• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.122-128
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• 2000

This study was carried out to survey trihalomethane formation potential(THMFP) levels in drinking underground water and to examine its characteristics in Kunsan area. In drinking underground water, THMFP increased with the lapse of reaction time and 96hr-THMFP was the highest of THMFPs examined. In many cases, 24hr-THMFP, 48hr-THMFP and 96hr-THMFP reflected 2hr-THMFP level due to the largest composition ratio of CHCl$_3$ decreased with the lapse of reaction of CHCl$_3$ among THM individuals. CHCl$_3$ was mostly formed within early 2hour of reaction time, but CHClBr$_2$ and CHBr$_3$ continued their formation until 48 hour. Accordingly, the composition ratio of CHCl$_3$ decreased with the lapse of reaction time while that of total Br derivatives increased. 96hr-THMFPs of drinking underground water in Kunsan area ranged from N.D.(not detected)~98.80 $\mu\textrm{g}$/$\ell$ and, in general, those of western section of Kunsan area, closer to the coast, showed the higher tendency. But, from their large range of variance, it could be considered that THMFPs differ individually even in the same section depending on such factors as the difference of water stream, circumstances of management and so on. All the parameters for water quality examined(pH, KMnO$_4$ consumption;UV$_{254}$ , TOC. Cl$^{[-10]}$ ) showed very week corelation with 96h-THMFP.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.378-381
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• 2009

The purpose of this research is the evaluation of removal efficiency of THMFP in BAC. The changes of four types of THMFP and total THMFP were examined in the influent and effluent of BAC filter from March to December in 2008. It turned out that the amounts of brominated THMFP were obviously higher in winter and autumn compared to the spring and summer, which also resulted in an increase of the total-THMFP levels during winter and autumn. In addition, long-term running of BAC filter shows the good removal function of chloroform formation potential, but not brominated THMFP; with further bromination, this function was declined, as it shows the formation of bromoform in BAC filter during October and December. These results were caused by changing of the proportion of $Br^-$/DOC.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1099-1107
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• 2005

The purpose of this study was to find the transformation of organic matter as well as chlorine by product formation potential with ozone dosage. The removal percents of $UV_{254}$ and DOC were $23%{\sim}65%$ and $2%{\sim}15%$ and THMFP and HAAFP were $17%{\sim}52%$ and $9%{\sim}29%$ respectively at $0.5{\sim}3\;mgO_3/mgDOC$ ozone dosage. The hydrophobic and transphobic organic matter were reduced to $37%{\sim}68%$ and $35%{\sim}64%$, on the other hand the hydrophilir organic matter was increased to $40%{\sim}49%$ at $0.5{\sim}3\;mgO_3/mgDOC$ ozone dosage. The produced THMFP and HAAFP from the hydrophobic and transphilic organic matter were decreased greatly with increasing ozone dosage but these by products were increased in the hydrophilic matter. The produced THMFP and HAAFP per unit DOC were decreased and reactivity was reduced greatly with increasing crone dosage. The removal rate of THMFP per unit DOC was much higher than HAAFP by ozone treatment. The Br-THMFP per unit DOC was much more removed than chloroformFP per unit DOC with increasing ozone dosage. and The removal rate of TCAAFP per unit DOC was increased with increasing ozone dosage but TCAAFP was not affected by ozone treatment. Br-HAAFP was decreased at $1\;mgO_3/mgDOC$ ozone dosage but was not more removed above $1\;mgO_3/mgDOC$ ozone dosage. Br-HAAFP had lower removal effect than Br-THMFP by ozone treatment. The optimal ozone dosage can be determined about $1\;mgO_3/mgDOC$ by considering both disinfection by product formation and economical efficiency.

• Journal of environmental and Sanitary engineering
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• v.19 no.2
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• pp.1-6
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• 2004

In Bok-Jeong water treatment plant, chlorination is the only technique used for disinfection of drinking water. This disinfecting treatment leads to the formation of trihalomethanes (THMs). This study was carried out to investigate the possibility of improving removal efficiency of THM precursor in the conventional water treatment processes by $TiO_2$ photocatalytic oxidation. Removal efficiencies of DOC, $UV_{254}$, THMFP were low in the conventional water treatment processes. With application of $TiO_2$ photocatalyst, DOC, $UV_{254}$, THMFP were reduced more effectively. As the $TiO_2$ photocatalytic reaction time increased, the removal efficiencies of DOC, $UV_{254}$, THMFP were increased. The $TiO_2$ photocatalytic removal efficiencies of DOC, $UV_{254}$, THMFP were increased with increasing $TiO_2$ dosage. However, over 0.6g/l of $TiO_2$ dosage, the efficiency reached a plateau.

• Advances in environmental research
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• v.1 no.3
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• pp.181-189
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• 2012

Trihalomethanes, produced as a result of chlorination of drinking water, are considered a potential health hazard. The trihalomethane formation potential (THMFP) of a raw water source may indicate the maximum trihalomethanes (THMs) that are likely to be produced when chlorine reacts with natural organic matter (NOM) present in the water. A study was conducted to evaluate the THMFP in seven different drinking water sources in the vicinity of Kalpakkam, a rural township, on the east coast of India. Water from seven stations were analysed for THMFP. THMFP was compared with surrogate parameters such as dissolved organic carbon (DOC), ultraviolet absorbance ($UV_{254}$) and bromide. The data showed that THMFP was high in water from open wells as compared to closed bore wells, possibly due to more photosynthetic activity. Proximity to sea, and consequently the levels of bromide, was an important factor that influenced THM formation. THM surrogate parameters showed good correlation with THMFP.

• Journal of Environmental Science International
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• v.19 no.3
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• pp.261-267
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• 2010

The variation of assimilable organic carbon(AOC) concentration at each condition of ozonation was investigated using a model water and drinking water resource. AOC concentration of model raw water and drinking water resource tended to increase at low ozone dose. The maximum AOC concentration was detected when the residual ozone begin to be measured. Also, the AOC concentration increase at pH 8 compared to both pH 6 and 7 while that for pH 9 decreased rapidly. The removal characteristics of trihalomethane formation potential(THMFP) by ozonation was also investigated. Unlike the trend of AOC, the THMFP concentration never increased by ozonation but decreased even at low ozone dosage. From these results, the ozone dosage would be effective to simultaneously decrease both AOC and THMFP.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.84-98
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• 2000

Control of Trihalomethanes(THMs) is a major concern of many water treatment plants. A number of researchers have studied the effectiveness of activated carbon adsorption process in removing THMs or organic halogen compounds. Recently, attention has been paid to the biological activated carbon (BAC) treatment of THM precursors as an alternative to the carbon adsorption treatment because of its effectiveness as well as its low running cost. In this study, changes of THM formation potential(THMFP) and removal of substrates in the SBR effluent were investigated in an attempt to clarify the mechanisms of the decrease/increase of THMFP in the BAC treatment. The increase and decrease of THMFP concentrations were observed in effluents during prolonged operation. When PCP or DBS was feeded as substrate contained in SBR effluent, the THMFPs were easyly removed with TOCs removal. But the case of SBR effluent containing SDS or glycine was introduced, and when microbial growth came to its near steady state, the THMFPs of treated effluents were increased more or less in comparison to those in the influents. Such increases of THMFP coincided with the increase in microbial growth within the activated carbon fiber(ACF) column. In the case of only sucrose was feeded as substrate on ACF colume, THMFP concentrations of effluent were higher than those of influent. The THMFP concentration was significantly increased on inlet part of ACF column, which biomass inhabits abundantly, then they were decreased gradually. These increases mean production of the secondary THM precursors by biological activities, which can be removed by adsorption and biological degradation on ACF column.

• Journal of Korean Society on Water Environment
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• v.38 no.2
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• pp.63-71
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• 2022

This study aimed to maximize the potential of fluorescence 3D excitation-emission matrix (EEM) for predicting the trihalomethane formation potential (THMFP) of DOM with various sources. Fluorescence spectroscopy is a useful tool for characterizing dissolved organic matter (DOM). In this study, differential spectroscopy was applied to EEM for the prediction of THMFP, in which the difference between the EEM before and after chlorination was taken into account to obtain the differential EEM (DEEM). For characterization of the original EEM or the DEEM, the maximum intensities of several different fluorescence regions in EEM, fluorescence EEM regional integration (FRI), and humification index (HIX) were calculated and used for the surrogates for THMFP prediction. After chlorination, the fluorescence intensity decreased by 77% to 93%. In leaf-derived and effluent DOM, there was a significant decrease in the protein-like peak, while a more pronounced decrease was observed in the humic-like peak of river DOM. In general, leaf-derived and effluent DOM exhibited a relatively lower THMFP than the river DOM. Our results were consistent with the high correlations between humic-like fluorescence and THMFP previously reported. In this study, HIX (r= 0.815, p<0.001), FRI region V (r=0.727, p<0.001), humic-like peak (r= 0.827, p<0.001) from DEEM presented very high correlations with THMF P. When the humic-like peak intensity was converted to a logarithmic scale, a higher correlation was obtained (r= 0.928, p<0.001). This finding suggests that the humic-like peak in DEEM can serve as a universal predictor for THM formation of DOM with various origins.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.123-128
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• 2008

The Dissolved Organic Carbon (DOC) existing in a water includes both hydrophobic and hydrophilic substances however, most of the discussion focuses on hydrophobic substances. The hydrophobic fraction was easily removed by absorption or coagulation more than hydrophilic fraction. Therefore, control of the hydrophilic fraction is very important in water treatment process. This study is to determine the variation of DOC, the removal efficiency of DOC, and Trihalomethane formation potential (THMFP) after each stage of water treatment process by fractionating Natural Organic Matters (NOM) into hydrophobic and hydrophilic substance. DOC from raw water was fractionated at acidic pH (pH<2) using XAD 8 resin column, into two fraction : hydrophobic substance (i.e. humic substance) adsorbed on XAD 8 and hydrophilic substance which represent the organics contained in the final effluent. THMFP was carried out according to the following set condition: Cl2/DOC=4 mg/mg, incubation at $25^{\circ}C$ in darkness, pH 7 adjust with HCl or NaOH as necessary, and 72hour-contact time. THMs analyzed in this study were chloroform, bromodichloromethane, dibromochloromethan, and bromoform. Sewage was almost evenly split between the hydrophobic (56%) and hydrophilic fraction (44%). But, Aldrich humic substance (AHS) was found to contain less hydrophilics (14%) than hydrophobics (86%). The formation of THMs may depend on the source which is characterized by the composition of organic matters such as AHS and sewage. The THMFP yield of sewage and AHS were assessed as follows. The value of the THMFP reaction yield, AHS $172.65{\mu}g/mg$, is much higher than that of sewage $41.68{\mu}g/mg$. This illustrates possible significant difference in THMFP according to the component type and the proportion of organic matter existing in water source. Apparently AHS react with chlorine to produce more THMFP than do the smaller molecules found in sewage. Water treatment process may reduce THMFP, nevertheless residual DOC (the more hydrophilic substance) has significant THMFP. Further reduction in organic halide precursors requires application of alternative treatment techniques.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1031-1041
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• 2012

This study was carried out to investigate the characteristics of disinfection by-products (DBPs-trihalomethanes (THMs), haloacetic acids (HAAs) and haloacetonitriles (HANs) formation in chlorination of principal raw waters used for drinking water on Jeju Island, Korea. The domestic water supply of other area and humic acid solution (HA) were used as a reference point. The effects of chlorine contact time, solution temperature and pH on DBPs formation potential (DBPFP) were investigated for raw waters. In addition, the effect of $Br^-$ was studied for HA. The DBPFP (THMFP, HAAFP and HANFP) were increased with increasing chlorine contact time. Comparing the individual DBPFPs for raw waters, they decreased in the order of HAAFP > THMFP ${\geq}$ HANFP. As the solution temperature was increased, the THMFP, HAAFP and HANFP increased. With increasing the solution pH, the THMFP was increased, but HAAFP and HANFP were decreased. With the addition of 0.3 mg/L $Br^-$ for HA, the DBPFP was increased and the major chemical species changed: from trichloromethane to dibromochloromethane and tribromomethane for THMs; from dichloroacetic acid and trichloroacetic acid to tribromoacetic acid for HAAs; and from dichloroacetonitrile to dibromoacetonitrile for HANs.