摘要

Recently, significant antibiotic residue is detected in the recovery of magnesium ammonium phosphate (MgNH4PO4?6H2O, MAP) from the digested livestock wastewater. In case MAP is adopted as fertilizer for the agriculcural use,the antibiotics will be transferred from soil to the plant, consequently do harm to human. In order to reduce antibiotic residues in the final products, coagulation was employed as the pretreatment method before MAP recovery from wastewater. Four coagulants, including PFS (polyferric sulfate), CTS (chitosan), CPAM (cationic polyacrylamides) and PAM(polyacrylamides) were employed to investigate their performance on antibiotic removal. Results revealed that PFS possessed the most effective performance by removing 22.8%~44.8% TCs and 32.2%~70.3% FQs from the wastewater, thereby reduced the antibiotic contents in the recovered solids to TCs 8.6mg/kg~19.6mg/kg, FQs 0.88~12.33mg/kg, respectively. Further experiments concerned the influences of pH and coagulant dosage showed that pH 7.5~8.0 and 17.5mg/L coagulant dosage were the optimal conditions for antibiotic removal, which significantly reduced 43.2%~54.1% TCs and 50.1%~69.5% FQs in