Recurring foodborne outbreaks, attributed to Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes, have identified irrigation water as a potential source of contamination, and creating the necessity for safe irrigation water in produce cultivation, as emphasized by the Food Safety Modernization Act (FSMA). In response to this imperative, this study explored the efficacy of surfactant-modified zeolite (SMZ) enhanced with Cetrimonium bromide (CTAB) as a sustainable water purification solution for surface water. The SMZ was assessed to have the capacity to filter contaminated water with high loads of foodborne pathogens. A laboratory study was conducted using a 100 g SMZ column. A liter of phosphate-buffered saline (PBS) was inoculated for each pathogen at 6 log CFU mL-1 concentrations. The study found that SMZ modified with CTAB at a concentration exceeding 20% by weight, indicating the ratio of CTAB to the total mass of the modifying solution, could eliminate >6 log CFU mL-1 of Escherichia coli O157:H7 and Listeria monocytogenes and >2 log of Salmonella sp. Subsequent field testing in strawberry farms demonstrated the system’s effectiveness, displaying significant bacterial reduction when contrasted with unfiltered pond water and sand filtration. The SMZ was able to filter more than 4 log CFU mL-1, from surface irrigation water spiked with a nonpathogenic Escherichia coli strain. The results indicate that the SMZ filtration approach holds promise as a remediation tool to control the risks of foodborne disease outbreaks associated with agricultural water. | Brotes alimentarios han sido atribuidos a Escherichia coli O157:H7, Salmonella sp., y Listeria monocytogenes, y se ha identificado el agua de riego como una posible fuente de contaminación. Esto realza la necesidad de agua de riego segura en productos hortofrutícolas, como lo enfatiza la Ley de Modernización de la Seguridad Alimentaria (FSMA). En respuesta a este imperativo, este estudio exploró la eficacia de la zeolita modificada con surfactante (SMZ) modificada con bromuro de cetrimonio (CTAB) como una solución para la purificación de agua superficial. Se determinó que el SMZ tiene la capacidad de filtrar agua contaminada con altas cargas de patógenos transmitidos por alimentos. Se realizó un estudio de laboratorio utilizando una columna de SMZ de 100 g. Para cada patógeno, se inoculó un litro de solución salina tamponada con fosfato (PBS) a concentraciones de 6 log UFC mL-1. Los resultados revelaron que SMZ, con una concentración de CTAB al 20% por peso total de la solución modificadora, podría eliminar >6 log UFC mL-1 de Escherichia coli O157:H7 y Listeria monocytogenes y >2 log UFC mL-1 de Salmonella sp. Las pruebas de campo en granjas de fresas demostraron la efectividad del sistema, mostrando una reducción bacteriana en comparación con el agua de estanque sin filtrar o filtrada con arena. El SMZ pudo filtrar más de 4 log UFC mL-1 del agua de riego superficial inoculada con una cepa no patogénica de Escherichia coli. Los resultados sugieren que la filtración SMZ podría controlar riesgos de brotes por agua agrícola.

Contaminants of emerging concern present in domestic waste streams include a highly diverse group of potentially biologically active compounds that can be detected at trace levels in wastewater. Concerns about potential uptake into crops arise when reclaimed water is used in food crop production. The present study investigated how 9 contaminants of emerging concern in reclaimed water are taken up into edible portions of two food crops. Two flame retardant chemicals, tris(1‐chloro‐2‐propyl) phosphate (TCPP) and tris(2‐chloroethyl) phosphate (TCEP) and several polar pharmaceuticals (carbamazepine, diphenhydramine, sulfamethoxazole, and trimethoprim) accumulated in a linear, concentration‐dependent manner in lettuce (Lactuca sativa) irrigated with reclaimed water, suggesting passive uptake of both neutral and ionizable chemical contaminants in lettuce. Furthermore, concentration‐dependent accumulation of TCEP and TCPP from reclaimed water was also observed in strawberry fruits (Fragaria ananassa). Collectively, these data suggest that highly polar or charged contaminants can be taken up by crops from water bearing contaminants of emerging concern and can be accumulated in the edible portions. Using these data, however, estimates of human exposure to these contaminants from reclaimed water food crop accumulation suggest that exposure to the contaminants of emerging concern examined in the present study is likely substantially lower than current exposure guidelines. Environ Toxicol Chem 2015;34:2213–2221. © 2015 SETAC