A5066368990- Water Treatment and Disinfection
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University of Massachusetts Amherst
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Amherst College
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Saint Francis University
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2006
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Siemens (Israel)
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University of Hartford
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University of North Carolina at Chapel Hill
1986
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChlorination of humic materials: byproduct formation and chemical interpretationsDavid A. Reckhow, Philip C. Singer, Ronald L. MalcolmCite this: Environ. Sci. Technol. 1990, 24, 11, 1655–1664Publication Date (Print):November 1, 1990Publication History Published online1 May 2002Published inissue 1 November 1990https://pubs.acs.org/doi/10.1021/es00081a005https://doi.org/10.1021/es00081a005research-articleACS PublicationsRequest reuse...
Natural organic matter (NOM) from five water sources was fractionated using XAD resins and ultrafiltration membranes into different groups based on hydrophobicity molecular weight (MW), respectively. The disinfection byproduct formation each fraction during chlorination chloramination studied. In tests chlorination, hydrophobic high MW (e.g., >0.5 kDa) precursors produced more unknown total halogen (UTOX) than corresponding hydrophilic low <0.5 precursors. Trihaloacetic acid (THAA) were...
Two natural waters were fortified with various levels of bromide or iodide ions (0−30 μM) and chlorinated in the laboratory to study impact on formation speciation disinfection byproducts. Trihalomethanes (THMs), haloacetic acids (HAAs), total organic halogen (TOX), its halogen-specific fractions chlorine (TOCl), bromine (TOBr), iodine (TOI), measured this work. The molar yields THMs HAAs increased as initial concentration increased. No significant change TOX was found for varying...
Despite extensive efforts in the identification of new disinfection by‐products (DBPs) by environmental scientists, a significant fraction total organic halogen (TOX) drinking water still cannot be accounted for known specific DBPs. The formation and control these unknown DBPs have not been well established. primary aim this study was to evaluate effect reaction time, pH, dosage, temperature on TOX (UTOX) during chlorination chloramination. Results showed that greater conversion UTOX...
Research Article| February 01 2001 Formation and degradation of dichloroacetonitrile in drinking waters David A. Reckhow; Reckhow 1Department Civil & Environmental Engineering, University Massachusetts, Amherst, MA 01003, USA Tel: 413-545-5392 Fax: 413-545-2202; E-mail: reckhow@ecs.umass.edu Search for other works by this author on: This Site PubMed Google Scholar Andrew L. MacNeill; MacNeill Teresa Platt; Platt 2Department Seattle Public Utilities, Water Engineering Division, Seattle,...
An increased awareness of potentially carcinogenic micropollutants in US drinking waters has led to a reevaluation several well‐established treatment techniques. The major focus this concern been on the recently recognized hazards chlorination—the formation both trihalomethanes and total organic halides. Coagulation also subject renewed investigation because its ability remove halogenated precursors. This article discusses effects preozonation alum coagulation, separately combination, removal halide
Haloacetonitriles (HANs) are an important class of drinking water disinfection byproducts (DBPs) that reactive and can undergo considerable transformation on time scales relevant to system distribution (i.e., from a few hours week or more). The stability seven mono-, di-, trihaloacetonitriles was examined under variety conditions including different pH levels disinfectant doses typical systems. Results indicated hydroxide, hypochlorite, their protonated forms could react with HANs via...
This study investigated the impacts of buffer ions, natural organic matter (NOM), and particulate Fe(III) on ferrate(VI) decomposition characterized Fe(VI) kinetics exposure in various waters. Homogeneous heterogeneous can be described as a second- first-order reaction with respect to Fe(VI), respectively. decay was catalyzed by products. Solutes capable forming complexes iron hydroxides retarded decay. Fractionation resulting solutions from self-decay ferric chloride addition borate-...
Studies were conducted evaluating the nature of particles that result from ferrate reduction in a laboratory water matrix and natural surface with moderate amount dissolved organic carbon. Particle characterization included size, charge, morphology, X-ray photoelectron spectroscopy, transmission Fourier transform infrared spectroscopy. Characteristics resultant compared to formed dosing ferric chloride, common treatment coagulant. In water, addition produced significantly more nanoparticles...
Oxidative treatment of iodide-containing waters can form toxic iodinated disinfection byproducts (I-DBPs). To better understand the fate iodine, kinetics, products, and stoichiometries for reactions ferrate(VI) with iodide (I–) hypoiodous acid (HOI) were determined. Ferrate(VI) showed considerable reactivities to both I– HOI higher at lower pH. Interestingly, reaction (k = 6.0 × 103 M–1 s–1 pH 9) was much faster than 5.6 102 9). The main pathway during I–-containing oxidation its further...
The potential formation of nitrogenous disinfection byproducts (N-DBPs) was investigated from the chloramination and non-nitrogenous aromatic compounds. All molecules led to known N-DBPs (e.g., dichloroacetonitrile, dichloroacetamide) with various production yields. Resorcinol, a major precursor chloroform, also formed di/trichloroacetonitrile, di/trichloroacetamide, haloacetic acids, indicating that it is both carbonaceous DBPs (C-DBPs) upon chloramination. More detailed experiments were...
Trihalomethanes (THM), a major class of disinfection by-products, are widespread and associated with adverse health effects. We conducted global evaluation current THM regulations concentrations in drinking water.
Cobalt(II) was examined as an ozonation catalyst. Laboratory-scale batch experiments were run at near-neutral pH and 24 °C. A hydroxyl radical probe compound, p-chlorobenzoic acid (pCBA), also included in the solution matrix. Batch showed that trace amounts of cobalt(II) accelerated oxalate. The rate oxalate removal increased with decreasing from 6.7 to 5.3. presence pCBA indicating generation radicals are byproducts cobalt(II)-catalyzed It is proposed first step catalytic reaction pathway...
The objective of the research described in this article was to partially bridge gap between formation potentials model systems, e.g., humic substances, and by‐product concentrations likely be encountered finished waters. chlorination by‐products chosen for study were trihalomethanes, total organic halide, trichloroacetic acid, dichloroacetic trichloroacetone, dichloroacetonitrile. By‐product from colored raw waters found similar that observed aquatic fulvic acids. Alum coagulation a...