Study On The Effect Of Micro-Oxygen Hydrolysis Acidification Reactor On The Treatment Of Printing And Dyeing Wastewater

The printing and dyeing waste discharged from textile industry has complex composition,large chroma and poor biodegradability,so it is very difficult to achieve economical and effective treatment.Hydrolytic acidification is the key to the treatment of printing and dyeing wastewater,but the low microbial abundance and low enzyme activity make its efficiency low and stability poor.Micro-oxygen hydrolytic acidizing enzyme activity is high,can accelerate hydrolysis,improve biodegradability,in petrochemical,pharmaceutical and other wastewater treatment field has a good effect,in printing and dyeing wastewater treatment will have a good prospect.However,it is difficult to control the oxygen concentration of microoxygen hydrolyzing and acidifying,and it is unclear to understand the composition of functional microorganisms.In this paper,the laboratory simulation printing and dyeing wastewater as the research object,the use of micro-oxygen hydrolysis acidification reactor to treat printing and dyeing wastewater,explore the control effect of micro-oxygen concentration and oxygen mass transfer efficiency,analysis of printing and dyeing wastewater treatment efficiency under the effect of micro-oxygen concentration,combined with microbial commnity composition and hydrolysis acidification function of microorganisms analysis,The effect mechanism of oxygen concentration on the degradation of printing and dyeing wastewater in micro-oxygen hydrolyzing acidification reactor was revealed,which provided scientific basis for the efficient treatment and resource treatment of printing and dyeing wastewater.Key results include:(1)The distribution of oxygen concentration in raw water aeration,membrane aeration and microporous intermittent aeration was studied.The DO distribution of the micro-oxygen hydrolyzing acidification reactor was stable,the effluent pH was neutral,and the ORP distribution was-283.9-136.4 mV.When the oxygen concentration increased from 0.1-0.3 mg/L,0.4-0.6 mg/L and 0.7-1.0m/L,the oxygen mass transfer efficiency OTR first increased and then decreased,the thickness of biofilm in the micro-oxygen environment showed an increasing rend,the first-order reaction rate constant of microbial metabolism first increased and then decreased,and the oxygen diffusion coefficient De showed a gradual increasing trend.(2)Microoxygen(0.1-0.3 mg/L)hydrolyzed acidification can remove COD,PVA and chroma with 4 1.40%±5.49%,34.03%±5.63%and 76.96%±7.53%,and B/C value increases from 0.36±0.049 to 0.554±0.046,showing the best effect.The eficiency of dissolved oxygen increased or decreased.The anaerobic(0-0.1 mg/L)VFAs yield and acidification rate were the highest.When the concentration of dissolved oxygen is lower than 0.3mg/L,N-H bonds of amines,primary amides,C-H bonds of alkanes and C=C bonds of olefin substances have good bond-breaking effect.No significant difference was found in the microoxygen and anaerobic hydrolysis acidification reactions of alcohols,phenols O-H and C-O.The fluorescent substances in effluent were mainly fulvic acid,protein-like substance and humic acid,and the fluorescence intensity of microoxygen hydrolysis acidification was lower than that of anaerobic hydrolysis acidification.(3)The abundance of microoxygen hydrolytic acidification was greater than that of anaerobic hydrolytic acidification.Proteobacteria occupies the largest proportion in anaerobic hydrolysis acidification reactor,and the proportion of Pleomorphomonas.Desulfovibrio,Aeromonas and Pelobacter is significantly higher than that in micro-oxygen hydrolysis acidification reactor,and is significantly positively correlated with chroma and acidification rate.The proportion of Chloroflexi in anaerobic and microaerobic hydrolysis acidification reactors was not significantly different.In the micro-oxygen hydrolytic acidification reactor,the proportions of Acidobacteria,Bacteroidetes and Firmicutes were significantly higher,and the proportions of Holophagaceae,Thioclava and Dechloromonas were significantly higher.When DO is low in the micro-oxygen hydrolytic acidification reactor,the proportion of DO is larger and has a significant positive correlation with COD,PVA and B/C.The abundance of functional microorganisms in the micro-oxygen hydrolytic acidification reactor was consistent with the treatment efficiency of printing and dyeing wastewater.