%,Brij35=98.9 and 98.8%,respectively,indicating that the first stage of shock load has little effect on the treatment effect of the device;From 184 to 213d,the organic loads of the control group and the experimental group were 0.158 and 0.385 kgCOD/kgMLSS/d,respectively.The average influent levels were COD=950.9 and 238.7 mg/L,EDTA=166.7and 368.6 mg/L,Brij35=461.8 and 1138.0 mg/L,respectively.The average removal rates of COD=95.8 and 82.3%,EDTA=88.9 and 69.3%,Brij35=96.6 and 90.5%at 48h effluent level,respectively.It shows that the further increase of organic load in the second stage of shock load reduces the removal rate of pollutants in the experimental group.4.The effects of lower biodegradability of influent[i.e.higher EDTA concentration?load?and lower Brij35 concentration?load?]on the treatment effect are investigated.The results showed that the organic loads of EDTA in the influent of the control group and the experimental group were 0.025 and 0.063 kgEDTA/kgMLSS/d during 214-237d,,respectively.The average influent levels were COD=952.0 and 957.9 mg/L,EDTA=151.9and 377.4 mg/L,Brij35=483.9 and 418.6 mg/L,respectively.The average removal rates at48h were COD=98.4 and 92.0%,EDTA=95.5 and 73.7%,Brij35=94.2 and 95.9%,respectively.In addition,the organic loading of EDTA was 0.028 and 0.15kgEDTA/kgMLSS/d in the control group and the experimental group from 238 to 261d,respectively.The average influent concentrations were COD=960.4 and 1149.0 mg/L,EDTA=170.1 and 899.1 mg/L,Brij35=472.0 and 380.2 mg/L,respectively.The average removal rates at 48 h were COD=95.9 and 59.9%,EDTA=86.9 and 11.8%,Brij35=95.7 and 93.8%,respectively.The results show that the average removal rates of COD and EDTA in the experimental group are reduced in the third and fourth stages of shock loading,but the average removal rates of Brij35 are almost unchanged.5.Brevundimonas,Thermomonas,Novosphingobium,Flavobacterium,Macellibacteroides,Rh-odobacter,Thalassospira,Bdellovibrio,Desulfomicrobium and Sulfuricurvum are respond to the increase of Brij35 and EDTA concentration;Thauera,Pseudomonas,Thermomonas,Rheinheimera,Pseudoxanthomonas,Pedobacter,Chryseobacterium,Brachymonas,Gemmobac-ter,Sphingobium,Arenimonas and Rheinheimera are respond to lower biodegradability?EDTA concentration increased?environment.Therefore,in order to ensure the stable and efficient operation of the detergent wastewater treatment system,relevant measures should be taken to optimize the control of the above microbial populations in the subsequent actual detergent wastewater treatment process.