Developing nitrogen removal models for stormwater bioretention systems

Li, Jiayi; Culver, Teresa B.; Persaud, P. P.; Hathaway, Jon M.

doi:10.1016/j.watres.2023.120381

Cited by 3 publications

(1 citation statement)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It also allows dosing rates to decrease when the “natural” performance of bioreactors is strong (e.g., longer HRTs in warm weather) and thereby decrease risks of overdosing acetate. Real-time control of “smart” stormwater systems is a rapidly growing topic in water quality engineering and research, − with most applications focused on the control of HRT in stormwater detention basins to promote sedimentation of suspended solids. , To our knowledge, this is the first use of real-time control to enable discharge-dependent C dosing to stimulate removal of nonpoint source N. The objectives of this study were 2-fold: first, to quantify the effects of real-time control of acetate dosing on cumulative NO 3 – load reductions achieved in a field-scale bioreactor over a 2-month period, including an assessment of cost-effectiveness, and second, to systematically evaluate environmental risks of adverse water quality impacts of exogenous C dosing.…”

Section: Introductionmentioning

confidence: 99%

Real-Time Control of Exogenous Carbon Dosing in a Denitrifying Woodchip Bioreactor Treating Agricultural Drainage

Zhang,

Echavarria,

Sang

et al. 2024

ACS EST Eng.

View full text Add to dashboard Cite

Nature-based treatment technologies such as denitrifying woodchip bioreactors (WBRs) are employed to manage nitrogen (N) pollution from agricultural nonpoint sources. Due to variability in environmental conditions like temperature and discharge, it is challenging to achieve consistent treatment effectiveness with these passive systems. To improve nitrate (NO 3 − ) load reductions in a field-scale WBR in New York State during cool spring weather, we designed a system for controlled exogenous carbon (C) dosing, allowing rates of C dosing to respond in real time to changing discharge and NO 3 − concentrations. Treatment efficiencies for NO 3 − , acetate mass balances, and other bioreactor properties were monitored from April 5 to June 10, 2023. Biostimulation with 7.5 mg C/L acetate (assuming complete mixing of injected acetate with bioreactor pore water) increased NO 3− removal rates up to 5-fold compared to a model-based scenario of baseline bioreactor performance, and were as high as 0.4 mg NO 3 − −N L −1 h −1 while water temperatures were <12 °C. Increasing acetate concentrations beyond 7.5 mg C/L did not confer a clear improvement in NO 3 − removal rates. Cumulative N load reductions increased from 11.3% under the baseline scenario without C dosing to 24.1% with C dosing. The mass ratio of metabolized C to additional N removal was 2.5:1, although the total dosed C/N mass ratio was 5.1:1 due to incomplete acetate utilization in the reactor. We found evidence that C dosing could enhance the future release of dissolved organic N (DON) and dissolved organic C related to biofilm sloughing. The expense of acetate, with a cost efficiency of 86 USD/kg N, was the main cost driver of the real-time control approach. Our results demonstrate the potential of real-time control of C dosing to meaningfully improve nonpoint source N removal during cool spring conditions but also highlight opportunities for methods to improve acetate utilization efficiencies in order to improve the overall cost-effectiveness of the approach.

show abstract