Premium
Release Timing and Duration Control the Fate of Photolytic Compounds in Stream‐Hyporheic Systems
Author(s) -
Hixson Jase L.,
Ward Adam S.,
McConville Megan B.,
Remucal Christina K.
Publication year - 2022
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2022wr032567
Subject(s) - photodissociation , reactivity (psychology) , environmental science , hyporheic zone , environmental chemistry , chemistry , photochemistry , biological system , environmental engineering , surface water , biology , medicine , alternative medicine , pathology
Predicting environmental fate requires an understanding of the underlying, spatiotemporally variable interaction of transport and transformation processes. Photolytic compounds, for example, interact with both time‐variable photolysis and the perennially dark hyporheic zone, generating potentially unexpected dynamics that arise from time‐variable reactivity. This interaction has been found to significantly impact environmental fate but is commonly oversimplified in predictive models. Our primary objective was to explore how time‐variable photolysis and hyporheic storage interact across a range of photolysis rates to control the fate and transport of photolytic solutes in stream‐hyporheic systems. In this study, we released a photolytic compound in a natural system at different times of day and simulated variable release timing and durations of photolytic compounds spanning half‐lives ranging from about 2 min to 900 hr. To contextualize these results, we simulated five photolytic compounds with varied half‐lives to systematically study the interaction between release timing, duration, and reactivity. We found that the environmental fate and transport of photolytic compounds are highly variable as a function of release timing, which controls when, where, and for how long solute is stored in the hyporheic zone or exposed to in‐channel photolysis. This knowledge can be used to improve predictions for photolytic compounds or assess potential impacts for an anticipated discharge or treatment.