Hydrolyzation characteristics of waste actived sludge and antibiotics release when improved with alkyl polyglycoside

Abstract

The purpose of this study was to find the optimal dosage of APG and initial pH to accelerate the hydrolysis of the waste activated sludge (WAS) and promote the release of antibiotics. In this study, the effects with APG dosage from 0.1 to 0.5 g/gSS and initial pH from 4.0 to 12.0 on WAS hydrolysis were investigated. Samples were regularly collected from different reaction conditions to determine SCODcr, protein, polysaccharide, antibiotics, antibiotic resistance genes (ARGs) and microbial diversity. The results showed that the combined action of APG+pH greatly promoted the solubilization of organic matter, and promoted the release of antibiotics. Compared with untreated sludge, when the optimal APG dosage was 0.3 g/gSS with pH 11.0 was combined, the release of organic matter was significantly increased, and the concentrations of the SCODcr, protein and polysaccharide reached 5650.4, 1386.4 and 794.2 mg/L, respectively within 2 h. At the same time, antibiotics (tetracyclines, sulfonamides, quinolones and macrolides) was also transferred from solid phase to liquid phase, among them roxithromycin (ROM) was 72.6 times higher than that in untreated control group, accordingly, the tetracycline ARGs tetB was 774.2 times higher than that in the control group. Meanwhile, APG greatly reduced the microbial diversity in the WAS samples, and greatly increased the relative abundance of proteobacteria, in which Gammaproteobacteria was the main microorganism.