Water Quality and Ecological Contributions of Urban Wetlands: Insights from The Ait Campus in Thailand

Abstract

Wetlands are integral to urban ecosystems, providing essential services such as water purification, nutrient cycling, biodiversity support, and carbon sequestration. This study characterized the physico-chemical and microbiological water quality of seven selected wetlands at the Asian Institute of Technology (AIT) campus in Thailand between November 2016 and March 2017. Parameters analyzed included Dissolved Oxygen (DO), pH, Turbidity, Electrical Conductivity (EC), Ammonia-Nitrogen (NH_3-N), Total Kjeldahl Nitrogen (TKN), Total Phosphorus (TP), Chemical Oxygen Demand (COD), Chlorophyll a, and Escherichia coli (E. coli). Additionally, sediment and macrophyte carbon sequestration, algal diversity, and zooplankton (rotifer) density were assessed. Results indicated slightly alkaline pH (7.5-8.3) and moderate to high DO levels (3.4-8.5 mg/L) across the wetlands. Elevated turbidity (12.9-16.7 NTU), nutrient enrichment (e.g., NH_3-N at 3.4 mg/L, TKN at 4.48 mg/L), and significant E. coli contamination (up to 7,420 MPN/100 mL) were observed in SV1 and Chiang Rak ponds. High chlorophyll a levels were notable in SV2 (195 µg/L) and Chiang Rak (928 µg/L). Carbon sequestration was substantial in macrophyte biomass (e.g., SV2: 9.4pm0.5 g C m² month⁻¹) and sediments (e.g., WD Pond: 6.6pm0.7 g C m² month⁻¹). While AIT wetlands provide considerable ecological services, these findings highlight pollution risks at certain sites, necessitating improved management for enhanced sustainability and ecosystem function.