Abstract
Statement of Problem
The application of anionic polyacrylamide in agricultural and construction settings is a common best management practice meant to reduce soil erosion, improve receiving water body water quality, and increase site infiltration. Acrylamide monomers, a known neurotoxin, constitute a portion of anionic polyacrylamide and are limited to less than 0.05% of sold polyacrylamide products. A definitive conclusion for potential acrylamide release from the degradation of polyacrylamide has not been reached, but it has been noted that under acidic or neutral conditions, acrylamide has been detected when anionic polyacrylamide was exposed to varying concentrations of ferric iron and sunlight. This project examined the causes of linear anionic polyacrylamide degradation and generation of acrylamide monomers in the environment. In addition, the degradation of acrylamide monomers under environmental conditions was considered. Ultimately, a model was created to estimate this process, resulting in an Excel based calculation tool for practitioners and researchers.
Sources of Data
Data for this project was collected via a review of the relevant scientific literature. Specifically, experimental data from Labahn et al. (2010) and Woodrow et al. (2008) was paired with a chemical modeling software, Visual MINTEQ, ver 3.1(Gustafsson, 2019), a United States Department of Agriculture, Natural Conservation Service Web Soil Survey (SSURGO, n.d.), and a United States Department of Agriculture Soil Conservation Service Curve Number Loss Model (USDA, 1986).
Conclusions Reached
Modeled applications of polyacrylamide on use sites may indeed result in acrylamide monomer release in stormwater runoff. Dissolved Fe3+, soil site pH, soil bacterial health, the PAM manufacturing process, among other application factors, are major considerations in the potential release of acrylamide monomer in stormwater runoff.