Inter-department of Environmental Management (International), Hazardous Waste Management, Graduate School, Chulalongkorn University, Bangkok, Thailand.
Environ Monit Assess. 2010 Jun;165(1-4):585-94. doi: 10.1007/s10661-009-0970-1. Epub 2009 May 20.
Mae Moh is a risky area for arsenic contamination caused by the effluent from biowetland ponds in Mae Moh lignite-fuelled power plant. The objective of this study was to investigate the arsenic concentrations of Mae Moh biowetland ponds and determine the main factors which are important for arsenic phytoremediation in the treatment system. The result revealed that arsenic concentrations in the supernant were in the range of less than 1.0 microg As L(-1) to 2.0 microg As L(-1) while those in the sediment were in the range of 25-200 microg As kg soil(-1). Both values were below the Thailand national standard of 0.25 mg As L(-1) for water and 27 mg As kg soil(-1) for the soil. Arsenic accumulation in the biomass of 5 aquatic plants at the biowetland ponds ranged from 123.83 to 280.53 mg As kgPlant(-1). Regarding the result of regression analysis (R (2) = 0.474 to 0.954), high concentrations of organic matter and other soluble ions as well as high pH value in the sediment could significantly enhance the removal of soluble arsenic in the wetland ponds. From the regression equation of accumulated arsenic concentration in each aquatic plant, Eichhornia crassipes (Mart.) Solms. (R (2) = 0.954), Ipomoea aquatica Forsk. (R (2) = 0.850), and Typha angustifolia (L.) (R (2) = 0.841) were found to be preferable arsenic removers for wastewater treatment pond in the condition of low Eh value and high content of solid phase EC and phosphorus. On the other hand, Canna glauca (L.) (R (2) = 0.749) appeared to be favorable arsenic accumulator for the treatment pond in the condition of high Eh value and high concentration of soluble EC.
湄宏顺地区的砷污染风险较高，这是由于湄宏顺褐煤火力发电厂生物湿地池塘的废水排放造成的。本研究的目的是调查湄宏顺生物湿地池塘中的砷浓度，并确定在处理系统中对砷植物修复重要的主要因素。结果表明，上清液中的砷浓度范围在小于 1.0 微克 As L(-1) 至 2.0 微克 As L(-1)，而沉积物中的砷浓度范围在 25-200 微克 As kg 土壤(-1)。这两个值均低于泰国国家标准规定的水为 0.25 mg As L(-1) 和土壤为 27 mg As kg 土壤(-1)。5 种水生植物在生物湿地池塘中的生物量砷积累范围为 123.83-280.53 mg As kgPlant(-1)。关于回归分析的结果（R (2) = 0.474 至 0.954），沉积物中高浓度的有机质和其他可溶性离子以及高 pH 值可显著提高湿地池塘中可溶性砷的去除率。从每种水生植物积累的砷浓度回归方程来看，水葫芦（R (2) = 0.954）、空心菜（R (2) = 0.850）和狭叶香蒲（R (2) = 0.841）被发现是在低 Eh 值和高固相 EC 和磷含量条件下处理废水处理池的优选砷去除剂。另一方面，美人蕉（R (2) = 0.749）在高 Eh 值和高可溶性 EC 浓度条件下似乎是有利于处理池的砷积累。
