Residual Of Antibiotics In Aquaculture Environment And Its Elimination Technology

Antibiotics are widely used in every aspects of aquaculture.On the one hand,antibiotics could prevent and treat aquatic diseases;on the other hand,they could promote the growth of the organism.But antibiotics were abused continually.The safety of aquatic animals and aquaculture environment were threated seriously,due to lacking of standard.Antibiotics in the environment will lead to the production of resistant strains easily,and destroy the micro-ecological balance of soil,animals,plants and humans.The main reason of antibiotic pollution in the environment includes the discharge of hospital wastewater and urban sewage,the effluent of sewage treatment plant and aquaculture.The pollution of antibiotics in environment was paid more and more attention and the usage of antibiotics in aquaculture was serious,so the antibiotic residues in aquaculture environment need to be studied deeply.In order to monitor the condition of antibiotics residues in seawater of aquaculture environment,the detection method of solid phase extraction-liquid chromatography tandem mass spectrometry(SPE-LC-MS/MS)has been established for 17 kinds of quinolones and 15 kinds of antibiotics included chloramphenicol,sulfonamides and tetracyclines in aquaculture seawater.The recoveries of these two methods were satisfacted after optimizating.The limits of detection(LOD)were from 2.00 to 10.00 ng/L and the limits of quantification(LOQ)were from 5.00 to 20.00 ng/L for the 17 kinds of quinolones.The averaged recoveries of 17 quinolones at the spiked concentrations of 20.00,100.00 and 200.00 ng/L were ranged from 71.33% to 124.60% with the standard deviation(RSD,n=5)ranged from 2.73% to 9.97%.The method can detected quinolone antibiotics in seawater comprehensively,and it has been approved by industry standards of the State Oceanic Administration.In order to improve the detection efficiency of antibiotics in seawater and increase the types of targets,the method of 15 antibiotics including chloramphenicol,sulfonamides and tetracycline was established.Calibration curves for antibiotics exhibited good linearity,and the limits of detection(LOD)were 1.00 to 10.00 ng/L and the limits of quantification(LOQ)were from 5.00 to 20.00 ng/L.The recoveries of 15 kinds of antibiotics were from 71.84% to 113.36% and the relative standard deviations(RSDs)were from 1.60% to 13.65%(n =5).Utilizing the developed analytical methods of 17 quinolones in the aquiculture environment,the contents of quinolones were determined for the seawater of outlet,inlet and ponds of industrial aquaculture in Lingshan Bay,yellow sea.Simultaneously,the contents of quinolones for seawater and biological samples(puffer fish,flounder and black fish)of the cage culture in Sanggou Bay were also determined.The results showed that quinolones were detected in these two typical culture areas,but the content level of quinolone antibiotics was different.The concentration of quinolone antibiotics in the aquaculture seawater of the cage culture area represented by Sanggou Bay was higher,and the concentration range of the two areas was from ND to 6880 ng/L and from ND to 32.48 ng/L.The quinolones in the seawater of the factory aquaculture area are polluted more seriously.The levels of quinolones in seawater and corresponding fish collected from different aquaculture species in Sanggou Bay were also different.The concentration of antibiotics in seawater was up to be 32.48 ng/L.The concentrations of quinolones in the Sanggou Bay aquaculture area ranged from ND to 32.48 ng/L.And the concentration of non-cultured areas ranged from ND to 17.47 ng/L.It was speculated that the use of antibiotics in aquaculture was one of the important sources of antibiotic residues in Sanggou Bay.In order to speed up the elimination of antibiotics in environment,the elimination technology of trace enrofloxacin was dicussed by means of photocatalytic degradation and microbial degradation on basis of the investigation of antibiotics pollution in the aquaculture environment.The results showed that the degradation rate of enrofloxacin was 88.11% after 100 min under UV irradiation,which initial concentration of enrofloxacin in seawater was 100ng/m L and the dosage of nanometer titanium dioxide was 2 g/L.The beneficial bacteriums including Yeast,Lactic acid bacteria,Bacillus natto and Bacillus licheniformis were added to the seawater containing enrofloxacinand incubated at 25 ? for 7 days in dark condition.The concentration of enrofloxacin changed but the difference was non-significant.The degradation rate ranged from 9.44% to 23.24%.The effect of enrofloxacin degradation under the photocatalytic with nanomaterials was rapid and effective,but microbial degradation technology for enrofloxacin still needed to be further study.