Performance of a pilot showcase of different wetland systems in an urban setting in Singapore

Abstract

The Alexandra Wetlands, part of PUB's Active, Beautiful, Clean Waters (ABC Waters) Programme, showcase a surface flow wetland, an aquatic pond and a sub-surface flow wetland on a 200 m deck built over an urban drainage canal. Water from the canal is pumped to a sedimentation basin, before flowing in parallel to the three wetlands. Water quality monitoring was carried out monthly from April 2011 to December 2012. The order of removal efficiency is sub-surface flow (81.3%) >aquatic pond (58.5%) >surface flow (50.7%) for total suspended solids (TSS); sub-surface (44.9%) >surface flow (31.9%) >aquatic pond (22.0%) for total nitrogen (TN); and surface flow (56.7%) >aquatic pond (39.8%) >sub-surface flow (5.4%) for total phosphorus (TP). All three wetlands achieved the Singapore stormwater treatment objectives (STO) for TP removal, but only the sub-surface flow wetland met the STO for TSS, and none met the STO for TN. Challenges in achieving satisfactory performance include inconsistent feed water quality, undesirable behaviour such as fishing, release of pets and feeding of animals in the wetlands, and canal dredging during part of the monitoring period. As a pilot showcase, the Alexandra Wetlands provide useful lessons for implementing multi-objective wetlands in an urban setting.

Performance Evaluation of a Full‐Scale Constructed Wetland for Treating Stormwater Runoff

“…In the 24‐h monitoring period, approximately 56.5% of NH 4 ‐N was transformed in the wetland system (Figure b). By comparison, Quek et al reported TN removal efficiencies of 22.0–44.9% in various types of CWs for treating stormwater at Alexandra Wetlands in Singapore. A comparable finding was also revealed by Terzakis et al who observed a TN removal of 49% on average in CWs treating highway runoff in the central Mediterranean region.…”

“…Birch et al reported that the average RE of NO x , total nitrogen (TN), total Kjeldahl nitrogen, and total phosphorous (TP) was 22, 16, 9, and 12%, respectively. In comparison, Quek et al evaluated the performance of a pilot showcase of different wetland systems in an urban setting in Singapore, and reported the RE of 50.7–81.3% for total suspended solids (TSS), 22.0–44.9% for TN, and 5.4–56.7% for TP, respectively. Wetland configurations, flow rate, wastewater type, and plant species, among other operational variables, can affect the performance of wetland systems with respect to water treatment .…”

Sustainable Urban Drainage Systems (2014-2023) by Using Bibliometric Analysis Method

“…Identify and profile the most influential authors, institutions, and journals in the SUDS domain (Pozo et al, 24 February 2021). Utilize VosViewer to showcase authorship networks, citation indices, and institutional collaborations, providing insights into the key players shaping the field (Quek et al, 2015). Analyze the emerging themes and keywords within the SUDS literature (Ritzema, February 2014).…”

The socio-ecological practice of building blue-green infrastructure in high-density cities: what does the ABC Waters Program in Singapore tell us?

“…Although neither GI, BGI, nor ecosystem services are mentioned, the ABC Waters Program exemplifies a shift from gray infrastructure to BGI in urban water management, showcasing a BGI-building program for a high-density city. Despite the ABC Waters Program has been carried out for more than a decade and has received several international awards, its literature remains limited to the technical aspects of stormwater management (e.g., Goh et al 2017;Quek et al 2015). Lim and Lu (2016) provide a comprehensive review of the program, but only as a stormwater management program.…”