Assessing recovery potential of aerobic sludge biomass stressed with amoxicillin

Abstract

Antibiotics, an emerging pollutant in domestic sewage, may likely to impact the performance of biological treatment plants; hence, assessing the health and quality of sludge biomass is essential. This study investigated the impact of 0, 500, 1000, and 2000 mg/L of amoxicillin intravenous form (AMX) on aerobic biomass and assessed its recovery potential when AMX has been stopped in the influent. Reactors have been operated for 43 d with AMX, then another 35 d without AMX in the feed. AMX stressed reactors have exhibited 23–74% COD removal during stressed phase operation, compared to 93% for the control reactor. A noticeable decrease in biomass activity, cell viability, and enzyme activities due to AMX stress have been observed. ARDRA has revealed 52–80% similarity in microbial community structure of control and AMX fed reactors. During the recovery phase, all reactors have exhibited 93% COD removal with increased biomass activity, cell viability, and enzyme activities. ARDRA has displayed 68–94% similarity between control and AMX stressed biomass. This study has demonstrated complete recovery of sludge biomass when AMX has been discontinued in the feed. SVI, ISV, and biomass activity have been identified as the preliminary test. In addition, cell viability, enzyme activity, and ARDRA have been identified as confirmation tests in assessing the health of sludge biomass.