The School of Resource and Environmental Management, Simon Fraser University, 8888 University Drive Burnaby, British Columbia, V5A 1S6, Canada.
The School of Resource and Environmental Management, Simon Fraser University, 8888 University Drive Burnaby, British Columbia, V5A 1S6, Canada.
Water Res. 2019 Mar 15;151:183-192. doi: 10.1016/j.watres.2018.12.020. Epub 2018 Dec 26.
A mechanistic model for assessing the fate and removal efficiency of hydrophobic organic contaminants in horizontal subsurface flow treatment wetlands was developed and evaluated using empirical concentration data from Singapore's Lorong Halus Treatment Wetland. This treatment wetland consists of a series of horizontal subsurface flow reed beds. The model, calibrated for the Lorong Halus Treatment Wetland, provided an adequate description of the concentrations of nine neutral organic substances in water, rhizomes and emergent vegetation in the wetland. The model was applied to investigate the sensitivity of the contaminant removal efficiency to environmental conditions and physicochemical properties of contaminants that enter the wetland. The water-budget of the wetland was found to exhibit an important influence on both the mass-removal efficiency and reduction of contaminant concentrations that can be achieved through wetland treatment. The model illustrated that removal pathways of organic contaminants in the wetland varied as a function of the properties of the contaminants. The mass-removal efficiency of the treatment wetland was greatest for chemicals with a log K between 3.0 and 5.0 and log K > -1.0. Removal of contaminants through volatilization was found to be greatest for substances with a log K between 3 and 5 and log K > 0. Transpiration flux in vegetation was found to be most important for substances with a log K between 4.5 and 5.5 and a log K between -5.0 and 0.0. Biotransformation rates of the contaminants in the wetland media play a crucial role in the removal of contaminants from wastewater. The model provides a tool for assessing the removal capacity of treatment wetlands for neutral organic contaminants and evaluating trade-offs in the design and operation of a horizontal subsurface flow treatment wetland.
开发了一种用于评估水平潜流人工湿地中疏水性有机污染物归宿和去除效率的机理模型，并使用来自新加坡 Lorong Halus 处理湿地的经验浓度数据对其进行了评估。该处理湿地由一系列水平潜流芦苇床组成。该模型针对 Lorong Halus 处理湿地进行了校准，能够充分描述湿地水中、根茎和挺水植物中 9 种中性有机物质的浓度。该模型被应用于研究环境条件和进入湿地的污染物的物理化学性质对污染物去除效率的敏感性。发现湿地的水量平衡对湿地处理可实现的质量去除效率和污染物浓度降低均有重要影响。该模型表明，湿地中有机污染物的去除途径随污染物性质的变化而变化。对于 log K 在 3.0 到 5.0 之间且 log K > -1.0 的化学品，处理湿地的质量去除效率最高。对于 log K 在 3 到 5 之间且 log K > 0 的物质，通过挥发去除污染物的效率最高。对于 log K 在 4.5 到 5.5 之间且 log K 在 -5.0 到 0.0 之间的物质，植被蒸腾通量最重要。湿地介质中污染物的生物转化速率在去除废水中污染物方面起着至关重要的作用。该模型为评估处理湿地对中性有机污染物的去除能力提供了工具，并为水平潜流处理湿地的设计和运行中的权衡提供了评估。
