Effect of hydraulic retention time on up-flow anaerobic stage reactor performance at constant loading in the presence of antibiotic tylosin

Abstract

-The present investigation was aimed at determining the impact of the macrolide antibiotic Tylosin in reduced HRT at constant organic loading rate (OLR) by varying feed substrate concentration in an up-flow anaerobic stage reactor (UASR). The antibiotic concentration was maintained at 200 mg.L , by varying feed substrate concentration to the UASR and the HRT was decreased gradually from 4 to 1 d. Throughout the operation period, brewery wastewater was used as simple feed substrate to elevate the concentration of easily biodegradable carbon in comparison with the concentrations of more recalcitrant Tylosin substrate. The reactor alkalinity was controlled in all the stages of UASR by adding 1000 -2000 mg.L -1 CaCO 3 . Results showed the total COD removal efficiency at 4 d HRT was around 92%, after which point there was a slight decrease at 3 and 2 d HRT (average 82%), and this was reduced further (average 77%) at a HRT of 1 d. The UASR showed stable operation with effluent volatile fatty acid (VFA) less than 300 mg.L -1 throughout the experimental period (HRT 4 -1 d). Moreover, the average methane yield (CH 4 .kg COD r -1 ) showed a relatively constant profile and was largely unaffected by HRT in all the stages of UASR. These results show that bacteria were readily adapted to wastewater containing Tylosin at lower HRTs and did not affect the reactor performance substantially.

UASB reactor startup for the treatment of municipal wastewater followed by advanced oxidation process

“…In the present work, 85% total nitrogen, 95% ammonia and 83% COD removals were observed at HRT 24 h where inoculum was collected from a domestic septic tank. In contrast, Chelliapan et al (2011) observed a 94% COD removal at 4 days HRT.…”

Seasonal Performance and Characteristic of Abr for Low Strength Wastewater

“…During summer and autumn seasons, compartment I had higher concentration of VFA than influent concentration at lower HRTs, but as HRTs increase compartment I shows decrease concentration compare to influent VFA. At lower HRT high flow rate cause acidification and supress the methanogen degradation of VFA (Chelliapan et al, 2011), however at higher HRTs when organic flow rate was low, most of the VFA was consumed. Throughout winter seasons mostly compartments showing higher VFA values than influent VFA.…”

Energy recovery evaluation in an up flow microbial electrolysis coupled anaerobic digestion (ME-AD) reactor: Role of electrode positions and hydraulic retention times

“…A sudden decrease in VFAs and ethanol concentration was observed in the reactor effluents at 12 h HRT. Chelliapan et al [35] operated a novel up-flow anaerobic sludge reactor (UASR) to investigate the effects of HRT on reactor performance in terms of biogas production, COD removal and VFAs concentration. They concluded that as HRT was reduced from 4d to 1d, COD removal and biogas production were reduced, whereas VFAs concentration increased giving rise to pH reduction.…”