title: Monitoring of arsenic in aquatic plants, water, and sediment of wastewater treatment ponds at the Mae Moh Lignite power plant, Thailand.
abstract: 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.
authors.affiliation: Inter-department of Environmental Management (International), Hazardous Waste Management, Graduate School, Chulalongkorn University, Bangkok, Thailand. jomjun_102@hotmail.com
authors.forename: Jomjun
authors.initials: J
authors.lastname: Nateewattana
authors.forename: Siripen
authors.initials: S
authors.lastname: Trichaiyaporn
authors.forename: Maliwan
authors.initials: M
authors.lastname: Saouy
authors.forename: Jintapat
authors.initials: J
authors.lastname: Nateewattana
authors.forename: Prasak
authors.initials: P
authors.lastname: Thavornyutikarn
authors.forename: Petch
authors.initials: P
authors.lastname: Pengchai
authors.forename: Somporn
authors.initials: S
authors.lastname: Choonluchanon
mesh_terms: D001151:Arsenic / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis*; D010944:Plants / Q000737:chemistry*; D011210:Power Plants; D012722:Sewage; D013785:Thailand; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D001151:Arsenic