Rate My Professor Suha Sanwar

Suha Sanwar holds a Doctor of Philosophy in Soil Science from Massey University, completed in 2023. Her doctoral research, conducted in the School of Agriculture and Environment and supervised by chief supervisor Dr. Lucy Burkitt along with co-supervisors Dr. Ranvir Singh, Dr. Mike Bretherton, and Dr. Gabor Kereszturi, focused on wetland hydrology and nitrate retention. The thesis, titled "CHARACTERISATION AND POTENTIAL OPTIMISATION OF SEEPAGE WETLANDS FOR NITRATE MITIGATION IN NEW ZEALAND HILL COUNTRY," investigated seepage wetlands as natural sinks for diffuse nitrate losses from pastoral hill country catchments intensified by sheep and beef farming in New Zealand. These low-gradient features leverage organic-rich, saturated sediments for denitrification processes to improve water quality.

The study characterized spatial variability in denitrification enzyme activity (DEA) and sediment properties (water content, pH, Eh, dissolved organic carbon, nitrate, ammonium, total carbon, total nitrogen, C:N ratio, dissolved Fe²⁺, Mn²⁺) across four wetlands in the Horizons Regional Council area. High-performing sites showed surface DEA >3000 μg N₂O-N kg⁻¹ DS h⁻¹, driven by high water content (>78%), nitrate (15.9-18.5 mg NO₃⁻-N kg⁻¹ DS), and organic matter, with sediment properties explaining 58-73% of DEA variation. Two-year hydrological monitoring at a low-performing site indicated streamflow-dominated inputs (83-87%) and average 23% annual nitrate removal, reaching 40.8% (2.78 kg NO₃⁻-N) in year two under dissipated flows and seasonal precipitation. Intact sediment column experiments achieved 50-96% removal of nitrate-rich runoff under anaerobic conditions, identifying optimal hydraulic residence times of 2 hours for 50% removal and 13 hours for near-complete reduction. These insights propose hydrological interventions to optimize wetland performance for nature-based nitrate mitigation under New Zealand's freshwater management policies. Suha Sanwar currently works as Resource Scientist in Lakes & Freshwater Ecology at Northland Regional Council.