Thorough removal of inorganic and organic mercury from aqueous solutions by adsorption on Lemna minor powder

• Published in: Journal of hazardous materials Vol. 186; no. 1; pp. 423 - 429
• Main Authors: Li, Shun-Xing, Feng-Ying, Zheng, Yang, Huang, Jian-Cong, Ni
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.02.2011; Elsevier
• Subjects: Adsorption; Applied sciences; Aqueous solutions; atomic absorption spectrometry; Cations; China; Drinking water; Drinking water and swimming-pool water. Desalination; electrostatic interactions; Environmental Restoration and Remediation - methods; Exact sciences and technology; General purification processes; Hydrogen-Ion Concentration; Inorganic Chemicals - isolation & purification; Lemna minor; Low residual concentration; Magnoliopsida - chemistry; Mercury; Mercury - isolation & purification; Mercury remove; methylmercury compounds; Organic Chemicals - isolation & purification; Pollution; powders; Solutions; Spectroscopy, Fourier Transform Infrared; Surface chemistry; Thermodynamics; United States Environmental Protection Agency; Waste water; wastewater; Wastewaters; Water - chemistry; Water Pollutants, Chemical - isolation & purification; Water treatment and pollution; China; China, People's Rep; Lemna minor; Adsorption; Low residual concentration; Mercury remove; Phosphates; Drinking water; Monocotyledones; Lemnaceae; Adsorption site; Selective adsorption; Electrostatic interaction; Powder; Heavy metal; Waste water; Angiospermae; Methylmercury; pH; Spermatophyta; Aqueous solution; Mercury; Organic compounds; Atomic absorption spectrometry
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2010.11.009

The adsorption ability of duckweed (Lemna minor) powders for removing inorganic and organic mercury (methyl and ethyl mercury) has been studied using cold vapour atomic absorption spectrometry. The optimal adsorption conditions were: (a) the pH value of the solution 7.0 for inorganic and ethyl mercury, 9.0 for methyl mercury, and (b) equilibrium adsorption time 10, 20, and 40min for inorganic mercury, methyl mercury, and ethyl mercury, respectively. After adsorption by L. minor powder for 40min, when the initial concentrations of inorganic and organic mercury were under 12.0μgL−1 and 50.0μgL−1, respectively, the residual concentrations of mercury could meet the criterion of drinking water (1.0μgL−1) and the permitted discharge limit of wastewater (10.0μgL−1) set by China and USEPA, respectively. Thorough removal of both inorganic and organic mercury from aqueous solutions was reported for the first time. The significant adsorption sites were C–O–P and phosphate groups by the surface electrostatic interactions with aqueous inorganic and organic mercury cations, and then the selective adsorption was resulted from the strong chelating interaction between amine groups and mercury on the surface of L. minor cells.