| In recent years,as the degree of industrialization continues to deepen,the environmental pollution caused by industrial wastewater has become more and more serious.Industrial wastewater includes two types:high concentration and difficult to degrade.The former has high COD,high organic content,good biodegradability,low p H,and is easily acidified;the latter has low biodegradability,and pollutants in the water are extremely difficult to be degraded by microorganisms.Traditional treatment methods can complete the treatment of wastewater to a certain extent,but they all have disadvantages such as large area,poor treatment effect,high investment cost,large amount of sludge,secondary pollution,etc.Therefore,it is urgent to develop new water treatment technologies for high-concentration refractory wastewater.In this paper,soybean products wastewater and polyacrylate wastewater were treated as high concentration refractory wastewater.The technology of combined treatment of SSSAB(Spiral Symmetry Stream Anaerobic Bioreactor)and AFB(Air-lift external circulation vortex enhancement nitrogen removal fluidized bed bioreactor)developed by the research group was adopted to carry out the demonstration test research of productive engineering.The operation performance of the demonstration project was studied from the aspects of reactor start-up,operation characteristics,degradation pathway of organic components and changes in the structure of anaerobic granular sludge,so as to provide theoretical and data support for the further application of the demonstration project.The specific research results are as follows:1.Combined anaerobic/aerobic biological fluidized bed treatment of polyacrylate wastewater(1)Start-up and operation characteristics of SSSAB:it took 30 days to start successfully,and the proportion of influent polyacrylate wastewater was 37.5%;during stable operation,the average COD concentration of influent was 1559 mg/L,and the average COD removal rate was 36.4%,the highest It can reach 40.2%;the effluent p H is stable at about 7.49,which is lower than the influent;it can withstand the impact of a volume load of 1.11～2.18 kg COD/(m~3·d).(2)Changes in organic components of influent and effluent of SSSAB:the influent contains42 kinds of organic matter,and the effluent organic matter is less than the influent.Alcohols,amino acids,alkenes,aromatic lipids and ethers appear in the effluent;small molecular organic matter in the effluent.The relative content has risen.(3)Start-up and operating characteristics of AFB:it took 12 days to start up;the average influent COD concentration during stable operation was 979 mg/L,the average effluent COD concentration was 135 mg/L,and the average COD removal rate was 86.0%;the average effluent ammonia nitrogen concentration at 0.7 mg/L,the removal rate of ammonia nitrogen is close to 100%;the p H of the effluent has risen compared with the influent,and remains at about 7.8.(4)Anaerobic/aerobic biological fluidized bed combined treatment effect:anaerobic section HRT=2 d,average OLR is 0.83 kg COD/(m~3·d),aerobic section HRT=3 d,average OLR is 0.31kg COD/(m~3·d);the average COD removal rate of the system is 91.0%,the contribution rate of the anaerobic section is 41%,and the contribution rate of the aerobic section is 59%.2.Combined anaerobic/aerobic biological fluidized bed treatment of soybean product wastewater(1)SSSAB startup and operating characteristics:successful startup lasted 60 days;the average OLR of the reactor during stable operation is 13.33 kg COD/(m~3·d),the influent is 3158-5409 mg/L,and the effluent water is reduced to 450-1043 mg/The average removal rate of L and COD is 84.7%.(2)Start-up and operating characteristics of AFB:it took 10 days to start up,the average influent COD concentration was 670 mg/L,and the average COD removal rate was 83.0%;the average influent ammonia nitrogen concentration was 179 mg/L,and the average removal rate was96%.(3)Anaerobic/aerobic biological fluidized bed combined treatment effect:anaerobic section HRT=7.2 h,average OLR is 13.33 kg COD/(m~3·d),aerobic section HRT=12 h,average OLR is 0.31kg COD/(m~3·d);the average removal rate of COD is 97.0%,the contribution rate of the anaerobic stage is 84%,and the contribution rate of the aerobic stage is 16%;the average ammonia nitrogen concentration in the final effluent is 3.1 mg/L,and the average removal rate is 96.0%;the average p H of anaerobic influent is 5.08,and the average p H of anaerobic effluent is 7.1.After aerobic treatment,the average p H is reduced to 6.71,and the operation is stable;compared with other treatment processes,the volume load of the anaerobic section of the treatment system has obvious advantages.(4)Long-term operation characteristics:within 7 months,the COD of the effluent of the system is stable between 47～329 mg/L,the COD removal rate has been above 90.0%,the system is stable and the effect is good.3.Study on the evolution of anaerobic granular sludge community structure(1)The evolution of bacterial community structure:compared with inoculated anaerobic granular sludge,the number of bacterial species in the sludge treated with polyacrylate wastewater is reduced,the community structure is simplified,and the relative abundance of each bacterial population has a small change,increasing or decreasing;bacterial species in the sludge for processing soybean wastewater increased,and the complexity of the community structure increased.Except for Bacteroidetes＿vadin HA17,the relative abundance of bacteria of other genera showed an upward trend.(2)The evolution of archaeal community structure:compared with the inoculation of anaerobic granular sludge,the sludge after treatment of the two types of wastewater showed a trend of decreasing archaeal species and increasing the number gap between species;the dominant populations changed in the same way.At the phylum taxonomic level,Euryarchaeota is the dominant population,and at the genus taxonomic level,the dominant population changes from Methanobacterium to Methanosaeta. |
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