Food, Beverage, and Feedstock Processing Facility Wastewater: a Unique and Underappreciated Source of Contaminants to U.S. Streams

Abstract

Process wastewaters from food, beverage, and feedstock facilities, although regulated, are an under-investigated environmental contaminant source. Food process wastewaters (FPWWs) from 23 facilities in 17 U.S. states were sampled and documented for a plethora of chemical and microbial contaminants. Of the 576 analyzed organics, 184 (32%) were detected at least once, with concentrations as large as 143 μg L–1 (6:2 fluorotelomer sulfonic acid), and as many as 47 were detected in a single FPWW sample. Cumulative per/polyfluoroalkyl substance concentrations up to 185 μg L–1 and large pesticide transformation product concentrations (e.g., methomyl oxime, 40 μg L–1; clothianidin TMG, 2.02 μg L–1) were observed. Despite 48% of FPWW undergoing disinfection treatment prior to discharge, bacteria resistant to third-generation antibiotics were found in each facility type, and multiple bacterial groups were detected in all samples, including total coliforms. The exposure–activity ratios and toxicity quotients exceeded 1.0 in 13 and 22% of samples, respectively, indicating potential biological effects and toxicity to vertebrates and invertebrates associated with the discharge of FPWW. Organic contaminant profiles of FPWW differed from previously reported contaminant profiles of municipal effluents and urban storm water, indicating that FPWW is another important source of chemical and microbial contaminant mixtures discharged into receiving surface waters.

Metformin Contamination in Global Waters: Biotic and Abiotic Transformation, Byproduct Generation and Toxicity, and Evaluation as a Pharmaceutical Indicator

“…The main source of metformin to aquatic systems is discharged through WWTPs, as well as food and pharmaceutical processing wastewater facilities, urban runoff, landfill leachates, etc. − , The concentration of metformin in wastewater (1.4–325 μg/L) is orders of magnitude higher than those in river and lake water (0.0005–107 μg/L), stormwater (0.0149–1.91 μg/L), and leachate (0.03–0.91 μg/L) (Figure A and Table S1). ,,,,, Differences in the operation performance of WWTPs result in a varied removal efficiency of metformin from 24% to >99%. , We hereby define “removal” as any decrease in metformin concentration, whereas “degradation” refers to the process leading to destruction of metformin and generation of TPs.…”

“…The extensive release of metformin to global water systems and the undesirable transformation of this compound to more persistent and toxic TPs make routine monitoring of metformin necessary for drinking water safety and ecosystem health. However, vast quantities of other human pharmaceuticals resulting from the same release sources, WWTPs, food and drug processes, landfills, municipal biosolids and runoff, share similar contamination patterns as metformin. ,− The aquatic environment of China alone received approximately 53800 t of 36 antibiotics in 2013 . These pharmaceuticals have become emerging contaminants owing to their prevalence and heavy loads in the environment and their continually verified negative effects on fish, algae, earthworms, and human cells. , Unfortunately, most of them are not monitored or cannot be quantified because of limitations in analytical techniques.…”

“…11,12 The demonstrated adverse effects for aquatic organisms make metformin a major contaminant of emerging concern, as reviewed elsewhere. 5,13−16 The environmental occurrence of metformin is attributable to its lack of metabolism in the human body 2 and discharge through municipal wastewater treatment plants (WWTPs), 17,18 urban stormwater runoff, 19 final landfill leachates, 20 food process wastewater facilities, 21 on-site septic systems, 22 land application of municipal biosolids, 23 etc. WWTPs cannot completely degrade metformin.…”

“…In the U.S., metformin was the fourth most commonly prescribed medication, and prescriptions rose from 54.5 million in 2006 to 85.7 million in 2019 . Notably, unlike most pharmaceuticals, metformin is not metabolized in the human body by design, and almost all of the intake dose is excreted through urine and feces. , Thus, the widespread use has resulted in the frequent detection of metformin in global aquatic systems since 1999. , The demonstrated adverse effects for aquatic organisms make metformin a major contaminant of emerging concern, as reviewed elsewhere. ,− The environmental occurrence of metformin is attributable to its lack of metabolism in the human body and discharge through municipal wastewater treatment plants (WWTPs), , urban stormwater runoff, final landfill leachates, food process wastewater facilities, on-site septic systems, land application of municipal biosolids, etc. WWTPs cannot completely degrade metformin. , As a result, metformin and the generated transformation byproducts (TPs) are continuously discharged into aquatic systems and spread worldwide. ,, Metformin is also subject to transformation during natural processes and drinking water disinfection. − However, previous reviews mainly summarized the removal efficiency of metformin by different treatment methods but ignored the transformation pathways, TP generation, and whether such transformation would alleviate ecotoxicity.…”