scholarly journals Formation of Haloforms during Chlorination of Natural Waters

10.14311/334 ◽  
2002 ◽  
Vol 42 (2) ◽  
Author(s):  
A. Grünwald ◽  
B. Šťastný ◽  
K. Slavíčková ◽  
M. Slavíček

Recent drinking water regulations have lowered the standards for disinfection by-products and have added new disinfection by-products for regulation. Natural organic matter (NOM), mainly humic compounds, plays a major role in the formation of undesirable organic by-products following disinfection of drinking water. Many disinfection by-products have adverse carcinogenic or mutagenic effects on human health. This paper deals with the formation potencial of disinfection by-products in water samples taken from different places in the Flaje catchment.

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Muhammad Firdaus Kamal ◽  
Euis Nurul Hidayah

Kehadiran NOM menurunkan kualitas air baku untuk air minum dengan mengubah sifat organoleptik, mengganggu sistem pengendapan dan meningkatkan penggunaan koagulan, menyebabkan penyumbatan pada saringan dan distribusi air minum. Komponen NOM, seperti humic acids (HA) dan fulvic acids (FA) yang bereaksi dengan logam berat menyebabkan terbentuknya senyawa toksik dan berkontribusi terhadap pembentukan disinfection by products (DBPs) yang menyebabkan potensi adanya senyawa karsinogenik dalam pengolahan air minum secara konvensional. Salah satu metode penyisihan bahan organik dalam air adalah dengan peningkatan proses koagulasi, dengan pretreatment sebelum proses koagulasi. Tujuan dari penelitian ini adalah mengetahui pengaruh pre-oksidasi dan koagulasi terhadap penyisihan bahan organik pada air Kali Jagir yang digunakan untuk produksi air minum. Berdasarkan hasil analisis, konsentrasi TOC pada air baku sebesar 11,67  mg/liter dan nilai UV absorbansi 254 nm sebesar 0,10895 cm-1, sehingga diperoleh nilai SUVA sebesar 0,934 L/mg/cm, sehingga diketahui karakteristik pada air Kali Surabaya yang cenderung hidrofilik dengan berat molekul rendah dan kebanyakan bukan humik yang mengindikasikan bahwa air tersebut dihasilkan dari kegiatan domestik dan industri. Pada kombinasi pre-oksidasi dan koagulasi, CaOCl2 dengan dosis 25 mg/liter mampu menurunkan TOC dari 11,67 mg/liter menjadi 9,11 mg/liter, sedangkan permanganat dengan dosis 0,8 mg/liter hanya mampu menurunkan TOC dari 11,67 mg/liter menjadi 11,25 mg/liter. Kombinasi pre-oksidasi dan koagulasi mampu menurunkan bahan organik aromatik, ditunjukkan dengan nilai absorbansi UV210 air baku yaitu 1,4983 cm-1 menjadi 1,2720 cm-1 dengan pre-oksidasi KMnO4-koagulan Al2(SO4)3 dan 1,3152 cm-1 pada pre-oksidasi CaOCl2-koagulan Al2(SO4)3. Kata kunci: bahan organik alami, koagulasi, pre-oksidasi. The presence of NOM reduces air quality for drinking water with changes in organoleptic properties, deposition systems and increased use of coagulants, blockages in filters and distribution of drinking water. NOM components, such as humic acid (HA) and fulvic acid (FA) which are printed with heavy metals cause the formation of toxic compounds and contribute to product disinfection (DBPs) which produce potential carcinogenic compounds in conventional drinking water treatment. One method of removing organic matter in water is by increasing the coagulation process, with pretreatment before the coagulation process. The purpose of this study was to determine the effect of pre-oxidation and coagulation on the removal of organic material in Kali Jagir water used for the production of drinking water. Based on the results of the analysis, TOC concentration in raw water is 11.67 mg/liter and UV absorbance value 254 nm is 0.10895 cm-1, so that the SUVA value is 0.934 L/mg/cm, so it is known the characteristics of the Surabaya River water which tend to be hydrophilic with low molecular weight and most not humic which indicates that the water is produced from domestic and industrial activities. In a combination of preoxidation and coagulation, CaOCl2 with a dose of 25 mg/liter was able to reduce TOC from 11.67 mg/liter to 9.11 mg/liter, while permanganate at a dose of 0.8 mg/liter was only able to reduce TOC from 11,67 mg/liter to 11.25 mg/liter. The combination of preoxidation and coagulation is able to reduce aromatic organic matter, indicated by the absorbance value of UV210 of raw water, namely 1.4983 cm-1 to 1.2720 cm-1 with the KMnO4-coagulant Al2(SO4)3 and 1.3152 cm-1 preoxidation in preoxidation CaOCl2-coagulant (SO4)3. Keywords: natural organic matter, coagulation, pre-oxidation.


2008 ◽  
Vol 8 (6) ◽  
pp. 701-707 ◽  
Author(s):  
S. A. Baghoth ◽  
S. K. Maeng ◽  
S. G. Salinas Rodríguez ◽  
M. Ronteltap ◽  
S. Sharma ◽  
...  

Natural organic matter (NOM) occurs throughout the hydrologic cycle, varying in both amount and character. In this paper, a description of NOM in surface and drinking water, in groundwater and in seawater is presented. Water samples representing these environments were collected and characterized using multiple NOM characterization techniques, including fluorescence excitation emission matrices (F-EEM) and size exclusion liquid chromatography with organic carbon detection (LC-OCD). The results show that the raw surface water as well as the treated water comprises mainly (>70%) of humic substances. The biopolymers, which are more readily biodegradable, contribute up to 2% of the NOM in the raw water but this is completely removed after treatment. For sea water samples, humic substances represent about 50% of the dissolved organic carbon concentration (DOC), while the fraction with size bigger than 20 kDa (biopolymers) represents about 7%. During soil passage, there was preferential removal of non-humic substances (i.e., biopolymers) from wastewater effluent-impacted surface water while the specific ultraviolet absorbance (SUVA), which reflects the aromatic characteristics of organics in a sample, showed an increasing trend along the depth of the soil column. This is a consequence of the removal of non-humic substances (biopolymers) which results in an increase in aromaticity.


2020 ◽  
Vol 6 (3) ◽  
pp. 779-794 ◽  
Author(s):  
Anna Andersson ◽  
Elin Lavonen ◽  
Mourad Harir ◽  
Michael Gonsior ◽  
Norbert Hertkorn ◽  
...  

Disinfection by-products (DBPs) are potentially toxic compounds formed upon chemical disinfection of drinking water. This study evaluate how treatment approaches affect DBP formation and composition.


2014 ◽  
Vol 5 (1) ◽  
pp. 72-82
Author(s):  
Dhaouadi Mellahi ◽  
Ridha Zerdoumi ◽  
Nacer Rebbani ◽  
Abdelhak Gheid

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 behavior and the THM formation potential of two major dams in east Algeria. A nonlinear regression modeling study showed a good correlation of the specific chlorine consumption and the specific THM formation. In the case of Ain Zeda dam and at pH = 7, the specific THM yield coefficients αS were: 6.57 and 10.22 μg-THM/mg-Cl2.mg-C.L−1 for hydrophobic and TRS fractions, respectively, while at the same pH, they were 12.07 and 23.66 μg-THM/mg-Cl2.mg-C.L−1 for Ain Dalia dam. Although the NOM concentration of Ain Zeda dam was higher than that of Ain Dalia dam, the THM formation potential of Ain Dalia dam was greater than that of Ain Zeda dam. It seems clear that the water source origin and characteristics play a key role in this case. They affect the THM formation due to the complex composition of humic substances which differs from one source to another.


2013 ◽  
Vol 13 (5) ◽  
pp. 1181-1187 ◽  
Author(s):  
Desmond F. Lawler ◽  
Anne M. Mikelonis ◽  
Ijung Kim ◽  
Boris L. T. Lau ◽  
Sungmin Youn

Silver nanoparticles are used in a wide variety of consumer products and are therefore rapidly becoming ubiquitous in the natural environment; they can be expected to be found in the natural waters used as drinking water supplies. This research investigated whether such particles could be expected to be removed in conventional water treatment plants such as flocculation and filtration. Both flocculation and granular media filtration experiments with citrate-capped silver nanoparticles were performed at different ionic strengths and in the presence and absence of natural organic matter. The results were generally consistent with theories of particle destabilization that have been developed for larger particles (greater than 1 μm), suggesting that silver nanoparticles are likely to be removed in conventional treatment processes.


2014 ◽  
Vol 15 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Y. Kadmi ◽  
L. Favier ◽  
D. Wolbert

The presence of N-nitrosamines in water bodies used for drinking water purposes may present a more serious risk for humans than regulated disinfection by-products (DBPs) species. Hence, understanding and controlling the incidence of N-nitrosamines represents a contemporary challenge to the water industry. Although many of these molecules potentially formed as DBPs are detected in chlorinated natural waters, few studies have focused on the formation, occurrence, and analysis of N-nitrosamines. Until now, nine N-nitrosamines have been detected in water samples; N-nitrosodimethylamine is the most frequently reported nitrosamine in drinking water. Although there are currently no federal regulations for these molecules in drinking water, this family of N-DBPs is one of three potential groups of contaminants highlighted for possible regulatory action in the near future. This paper gives an overview of the current knowledge concerning the occurrence, precursors, and formation mechanisms of N-nitrosamines in water. In addition, the existing regulations are described and relevant analytical methods used for their quantification in water samples are also discussed.


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