Graduation Semester and Year
Summer 2026
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Civil Engineering
Department
Civil Engineering
First Advisor
Dr. Srinivas Prabakar
Second Advisor
Dr. Melanie Sattler
Third Advisor
Dr. Hyeok Choi
Fourth Advisor
Dr. Habib Ahmari
Fifth Advisor
Dr. Un-Jung Kim
Abstract
ABSTRACT
Enhancing Nutrient Removal Efficiency in Constructed Wetlands Using Macrophytes through Bio-stimulants and Fungal Root Inoculation
Nutrient enrichment from stormwater runoff and wastewater effluents has become a major environmental challenge, contributing to eutrophication, harmful algal blooms, oxygen depletion, and deterioration of aquatic ecosystems. Constructed wetlands have emerged as sustainable and cost-effective treatment systems that utilize physical, chemical, and biological processes to remove contaminants while requiring minimal energy and operational costs. Although constructed wetlands effectively remove nutrients from contaminated waters, their performance is often limited by plant productivity and nutrient assimilation, highlighting the need for strategies that enhance vegetation growth and treatment efficiency.
Previous studies have demonstrated that biostimulants can improve plant growth, physiological activity, and nutrient uptake. At the same time, arbuscular mycorrhizal (AM) fungi establish beneficial symbiotic relationships with plant roots that enhance nutrient acquisition and stress tolerance. However, the application of these biological enhancement strategies to improve nutrient removal in constructed wetlands remains insufficiently understood, particularly for native wetland macrophytes. Furthermore, the individual and combined effects of biostimulants and AM fungi on nutrient removal performance have received limited investigation.
Therefore, this study investigated biological approaches to enhance nutrient removal in laboratory-scale constructed wetlands using the native wetland macrophyte Echinodorus berteroi. The baseline nutrient removal performance of E. berteroi was first evaluated, followed by investigations of the effects of banana peel extract as a natural biostimulant and arbuscular mycorrhizal fungi inoculation on nutrient removal efficiency. Finally, the combined application of both enhancement strategies was assessed to determine their potential synergistic effects on treatment performance. Laboratory-scale mesocosms were operated under controlled conditions using synthetic wastewater containing nitrogen, phosphorus, and organic matter. Treatment performance was evaluated by monitoring total nitrogen (TN), ammonia nitrogen (NH₃–N), total phosphorus (TP), orthophosphate (PO₄³⁻–P), and chemical oxygen demand (COD. The study also quantified soil nutrient accumulation, plant growth characteristics, and AM fungi root colonization to investigate nutrient retention mechanisms and the relationship between plant development and treatment performance.
The results demonstrated that E. berteroi significantly enhanced nutrient removal compared with unplanted systems, confirming its suitability as a treatment macrophyte for constructed wetlands. Inoculation with arbuscular mycorrhizal fungi significantly improved nitrogen and organic matter removal by enhancing nutrient uptake and plant development, while application of banana peel extract as a natural biostimulant further increased volumetric nutrient removal rates and vegetation growth. The combined treatment produced the greatest overall improvement in constructed wetland performance. In contrast, phosphorus removal exhibited comparatively smaller improvements with biological enhancement, indicating that physical retention and adsorption within the substrate remained the dominant mechanisms governing phosphorus removal.
Overall, this research demonstrates that biological enhancement using natural biostimulants and arbuscular mycorrhizal fungi can significantly improve the treatment efficiency of constructed wetlands by increasing plant productivity and nutrient assimilation. The findings provide new insights into the interactions among macrophytes, microbial symbioses, and natural biostimulants and establish a sustainable framework for optimizing nature-based treatment systems for stormwater and wastewater management.
Keywords
Nutrient Removal, Constructed Wetlands. Biostimulnat, AMF, Arbuscular Mycorrhizal Fungi, Macrophytes, Echinodorus berteroi.
Disciplines
Civil Engineering | Environmental Engineering
License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Alsaud, Hasan Abdulmonem A., "Enhancing Nutrient Removal Efficiency in Constructed Wetlands Using Macrophytes through Bio-stimulants and Fungal Root Inoculation" (2026). Civil Engineering Dissertations. 13.
https://mavmatrix.uta.edu/civilengineering_dissertations2/13