Fractionation and characterization of ozonated and post chlorinated aquatic fulvic acid using gel chromatography

Extracted aquatic fulvic acid samples (HO10FA) from a brown lake Hohloh in the Black Forest (Germany) were ozonated at two different ozone doses and then chlorinated. In connection with liquid chromatography and further detection systems (UV and DOC) on gel matrix, a combined system (gel chromatography) was used for a detailed characterization of ozonated and post-chlorinated fulvic acid samples. The gel chromatographic characterization showed a slight decrease in DOC (14%) and SAC254 (36%) at the end of 20 min ozonation whereas the low ozonation time (5 min) caused increased in DOC (6%) and SAC254 (56%).Extracted aquatic fulvic acid samples (HO10FA) from a brown lake Hohloh in the Black Forest (Germany) were ozonated at two different ozone doses and then chlorinated. In connection with liquid chromatography and further detection systems (UV and DOC) on gel matrix, a combined system (gel chromatograpy) was used for a detailed characterization of ozonated and post-chlorinated fulvic acid samples. The gel chromatographic characterization showed a slight decrease in DOC (14%) and SAC254 (36%) at the end of 20 min ozonation whereas the low ozonation time (5 min) caused increases in DOC (6%) and SAC254 (56%).German Academic Exchange Service London Deutscher Akademischer Austauschdienst Deutsche ForschungsgemeinschaftThe authors thank the 32nd International Seminar(IS), German Academic Exchange Service (DAAD) and Deutsche Forschungsgemeinschaft (DFG, ROSIG) for financial support. We are grateful to Sebastian Hesse for experimental assistance

Use of gel permeation chromatography to characterize the changes in natural organic matter through oxidative treatments

Gel permeation chromatography (GPC) in combination with ultraviolet (UV) and sensitive dissolved organic carbon (DOC) detection was used to investigate the structural changes caused by ozonation and chlorination. Oxidation processes were applied to a fulvic acid (HO10FA) sample which was extracted from Hohloh Lake, Germany. Biological degradation by means of assimilable organic carbon (AOC) of the FA sample was monitored by GPC elution diagrams. It is shown that ozonation and subsequent chlorination result in partial decomposition of the high-molecular-mass components of FA to low-molecular-mass hydrophilic compounds which are more biodegradable by microorganisms

Effects of humic substances on the bioconcentration of polycyclic aromatic hydrocarbons: Correlations with spectroscopic and chemical properties of humic substances

Haitzer M, Abbt-Braun G, Traunspurger W, Steinberg C. Effects of humic substances on the bioconcentration of polycyclic aromatic hydrocarbons: Correlations with spectroscopic and chemical properties of humic substances. Environmental Chemistry and Toxicology. 1999;18(12):2782-2788

Dissolved organic carbon from the traditional jute processing technique and its potential influence on arsenic enrichment in the Bengal Delta

Dissolved organic C (DOC) plays an important role in the mobilization of As from sediments. In West Bengal, the widely used technique for obtaining jute fiber involves retting of the jute plant in ponds (hereafter such ponds are termed jute decomposing ponds) for several weeks, which produces significant amounts of DOC in the ponds. These ponds thus act as point sources of DOC and supply huge quantities of organic C to the Bengal Delta sediments. This study has been carried out to investigate the role of such DOC in enriching the groundwater with As in the Bengal Delta. Data clearly show that due to the effect of DOC, As is mobilized from the upper 2.6 m of the sediment profile, and is fixed between 2.6 and 6.1 m, while the lower part (6.1-9 m) largely remains unaffected. The reducing conditions mainly developed due to the decay of the percolating DOC seem to help the mobilization and transportation of As and other redox sensitive elements (Fe, Mn), as well as elements (Cu, Zn) attached to oxy-hydroxides of those redox-sensitive elements. Experiments also indicate that if the DOC production at the surface continues for a longer period of time, the zone of As fixation (2.6-6.1 m) may get shifted further downwards and ultimately intercept the water table resulting in As enrichment of groundwater. (C) 2011 Elsevier Ltd. All rights reserved