scholarly journals Effect of Oxidation on the Formation of Disinfectant By-products of Low Molecular Weight Organic Matter

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
E. N. Hidayah ◽  
O. H. Cahyonugroho ◽  
M. Mirwan ◽  
R. B. Pachwarya ◽  
M. K. Asrori
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Compounds ◽  
Aromatic Compound ◽  
Aromatic Compounds ◽  
Sinapic Acid ◽  
Oxidation Potential ◽  
Low Molecular Weight ◽  
Safe Alternative ◽  
By Products

Some natural organic compounds (NOC) such as aromatic compounds can trigger the formation of disinfection by-products (DBPs). In chlorination (disinfectant) process resultant water quality depletes. Some safe alternative oxidants are needed for cleaning water pollutants. KMnO4 had shown better oxidation results, especially for reducing aromatic and non-aromatic organic compounds present in water. The aim of this study was to analyze the effect of KMnO4 and Ca(OCl)2 oxidants on the concentration of high and low molecular weight organic matter including aromatic compounds in the water sample. In this experiment, artificial organic compounds, namely sinapic acid (high molecular weight aromatic compound) and resorcinol (low molecular weight aromatic compound) were used to identify the characteristic of organic matter under different molecular weights. Sinapic acid and resorcinol were oxidized by using KMnO4 and Ca(OCl)2 with a minimum contact time of 60 minutes. Samples were analyzed for aromatic contents and total organic carbon (TOC) before and after completion of the experiment by using UV-Vis spectrophotometer at 254 nm wavelength (UV254). It has been observed that both oxidants increased TOC concentration. Ca(OCl)2 produces a higher percentage of organic matter degradation by-products (DBPs) such as chloroform (CHCl3) a highly toxic compound than KMnO4. Since Ca(OCl)2 has a higher oxidation potential than KMnO4. It has been observed that KMnO4 is a safer oxidant than Ca(OCl)2 as potassium permanganate produces less amount of DBPs.

scholarly journals Removal of Trihalomethane Precursors by Nanofiltration in Low-SUVA Drinking Water

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1370 ◽  
Author(s):  
Yael Dubowski ◽  
Roni Greenberg-Eitan ◽  
Menachem Rebhun
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Low Molecular Weight ◽  
Water Recovery ◽  
Formation Potential ◽  
Pressure Water ◽  
Membrane Type ◽  
Hydrophilic Organic Matter ◽  
By Products

Trihalomethanes (THMs) are prevalent disinfection by-products. High THM formation is usually associated with natural organic matter with high molecular weight and aromatic characteristics, which is efficiently removed by nanofiltration (NF). In the Sea of Galilee and the Israeli National Water Carrier (NWC), water shows high THM formation potential, although it mainly contains low molecular weight and hydrophilic organic matter with low aromaticity. In the present study, NF removal abilities were tested on treated NWC water using three different spiral wound membranes (NF90, NF270, and DL). Rejections and fluxes were tested as a function of pressure, water recovery, and membrane type. Feed and permeate dissolved organic carbon (DOC), UVA254, total THM formation (THMF), and total THM formation potential (THMFP), as well as alkalinity, conductivity, hardness, Ca2+, Mg2+, and Cl− were measured to evaluate rejection and THM formation reduction. The results demonstrated that NF can efficiently remove natural organic matter (NOM) and reduce THM formation, even in this challenging type of water. At low water recovery, membranes showed average rejection of about 70–85% for THMFP and THM. Upon elevating recovery, average THM and THMFP rejection decreased to 55–70%, with THM content still well below regulation limits. Of the membranes tested, the higher permeability of NF270 appears to make it economically favorable for the applications tested in this work.

Phase-partitioning and chemical reactions of low molecular weight organic compounds in fog

Tellus B ◽  
1992 ◽  
Vol 44 (5) ◽  
pp. 533-544 ◽  
Author(s):  
M. C. Facchini ◽  
S. Fuzzi ◽  
J. A. Lind ◽  
H. Fierlinger-Oberlinninger ◽  
M. Kalina ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Compounds ◽  
Chemical Reactions ◽  
Low Molecular Weight ◽  
Phase Partitioning

scholarly journals Effect of WC/Ni–Cr additive on changes in the composition of an atmospheric residue in the course of cracking

2019 ◽  
Vol 17 (2) ◽  
pp. 499-508 ◽  
Author(s):  
Galina S. Pevneva ◽  
Natalya G. Voronetskaya ◽  
Nikita N. Sviridenko ◽  
Anatoly K. Golovko
Keyword(s):  
Molecular Weight ◽  
Tungsten Carbide ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Low Molecular Weight ◽  
Nickel Chromium ◽  
Atmospheric Residue ◽  
Sulfur Containing ◽  
Catalytic Additive ◽  
Sulfur Containing Compounds

AbstractThe paper presents the results of investigation of changes in the composition of hydrocarbons and sulfur-containing compounds of an atmospheric residue in the course of cracking in the presence of a tungsten carbide–nickel–chromium (WC/Ni–Cr) catalytic additive and without it. The cracking is carried out in an autoclave at 500 °C for 30 min. The addition of the WC/Ni–Cr additive promotes the deepening of reactions of destruction not only of resins and asphaltenes, but also high molecular weight naphthene-aromatic compounds of the atmospheric residue. It is shown that the content of low molecular weight C9–C17 n-alkanes and C9–C10 alkylbenzenes rose sharply in the products of cracking with addition of WC/Ni–Cr in comparison with those produced without the additive. Alkyl- and naphthene-substituted aromatic hydrocarbons of benzene, naphthalene, phenanthrene series, polyarenes, benzo- and dibenzothiophenes are identified.

scholarly journals A new bacterial alcohol dehydrogenase active on degraded lignin and several low molecular weight aromatic compounds

1989 ◽  
Vol 57 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Jean Pelmont ◽  
Catherine Tournesac ◽  
Ahmed Mliki ◽  
Michel Barrelle ◽  
Claude Beguin
Keyword(s):  
Molecular Weight ◽  
Alcohol Dehydrogenase ◽  
Aromatic Compounds ◽  
Low Molecular Weight
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