Effects of C: N:P ratios on wastewater treatment in arbuscular mycorrhizal fungi assistant constructed wetlands

Nina Ninovska

Bachelor's thesis

Abstract:

Arbuscular mycorrhizal fungi (AMF) have been widely reported to play an essential role in enhancing resistance to abiotic stresses for terrestrial plants. However, it is unclear whether different nutrient concentrations of carbon (C), nitrogen (N), and phosphorus (P) in wastewater affect the purification process in constructed wetlands (CWs) under submerged water levels. Moreover, the effect of AMF in CWs with different nutrient concentrations is poorly studied. Therefore, this thesis investigates how different nutrient concentrations affect wastewater purification in CWs, and whether the presence of AMF influence wastewater purification in CWs under different nutrient concentrations. The methodology consisted of vertical substrate flow CWs filled with a substrate and planted with Iris Pseudacorus as wetland vegetation and Rhizophagus irregularis as AMF inoculum. The influencing factors of this thesis are N concentrations (low, high), P concentrations (low, high), and AMF (with, without). Furthermore, water samples were taken for analysis which included the measurement of C (Total Organic Carbon, Total Carbon (TC), Inorganic Carbon), N (Ammonia, Total Nitrogen (TN), Nitrates, Nitrites) and P (Phosphates (PO43--P)). The results demonstrated that the application of different concentrations of N:P influenced the pollutant removal efficiency, where TC removal was higher with low N and high P concentrations at 80%, TN removal was higher when concentrations of N were initially high at 96%, and PO43--P removal rate was higher when N and P concentrations were both low with 98%. Meanwhile, AMF enhanced removal efficiency for TN and PO43--P, specifically by 2% and 5%. However, the removal of TC was more effective without AMF presence, by 4%. Therefore, these results indicated that different nutrient concentration ratios, as well as AMF presence, could influence pollutant removal effectiveness in CW wastewater purification. This research could present useful information for potentially applying AMF in CWs for removing pollutants, as well as monitoring different nutrient concentrations for more successful future treatments.

Keywords

C, N, P ratios, wastewater treatment, arbuscular mycorrhizal fungi, constructed wetlands

Language used: English

Date on which the thesis was submitted / produced: 4. 4. 2023

Thesis defence

• Date of defence: 24. 5. 2023
• Supervisor: doc. Zhongbing Chen
• Reader: Kristina Kralj, Ing.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Bachelor programme:
Environmental Engineering