Synthesis of an amphoteric chitosan-based flocculant and its flocculation performance in the treatment of dissolved organic matter from drinking water

2020 ◽  
Vol 174 ◽  
pp. 171-177 ◽  
Author(s):  
Xiaomin Tang ◽  
Ting Huang ◽  
Shixin Zhang ◽  
Jie Zheng ◽  
Huaili Zheng
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Dissolved Organic Matter

Resolution of photo chemically induced changes of dissolved organic matter as function of cumulated radiation in a sample of a humic-rich and forested stream

2020 ◽  
Author(s):  
Peter Herzsprung ◽  
Christin Wilske ◽  
Wolf von Tümpling ◽  
Norbert Kamjunke ◽  
Oliver J. Lechtenfeld
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Fluorescence Intensity ◽  
Solar Irradiation ◽  
Large Reservoir ◽  
Photo Degradation ◽  
Peak Intensity ◽  
Ft Icr Ms ◽  
Ft Icr

<p>Photochemical processing is a major transformation pathway for allochthonous and autochthonous dissolved organic matter (DOM). DOM consists of thousands or even millions of different molecules and the isomer-resolved identification molecular structures is still far from any analytical realization. The highest analytical resolution of DOM can be achieved on a molecular mass basis via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). With this technique, the molecular elemental compositions of thousands of DOM components can be assessed, given that they are extractable from water (via e.g. solid phase extraction, SPE-DOM) and ionizable (e.g. via electrospray ionization).</p><p>Increasing levels of DOC in drinking water reservoirs pose serious challenges for drinking water processing. Photochemical processes potentially influence the DOM quality in the reservoir water. The photo degradation and / or the photo production of DOM components in surface freshwater as function of cumulated radiation was rarely investigated. In order to fill this gap we performed an irradiation experiment with water from a shaded forest stream flowing into a large reservoir (Muldenberg, Germany). DOC concentration, UV absorption, excitation-emission-matrices (EEMs) including calculated PARAFAC components and fluorescence indices, and FT-ICR MS derived molecular formulas of SPE-DOM were recorded at 13 different time points. The cumulated radiation was recorded during six days of solar irradiation (sunny days in August at 50.401847 deg. latitude and 12.380528 deg. longitude). Changes in relative peak intensity of DOM components as function of cumulated radiation were evaluated both by Spearman`s rank correlation and linear regression.</p><p>We found components with different types of photo reaction behavior. Relative aliphatic components like C<sub>9</sub>H<sub>12</sub>O<sub>5</sub> were identified as photo products showing a monotonous mass peak intensity increase with irradiation time. Highly unsaturated and oxygen-rich components like C<sub>15</sub>H<sub>6</sub>O<sub>8</sub> showed a more or less monotonous intensity decrease indicating photo degradation. Many similar components were positively correlated to the humic-like fluorescence intensity and the humification index (HIX). The strong degradation of these components can explain the high loss of fluorescence intensity and the drop of the HIX in our experiment. As a result of the high temporal resolution in our experiment (i.e. intensity change as function of cumulated irradiation) we found another type of photo reaction. Components like C<sub>15</sub>H<sub>16</sub>O<sub>8</sub> showed first increasing and then decreasing intensity indicating the formation of intermediate products.</p><p>In general, the river DOM from the forested catchment area showed high potential for photochemical transformations which probably occur in the sunlight exposed predam of the drinking water reservoir.</p>

Fluctuations of Dissolved Organic Matter in River Used for Drinking Water and Impacts on Conventional Treatment Plant Performance

2005 ◽  
Vol 39 (11) ◽  
pp. 4258-4264 ◽  
Author(s):  
Christian Volk ◽  
Louis A. Kaplan ◽  
Jeff Robinson ◽  
Bruce Johnson ◽  
Larry Wood ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Conventional Treatment ◽  
Treatment Plant ◽  
Plant Performance

scholarly journals Will UK peatland restoration reduce dissolved organic matter concentrations in upland drinking water supplies?

2020 ◽  
Author(s):  
Jennifer Williamson ◽  
Christopher Evans ◽  
Bryan Spears ◽  
Amy Pickard ◽  
Pippa J. Chapman ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Field Studies ◽  
Organic Soils ◽  
Catchment Management ◽  
Raw Water ◽  
Considerable Uncertainty ◽  
Published Evidence ◽  
Peatland Restoration

Abstract. Rising dissolved organic matter (DOM) concentrations, and associated increases in water colour, have posed a potential problem for the UK water industry since the phenomenon was first reported in the early 1990s. Elevated DOM concentrations in raw water are of particular concern in upland catchments dominated by organic soils where DOM production tends to be highest. In recent years, water companies have considered the capacity for catchment interventions to improve raw water quality at source, relieving the need for costly and complex engineering solutions in treatment works, but there is considerable uncertainty around the effectiveness of these measures. One of the primary evidence gaps is the extent to which catchment management is capable of influencing DOM concentrations at the point of abstraction, field studies rarely extending beyond sub-catchment or stream scale. Our review of the published evidence suggests that catchment management could make a contribution to mitigating recent DOM increases in some circumstances, particularly where plantation forestry has been grown on peat, and where control of nutrients in runoff could reduce in-reservoir DOM production. Evidence for the efficacy of most other measures that target reductions in DOM loading for catchment to reservoir remains insufficient to support wider scale application. Collectively, these measures have the potential to reduce DOM concentrations in drinking water reservoirs but they must be selected on a site-specific basis, where the scale, effect size and duration of the catchment intervention are considered in relation to both the treatment capacity of the works and future projected DOM trends.

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