Multidimensional spectrofluorometry characterization of dissolved organic matter in arsenic-contaminated shallow groundwater

Abstract

Multidimensional spectrofluorometry was employed to characterize dissolved organic matter (DOM) in arsenic-contaminated shallow aquifers at Jianghan Plain (JHP), central China, to better understand the effect of biogeochemical processes on arsenic mobilization. The microbial humic quinone and amino acid components identified indicate the importance of microbially mediated processes in the reduction of iron oxyhydroxides. The relationship of quinone and amino acid-like components with Fe(2+) and S(2-) helps us understand the sequential redox transformation (SRT) in the high arsenic aquifer system and the origin of bicarbonate in groundwater. Correlation between DOM components and dissolved arsenic and Fe suggests that arsenic mobilization could be linked to the microbial reduction of iron oxyhydroxides with liable DOM as electron donors as well as to the electron shuttling function served by humic quinones.

Trends and Future Projections for Marine Biogeochemistry Research in Indonesia (Tren dan Proyeksi Penelitian Biogeokimia Laut di Indonesia)

“…Furthermore, dissolved organic matter seems to be the leading topic within this 11.0% (e.g. research by Cai et al, 2012;Fernanda-Adame et al, 2012, Huang et al, 2012Li et al, 2012;Lutz et al, 2012;Man et al;). …”

Hydrochemistry Indicating Groundwater Contamination and the Potential Fate of Chlorohydrocarbons in Combined Polluted Groundwater: A Case Study at a Contamination Site in North China

“…, generally occur in sequence (Huang et al 2012;Stumm and Morgan 1996). Groundwater has no significant amounts of DO and low concentration of NO 3 -, but high concentration of dissolved manganese (Table 1).…”

“…The samples for cation analysis were filtered by a 0.45 lm cellulose acetate membrane, and the pH was adjusted to \2 with ultra-pure HNO 3 (Huang et al 2012). Samples for DOC analysis were adjusted to pH 2 with HCl.…”

Zinc Binding to Fulvic acids: Assessing the Impact of pH, Metal Concentrations and Chemical Properties of Fulvic Acids on the Mechanism and Stability of Formed Soluble Complexes

“…FAs compared to other fractions of humic substances (humic acids and humins) reveal a lower molecular weight (~500-2000 Da) [1,2], lower sensitivity to pH and better solubility [3], a structure richer in oxygen compounds [2,4] as well as lower aromaticity [5]. FAs find a wide variety of applications, however the greatest potential of these compounds comes from their chelating properties due to a large number of carboxylic, phenolic and alcoholic hydroxyl functional groups (900-1400 cmol kg −1 ) [6,7] as well as others including quinines, semiquinones [8,9], amino and sulphydryl groups [5,10]. As a consequence, FAs exhibit a high sorption capacity to cationic substances, hence they can play a key role in controlling speciation, bioavailability, toxicity and mobility of metals [11][12][13].…”