scholarly journals Simultaneous Compliance of TOC and Turbidity Related to Pathogen Breakthrough and THMs Control by Enhanced Coagulation

2013 ◽  
Vol 7 (1) ◽  
pp. 145-153
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Drinking Water Treatment ◽  
The Other ◽  
Haloacetic Acids ◽  
Enhanced Coagulation ◽  
Toc Removal ◽  
Jar Test ◽  
By Products

Since discovery of harmful disinfection by products (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs) in chlorinated waters the removal of organic DBPs precursors gained priority in drinking water treatment. Historically, coagulation process was arranged to remove turbidity, typically related to pathogens occurrence, but nowadays it is usually optimized/enhanced for total organic carbon (TOC) reduction. This work dealt with the removal of TOC and turbidity by means of enhanced coagulation process using Al2(SO4)3⋅18 H2O and FeCl3⋅6H2O as coagulants for jar test without pH adjustment according to USEPA procedure. 15% of TOC removal required by USEPA D/DBPs rule (1998) was achieved using 30-50 mg l-1 of both coagulants. On the other hand, for compliance with more stringent MCL for total THMs in Italy (30 μg l-1) higher TOC removal (>30%) which needed of higher coagulants doses (80 mg l-1), was obviously required. Those high coagulant doses were also to be used for the compliance with the turbidity standard (<1NTU).

Factors Influencing the Formation of Trihalomethanes and Haloacetic Acids in Source Water

2011 ◽  
Vol 183-185 ◽  
pp. 347-351 ◽  
Author(s):  
Gai Mei Guo
Keyword(s):  
Drinking Water ◽  
Humic Acid ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Haloacetic Acids ◽  
Effective Control ◽  
Source Water ◽  
Functional Relationships ◽  
Water Treatment Process ◽  
By Products

Humic acid and aromatic organic compounds (AOCs) detected generally in source water recently could react with chlorine during drinking water treatment process to generate disinfection by-products (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs). To simulate the real contaminated water, in the samples containing humic acid, 1,3-benzenediol, 1,4-benzenediol, 1,2-benzenediol, phenol and benzoic acid as representative AOCs were added to conduct chlorination test in order to analyze the impacts of some factors on the formation of THMs and HAAs. The research results indicated that THMs concentration increased with pH but HAAs concentration decreased with pH, and chlorine time, temperature and chlorine dosage all had the functional relationships with the formation of THMs and HAAs. These results could provide the valuable information for the effective control of DBPs during drinking water treatment operation.

Characterization of NOM in a drinking water treatment process train with no disinfectant residual

2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Distribution System ◽  
Chemical Properties ◽  
Drinking Water Treatment ◽  
Building Blocks ◽  
Fluorescence Excitation ◽  
Water Treatment Process ◽  
Water Treatment Plants

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.

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 Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

2013 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Sand Filtration ◽  
Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

scholarly journals OPTIMIZATION OF THE DRINKING WATER TREATMENT PROCESS OF A SUGAR PLANT STATION IN COTE DIVOIRE

2021 ◽  
Vol 9 (01) ◽  
pp. 512-524
Author(s):  
Konan Lopez Kouame ◽  
◽  
Nogbou Emmanuel Assidjo ◽  
Andre Kone Ariban ◽  
◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Process ◽  
Polynomial Regression ◽  
Drinking Water Treatment ◽  
Optimal Dose ◽  
Raw Water ◽  
Water Treatment Process ◽  
Jar Test ◽  
Coagulation And Flocculation

This article presents an optimization of the drinking water treatment process at the SUCRIVOIRE treatment station. The objective is to optimize the coagulation and flocculation process (fundamental process of the treatment of said plant)by determining the optimal dosages of the products injected and then proposes a program for calculating the optimal dose of coagulant in order to automatically determine the optimal dose of the latter according to the raw water quality. This contribution has the advantage of saving the user from any calculations the latter simply enters the characteristics of the raw effluent using the physical interface of the program in order to obtain the optimum corresponding coagulant concentration. For the determination of the optimal coagulant doses, we performed Jar-Test flocculation tests in the laboratory over a period of three months. The results made it possible to set up a polynomial regression model of the optimal dose of alumina sulfate as a function of the raw water parameters. A program for calculating the optimal dose of coagulant was carried out on Visual Basic. The optimal doses of coagulant obtained vary from 25, 35, 40 and 45 mg/l depending on the characteristics of the raw effluent. The model obtained is: . Finally, verification tests were carried out using this model on the process. The results obtained meet the WHO drinkability standards for all parameters for a settling time of two hours.

Characterization of organic matter and disinfection by-products in membrane backwash water from drinking water treatment

2009 ◽  
Vol 168 (2-3) ◽  
pp. 753-759 ◽  
Author(s):  
Lingling Zhang ◽  
Ping Gu ◽  
Zijie Zhong ◽  
Dong Yang ◽  
Wenjie He ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
By Products

Organic THMs precursors removal from surface water with low TOC and high alkalinity by enhanced coagulation

2004 ◽  
Vol 4 (5-6) ◽  
pp. 103-111 ◽  
Author(s):  
L. Rizzo ◽  
V. Belgiorno ◽  
S. Meriç
Keyword(s):  
Surface Water ◽  
Drinking Water Treatment ◽  
Residual Chlorine ◽  
Enhanced Coagulation ◽  
Toc Removal ◽  
Jar Test ◽  
High Alkalinity ◽  
Surface Water Resource ◽  
Free Residual Chlorine ◽  
Residual Al

NOM removal from surface waters is needed because of potentially carcinogen compound (trihalomethane, THM) formation due to reaction between NOM and free residual chlorine used for disinfection. The stringent limits for THMs (e.g., 30 μg/l in Italy) force conventional drinking water treatment plants to increase TOC removal efficiency by enhanced coagulation. This study was performed on 17 samples taken from a surface water resource with low TOC content (&lt;3 mg/l) and high alkalinity (190 mg as CaCO3/l) to remove TOC and other parameters (DOC, UV254, SUVA, turbidity), typically used to characterize NOM content. Four different coagulants (Al2(SO4)3·18H2O, FeCl3·6H2O, FeSO4·7H2O and PACl) were used in jar test without adding polymer as flocculant. There was no correlation between DOC and SUVA in raw and treated water. TOC removal efficiencies (15–30%) required by the USEPA D/DBPs rule were obtained using 30–50 mg/l alum, 30–50 mg/l of FeCl3, and less than 20 mg/l of PACl (as Al2O3, 10%). The use of PACl is suggested for both lesser TTHMFP and residual Al levels (&lt;100 μg/l) occurrences without any pH adjustment.

scholarly journals Small-scale drinking water treatment unit of filtration and UV disinfection for remote area

2020 ◽  
Vol 20 (6) ◽  
pp. 2106-2118
Author(s):  
Kassim Chabi ◽  
Jie Zeng ◽  
Lizheng Guo ◽  
Xi Li ◽  
Chengsong Ye ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Bacterial Community Composition ◽  
Drinking Water Treatment ◽  
Small Scale ◽  
Treatment Unit ◽  
Remote Areas

Abstract People in remote areas are still drinking surface water that may contain certain pollutants including harmful microorganisms and chemical compounds directly without any pretreatment. In this study, we have designed and operated a pilot-scale drinking water treatment unit as part of our aim to find an economic and easily operable technology for providing drinking water to people in those areas. Our small-scale treatment unit contains filtration and disinfection (UV–C irradiation) stages to remove pollutants from source water. The water quality index was determined based on various parameters such as pH, temperature, dissolved oxygen, nitrate, nitrite, ammonium, phosphorus, dissolved organic carbon and bacteria. Water and media samples after DNA extraction were sequenced using Illumina MiSeq throughput sequencing for the determination of bacterial community composition. After the raw water treatment, the reduction of bacteria concentration ranged from 1 to 2 log10. The average removal of the turbidity, ammonium, nitrite, phosphorus and dissolved organic carbon reached up to 95.33%, 85.71%, 100%, 28.57%, and 45%, respectively. In conclusion, multiple biological stages in our designed unit showed an improvement of the drinking water quality. The designed drinking treatment unit produces potable water meeting standards at a lower cost of operation and it can be used in remote areas.

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