Zerovalent iron-sand filtration can reduce the concentration of multiple antimicrobials in conventionally treated reclaimed water

Prachi Kulkarni; Greg A Raspanti; Anthony Q Bui; Rhodel N Bradshaw; Kalmia E Kniel; Pei C Chiu; Manan Sharma; Amir Sapkota; Amy R Sapkota

doi:10.1016/j.envres.2019.02.012

Zerovalent iron-sand filtration can reduce the concentration of multiple antimicrobials in conventionally treated reclaimed water

Environ Res. 2019 May:172:301-309. doi: 10.1016/j.envres.2019.02.012. Epub 2019 Feb 10.

Authors

Prachi Kulkarni¹, Greg A Raspanti¹, Anthony Q Bui¹, Rhodel N Bradshaw¹, Kalmia E Kniel², Pei C Chiu³, Manan Sharma⁴, Amir Sapkota¹, Amy R Sapkota⁵

Affiliations

¹ Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 4200 Valley Drive, College Park, MD 20742, USA.
² Department of Animal and Food Sciences, University of Delaware, 531 S College Ave, Newark, DE 19716, USA.
³ Department of Civil and Environmental Engineering, University of Delaware, 127 The Green, Newark, DE 19716, USA.
⁴ United States Department of Agriculture, Agricultural Research Service, Environmental and Microbial Food Safety Laboratory, 10300 Baltimore Avenue, BARC-East, Bldg. 201, Beltsville, MD 20705, USA.
⁵ Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 4200 Valley Drive, College Park, MD 20742, USA. Electronic address: ars@umd.edu.

PMID: 30822564
DOI: 10.1016/j.envres.2019.02.012

Abstract

Irrigation with reclaimed water is increasing in areas that lack access to, and infrastructure for, high-level treatment and distribution. Antimicrobial residues are known to persist in conventionally treated reclaimed water, necessitating the investigation of reuse site-based mitigation options to further reduce these contaminants. We examined the effectiveness of a 50:50 volume/volume, particle matched, micro-scale zerovalent iron (ZVI)-sand filter in reducing concentrations of mixtures of antimicrobials present in pH-unadjusted conventionally treated reclaimed water. Twelve antimicrobials (azithromycin, ciprofloxacin, erythromycin, linezolid, oxacillin, oxolinic acid, penicillin G, pipemidic acid, sulfamethoxazole, triclocarban, tetracycline and vancomycin) were quantified using high performance-liquid chromatography-tandem mass spectrometry in reclaimed water, and ZVI-sand filtered reclaimed water, in a two-month long greenhouse-based experiment. Data were analyzed using a non-parametric rank-based approach. ZVI-sand filtration significantly reduced concentrations of azithromycin, ciprofloxacin, oxolinic acid, penicillin G, sulfamethoxazole, linezolid, pipemidic acid and vancomycin. Azithromycin, the antimicrobial with the highest median concentration (320 ng/L), was reduced to below the limit of detection after ZVI-sand filtration. Inorganic element (antimony, beryllium, cadmium, chromium, iron, lead, selenium and thallium) and water quality (free and total chlorine, nitrates, nitrites, pH and total dissolved solids) analyses showed that ZVI-sand filtered reclaimed water quality (nitrate, salinity, and inorganic elements) met the recommended guidelines for agricultural irrigation with reclaimed water. Based on our initial results, ZVI-sand filtration may be a promising basis for a point-of-use filtration system for reclaimed water irrigation on small-scale farms.

Keywords: Antimicrobial; Filtration; Irrigation; Liquid chromatography tandem mass spectrometry; Reclaimed water; Zerovalent iron.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Agricultural Irrigation
Anti-Infective Agents* / isolation & purification
Filtration*
Iron* / chemistry
Water Pollutants, Chemical* / isolation & purification
Water Purification* / methods
Water* / chemistry

Substances

Anti-Infective Agents
Water Pollutants, Chemical
Water
Iron