The objective of the study was to compare the trihalomethanes (THMs) produced from ferrate with hypochlorite and to determine how different the THM production would be for a given degree of disinfection (3 log reduction in Heterotrophic Plate Count (HPC)). Different water samples were collected from Lake Claire, Atlantic Ocean, and secondary effluent from an advanced wastewater treatment plant. THM formation was determined using a standard assay over 7 days at room temperature. In addition samples were tested for Total Coliform Escherichia coli (TC/E.coli), and heterotrophic bacteria using HPC by spreadplating on R2A agar. Dissolved organic carbon (DOC) was measured as well. Dosages of 2, 5, and 10 ppm of hypochlorite and ferrate were used for Lake Claire and Atlantic Ocean water, while 1, 2, and 5 ppm dosages were used for wastewater treatment effluent. Ferrate resulted in 48.3% ± 11.2% less THM produced for the same level of disinfection (i.e. approximately 3 logs reduction in HPC). Oxidation of DOC was relatively small with a 6.1 to 11.6 % decrease in DOC being observed for ferrate doses from 2 to 10 mg/L. Free chlorine oxidation of DOC was negligible.

Ferrate (VI) has been studied as an alternative chemical to disinfect water and wastewater in recent years. The disinfection effectiveness of two different wet oxidation ferrate (VI) synthesis formulas in wastewater and Econlockhatchee River water was evaluated. Ferrate (VI) is synthesized by addition of ferric chloride to a mixture of sodium hydroxide and calcium hypochlorite (refer to U.S. Patent 6,790,429). One ferrate (VI) synthesis formula uses below the stoichiometric requirement of hypochlorite (Low Chlorine Formula) while the other ferrate (VI) synthesis formula uses more than the stoichiometric requirement of hypochlorite (Standard Chlorine Formula). For applications requiring low chlorine residual effluent quality, the Low Chlorine Formula intuitively is a more suitable disinfectant than the Standard Formula. For applications where chlorine residual is of little or no significance, the Standard Formula is logically a more suitable disinfectant due to lower production cost and production of higher ferrate (VI) concentrations than the Low Chlorine Formula. The total chlorine concentration, unfiltered and filtered ferrate (VI) concentration, and dissolved organic carbon concentration before and after treatment using both ferrate (VI) formulas in wastewater and Econ River water was measured at a contact time of 30 minutes. Disinfection capabilities were measured by comparing the quantity of Heterotrophic bacteria, Total Coliform, Escherichia coli, and Enterococcus bacteria pre-ferrate (VI) to post-ferrate (VI) at dosages of 2, 4, and 7.5 mg/L as ferrate (VI) using both ferrate (VI) formulas. The rate of disappearance of both ferrate (VI) formulas in wastewater at an unadjusted pH and pH of 6.0-6.35 was determined. In addition the total oxidant absorbance and total chlorine concentration were measured over a 30-minute period. Both ferrate (VI) formulas were effective at inactivating Total Coliform, E. Coli, Enterococcus, and heterotrophic bacteria at a 30-minute contact time and lowering DOC concentrations in Econlockhatchee River water and secondary wastewater. The Standard Formula demonstrated better disinfection at lower dosages than the Low Chlorine Formula. In both ferrate (VI) formulas, there was a presence of an instantaneous demand of ferrate (VI) and a first-order reaction rate of ferrate (VI) over 30 minutes. The chlorine residual of 7.5 mg/L ferrate (VI) dose in wastewater at a 30-minute contact time was 0.2 to 0.6 mg/L Cl2 for the Low Chlorine Formula and 0.8 to 1.4 mg/L Cl2 for the Standard Formula. These experiments indicate that both ferrate (VI) formulas can serve as effective environmentally friendly disinfectants for wastewater and Econ River water.

The purpose of this research was to investigate the relationship between watershed land use and seasonal changes on THM-formation potential from the waters of four streams located in northern Virginia. Specific objectives were to observe the effect of impoundment on downstream THM precursor concentrations and to evaluate the molecular-size distributions of THM-precursors in stream waters as to the influence of seasonal changes, storm events, and watershed land use. Raw water samples were collected from October 1989 through May 1990 during baseflow and storm conditions. The samples were fractionated through 500, 1000, 5000, 10000, and 30000 dalton ultrafilters and were then chlorinated to determine the THM-formation potential based on the total organic concentration of the water fraction. From the data collected, it was shown that seasonal changes influenced the TOC and THM-precursor loadings in runoff from the watersheds. Fall runoff from Broad Run contributed the highest mass loading. Impoundment was seen to increase the amount of THM precursors downstream of Lake Manassas on Broad Run with the largest difference observed during the fall event. The more-rural watersheds draining into Broad Run contributed the most TOC and THM precursors during the fall runoff event, while the more-urban watersheds (Bull Run and Holmes Run) contributed more TOC and THM precursors in the winter and spring runoff. / Master of Science

The major objectives of this study were to investigate the effects of seasonal changes in Lake Manassas and its watershed (late winter to late summer), the impoundment of Broad Run, and the stratification of Lake Manassas on trihalomethane (THM)-precursors in Broad Run, upstream and downstream of the reservoir, and in Lake Manassas. An additional objective was to determine the molecular-size distributions of the dissolved organic carbon, and the THM precursors of the organic carbon pool in Lake Manassas during stratification. Raw water samples were collected from March through August on Broad Run immediately upstream of the reservoir, at two sites in the reservoir-- one approximately 0.27 miles from the dam and the second, at a more central location, 0.73 miles from the dam, and on Broad Run 2.81 miles below the dam. During stratification two samples were collected from each lake site-- one from the epilimnion, and the second from the hypolimnion. All of the samples were size fractionated by ultrafiltration and chlorinated for determination ofTHMFP. The differences in THMprecursor characteristics were determined by assessing the differences in the total organic carbon (TOC) concentrations and THM-formation potentials (THMFPs) of the various size fractions. The TOe and THM concentrations generally increased from late winter to late summer at all stations. The concentrations in Lake Manassas and in Broad Run below the dam were consistently higher than those observed in Broad Run upstream of the lake, indicating that impoundment causes an increase in levels of THM precursors. In addition, during stratification higher THM yields were produced by the predominantly low-molecular-weight precursors « 5,000) in the epilimnion of Lake Manassas, while the predominantly high-molecular-weight precursors (> 5,000 daltons) were low-yielding-THM precursors. / Master of Science

A study was undertaken to evaluate the effectiveness of alum coagulation, permanganate and chlorine dioxide preoxidation, and powdered activated carbon pretreatment for the removal of trihalomethane (THM) precursors from the Po River, the Ni River and the Ni River Reservoir waters in eastern Virginia. The effects of temperature and storage were also studied. Samples were collected on two occasions and were analyzed for total organic carbon (TOC), THM-formation potential (THMFP), color, UV-absorbance and pH. Samples were then treated in a manner similar to that ina typical water treatment plant by bench-scale jar tests and reanalyzed for TOC, THMFP, color and UV-absorbance. The results indicate that the THMFPs of both Po and Ni River waters were high. Alum coagulation at pH 6.0 reduced TOC by as much as 48 percent while THMFP reductions averaged 63 percent. Permanganate preoxidation at dosages as high as 2.0 mg/L reduced THM precursors by less than 14 percent. Powdered activated carbon at 10 to 20 mg/L reduced THM precursors by less than four percent. Application of 2 mg/L chlorine dioxide reduced THM<-precursors by eight percent over what could be achieved by alum coagulation alone. A major conclusion was that treatment of the Po River by conventional measures to meet existing and future drinking water standards for THMs would be difficult, if not impossible. / Master of Science

O presente trabalho teve como objetivo avaliar a eficiência de pós-filtros adsorvedores constituídos de Carvão Ativado Granular (CAG) na remoção de compostos orgânicos precursores e na formação de subprodutos da desinfecção, em particular dos trialometanos (THM) na Estação de Tratamento de Água Alto da Boa Vista (ETA ABV), abastecida por reservatórios de água bruta com elevado grau de eutrofização. Os ensaios foram conduzidos em ETA Piloto composta por tanque de reservação de água filtrada, ozonizador, tanque de reservação de água ozonizada e 4 pós-filtros adsorvedores, sendo duas unidades dotadas de CAG de origem mineral e duas unidades dotadas de CAG de origem vegetal. Os filtros foram operados em paralelo, sendo que duas colunas foram alimentadas com água filtrada da ETA ABV (Filtro F3 CAG de origem mineral e Filtro F4 CAG de origem vegetal) e as outras duas alimentadas com água filtrada e ozonizada (Filtro F1 CAG de origem mineral e Filtro F2 CAG de origem vegetal). A avaliação da remoção de compostos orgânicos precursores e formação de subprodutos da desinfecção foi feita através de análises de carbono orgânico total (COT), UV-254 nm e formação de THM. A análise dos resultados gerados de julho de 2007 a dezembro de 2008 permitiu concluir que 93% do THM é formado nas primeiras 24 horas de contato da amostra com o cloro, simulando a pós cloração e pós alcalinização da ETA ABV. O processo de oxidação por ozônio não foi efetivo na remoção de THM instantâneo, visto que a média dos 38 valores de THM instantâneo para a água filtrada (17,8 ± 5,6 g/L) foi igual a média obtida para o THM instantâneo na água ozonizada. A remoção de THM pelos filtros de CAG foi mais significativa nos primeiros três meses de operação do sistema, apresentando remoção de 80% para os filtros com CAG de origem mineral e 70% para os filtros com CAG de origem vegetal, a partir do quarto mês de operação do sistema a remoção de THM caiu para um valor médio de 34%, o que mostra uma iminente saturação do leito adsorvedor. Os pós-filtros adsorvedores constituídos de CAG de origem mineral apresentaram melhor comportamento com respeito a remoção de THM e COT quando comparado com os pós-filtros dotados de CAG de origem vegetal. / The main purpose of this work was to evaluate the performance of a Granular Activated Carbon (GAC) post-filter adsorbers in the removal of organic precursors and in the formation of disinfection byproducts, especially trihalomethanes (THM) in Alto da Boa Vista Water Treatment Plant (ABV WTP), which takes raw water from a highly eutrophized reservoirs. The tests was conducted on a Pilot WTP composed of filtered water tank, ozonator, ozonized water tank, and four post-filter adsorbers: two units with mineral GAC media and two units with vegetal GAC media. The filters were operated in parallel, with two columns fed with filtered water from ABV WTP (F3 Filter mineral GAC and F4 Filter vegetal GAC) and the other fed with ozonized water (F1 Filter mineral GAC and F2 Filter vegetal GAC). The evaluation of the removal of organic precursors and the formation of disinfection byproducts was made through analysis of Total Organic Carbon (TOC), UV-254 nm and THM formation. The results generated from July 2007 to December 2008 showed that 93% of THM is formed in the first 24 hours of contact with the chlorine in the sample, simulating the post chlorination and post alkalinization of ABV WTP in samples of filtered water, ozonized water, and post-filter adsorbers effluent. Ozone oxidation process was not effective in removing THM. Was found the same instantaneous THM values in the filtered water (17.8 g/L± 5.6 g/L) and in the ozonized water. During the first three months of post-filter adsorber operation, THM removal efficiencies were around 80% for F1 and F3 (mineral GAC media) and around 70% for F2 and F4 (vegetal GAC media). After four months of operation, THM removal efficiencies decreased to 34% average value, thus indicative of GAC saturation. Regarding THM and TOC removal efficacy, the mineral GAC performed better than the vegetal GAC.

by Lai-nor Cheng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 51-55). / Abstract also in Chinese. / TABLE OF CONTENTS --- p.i / ABSTRACT --- p.v / LIST OF FIGURES --- p.vi / LIST OF TABLES --- p.vii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Water Treatment Process --- p.1 / Chapter 1.2 --- Disinfectants --- p.3 / Chapter 1.3 --- THMs formation --- p.4 / Chapter 1.4 --- Various Guideline Values --- p.6 / Chapter 1.5 --- WHO Guideline Values in 1993 (used in HK) --- p.6 / Chapter 1.6 --- THM-FP --- p.7 / Chapter 1.7 --- Removal Methods --- p.7 / Chapter Chapter 2 --- "Sample Collection, Pretreatment & Storage" --- p.8 / Chapter 2.1 --- Cleaning of Sample Bottles --- p.8 / Chapter 2.2 --- Sample Collection --- p.8 / Chapter 2.3 --- Sample Pretreatment & Storage --- p.8 / Chapter Chapter 3 --- Experimental --- p.9 / Chapter 3.1 --- Analysis Methods --- p.9 / Chapter 3.1.1 --- Sample Preparation Methods --- p.9 / Chapter 3.1.1.1 --- Liquid-liquid Extraction (LLE) --- p.9 / Chapter 3.1.1.2 --- Purge & Trap (P&T) --- p.9 / Chapter 3.1.1.3 --- Static and Dynamic Headspace (HS) --- p.9 / Chapter 3.1.1.4 --- Direct Aqueous Injection --- p.10 / Chapter 3.1.2 --- GC Detectors --- p.10 / Chapter 3.1.3 --- Sensitivity --- p.10 / Chapter 3.2 --- LLE & GC/MS (SIM) --- p.11 / Chapter 3.3 --- Reagents & Apparatus --- p.12 / Chapter 3.3.1 --- Reagents --- p.12 / Chapter 3.3.2 --- Apparatus --- p.12 / Chapter 3.4 --- Procedure --- p.13 / Chapter 3.4.1 --- Pentane Extraction --- p.13 / Chapter 3.4.2 --- Instrument Configuration --- p.14 / Chapter 3.4.3 --- GC Parameters --- p.14 / Chapter 3.4.4 --- MS Parameters --- p.19 / Chapter 3.5 --- Preparation of Standards --- p.19 / Chapter 3.5.1 --- Stock Standard Solution --- p.19 / Chapter 3.5.2 --- Primary Dilution Standard --- p.20 / Chapter 3.5.3 --- Secondary Dilution Standard --- p.20 / Chapter 3.5.4 --- Calibration Standards --- p.20 / Chapter 3.6 --- Validation of the method --- p.21 / Chapter 3.6.1 --- Calibration Graphs --- p.21 / Chapter 3.6.2 --- Recovery & Precision --- p.27 / Chapter 3.6.3 --- Detection Limits --- p.30 / Chapter 3.7 --- Quality Control --- p.30 / Chapter Chapter 4 --- THMs levels and THM-FP of Tapwater --- p.31 / Chapter 4.1 --- Sample Collection Sites in HK --- p.31 / Chapter 4.2 --- Data Acquisition --- p.31 / Chapter 4.3 --- Calculations --- p.31 / Chapter 4.3.1 --- Blank Correction --- p.31 / Chapter 4.3.2 --- Calculation of THMs concentration --- p.31 / Chapter 4.3.3 --- "Mean, Standard Deviation & RSD %" --- p.32 / Chapter 4.4 --- Summary of THMs levels & THM-FP in tapwater of HK --- p.32 / Chapter 4.4.1 --- THMs levels in tapwater of HK --- p.33 / Chapter 4.4.2 --- THM-FP in tapwater of HK --- p.34 / Chapter 4.5 --- THMs levels & THM-FP in the 19 districts of HK --- p.34 / Chapter Chapter 5 --- "THMs levels of Well, Distilled & Mineral water" --- p.42 / Chapter 5.1 --- THMs levels and THM-FP of Well water --- p.42 / Chapter 5.2 --- THMs levels of Distilled water --- p.42 / Chapter 5.2 --- THMs levels of Mineral water --- p.43 / Chapter Chapter 6 --- Removal Methods --- p.44 / Chapter 6.1 --- Heating --- p.44 / Chapter 6.1.1 --- Procedure --- p.44 / Chapter 6.1.2 --- Results --- p.45 / Chapter 6.2 --- Activated Carbon Filter --- p.47 / Chapter 6.2.1 --- Procedure --- p.48 / Chapter 6.2.2 --- Results --- p.48 / Chapter Chapter 7 --- Conclusion --- p.49 / References --- p.51 / Appendix --- p.56 / Chapter A. --- Properties & Toxicity of THMs --- p.57 / Chapter B. --- Collection Date & Time of Tapwater samples & Well water samples --- p.59 / Chapter C. --- THMs levels of Tapwater in the 57 collection sites of HK --- p.62 / Chapter D. --- THM-FP of Tapwater in the 57 collection sites of HK --- p.69 / Chapter E. --- Raw data ofTHMs levels (μg/L) in Tapwater of HK --- p.76 / Chapter F. --- Raw data of THM-FP levels (μg/L) in Tapwater of HK --- p.90 / Chapter G. --- Raw data of THMs concentrations in Well，Distilled & Mineral water --- p.104 / Chapter H. --- Specification of Activated Carbon Filter --- p.106 / Chapter I.(1) --- Mass Spectrum of Chloroform --- p.108 / Chapter (2) --- Mass Spectrum of Chlorodibromomethane --- p.109 / Chapter (3) --- Mass Spectrum of Bromodichloromethane --- p.110 / Chapter (4) --- Mass Spectrum of Bromoform --- p.111

Made available in DSpace on 2016-12-23T14:04:32Z (GMT). No. of bitstreams: 1 Alexandre Demo Agrizzi.pdf: 7003943 bytes, checksum: 32fa12e406ceb8e9b8ef241ea1ee79ed (MD5) Previous issue date: 2011-02-25 / O cloro tem sido utilizado como principal pré-oxidante da matéria orgânica, inativando microrganismos patogênicos que vivem em águas naturais há mais de cem anos. A matéria orgânica encontrada em mananciais superficiais contém substâncias húmicas que podem reagir com o cloro, gerando compostos orgânicos halogenados potencialmente cancerígenos, destacando-se os trialometanos. Os principais trialometanos que se formam são o clorofórmio, o bromodiclorometano, o dibromoclorometano e o bromofórmio, e, a soma das concentrações destes quatro subprodutos é denominada trialometanos totais. Nas estações de tratamento de água (ETAs), a etapa de pré-oxidação com o cloro contribui significativamente para a formação desses compostos. A presente pesquisa teve como objetivo avaliar a formação de trialometanos após o tratamento convencional de água a partir da simulação de quatro rotas distintas em ensaios de bancada (jarteste), além de amostras retiradas diretamente das ETAs envolvidas no estudo. Os trialometanos foram quantificados por cromatografia gasosa com detector de captura de elétrons. Foram coletadas amostras de água bruta de dois mananciais do estado do Espírito Santo (Rio Jucu e Rio Sahy), com cor, absorvância em 254 nm e turbidez diferentes. Foram testados dois oxidantes nas análises: o cloro (na forma de hipoclorito de cálcio) e o permanganato de potássio. Os resultados obtidos mostraram que a formação de trialometanos foi menor quando as amostras de água foram tratadas com permanganato de potássio na etapa de pré-oxidação, quando comparadas com as amostras tratadas com cloro. Resultado semelhante ocorreu no potencial de formação de trialometanos de 24 horas. Em relação ao potencial de formação de sete dias, ambos mananciais mostraram ser capazes de formar compostos precursores dos trialometanos. Concentrações de trialometanos acima do limite permitido pela Portaria do Ministério da Saúde nº 518 (2004) foram detectadas somente nas amostras de água tratada do Rio Sahy / Chlorine has been used as the main pre-oxidation of organic matter, inactivating pathogenic microorganisms that live in fresh water for over one hundred years. The organic matter found in surface waters containing humic substances that can react with chlorine, generating potentially carcinogenic halogenated organic compounds, especially trihalomethanes. The main trihalomethanes that are formed are chloroform, bromodichloromethane, bromoform and the dibromochloromethane, and the sum of the concentrations of these four products is called total trihalomethanes. In water treatment plants (WTP), the stage of pre-oxidation with chlorine significantly contributes to the formation of these compounds. This research aimed to evaluate the formation of trihalomethanes after conventional treatment of water from the simulation of four different routes in bench tests (Jar-test), and specimens removed from the water treatment plants in the study. The trihalomethanes were quantified by gas chromatography with electron capture detector. Samples were collected from raw water from two springs of the state of Espirito Santo (Jucu and Sahy River), with different color, absorbance at 254 nm and turbidity. Two Oxidants were tested in analyses: chlorine (as calcium hypochlorite) and potassium permanganate. The results showed that the formation of trihalomethanes was lower when the water samples were treated with potassium permanganate in the pre-oxidation, when compared with samples treated with chlorine. A similar result occurred in the potential for trihalomethane formation for 24 hours. In relation to the potencial formation of seven days, both springs were shown to be capable of forming compounds precursors of trihalomethanes. Concentrations of trihalomethanes above the limit allowed by the Ordinance of Ministry of Health number 518 were only detected in samples of treated water from the Sahy River

O presente trabalho teve como objetivo avaliar a eficiência de pós-filtros adsorvedores constituídos de Carvão Ativado Granular (CAG) na remoção de compostos orgânicos precursores e na formação de subprodutos da desinfecção, em particular dos trialometanos (THM) na Estação de Tratamento de Água Alto da Boa Vista (ETA ABV), abastecida por reservatórios de água bruta com elevado grau de eutrofização. Os ensaios foram conduzidos em ETA Piloto composta por tanque de reservação de água filtrada, ozonizador, tanque de reservação de água ozonizada e 4 pós-filtros adsorvedores, sendo duas unidades dotadas de CAG de origem mineral e duas unidades dotadas de CAG de origem vegetal. Os filtros foram operados em paralelo, sendo que duas colunas foram alimentadas com água filtrada da ETA ABV (Filtro F3 CAG de origem mineral e Filtro F4 CAG de origem vegetal) e as outras duas alimentadas com água filtrada e ozonizada (Filtro F1 CAG de origem mineral e Filtro F2 CAG de origem vegetal). A avaliação da remoção de compostos orgânicos precursores e formação de subprodutos da desinfecção foi feita através de análises de carbono orgânico total (COT), UV-254 nm e formação de THM. A análise dos resultados gerados de julho de 2007 a dezembro de 2008 permitiu concluir que 93% do THM é formado nas primeiras 24 horas de contato da amostra com o cloro, simulando a pós cloração e pós alcalinização da ETA ABV. O processo de oxidação por ozônio não foi efetivo na remoção de THM instantâneo, visto que a média dos 38 valores de THM instantâneo para a água filtrada (17,8 ± 5,6 g/L) foi igual a média obtida para o THM instantâneo na água ozonizada. A remoção de THM pelos filtros de CAG foi mais significativa nos primeiros três meses de operação do sistema, apresentando remoção de 80% para os filtros com CAG de origem mineral e 70% para os filtros com CAG de origem vegetal, a partir do quarto mês de operação do sistema a remoção de THM caiu para um valor médio de 34%, o que mostra uma iminente saturação do leito adsorvedor. Os pós-filtros adsorvedores constituídos de CAG de origem mineral apresentaram melhor comportamento com respeito a remoção de THM e COT quando comparado com os pós-filtros dotados de CAG de origem vegetal. / The main purpose of this work was to evaluate the performance of a Granular Activated Carbon (GAC) post-filter adsorbers in the removal of organic precursors and in the formation of disinfection byproducts, especially trihalomethanes (THM) in Alto da Boa Vista Water Treatment Plant (ABV WTP), which takes raw water from a highly eutrophized reservoirs. The tests was conducted on a Pilot WTP composed of filtered water tank, ozonator, ozonized water tank, and four post-filter adsorbers: two units with mineral GAC media and two units with vegetal GAC media. The filters were operated in parallel, with two columns fed with filtered water from ABV WTP (F3 Filter mineral GAC and F4 Filter vegetal GAC) and the other fed with ozonized water (F1 Filter mineral GAC and F2 Filter vegetal GAC). The evaluation of the removal of organic precursors and the formation of disinfection byproducts was made through analysis of Total Organic Carbon (TOC), UV-254 nm and THM formation. The results generated from July 2007 to December 2008 showed that 93% of THM is formed in the first 24 hours of contact with the chlorine in the sample, simulating the post chlorination and post alkalinization of ABV WTP in samples of filtered water, ozonized water, and post-filter adsorbers effluent. Ozone oxidation process was not effective in removing THM. Was found the same instantaneous THM values in the filtered water (17.8 g/L± 5.6 g/L) and in the ozonized water. During the first three months of post-filter adsorber operation, THM removal efficiencies were around 80% for F1 and F3 (mineral GAC media) and around 70% for F2 and F4 (vegetal GAC media). After four months of operation, THM removal efficiencies decreased to 34% average value, thus indicative of GAC saturation. Regarding THM and TOC removal efficacy, the mineral GAC performed better than the vegetal GAC.

Thesis submitted in partial fulfilment of the requirements for the degree of MAGISTER TECHNOLOGIAE: CHEMICAL ENGINEERING in the FACULTY OF ENGINEERING at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2013 / This study focused on quantifying two types of internationally regulated contaminants found in drinking water: 1) Trihalomethanes (THMs) and 2) Perfluorinated compounds (PFCs). The first contaminants monitored were THMs, classified as a group of chemicals that are formed along with others during the disinfection of water using liquid chlorine, chlorine dioxide or chlorine gas. Hence, the resulting compounds are called disinfection by-products (DBPs). The disinfectant reacts with natural organic matter in water to form common THMs, which include chloroform (CHCl3 or CF), bromodichloromethane (CHCl2Br or BDCM), dibromochloromethane (CHClBr2 or DBCM) and bromoform (CHBr3 or BF), with chloroform being the most common in chlorinated water systems. The current study has focused on THMs for two primary reasons: 1) THMs have raised significant concern as a result of evidence that associate their presence in drinking water with potential adverse human health effects, including cancer and 2) the levels of THMs in drinking water post-treatment is not monitored regularly in South Africa and thus far, there is inadequate and limited information about their concentration levels for drinking water treatment plants (DWTPs) and distribution stations (DWDSs) of the Western Cape, South Africa before, distribution to various suburbs, including townships. THMs normally occur at higher levels than any other known DBPs and their presence in treated water is a representative of the occurrence of many other DBPs. THMs were quantified in chlorinated drinking water obtained from seven (7) DWTPs, namely; Atlantis, Blackheath, Faure, Brooklands, Steenbras, Voelvlei and Wemmershoek, and one DWDS in Plattekloof. This included determining THMs concentration in tap water collected from various suburbs including townships, to assist local authorities in obtaining information on their concentration and whether or not the presence of residual chlorine and organic matter on post-treatment results has increased THMs at the point of use. THM analysis was performed using liquid-liquid extraction/gas chromatography with electron capture detector (LLE-GC-ECD) analytical process according to the EPA method 501.2, which was used with minor modifications. The instrument operational conditions were as follows: Column → DB5-26, 30 mm, 0.53 mm, 1.0 μm df HP-1 (Agilent Technologies, USA); Carrier gas → Helium at a constant inlet pressure of 15 kPa; Make-up gas → 99.9% Nitrogen gas at 60 L/min; Injector temperature → 40°C; Oven temperature → 270°C and Detector temperature → 300°C. Since natural organic matter (NOM) in raw water is a precursor for THM formation, NOM analysis was performed as total organic carbon (TOC) using Spectroquant TOC test kits. Other drinking water quality parameters analysed were pH, residual free chlorine, conductivity and total dissolved solids (TDS). The average Total THM concentrations detected from seven of the DWTPs, including the DWDS, ranged from 26.52 μg/L (for Plattekloof) to 32.82 μg/L (for Brooklands), with the observed concentrations being comparable. The average chloroform concentrations were the highest in all the water samples, ranging from 11.74 μg/L (for Plattekloof) to 22.29 μg/L (for Voelvlei), while DBCM had the lowest concentration. The only DWTP that was not comparable with the seven DWTPs was Atlantis, with the highest average TTHM concentration of 83.48 μg/L and a chloroform concentration of 46.06 μg/L. From the tap water samples collected from 14 Western Cape suburbs, the average TTHM concentrations ranged from 5.30 ug/L (for Mandalay) to 13.12 μg/L (for Browns Farm, Philippi), and all these concentrations were lower than the TTHM concentrations detected in the water samples from the DWTP. Overall, the average total THM and individual THM species concentrations were below the recommended SANS 241:2011 and WHO drinking water guideline limits. This included the observed pH (6.39 to 7.73), residual free chlorine (0.22 to 1.06 mg/L), conductivity (121 to 444 μS/cm), TDS (93.93 to 344.35 mg/L) and TOC (0.38 to 1.20 mg/L). All these water quality parameters were within the specification limits stipulated in SANS 241. However, the average residual free chlorine concentration for Atlantis was very low (0.06 mg/L), which was below the WHO minimum residual free chlorine concentration guideline value of 0.2 mg/L for a distribution network – an indication that suggested the need for a re-chlorination station prior to distribution to households. Low chlorine content might result in the formation of unwanted biofilms in the distribution network, thus reducing the organoleptic properties of the water. Additionally, there was no direct link between several water quality parameters quantified (i.e. pH, TOC and water temperature) to TTHM formation. However, a high chlorine dose was observed to result directly in a higher concentration of chloroform in treated water prior to distribution. The second contaminants monitored were Perfluorinated compounds (PFCs), which are non-biodegradable, persistent and toxic organic chemicals known for their ability to contaminate environmental matrices, including drinking water sources. In recent years, many researchers considered it essential to identify and quantify PFC levels in drinking water worldwide with the main focus being on the two most abundant PFCs; namely Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS). Their toxic effects to human health, plants and wildlife were also evaluated, classifying them as possible carcinogens. We know from the literature reviewed that, although the presence of PFCs in drinking water has been documented worldwide, there is limited information about their presence specifically in South African drinking water sources, even about less studied PFCs such as Perfluoroheptanoic acid (PFHpA), Perfluorododecanoic acid (PFDoA), Perfluorononanoic acid (PFNA), Perfluoroundecanoic acid (PFUA), Perfluorodecanoic acid (PFDeA) and the well-known PFOA including PFOS. Although several other PFCs have been detected in water sources and reported in various studies, the USEPA only issued drinking water guideline limits for Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) of 400 ng/L and 200 ng/L, respectively, with no mention of the other PFCs. However, these PFCs have similar properties to those of PFOA and PFOS as they have been shown to impose similar detrimental health effects on human health. This study thus focused on the detection of PFCs in both raw and treated drinking water in the Western Cape DWTPs such as Atlantis, Blackheath, Faure, Brooklands, Steenbras, Voelvlei and Wemmershoek, and one DWDS in Plattekloof. Water samples (raw and treated water) used in this study for PFC analysis were collected in 2L polypropylene screw capped bottles. PFC analysis was performed in four sample batches for each location collected through the period of October to December 2012 (summer). PFCs were analysed in accordance with a modified EPA method 537, which entails solid phase extraction (SPE) followed by analysis using a liquid chromatography/tandem mass spectrometer (LC/MS/MS). The slight modification was with the water sample volume used for extraction, which was increased from 250 mL to 500 mL. The instrument used was an HPLC - Ultimate 3000 Dionex HPLC system and MS model - Amazon SL Ion Trap, with the following MS/MS operational conditions and Ion mode: MS Interface → ESI; Dry temp → 350C; Nebulizing pressure → 60 psi; Dry gas flow → 10 L/min; Ionisation mode → negative; capillary voltage → +4500V; End plate offset → −500V while the separation column was a Waters Sunfire C18, 5 μm, 4.6 × 150 mm column (Supplier: Waters, Dublin, Ireland) with an operational temperature of 30C. From the results obtained in this study, seven different PFCs (i.e. PFHpA, PFDoA, PFNA, PFUA, PFDeA, PFOA and PFOS), were detected in raw and treated water with PFOA and PFOS being the least detected PFCs as they were detected only in raw water (PFOA) from Faure, as well as raw and treated water (PFOS) from Brooklands. The highest concentration observed in treated water was for PFHpA, which was quantified at a maximum average concentration of 43.80 ng/L (Plattekloof). The maximum average concentrations of other PFCs detected were as follows: PFDoA - 4.415 ng/L for Faure raw water; PFNA - 2.922 ng/L for Plattekloof outlet; PFUA - 7.965 ng/L for Brooklands treated water and PFDeA - 2.744 ng/L for Faure raw water. Another observation from the results was that the concentration of the majority of the PFCs detected in treated water was higher than that quantified in raw water, suggesting possible contamination by materials used during water treatment. In conclusion, THMs detected in treated water from various DWTPs and one DWDS in the Western Cape met the required local and international drinking water quality guidelines, while the presence of PFOS, PFOA, PFHpA, PFDoA, PFNA, PFUA and PFDeA in treated water requires that local water professionals continue to monitor their presence to ensure that measures for their reduction are in place. Furthermore, the National standards (SANS 241) for municipal drinking water guidelines must be updated to include the monitoring of PFCs, including the lesser known and less studied PFCs such as PFHpA, PFDoA, PFNA, PFUA and PFDeA.