Time-Integrative Passive Sampling of Very Hydrophilic Chemicals in Wastewater Influent

Abstract

Passive sampling of very hydrophilic chemicals is challenging due to the weak adsorption affinity to commonly used sorbent phases. Here we present a technique for the passive time-integrative sampling of highly water-soluble chemicals in wastewater influent, using a new diffusion-based sampling device. The sampler is a sealed chamber covered at one end by a porous polyethylene membrane, allowing chemicals to diffuse through the water-filled pores into the receiving phase of water. When submerged, the concentration gradient drives diffusion into the sampler, increasing the concentration of analytes in the receiving phase over time. To calibrate and test sampler performance, the sampler was deployed in wastewater influent for 31 d. The accumulation of acesulfame, ethyl sulfate, methamphetamine, and benzoylecgonine into the sampler was modeled using simultaneously collected 24 h composite samples. The four chemicals are typically monitored in wastewater-based surveillance programs and ranged in log K ow from −2.49 (ethyl sulfate) to 2.22 (methamphetamine). In situ calibration showed linear increases in concentration over the deployment period, and calculated sampling rates ranged from 2.2 mL d–1 (methamphetamine) to 4.0 mL d–1 (ethyl sulfate). This technique is useful for the time-integrative sampling of a range of hydrophilic chemicals in wastewater and shows potential for other aquatic matrices.

In Situ Calibration of Passive Samplers for Viruses in Wastewater

“…Grab sampling is sometimes applied but can provide only a snapshot that does not represent the real concentration levels of analytes over longer monitoring periods (e.g., 24 h) . Passive samplers are being developed as an alternative technique with the intention of providing time-integrative sampling with high sensitivity, ease of use, and lower costs and energy requirements. , Thus, there is potential to use passive samplers for cost-effective sampling and source tracking in sewage networks …”

“…17 Passive samplers are being developed as an alternative technique with the intention of providing time-integrative sampling with high sensitivity, ease of use, and lower costs and energy requirements. 18,19 Thus, there is potential to use passive samplers for cost-effective sampling and source tracking in sewage networks. 20 Although a range of passive samplers are already being applied for monitoring SARS-CoV-2 due to the emergent threat of COVID-19, 21−26 studies that used gauzes and membranes to adsorb pathogenic viruses (e.g., poliovirus) and bacteria (e.g., paratyphoid B bacillus) in water matrices.…”

Multisite Calibration of a Microporous Polyethylene Tube Passive Sampler for Quantifying Drugs in Wastewater

“…Calibration studies can be conducted in the laboratory or in situ, where they can account for conditions that could affect sampling kinetics such as temperature, flow, composition of the wastewater, and biofouling. In situ calibrations for drugs in wastewater influent have been investigated for a range of chemicals, such as methylamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), and benzoylecgonine (cocaine metabolite), and in multiple samplers, including POCIS, o-DGTs, and MPTs, and more recently for very hydrophilic chemicals with gradient time integrative passive samplers (G-TIPs). ,,, A common approach has been used to evaluate the linearity of chemical mass uptake into the sampler relative to the measured concentration in simultaneously collected autosampler composite samples to determine the sampling rate within one WWTP. ,,, The MPT sampler showed linear uptake over 29 days for most chemicals addressed in that study . Studies then applied these sampling rates to further evaluate sampler performance within the same WWTP where the calibration took place or at other sites. ,, However, it is possible that different wastewater conditions between sites (particulate load, temperature, pH, and flow rate) may influence the performance of the samplers.…”