TY - JOUR
T1 - The fate of sulfamethoxazole and trimethoprim in a micro-aerated anaerobic membrane bioreactor and the occurrence of antibiotic resistance in the permeate
AU - Piaggio, Antonella
AU - Mittapalli, Srilekha
AU - Calderon-Franco, David
AU - Weissbrodt, David
AU - van Lier, Jules
AU - de Kreuk, Merle
AU - Lindeboom, Ralph
PY - 2023
Y1 - 2023
N2 - This study investigates the effects, conversions, and resistance induction, following the addition of 150 μg·L−1 of two antibiotics, sulfamethoxazole (SMX) and trimethoprim (TMP), in a laboratory-scale micro-aerated anaerobic membrane bioreactor (MA-AnMBR). TMP and SMX were removed at 97 and 86%, indicating that micro-aeration did not hamper their removal. These antibiotics only affected the pH and biogas composition of the process, with a significant change in pH from 7.8 to 7.5, and a decrease in biogas methane content from 84 to 78%. TMP was rapidly adsorbed onto the sludge and subsequently degraded during the long solids retention time of 27 days. SMX adsorption was minimal, but the applied hydraulic retention time of 2.6 days was sufficiently long to biodegrade SMX. The levels of three antibiotic-resistant genes (ARGs) (sul1, sul2, and dfrA1) and one mobile genetic element biomarker (intI1) were analyzed by qPCR. Additions of the antibiotics increased the relative abundances of all ARGs and intI1 in the MA-AnMBR sludge, with the sul2 gene folding 15 times after 310 days of operation. The MA-AnMBR was able to reduce the concentration of antibiotic-resistant bacteria (ARB) in the permeate by 3 log.
AB - This study investigates the effects, conversions, and resistance induction, following the addition of 150 μg·L−1 of two antibiotics, sulfamethoxazole (SMX) and trimethoprim (TMP), in a laboratory-scale micro-aerated anaerobic membrane bioreactor (MA-AnMBR). TMP and SMX were removed at 97 and 86%, indicating that micro-aeration did not hamper their removal. These antibiotics only affected the pH and biogas composition of the process, with a significant change in pH from 7.8 to 7.5, and a decrease in biogas methane content from 84 to 78%. TMP was rapidly adsorbed onto the sludge and subsequently degraded during the long solids retention time of 27 days. SMX adsorption was minimal, but the applied hydraulic retention time of 2.6 days was sufficiently long to biodegrade SMX. The levels of three antibiotic-resistant genes (ARGs) (sul1, sul2, and dfrA1) and one mobile genetic element biomarker (intI1) were analyzed by qPCR. Additions of the antibiotics increased the relative abundances of all ARGs and intI1 in the MA-AnMBR sludge, with the sul2 gene folding 15 times after 310 days of operation. The MA-AnMBR was able to reduce the concentration of antibiotic-resistant bacteria (ARB) in the permeate by 3 log.
KW - antibiotic resistance
KW - antibiotics
KW - micro-aerated AnMBR
KW - SMX
KW - TMP
UR - http://www.scopus.com/inward/record.url?scp=85179383764&partnerID=8YFLogxK
U2 - 10.2166/wst.2023.324
DO - 10.2166/wst.2023.324
M3 - Article
C2 - 37966187
SN - 0273-1223
VL - 88
SP - 2344
EP - 2363
JO - Water Science and Technology
JF - Water Science and Technology
IS - 9
ER -