Capability of HYDRUS wetland module to simulate flow and nitrogen removal processes in pilot-scale treatment peatlands under frost and no-frost conditions

The HYDRUS wetland module is widely used together with the biokinetic model CWM1 to simulate reactive transport of contaminants in constructed wetlands. However, this approach has not been previously processes peat-based wetlands operating cold climates and treating mining-influenced water. In study, goal was clarify changes flow, transport, nitrogen removal climate treatment peatlands by assessing performance HYDRUS-CWM1. Flow non-reactive tracer, ammonium, nitrite, nitrate, two pilot operated under controlled conditions representing frozen (winter) frost-free (summer) periods were simulated. Model simulation outputs compared against data obtained from a full-scale peatland water an Arctic region. Initial peaks tracer concentration simulated satisfactorily, but transformation species peatlands, especially partially conditions, modeled only limited success. Limitations assumptions made for simulations have discussed highlight challenges modeling peatlands. • satisfactorily. Transport winter possibilities improvement are discussed. Possibility use multiple add-ons simultaneously may be critical.