trihalomethane THM Articles
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Health effects of disinfection by-products in Australian drinking waters
The disinfection of drinking water has greatly diminished the occurrence of diseases known to be caused by water-borne pathogens, but technological advances subsequent to the initial discovery of chloroform in 1974 have enabled the identification of a plethora of Disinfection By-Products (DBPs), particularly trihalomethanes (THMs), that may have injurious health effects on humans. DBPs are widely ...
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Preventing trihalomethane formation: the ability of granular activated carbon and brimac media to remove colour and total organic carbons, from drinking water in the north west of Scotland
Background: Granular activated carbon (GAC) and Brimac media has been used for many years in water treatment works to reduce and remove colour and total organic carbon (TOCs). This reduces the formation of trihalomethanes (THMs) formed by disinfection with chlorine. The TOCs arise from humic and fulvic acids found in source waters for many, small, scattered remote communities in Scotland. A ...
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Catalytic Carbons Help Remove Chloramine
Untitled Document Summary: Where chlorine creates high levels of trihalomethanes (THMs), chloramine can be an alternative for disinfecting drinking water. Removing it at the point of use (POU), however, can be more difficult than removing chlorine. When your job requires chloramine removal, you may consider using catalytic activated carbons. To view ...
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Formation potential of trihalomethanes (THMs) in blended water treated with chlorine
This study was conducted in the laboratory to assess the formation potential of trihalomethanes (THMs) in blended water under various treatment conditions. Three batches of water samples prepared by mixing desalinated (product) water and ground brackish water with three different proportions (i.e. 1:2, 1:5 and 1:10 – brackish:product water) were treated with three concentration levels of calcium ...
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Using HPSEC to identify NOM fraction removal and the correlation with disinfection by-product precursors
In this study high performance size exclusion chromatography (HPSEC) was used to compare an ultrafiltration (UF) membrane and alum coagulation for their capacity to remove different fractions of natural organic matter (NOM) from water. At the same time, the removal of disinfection by-product (DBP) precursors, as measured by trihalomethane formation potential (THMFP) and haloacetic acid ...
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THM Removal in Potable Water Storage Tanks - Case Study
City tests various trihalomethane removal systems to ensure full EPA compliance. Topics: trihalomethane, THM, TTHM, spray aeration, potable water tanks, GridBee® SN Series THM Removal System Project Overview: This location had a tank battery of four similar 1.5 MG bolted steel tanks installed serving as temporary storage during the planning & construction of two 6 MG pre-stressed ...
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NOM reactivity with chlorine in low SUVA water
Natural organic matter (NOM) in surface water with low specific UV absorbance in Tianjin, China, was fractionated using XAD resins and ultra-filtration membranes into different groups based on hydrophobicity and molecular weight (MW), respectively. The effects of the pre-chlorination process on each fraction were also studied. The hydrophilic acid (HPIA) fraction was the main organic component of ...
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Should We Be Concerned About Disinfection Byproducts?
Chlorinating water can lead to the formation of harmful compounds, but there are treatment alternatives Water utilities often chlorinate drinking water to kill pathogens that could pose a risk to human health. However, when chlorine is used to treat water, it can cause a chemical reaction with natural inorganic or organic compounds, which may be derived from decaying plants, algae, or animal ...
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Factors affecting formation of disinfection by-products during chlorination of Cyclops
Effects of reaction time, chlorine dosages, pH, temperature and ammonia concentrations on the formation of disinfection by-products (DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), haloketones (HKs), chloral hydrate (CH), and chloropicrin (TCNM), were investigated during the chlorination of Cyclops metabolite solutions containing 4 mg/L (as total ...
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Pennsylvania Water Utility Converts to Chlorine Dioxide - Case Study
Trial achieved reduced THMs, easier maintenance, and better water qualitySituation The central water treatment department saw a need to improve their trihalomethane (THM) levels, which are a byproduct of the disinfection process using chlorine. An engineering firm was hired to evaluate the use of chlorine dioxide, and International Dioxcide was chosen to execute a trial. The project approach was ...
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Evaluation of DBPs formation from SMPs exposed to chlorine, chloramine and ozone
Soluble microbial products (SMPs) are an important group of components in wastewater effluents. In this study, the formation of disinfection by-products (DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), chlorinated solvents (CSs), haloketones (HKs), haloacetonitriles (HANs) and trichloronitromethane (TCNM) (chloropicrin), from SMPs during chlorination, chloramination and ...
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Development of point-of-use water disinfection technology using ceramic water filter and electrochemical hybrid system
The efficiency of water disinfection using a ceramic water filter and electrochemical hybrid system was investigated. Escherichia coli O157:H7 was effectively inactivated even when a storage battery, charged using a solar panel device, was used for the electrolysis process. During electrolysis, the rate of microbial inactivation was higher at higher initial Cl− concentrations. This was ...
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Evaluation of photocatalytic degradation of a commercial humic acid in water using a simulated solar UV irradiation and monitoring the changes by size exclusion chromatography
Much research has been undertaken on the photocatalytic degradation of humic substances with titanium dioxide using commercial humic acids (HA), which are extracts from either peat or coal. Most of the research has been focused on the changes in dissolved organic carbon (DOC) and UV254 absorption. These parameters only give a general assessment. This work studies the changes in the physical and ...
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Method for trihalomethane analysis in drinking water by solid-phase microextraction with gas chromatography and mass spectrometry detection
Headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry detection (HS/SPME-GC/MSD) was optimized for trihalomethane (THM) determination in drinking water. A 75 μm fiber coated with carboxen/polydimethylsiloxane (75-CAR.PDMS) was used. Experimental parameters such as sample volume, time and temperature of extraction, time and temperature of desorption, ...
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Disinfection byproduct formation kinetics of a water treatment plant on Kinmen Island
Chloramine has often been used as a chlorine alternative for trihalomethane (THM) and haloacetic acid (HAA) control. However, nitrogenous disinfection byproduct (N-DBP) formation and nitrification in distribution have always been major concerns in chloramination practices. On Kinmen Island, the high organic nitrogen content in raw water may increase the nitrogenous DBP formation. Simulated ...
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Relationships between trihalomethanes, haloacetic acids, and haloacetonitriles formed by the chlorination of raw, treated, and fractionated surface waters
This study examined effects of coagulation and fractionation of natural organic matter on the distribution of trihalomethanes (THM), haloacetic acids (HAA), and haloacetonitriles (HAN) formed in chlorinated water. The precursors of HAA and THM were determined to be associated primarily with the hydrophobic fraction although the hydrophilic fraction is important as well. On the other hand, the ...
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Effects of plumbing systems on human exposure to disinfection byproducts in water: a case study
Disinfection byproducts (DBPs) in water distribution systems (WDS) are monitored for regulatory compliance, while populations are exposed to DBPs in tap water that may be different due to stagnation of water in plumbing pipes (PP) and heating in hot water tanks (HWT). This study investigated the effects of water stagnation in PP and HWT on exposure and risk of DBPs to humans. Trihalomethanes ...
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Trihalomethane reduction in drinkable water by controlled chlorination and use of hydrogen peroxide
The reduction of trihalomethane (THM) formation in the water treatment process by a controlled chlorination of ammonia and successive quenching with hydrogen peroxide has been studied. The optimum values of the process parameters have been determined with a calculation programme that makes use of the kinetic constants determined with the water to be treated. The obtained data have been verified ...
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The relationship between chlorine consumption and trihalomethane formation from hydrophobic and transphilic fractions: a comparative study between two dams of east Algeria
In Algeria, the use of chlorine in drinking water treatment is a widespread practice. When chlorine combines with natural organic matter (NOM), it forms various chlorine by-products such as trihalomethanes (THMs). In this work, we studied the relationship between chlorine consumption and THM formation, by chlorination of hydrophobic and transphilic (TRS) fractions. We compared the kinetic ...
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Study of the effect of pipe materials and mixing phenomenon on trihalomethanes formation and diffusion in a laboratory-scale water distribution network
The objective of this study was to evaluate the factors that affect the formation and diffusion of disinfection by-products, especially trihalomethanes (THM), in a laboratory-scale water distribution network constructed with three different pipe materials. Sampling locations were chosen on the basis of residence time, pipe material and mixing zone. Water samples were collected and analyzed ...
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