Anaerobic Co-digestion Of Antibiotics Contained Pig Manure And Straw

In China,about 700 million tons of waste straw and 4.5 billion tons of manure are produced each year.It is reported that China currently produces about 700 million tons of waste straw and 4.5 billion tons of manure each year.Most of the straws are directly discarded or burned,causing serious pollution to the environment.About 80% of the manures,which contain a large number of pathogens that may cause harm to animals and plants,are discharged without any treatment.This phenomenon is even more serious in poultry manure.In order to reduce the incidence of livestock,a large amount of antibiotics are fed to them.But most of these antibiotics are excreted without digestion and this causes serious problem to the environment.Anaerobic digestion is a common way to treat manure and waste strew in rural areas.Therefore,it is important to study the process about the anaerobic digestion of straw and manure which contain antibiotics.In this study,the effects of different total solids(TS)concentrations and material ratios on the anaerobic digestion of pig manure and corn stalk were verified by static batch test,which provided the basis for the operation of semi-continuous flow reactor.Then,two kinds of antibiotics,norfloxacin and sulfamethoxazole,which were commonly used in veterinary drugs,were used as the research objects.A semicontinuous flow single-phase anaerobic reactor and a pre-treated semi-continuous flow single phase anaerobic reactor were used to investigate the inhibition of two antibiotics on anaerobic digestion.The effect of high temperature pretreatment on anaerobic digestion and the enhancement of antibiotic removal were also studied.Finally,the prediction model of anaerobic gas production was established by using the operation data of semi-continuous flow single-phase anaerobic reactor.The feed which had not undergo high temperature pretreatment were dosed with norfloxacin and sulfamethoxazole to the concentrations of 0,20 and 60 mg / L,respectively.The methane production were 205.2,163.1 and 128.2 ml CH4/gVS,respectively.The degradation efficiencies of norfloxacin were 60.79 ± 1.17% and 71.10 ± 0.58%.The degradation efficiencies of sulfamethoxazole were 65.39 ± 0.78% and 73.56±1.08%.In the reactor which the feed was disposed with high temperature pretreatment,the methane yields were 222.1,185.9 and 173.4 ml CH4/gVS.The degradation efficiencies of norfloxacin were 72.87 ± 0.69% and 77.39 ± 0.78%.The degradation efficiencies of sulfamethoxazole were 72.19 ± 0.69% and 80.95 ± 1.01%.Indicating that high temperature pretreatment will improve the effect of anaerobic digestion and strengthen the removal of antibiotics.Based on the data obtained from two semi-continuous flow single-phase reactors,the gas production prediction model of anaerobic digestion was established by using SPSS and MATLAB artificial neural network toolbox.The accuracy and applicability of the model are verified by the data obtained from the anaerobic bioreactor with different feed condition.The results are in good agreement with the prediction.This indicated that the prediction mode had good veracity and a certain applicability.