Synergistic Co-digestion Of Echinocandin Bacterial Residue And Sewage Sludge

As the residue of antibiotic drug ingredients in the antibiotic bacterial residues,which have the potential risk to the environment.Therefore,antibiotics bacterial residues has been added into the list of national hazardous waste category since 2008.The problem of antibiotic residues treatment and disposal has become a bottleneck that restricts the development of drug industry in china.This study mainly focused on echinocandin bacterial residue.The effect of hydrothermal,microwave,ultrasonic,alkaline-thermal pretreatment method on echinocandin bacterial residue were investigated.Then,the best pretreatment method was selected from four pretreatment methods.The anaerobic co-digestion of the treated echinocandin bacterial residue and sewage sludge was carried out to investigate the effect of anaerobic digestion.Anaerobic fermentation residue was treated under different reaction conditions namely separate CTAB regulation,FeC13 regulation,oxidated by Fenton,s reagent.The efficiency of the solid-liquid separation was evaluated.The research results were summarized as follows:The results show that there are 70%moisture contents and 29%volatile matter.The bacterial residues contain 44%C element and 4.4%N element.The carbon-nitrogen ratio were 10/1.The content of crude protein is 38%.The bacterial residues contain variety of amino acids.The effect of hydrothermal,microwave,ultrasonic,alkaline-thermal pretreatment methods on echinocandin bacterial residue is investigated.It is ascertained that the optimal pretreatment process is alkaline-thermal.The concentration of SCOD enhances 47%and the accumulative methane yield is 489 mL/gVS.The optimal pretreatment parameter is 70?,0.08 gNaOH/gTS and 75 min.The pretreated echinocandin bacterial residue was anaerobically co-digested with sewage sludge.The organic matter in the two kinds of solid waste is converted into a new energy source of methane.There have a shorter stable period under bacterial residue and sewage sludge with mass ratio of 1:1 and 1:2.The more ratio of bacterial residue have,the more biogas yield and COD removal load can be obtained.The biogas yield finally reached about 0.33 L/(gVS.d)and 0.23 L/(gVS.d)respectively.The COD removal rate finally reached about 0.35 kg/(m3.d)? 0.25 kg/(m3.d)respectively.The stability of the system for bacterial residue was longer,but it could get higher biogas yield and COD removal load.The biogas yield could reach 0.68 L/(gVS.d)and COD removal rate finally reached about 0.6 kgV(m3.d).The content of antibiotic residues in anaerobic fermentation residue is lower than the detectable level.So the anaerobic digestion process can be beneficial to remove antibiotic residues.Anaerobic fermentation residue was treated under three conditions namely separate CTAB regulation,FeC13 regulation,oxidated by Fenton's reagent.Results showed that the three conditions can reduce the CST and SRF significantly.Favorable dewaterability was achieved when the anaerobic fermentation residue was conditioned at Fenton's reagent.At the optimized dosages of H2O2(40mg/g)and Fe2+(20mg/g),the CST declined by 95.9%and the SRF declined by 99.1%.