Removal Of Typical Antibiotics From Aquaculture Wastewater By GAC/PC/PSBR Processes And Study On Its Migration And Transformation Mechanism

As China is the major producer of aquatic products in the world,massive aquaculture wastewater containing high nutrients and antibiotics is generated and needs to be appropriately treated.The widespread use of antibiotics in aquaculture has become an important source of antibiotic pollution in the natural environment.At present,antibiotics has been widely detected in various aquaculture waters in China,with concentrations ranging from ng/L toμg/L.In order to effectively control the antibiotic residues in the effluent wastewater from the aquaculture industry,it is necessary to explore the effect of common wastewater removal processes on the removal of typical antibiotics in aquaculture wastewater and optimize the process conditions.Therefore,the subject first established an antibiotic detection method,which includes six antibiotics,sulfonamides and quinolones,and has a good linear relationship in the concentration range of 0.1 to 10000μg/L.Secondly,the effect of different process conditions on the removal of antibiotic wastewater was investigated.According to laboratory conditions,the photo-sequence batch reactor（PSBR）was selected as the main process,and the active adsorption and advanced oxidation methods were used as the advanced treatment process.The treatment effects of these three types of treatment methods on typical antibiotics in aquaculture wastewater were explored.The PSBR method was used to treat the aquaculture simulated wastewater.Experimental study on the treatment effects of six common antibiotics in aquaculture wastewater,and the corresponding preparation of the corresponding characteristics Concentrations of COD,NH₄⁺-N and TP,and antibiotic concentrations closer to the actual wastewater were used.After treatment,the removal rates of COD,NH₄⁺-N and TP and TP reached 97%,98%and 89%,respectively.Compared with the traditional SBR process,PSBR has advantages in the removal of antibiotics.In the stable stage,the removal rates of sulfonamides and quinolone antibiotics are more than 90%,showing a good removal effect.At the same time,the ENR degradation products obtained in the PSBR reactor were analyzed to deduce possible antibiotic degradation pathways.In addition,16Sr DNA biodiversity sequencing was performed on sludge samples to compare the differences in bacterial community diversity at different stages of the two groups of reactors.Finally,the change law of resistance genes in the two reactors was analyzed.Compared with the traditional SBR reactor,the resistance genes in PSBR were significantly reduced,which actually inhibited the spread of resistance genes to a certain extent.In the process of aquaculture,the sudden illness and other factors may lead to the increase of the concentration of antibiotics in the wastewater.In order to ensure the effluent quality,this paper further studied the removal effect of antibiotics by activated carbon and photocatalytic methods.Adopting activated carbon technology to treat SMX and SDZ two kinds of sulfonamide antibiotics has a good removal effect,and the adsorption equilibrium can be achieved after 360 minutes.The removal effect of antibiotics on different types of activated carbon was determined.The adsorption efficiency of the three activated carbons in order from small to large was columnar activated carbon<fiber activated carbon<granular activated carbon.At the same time,by changing the amount of activated carbon to choose a suitable ratio,when the amount of activated carbon is increased to 1000 mg/L,the removal rate of antibiotics will no longer increase with the increase of the amount of activated carbon.After the advanced treatment of activated carbon adsorption,the antibiotic removal rate was stable between63.1%and 71.7%.BiVO₄ photocatalytic method was used to treat simulated antibiotic wastewater containing SMX and SDZ.The photocatalytic degradation rate of antibiotics was positively correlated with the dosage of BiVO₄,light intensity and reaction time,and negatively correlated with the initial antibiotic concentration.Photocatalytic degradation With the increase of the p H value of BiVO₄ synthesis,the rate first increased and then decreased.After screening the control variables,the optimal working conditions were as follows:the preparation p H of BiVO₄ was 5,the dosage was 0.25 g/L,and the reaction was carried out under UV light intensity of 10000 lux for 4 h.Under optimized conditions,the average removal rate of antibiotics in simulated wastewater can reach 90.97%,which has good stability and reusability.PSBR is a low energy consumption process,which can achieve the effective removal of antibiotics in aquaculture wastewater,and effectively inhibit the production and transmission of resistance genes.The GAC and PC of the advanced treatment process can provide further guarantee for the effluent quality during the operation of high concentration load condition.