Polymeric Nanofiber-Carbon Nanotube Composite Mats as Fast-Equilibrium Passive Samplers for Polar Organic Contaminants

Abstract

To improve the performance of polymeric electrospun nanofiber mats (ENMs) for equilibrium passive sampling applications in water, we integrated two types of multiwalled carbon nanotubes (CNTs; with and without surface carboxyl groups) into polyacrylonitrile (PAN) and polystyrene (PS) ENMs. For 11 polar and moderately hydrophobic compounds (−0.07 ≤ logK OW ≤ 3.13), 90% of equilibrium uptake was achieved in under 0.8 days (t 90% values) in nonmixed ENM-CNT systems. Sorption capacity of ENM-CNTs was between 2- and 50-fold greater than pure polymer ENMs, with equilibrium partition coefficients (K ENM‑W values) ranging from 1.4 to 3.1 log units (L/kg) depending on polymer type (hydrophilic PAN or hydrophobic PS), CNT loading (i.e., values increased with weight percent (wt %) of CNTs), and CNT type (i.e., greater uptake with carboxylated CNTs composites). During field deployment at Muddy Creek in North Liberty, Iowa, optimal ENM-CNTs (PAN with 20 wt % carboxylated CNTs) yielded atrazine concentrations in surface water with a 40% difference relative to analysis of a same-day grab sample. We also observed a mean percent difference of 30 (±20)% when comparing ENM-CNT sampler results to grab sample data collected within 1 week of deployment. With their rapid, high capacity uptake and small material footprint, ENM-CNT equilibrium passive samplers represent a promising alternative to complement traditional integrative passive samplers while offering convenience over large volume grab sampling.

Occurrence and Spatiotemporal Dynamics of Pharmaceuticals in a Temperate-Region Wastewater Effluent-Dominated Stream: Variable Inputs and Differential Attenuation Yield Evolving Complex Exposure Mixtures

“…Additionally, the treated wastewater effluent effectively diluted the agricultural herbicide atrazine and E. coli derived from upstream runoff (Figures S19 and S20). Previous research has also summarized the economic and ecological contributions of effluent-dominated systems. , Effluent-dominated streams are becoming increasingly common globally due to climate change and the increasing reliance on the reuse of reclaimed municipal wastewater; thus, quantifying evolving complex exposure mixtures from wastewater-derived chemical mixtures is crucial to characterizing potential impacts.…”

“…33 Our work also demonstrates the potential benefits of treated wastewater effluent in a small stream, such as maintaining the streamflow during baseflow/drought conditions and modulating water temperature fluctuations (i.e., cooling effect in the summer and warming effect in the winter). Additionally, the treated wastewater effluent effectively diluted the agricultural herbicide atrazine and E. coli derived from upstream runoff 95 (Figures S19 and S20). Previous research has also summarized the economic and ecological contributions of effluent-dominated systems.…”

RNA-seq reveals potential gene biomarkers in fathead minnows (Pimephales promelas) for exposure to treated wastewater effluent

“…Further characterization of the eld sites are published elsewhere. 10,21,23,41 Only sh from sites US1 and DS1 were used in the present study to simplify the assessment of the impacts of exposure to effluent-derived CEC mixtures.…”

Electrospun nanofiber mats as sorbents for polar emerging organic contaminants: Demonstrating tailorable material performance for uptake of neonicotinoid insecticides from water

“…Recently, we have explored polymer nanomaterials fabricated via electrospinning to solve various problems caused by regulated and emerging pollutants ( Greenstein et al, 2021 ; Peter et al, 2016 ; Qian et al, 2020 ). Electrospinning is a well-established synthesis process for nonwoven polymer nanofibers ( Ghosal et al, 2018 ), which involves dissolving a polymer precursor into an appropriate solvent creating a sol gel solution.…”