TY - JOUR
T1 - Upgrading residues from wastewater and drinking water treatment plants as low-cost adsorbents to remove extracellular DNA and microorganisms carrying antibiotic resistance genes from treated effluents
AU - Calderon Franco, D.
AU - Apoorva, Seeram
AU - Medema, G.J.
AU - van Loosdrecht, Mark C.M.
AU - Weissbrodt, D.G.
PY - 2021
Y1 - 2021
N2 - Wastewater treatment is challenged by the continuous emergence of chemical and biological contaminants. Disinfection, advanced oxidation, and activated carbon technologies are accessible in high-income countries to suppress them. Low-cost, easily implementable, and scalable solutions are needed for sanitation across regions. We studied the properties of low-cost absorbents recycled from drinking water and wastewater treatment plant residues to remove environmental DNA and xenogenetic elements from used water. Materials characteristics and DNA adsorption properties of used iron-oxide-coated sands and of sewage-sludge biochar obtained by pyrolysis of surplus activated sludge were examined in bench-scale batch and up-flow column systems. Adsorption profiles followed Freundlich isotherms, suggesting a multilayer adsorption of nucleic acids on these materials. Sewage-sludge biochar exhibited high DNA adsorption capacity (1 mg g−1) and long saturation breakthrough times compared to iron-oxide-coated sand (0.2 mg g−1). Selected antibiotic resistance genes and mobile genetic elements present on the free-floating extracellular DNA fraction and on the total environmental DNA (i.e., both extra/intracellular) were removed at 85% and 97% by sewage-sludge biochar and at 54% and 66% by iron-oxide-coated sand, respectively. Sewage-sludge biochar is attractive as low-cost adsorbent to minimize the spread of antimicrobial resistances to the aquatic environment while strengthening the role of sewage treatment plants as resource recovery factories.
AB - Wastewater treatment is challenged by the continuous emergence of chemical and biological contaminants. Disinfection, advanced oxidation, and activated carbon technologies are accessible in high-income countries to suppress them. Low-cost, easily implementable, and scalable solutions are needed for sanitation across regions. We studied the properties of low-cost absorbents recycled from drinking water and wastewater treatment plant residues to remove environmental DNA and xenogenetic elements from used water. Materials characteristics and DNA adsorption properties of used iron-oxide-coated sands and of sewage-sludge biochar obtained by pyrolysis of surplus activated sludge were examined in bench-scale batch and up-flow column systems. Adsorption profiles followed Freundlich isotherms, suggesting a multilayer adsorption of nucleic acids on these materials. Sewage-sludge biochar exhibited high DNA adsorption capacity (1 mg g−1) and long saturation breakthrough times compared to iron-oxide-coated sand (0.2 mg g−1). Selected antibiotic resistance genes and mobile genetic elements present on the free-floating extracellular DNA fraction and on the total environmental DNA (i.e., both extra/intracellular) were removed at 85% and 97% by sewage-sludge biochar and at 54% and 66% by iron-oxide-coated sand, respectively. Sewage-sludge biochar is attractive as low-cost adsorbent to minimize the spread of antimicrobial resistances to the aquatic environment while strengthening the role of sewage treatment plants as resource recovery factories.
KW - Xenogenetic elements
KW - sewage-sludge biochar
KW - iron-oxide
KW - Adsorption
KW - Wastewater
KW - Free-floating extracellular DNA
UR - http://www.scopus.com/inward/record.url?scp=85102618769&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.146364
DO - 10.1016/j.scitotenv.2021.146364
M3 - Article
SN - 0048-9697
VL - 778
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 146364
ER -