Study On Treatment Technology Of Cephalosporin Bacterial Residue With Physical-chemical Pre-treatment And Anaerobic Digestion

Antibiotic bacterial residues（ABRs）were produced in large amounts,when pharmaceutical enterprises produced antibiotics.Because containing some traces residual antibiotics,ABRs were listed as the hazardous waste in national list of China in 2008,but for which now it hasn’t a set of effective processing method of disposal.This study mainly focused on cephalosporin bacterial residues（CBRs）,which were treated by ultrasonic/alkaline pretreatment to break the cell wall,firstly.Then the anaerobic digestion of the treated CBRs and residues which were treated by centrifugalization after ultrasonic/alkaline pretreatment was carried out to determine the optimal control parameters.Under the best anaerobic digestion conditions,trace elements such as Fe,Co,Ni were studied for the influence of anaerobic reaction.The results were summarized as follows.1)The results of orthogonal experiments of ultrasonic/alkaline pretreatment indicated that the best operating conditions were moisture content of 94%,pH value of 10,reaction time of 30 min,and sound energy density of 2W/mL.Under this condition,the concentration of SCOD increased from 14536mg/L to 53094mg/L,and the solubility of SCOD was 265.26%.The concentration of total nitrogen increased from 941.5mg/L to 2404mg/L,and the solubility of total nitrogen was 155.28%.2)The results of anaerobic digestion of the CBRs treated by ultrasonic/alkaline showed that the best OLR was 1.16gVS/（L·d）.Under this conditions,the concentration of SCOD was 7 500mg/L,the concentration of ammonia nitrogen was 2200mg/L,and the biogas production rate was 325mL/（gVS·L·d）,respectively.3)The results of anaerobic digestion of the residues which were treated by centrifugalization after ultrasonic/alkaline pretreatment showed that the best OLR was 3.48gVS/（L·d）.Under this condition,the concentration of SCOD was 7000mg/L,the concentration of ammonia nitrogen was 1200mg/L,and the biogas production rate was 170mL/（gVS·L·d）,respectively.4)Under OLR of 3.48gVS/（L·d）of the residues treated by centrifugalization after ultrasonic/alkaline pretreatment,the results showed the addition of trace elements such as [Fe²⁺],[Co²⁺] and [Ni²⁺] of low concentration,could promote the efficiency of anaerobic digestion.The results of orthogonal experiments indicated that the best operating conditions were [Fe²⁺] of 10mg/L,[Co²⁺] of 0.5mg/L,and [Ni²⁺] of 1.0mg/L,respectively.Under this condition,the concentration of SCOD and ammonia nitrogen reduced to 3 000mg/L and 504mg/L,and the biogas production rate increased to 241.4mL/（gVS·L·d）,which increased by 43.67% than the blank control group,respectively.