Research On Controlling Antibiotic Residues Inhibitors During Anaerobic Biotreatment

In the present, the anaerobic biochemistry craft is the main wastewater disposal process, but that it included a large number of toxic material such as antibiotic residues in the pharmaceutical wastewater that could inhibit the anaerobic microorganism biochemistry action. This article was in view of penicillin and oxytetracycline wastewater, to determine their residual concentration,inhibition level and elimination methods. The main research results are as follows:(1) This experiment has established SPE-HPLC-MS technique method to determine the residual penicillin concentration, the recovery ratio is 64.9～76.3%,the detection limit is 5μg·L-1.It has established SPE-HPLC technique method to determine the residual oxytetracycline concentration, the recovery ratio is 87～115%, the detection limit is 2.8 mg·L-1.The result indicated that in wastewater the residual penicillin concentration is about 0.371 mg·L-1,the oxytetracycline concentration is about 1122 mg·L-1.(2) The anaerobic biochemistry toxicity test research indicated that two kinds of antibiotics could restrain the anaerobic microorganism biochemistry action, and the inhibition level was related to antibiotic concentration. Slight inhibition was caused when concentration of penicillin was below 10 mg·L-1,and middle inhibition when penicillin concentration was increased. Middle inhibition when concentration of oxytetracycline was excess 200 mg·L-1, and high inhibition when concentration of oxytetracycline was excess 800 mg·L-1.The scanning electron microscope demonstrated that low concentration penicillin has poor influence to microorganism, the highly concentrated penicillin would stimulated the microorganism to produce the massive secretions. But oxytetracycline has deep toxic action to microbe group in granular sludge, and highly concentration oxytetracycline may cause the bacterium massive deads or to enter dormant period. In the actual wastewater it existed only a trace amount of penicillin residues, and maybe not need to take additional measures. But the oxytetracycline residues concentration was too high to need take measures to control the concentration less than 200 mg·L-1.(3)The orthogonal test result indicated that the influencing factor order of Fenton reagent processing oxytetracycline is:H2O2 dosage>H2O2/Fe2+ratio> the initial pH>the reaction time. When initial pH is 4.0, H2O2 option dosage is 1.0 mL·L-1,H2O2/Fe2+ratio is 20:1,reaction time is 30min, the OTC elimination rate can achieve above 90%.The influencing factor order of ClO2 reagent processing oxytetracycline is:ClO2 dosage >the reaction time>the initial pH. When initial pH is 4.0, ClO2 option dosage is 200 mg-L"1, the reaction time is 30 min, the OTC elimination rate can achieve above 96%.(4) The best operating condition of Fenton reagent processing oxytetracycline waste water is:FeSO4·7H2O dosage is 0.05g,30%H2O2 dosage ratio is 0.14, the OTC result concentration is 185 mg·L-1.The best operating concentration of ClO2 reagent is 300 mg·L-1, and the OTC result concentration is 163 mg·L-1 after reaction. By ClO2 disposal wastewater in oxytetracycline, the wastewater production the methane quantity can be enhanced 39.12%. But after Fenton reagent disposal oxytetracycline wastewater, the production of methane quantity could be enhanced 35.27%. After this operation, the suppression of oxytetracycline on anaerobic micro-organisms would reduced effectually.