Evaluation of formation and health risks of disinfection by-products in drinking water supply of Ggaba waterworks, Kampala, Uganda (original) (raw)
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INTERNATIONAL SYMPOSIUM ON GREEN AND SUSTAINABLE TECHNOLOGY (ISGST2019), 2019
The use of chlorine as the control of waterborne infectious diseases has been successfully used. However, the use of chlorine poses potential health risks due to the formation of disinfection by-products (DBPs) such as trihalomethanes (THMs). The purpose of this article is to provide a general understanding of disinfection by-products (DBPs), especially in the aspects of the formation of DBPs in treated drinking water. This paper also discusses the factors affecting the formation of DBPs in drinking water and the potential health risk to the user. In this review, the study of DBPs in Perlis, Malaysia are emphasized.
Disinfection of Drinking Water and Trihalomethanes: A Review
Trihalomethanes (THMs) as the main disinfection by-products (DBPs) during the last four decades have concerned the public and scientific opinion for the possible carcinogenic effect on human health. The purpose of this paper is to investigate the disinfection of drinking water, types of DBPs and the formation of THMs. The formation of THMs during the chlorination process represents a serious health problem, as they significantly increase the possibility of the risk of several types of cancers. In this article we are discuss the health risk imposed by THMs, considered toxic and possible carcinogenic as well as mutagenic to the human body. Thus, their elimination and regular monitoring is imperative. In this article we present the removal technologies for the THMs and their precursors. This article also provides the basic information related to the analytical methods for the determination of the THMs.
Journal of Environment and Earth Science, 2015
Ahmadu Bello University (ABU) drinking water treatment plant (ABUDWTP) uses calcium hypochlorite to supply chlorine in disinfecting drinking water supply to the university community. Between 2008 and 2010, 252 water samples were taken in duplicates along the treatment and distribution systems of ABUDWTP with ammonium chloride as de-chlorinating agent in accordance with United States Environmental Protection Agency (USEPA) Method 551.1. This was aimed at determining the concentrations of trihalomethanes (THMs) disinfection by-products (THM-DBPs) and the degree of wholesomeness of the drinking water supplied. The THM concentrations in the samples were analysed using Agilent Gas Chromatograph after preliminary extraction with methyl tert-butyl ether (MTBE). Samples' analyses identified six THMs-two additional to the regulated four. These are Dichlorobromomethane and 1,2-Dibromomethane here classified as emerging THM disinfection by-products (EmerTHM-DBPs). Measured total mean concentration of the regulated THMs (TRegTHM-DBPs) at house level was 1.0601E-02±1.6625E-05 mg/L as against 9.9704E-02±6.4706E-05 mg/L for total mean emerging THM-DBPs (TEmergTHM-DBPs). This TRegTHMs concentration indicates house level water is within acceptable limits of international standards despite being above the national permissible limit of 0.001 mg/L. Though not considered under exiting drinking water quality index TEmergTHM-DBPs were found to account for over 90% of gross THM-DBPs (GTTHM-DBPs) at each sampling stage. These TEmergTHM-DBPs could create health complications on consumers as they are either suspected carcinogens or recognised to increase the risk of carcinogenicity and mutagenicity in humans. Both are irritants of several body tissues and are implicated in several health abnormalities including reproductive and fertility disorders as well as liver and kidney damage. In view of these likely supplementary health burdens, this paper advocates additional stricter monitoring and control of these emerging THM-DBPs as they will most probably compound and increase the frontline of health challenges from chlorine disinfected ABU drinking water supply to its consumers.
Determination of Trihalomethanes in Raw and Treated Water Supply to a Local City in Zimbabwe
Concentration levels of trihalomethanes in raw and treated water for the city of Gweru were determined by solvent extraction followed by gas chromatograph detection. The trihalomethanes found were chloroform, dichlorobromomethane, dibromochloromethane and bromoform. Chloroform was the most abundant trihalomethane with concentration levels ranging from 3.70 µg/L to 45.89µg/L. The concentration levels of trihalomethanes increased with increasing distance from the chlorination point . Total trihalomethane concentration in raw water ranged from nondetectable levels to 18.13µg/L and in treated water ranged from 6.83µg/L to 145.50 µg/L. A slight increase in concentration levels of trihalomethanes was shown in warmer months with the highest concentration level of 145.80 µg/L being recorded in September. Generally, the concentration levels obtained were lower than the maximum permissible limits of 460µg/L set by World Health Organisation (WHO).
IJERT-DETERMINATION OF TRIHALOMETHANES IN RAW AND TREATED WATER SUPPLY TO A LOCAL CITY IN ZIMBABWE
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/determination-of-trihalomethanes-in-raw-and-treated-water-supply-to-a-local-city-in-zimbabwe https://www.ijert.org/research/determination-of-trihalomethanes-in-raw-and-treated-water-supply-to-a-local-city-in-zimbabwe-IJERTV2IS2549.pdf Concentration levels of trihalomethanes in raw and treated water for the city of Gweru were determined by solvent extraction followed by gas chromatograph detection. The trihalomethanes found were chloroform, dichlorobromomethane, dibromochloromethane and bromoform. Chloroform was the most abundant trihalomethane with concentration levels ranging from 3.70 µg/L to 45.89µg/L. The concentration levels of trihalomethanes increased with increasing distance from the chlorination point. Total trihalomethane concentration in raw water ranged from nondetectable levels to 18.13µg/L and in treated water ranged from 6.83µg/L to 145.50 µg/L. A slight increase in concentration levels of trihalomethanes was shown in warmer months with the highest concentration level of 145.80 µg/L being recorded in September. Generally, the concentration levels obtained were lower than the maximum permissible limits of 460µg/L set by World Health Organisation (WHO).
Factors Influencing the Formation of Trihalomethanes in Drinking Water Supplies
Presence of Trihalomethanes (THMs) in drinking water has become a major concern worldwide because of their adverse health impacts. These THMs are formed due to reaction of chlorine with natural organic matter and other precursors found in water. This study aims at establishing the concentration range of THMs in drinking water supplies. The concentrations of THMs (274-511 μg/l) found to be much higher than the prescribed USEPA standards and WHO guidelines. The study also revealed that amongst various THMs, contribution of chloroform was highest (93.07-98.9%) followed by other THMs. Correlation study delineated that TOC, DOC and UV254 are the main organic precursors responsible for the formation of THMs in drinking water. Bromoform was not detected in the water which can be attributed to the absence of bromide in raw water. Pearson correlation matrix revealed that pH and temperature have also significant and definite correlation (r = 0.767 and 0.945, respectively) with the THMs.
2016
In Iraq the surface water is one of the important sources of potable water. Water chlorination is the disinfection method most widely used, having however the disadvantage of producing Trihalomethanes (THMs) as secondary compounds. THMs formation is influenced by the raw water composition and chlorine from the disinfection process.This research estimated the THMs concentration and the changes in Purification Water Plants and surrounding Feeding Stations. The duration of these monitoring tasks was three months (February, April and August) in 2014. There were forty eight water samples were collected from four Water Purification Water Plants (Qadisiyah, Karama, Al-Wethba and Al-Wehda) and from four Feeding Stations (Karrada, Bab-Almuadam, Utaifiyya and Qadisiyah). The total concentration of THMs ranged between (64 – 84.5 ppb), (68 – 92.6 ppb) and (74.3 –105.9 ppb) at Water Purification Water Plants in February, April and August, respectively. While the total concentration of THMs range...
The study assessed the levels of trihalomethanes in drinking water from Ahmadu Bello University treatment plant between 2008 and 2010. Two hundred and fifty-two (252) samples of processed drinking water at various stages of treatment and distribution were taken in duplicates. In accordance with the United States Environmental Protection Agency (USEPA) Method 551.1, samples were taken using ammonium chloride as de-chlorinating agent and methyl tert-butyl ether (MTBE) as solvent extractant during samples’ analyses. Concentrations of the four regulated trihalomethanes (trichloromethane – CHCl3-, tribromomethane – CHBr3 -, dibromochloromethane and bromodichloromethane) were analysed using Agilent gas chromatograph (GC) model 19091-413 with Chemstation software. From the study only tribromomethane was detected immediately after chlorination while trichloromethane and bromodichloromethane were detected at storage in the booster station. Peak values of these analytes were also obtained at the booster station. Maximum permissible levels of the analytes are set only as total mean trihalomethanes. In the study, total mean trihalomethane (TTHMs) values ranged from zero in the raw water and water after sedimentation to 1.3140E-02±1.4614E-05 mg/L in the booster station water samples but decreased to 1.0601E-02±1.6625 mg/L at household level. These values exceeded the national limit of 0.001 mg/L but fall within acceptable limits under the United States Environmental Protection Agency (USEPA), European Union (EU), Canadian and World Health Organization (WHO) standards. Statistically, the observed mean values showed some significant differences and also had significant relationships with some of the sampled waters’ physical parameters such as pH, residual chlorine, total organic carbon and temperature. Furthermore, the study highlights total dissolved solids and nitrates as additional contributors to total mean trihalomethanes in drinking water sampled but found seasonal influence to be insignificant despite significant temperature influence. As these trihalomethanes (THMs) are implicated in carcinogenicity and mutagenicity their presence in conventionally treated drinking water creates serious health challenges.
Disinfection by-products and extractable organic compounds in South African tap water
2008
An important step in urban purification of drinking water is disinfection by e.g. chlorination where potential pathogenic micro-organisms in the water supply are killed. The presence of organic material in natural water leads to the formation of organic byproducts during disinfection. Over 500 of these disinfection by-products (DBPs) have been identified and many more are estimated to form during the disinfection step. Several DBPs such as trihalomethanes (THMs), which is carcinogenic, poses serious health risks to the community. There is very few quantitative data available which realizes the actual levels of these compounds present in drinking water. The levels of four THMs present in drinking water were measured. It included chloroform, bromodichloromethane, chlorodibromomethane and bromoform. Although microbiological parameters are considered to get more attention than disinfection by-products, the measurement of the levels of these compounds in South-African drinking water is essential together with establishing minimum acceptable concentration levels. The target range for total trihalomethanes (TTHMs) established by the US EPA at the end of 2003 is 0-0.08ug/mL. The aim of this paper is to create an awareness of the problem as well as presenting preliminary results obtained with the method of analysis. Preliminary results indicate that urgent attention must be given to the regulation and monitoring of DBPs in South African drinking water.