Humic Substances as Precursors for Potentially Harmful Disinfection By-Products

1999 ◽  
Vol 40 (9) ◽  
pp. 25-30 ◽  
Author(s):  
P.C. Singer
Keyword(s):  
Drinking Water ◽  
Carbon Content ◽  
Human Health ◽  
Humic Substances ◽  
Organic Material ◽  
Haloacetic Acids ◽  
Aromatic Carbon ◽  
Ultraviolet Absorbance ◽  
Natural Organic Material ◽  
By Products

During the chlorination of drinking water, chlorine reacts with natural organic material to produce disinfection by-products, such as trihalomethanes and haloacetic acids, which are believed to be harmful to human health. The formation of these by-products is related to the aromatic carbon content of the water, for which specific ultraviolet absorbance serves as a useful surrogate. Because humic substances in water tend to have a higher aromatic carbon content and a higher specific ultraviolet absorbance than non-humic substances, they produce greater levels of disinfection by-products.

Risk assessment of haloacetic acids in the water supply of Tehran, Iran

2016 ◽  
Vol 17 (4) ◽  
pp. 958-965 ◽  
Author(s):  
Mahboobeh Ghoochani ◽  
Noushin Rastkari ◽  
Behzad Heibati ◽  
Mohammad Ghanbari Ghozikali ◽  
Maryam Zare Jeddi ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Human Health ◽  
Environmental Protection Agency ◽  
Tap Water ◽  
Human Health Risk ◽  
The United States ◽  
Haloacetic Acids ◽  
Health Concern ◽  
By Products

Disinfection by-products are compounds occurring in drinking water as a result of reactions between disinfectants and impurities in raw water, and their occurrence has been a public health concern for the last four decades. Haloacetic acids (HAAs) are one of the major by-products of chlorination. The concentration and variation of HAAs was monitored in 540 samples taken from tap water in six water and wastewater districts of Tehran, Iran. Seasonal variation indicated that natural organic matter and HAA levels were much higher in the spring and fall seasons. The concentrations of HAAs in drinking water samples varied with water sources. They were higher in drinking water obtained from surface water. In this study, the analysis method of human health risk assessment with regard to exposure to HAAs by drinking water in Tehran was based on the United States Environmental Protection Agency (USEPA) guideline. It was found from these studies that the risk to human health appears to be negligible.

scholarly journals Formation of DBPs in the drinking eater of Athens, Greece: a Ten-Year study

2013 ◽  
Vol 7 (1) ◽  
pp. 106-118
Keyword(s):  
European Union ◽  
Drinking Water ◽  
Water Treatment ◽  
Chloral Hydrate ◽  
Haloacetic Acids ◽  
The European Union ◽  
Water Treatment Plants ◽  
Naturally Occurring ◽  
By Products ◽  
The Eu

The formation of Disinfection By-Products (DBPs) in drinking water results from the reaction of chlorine or other disinfectants added to the water with naturally occurring organic materials, and has raised concerns during the last decades because these compounds are harmful for human health. During the present work, the formation of different categories of DBPs was investigated in four water treatment plants (WTP) using chlorine as disinfectant, and in selected points of the distribution network of Athens, Greece, which is supplied from these four WTP, during a period of ten years. The concentrations of DBPs were generally low and the annual mean concentrations always well below the regulatory limit of the European Union (EU) for the total trihalomethanes (TTHMs). The haloacetic acids (HAAs) have not been regulated in the EU, but during this investigation they often occurred in significant levels, sometimes exceeding the levels of TTHMs, which highlights the importance of their monitoring in drinking water. Apart from THMs and HAAs, several other DBPs species were detected at much lower concentrations in the chlorinated waters: chloral hydrate, haloketones and, in a limited number of cases, haloacetonitriles.

scholarly journals Biodegradation of six haloacetic acids in drinking water

2007 ◽  
Vol 6 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Walt Bayless ◽  
Robert C. Andrews
Keyword(s):  
Drinking Water ◽  
Trichloroacetic Acid ◽  
Distribution Systems ◽  
Water Distribution ◽  
Haloacetic Acids ◽  
Health Concern ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Monobromoacetic Acid ◽  
By Products

Haloacetic acids (HAAs) are produced by the reaction of chlorine with natural organic matter and are regulated disinfection by-products of health concern. Biofilms in drinking water distribution systems and in filter beds have been associated with the removal of some HAAs, however the removal of all six routinely monitored species (HAA6) has not been previously reported. In this study, bench-scale glass bead columns were used to investigate the ability of a drinking water biofilm to degrade HAA6. Monochloroacetic acid (MCAA) and monobromoacetic acid (MBAA) were the most readily degraded of the halogenated acetic acids. Trichloroacetic acid (TCAA) was not removed biologically when examined at a 90% confidence level. In general, di-halogenated species were removed to a lesser extent than the mono-halogenated compounds. The order of biodegradability by the biofilm was found to be monobromo > monochloro > bromochloro > dichloro > dibromo > trichloroacetic acid.

Coagulation of natural organic material: effects on speciation of halogenated disinfection by-products

2004 ◽  
Vol 4 (4) ◽  
pp. 245-250 ◽  
Author(s):  
P.C. Singer ◽  
L. Liang
Keyword(s):  
Organic Material ◽  
Similar Degree ◽  
Haloacetic Acid ◽  
The Us ◽  
Natural Organic Material ◽  
By Products

A recent paper by Liang and Singer showed that haloacetic acid (HAA) precursors were removed by coagulation to a greater degree than trihalomethane (THM) precursors. Furthermore, they showed that coagulation generally removed more trihaloacetic acid precursors than THM precursors but removed dihaloacetic acid precursors and THM precursors to a similar degree. The objectives of this current study were to compare the findings by Liang and Singer to those of three other investigations conducted in the senior author's laboratory to demonstrate the extent to which coagulation removes THM and HAA precursors, and to contrast the removal of dihaloacetic acid and trihaloacetic precursors by coagulation. These other studies were conducted on seventeen other waters from across the US.

scholarly journals Evaluation of Human Health Risks Associated with Exposure to Disinfection by-Products (Dbps) in Drinking Water of Wassit Province Southeast Iraq

2018 ◽  
Vol 15 (3) ◽  
pp. 270-277
Author(s):  
Baghdad Science Journal
Keyword(s):  
Drinking Water ◽  
Human Health ◽  
Human Health Risk ◽  
World Health ◽  
Mean Values ◽  
Guideline Value ◽  
Exposure Routes ◽  
Health Organization ◽  
Risk Of Cancer ◽  
By Products

The toxicological risks and lifetime cancer risks associated with exposure to disinfection by-products (DBPs) including Halloacetic acids (HAAs) and trihalomethanes (THMs) compounds by drinking water in several districts in Wassit Province were estimated. The seasonal variation of HAAs and THMs compounds in drinking water have indicated that the mean values for total HAAs (THAAs) and total THMs (TTHMs) ranged from 43.2 to 72.4 mg/l and from 40 to 115.5 mg/l, respectively. The World health organization index for additive toxicity approach was non-compliant with the WHO guideline value in summer and autumn seasons and this means that THMs concentration has adverse toxic health effects. The multi-pathway of lifetime human health risk of cancer credited to THMs and HAAs in drinking water via three exposure routes for THMs and only one exposure route for HAAs was evaluated and found to be 6.13×10-4 and 1.78×10-4 respectively and these values were higher than the US.EPA range of concern limit of 1×10-6. The risk ratio of THAAs to TTHMs was 3.44. Also, the highest cancer risk was recorded for BDCM followed by DBCM, CF, TCAA, DCAA, and BF.

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