Organic characterisation of cave drip water by LC-OCD and fluorescence analysis

Abstract

Organic characterisation of cave drip water by LC-OCD and fluorescence analysis, Geochimica et Cosmochimica Acta (2015), doi: http://dx.Abstract 20 Cathedral Cave, Wellington, Australia, is a natural laboratory for studying water movement 21 and geochemical processes in the unsaturated zone by using artificial irrigation to activate 22 drip sites within the cave. Water sampled from two drip sites activated by irrigations carried 23 out in summer 2014 was analysed for dissolved inorganic ions and fluorescent organic 24 matter. The analysis allowed the development of a conceptual flow path model for each drip 25 site. DOM analysis was further complemented by liquid chromatography with organic carbon 26 detection (LC-OCD), applied for the first time to karst drip waters, allowing the 27 characterisation of six organic matter fractions. The differences in organic matter fractions at 28 each drip site are interpreted as a signature of the proposed flow paths. LC-OCD was also 29 compared with parallel factor analysis (PARAFAC) of the fluorescence and good correlations 30 were observed for high molecular weight organic matter. Strong positive correlations were 31 also observed for high molecular weight matter and Cu and Ni. This is suggestive of colloidal 32 transport of Cu and Ni by organic matter with high molecular weight, while small molecular 33 weight colloids were not efficient transporters. LC-OCD uniquely provides information on 34 2 non-fluorescent organic matter and can be used to further quantify drip water organic matter 35 composition. 36 37

Biodegradation kinetics of dissolved organic matter chromatographic fractions in an intermittent river

“…However, despite showing the slowest bulk DOM decay, the pools included a fraction of HMWS that presented high biodegradation (Figure ). The HMWS fraction, also called biopolymers [ Huber et al ., ], is related with high molecular weight compounds (>10 kDa [ Rutlidge et al ., ]), usually polymers as polysaccharides with some contribution of nitrogen‐containing materials such as proteins or amino sugars [ Huber et al ., ]. Structural polysaccharides are major components of leaf litter detritus [ Mansfield and Baerlocher , ; Engelhaupt and Bianchi , ], which accumulates in the studied temporary pools [ Casas‐Ruiz et al ., ].…”

“…However, pool samples also present an important fraction of HS and BB. This fraction represents different acids resulting from the biodegradation of dead organic matter [ Rutlidge et al ., ] and may be related to the presence of a very large reactivity class with very low decay rates (Figure b and Table ). Accordingly, as sugars from fresh litter leachate are consumed, the humic fraction might become relatively more abundant [ Cleveland et al ., ].…”

Application of a combination of oxidants improves treatment performance for NOM and manganese

“…4 and S3(a) †). The biopolymer fraction, comprising of polysaccharides, proteins, amino sugars and amino acids, and other large organic compounds of molecular weight higher than 10 kDa, 53,79 which accounted for 4.3% of total DOC, was removed by oxidation and C-F by more than 90%, irrespective of the oxidation location when KMnO 4 and Cl 2 were dosed. The biopolymer fraction was the most susceptible molecular weight fraction to oxidation attack or entrapment by coagulant hydrolysis products during floc formation.…”

Characteristics of Bacterial Communities in Biological Filters of Full-Scale Drinking Water Treatment Plants

“…Neutrals are uncharged, small organic matter of <350 Da including alcohols, aldehydes, and ketones. Organic acids represent protic organic acids of low molecular weight of <350 Da [43]. Pre-chlorination can increase high-molecular-weight substrates by disrupting particulate organic matter, including algae in raw water [41,44].…”