scholarly journals Size and resin fractionations of dissolved organic matter and characteristics of disinfection by-product precursors in a pilot-scale constructed wetland

2021 ◽  
Author(s):  
Jiachang Pi ◽  
Guangcan Zhu ◽  
Lianqing Liu ◽  
Chuya Wang ◽  
Zhonglian Yang
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Constructed Wetland ◽  
Weight Fraction ◽  
Pilot Scale ◽  
High Molecular Weight Fraction ◽  
Raw Water ◽  
Wetland Treatment ◽  
Hydrophobic Fraction

Abstract Controlling the formation of disinfection by-products (DBPs) is a major issue in the drinking water industry, and understanding the characteristics of DBP precursors in treatment processes for micro-polluted raw water is key to improving water quality. In this study, a sampling program was undertaken to investigate the fate of dissolved organic matter (DOM) and the characteristics of DBP precursors in a pilot constructed wetland imitating the Yanlong Lake ecological project. Using XAD resin adsorption and ultrafiltration techniques, the dissolved organic carbon, UV254, and DBP formation potential (DBPFP) were measured in different DOM fractions in raw water and wetland effluents. After the constructed wetland treatment, the low molecular weight fraction (<3 kDa) of DOM and DBPFP generally showed a decreasing trend along the water path, while the high molecular weight fraction (>3 kDa) of DOM increased. The specific DBPFP (SDBPFP) was much higher in the <1 kDa fraction than in the other fractions. Although the hydrophobic fraction of DOM was the most abundant in all stages of the wetland treatment, the SDBPFP of the hydrophilic fraction was higher than that of the hydrophobic fraction. Furthermore, compared with raw water, the DOC, UV254 and DBPFP in the treated wetland effluents increased; however, all of the chemical DOM fractions exhibited decreased SDBPFP in accordance with a decrease in the specific ultraviolet absorbance during wetland treatment. These conclusions indicate that the DOM produced by the wetland system may generate DBPs less readily compared with the DOM of raw water.

scholarly journals Characterization of dissolved organic matter at a water treatment plant with closed systems in different seasons

2020 ◽  
Vol 20 (5) ◽  
pp. 2013-2020
Author(s):  
Hudori Hudori ◽  
Toshiro Yamada ◽  
Yukitaka Suzuki ◽  
Maulana Yusup Rosadi ◽  
Hiroto Tamaoki ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Water Treatment ◽  
Dissolved Organic Matter ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Raw Water ◽  
Recycled Water ◽  
Water Treatment Process ◽  
Closed Systems

Abstract This research focuses on characterizing the dissolved organic matter found at water treatment plants with closed systems. Recycled water generated as a by-product of water treatment is added to raw water in those systems. The dissolved organic matter in the raw water was found to be higher in summer than in winter, but the water treatment process was able to produce purified water of the similar quality in both seasons. The recycled water contained mostly low molecular weight and protein-like substances, and this composition was different from that of the raw water, which mainly contained humic-like substances. The recycled water did not influence the concentration of humic-like substances or the molecular weight distribution in the influent water.

scholarly journals Characteristics of dissolved organic matter in a water purification plant and distribution pipes

2019 ◽  
Vol 280 ◽  
pp. 03007 ◽  
Author(s):  
Toshiro Yamada ◽  
Maulana Yusup Rosadi ◽  
Hudori ◽  
Yukitaka Suzuki ◽  
Eri Ito ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Water Treatment ◽  
Dissolved Organic Matter ◽  
Three Dimensional ◽  
Quality Parameters ◽  
Raw Water ◽  
Treatment Unit ◽  
Treatment Processes ◽  
Doc Concentration

Dissolved organic matter (DOM) needs to be characterized todetermine the ability of a water treatment unit to reduce organic matter andits relationship to the levels of chlorine required for disinfection. Weinvestigated water quality parameters, including DOM, in a waterpurification plant and distribution pipes located in central Japan. Thedissolved organic carbon (DOC) concentration decreased from 0.73 mg/Lin raw water to 0.50 mg/L in purified water by conventional treatmentprocesses. The DOC of purified water decreased slightly in the pipesdownstream of the plant. The three-dimensional excitation-emission matrixfluorescence spectra showed some specific peaks for humic-like substancesand protein-like substances in all water samples, and the compositions ofDOM in purified water were close to those in raw water. However, therewas a peak of protein-like substances in purified and returned water, whichwas not observed for raw water. The fluorescence intensities of humic-likesubstances in purified water decreased downstream of the plant, while thefluorescence intensities of protein-like substances increased in the pipes. The measured molecular weight distributions of DOM in water presentedsome specific peaks, and DOM with a smaller molecular weight was noteasily removed by water treatment processes. There were positiverelationships between decreases in the intensities of some peaks andresidual chlorine decay.

Dissolved organic matter degradation by sunlight coagulates organo-mineral colloids and produces low-molecular weight fraction of metals in boreal humic waters

2017 ◽  
Vol 211 ◽  
pp. 97-114 ◽  
Author(s):  
Olga V. Oleinikova ◽  
Olga Yu. Drozdova ◽  
Sergey A. Lapitskiy ◽  
Vladimir V. Demin ◽  
Andrey Yu. Bychkov ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
Organic Matter Degradation

Studies on the Functionality of Newly Synthesized Fibrinogen after Treatment of Acute Myocardial Infarction with Streptokinase, Increase in the Rate of Fibrinopeptide Release

1993 ◽  
Vol 70 (06) ◽  
pp. 0978-0983 ◽  
Author(s):  
Edelmiro Regano ◽  
Virtudes Vila ◽  
Justo Aznar ◽  
Victoria Lacueva ◽  
Vicenta Martinez ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Molecular Weight ◽  
Steady State ◽  
High Molecular Weight ◽  
Coronary Arteries ◽  
Risk Index ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Fibrinopeptide A

SummaryIn 15 patients with acute myocardial infarction who received 1,500,000 U of streptokinase, the gradual appearance of newly synthesized fibrinogen and the fibrinopeptide release during the first 35 h after SK treatment were evaluated. At 5 h the fibrinogen circulating in plasma was observed as the high molecular weight fraction (HMW-Fg). The concentration of HMW-Fg increased continuously, and at 20 h reached values higher than those obtained from normal plasma. HMW-Fg represented about 95% of the total fibrinogen during the first 35 h. The degree of phosphorylation of patient fibrinogen increased from 30% before treatment to 65% during the first 5 h, and then slowly declined to 50% at 35 h.The early rates of fibrinopeptide A (FPA) and phosphorylated fibrinopeptide A (FPAp) release are higher in patient fibrinogen than in isolated normal HMW-Fg and normal fibrinogen after thrombin addition. The early rate of fibrinopeptide B (FPB) release is the same for the three fibrinogen groups. However, the late rate of FPB release is higher in patient fibrinogen than in normal HMW-Fg and normal fibrinogen. Therefore, the newly synthesized fibrinogen clots faster than fibrinogen in the normal steady state.In two of the 15 patients who had occluded coronary arteries after SK treatment the HMW-Fg and FPAp levels increased as compared with the 13 patients who had patent coronary arteries.These results provide some support for the idea that an increased synthesis of fibrinogen in circulation may result in a procoagulant tendency. If this is so, the HMW-Fg and FPAp content may serve as a risk index for thrombosis.

In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

1981 ◽  
Vol 46 (03) ◽  
pp. 612-616 ◽  
Author(s):  
U Schmitz-Huebner ◽  
L Balleisen ◽  
F Asbeck ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Day Treatment ◽  
Gel Filtration ◽  
Weight Fraction ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Platelet Factor ◽  
Heparin Fractions

SummaryHigh and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

scholarly journals ‘Tanned’ gelatin spheres and granules for exclusion chromatography

1968 ◽  
Vol 108 (4) ◽  
pp. 641-646 ◽  
Author(s):  
A. Polson ◽  
W. Katz
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
High Molecular Weight ◽  
Weight Fraction ◽  
High Flow ◽  
High Molecular Weight Fraction ◽  
Flow Rates ◽  
Protein Molecules ◽  
Exclusion Chromatography

1. The preparation of tanned gelatin spheres and granules from high-molecular-weight gelatin is described. This material is comparatively hard, giving high flow rates, is insoluble in water at temperatures between 0° and 100° and is resistant to digestion by trypsin and chymotrypsin. The high-molecular-weight fraction of gelatin was prepared by precipitation with polyethylene glycol, and the spheres and granules prepared from this fraction were hardened and insolubilized by tanning with either formalin or chromium salts or both. 2. The spheres and granules were used successfully for the separation of protein molecules and other protein-aceous materials ranging in molecular weight from 200 to greater than 6000000. This gel exclusion material has several properties superior to those of other products used for similar purposes. Further, it was noticed that the porosity of the spheres differed considerably from that of the granules.

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