Formation of HAAs and THMs in the Water Treatment and Distribution System of Macau

2008 ◽  
Vol 3 (3) ◽  
Author(s):  
H. Wong ◽  
K.M. Mok
Keyword(s):  
Water Treatment ◽  
Distribution System ◽  
Mass Concentration ◽  
Treatment Process ◽  
Distribution Network ◽  
Treatment Plant ◽  
Effect Of Temperature ◽  
Alkaline Condition ◽  
Treated Water ◽  
Formation Behavior

This study investigated the formation behavior of two CDBPs, namely THMs and HAAs, in a treatment plant and the distribution network of Macau. Concentrations of the four species of THMs and the six species of HAAs were monitored at different stages of the treatment process and at two separate points in the distribution network during February 2006 to January 2007. The results show that the mass concentration of THMs was generally higher than that of HAAs in treated water with a ratio ranging from around 1:1 to 2:1. The results suggested that two steps, pre-chlorination and coagulation, performed in the treatment process influenced the formation of CDBPs in the plant. The CDBPs formation was found to continue in the distribution system with the concentration of THMs increasing faster. The effect of temperature on the formation of HAAs was found to be more significant than on that of THMs. In an alkaline condition, both THMs and dihaloacetic acids were easier to form but the concentration of some trihaloacetic acid decreased.

Water treatment to reduce internal corrosion in the drinking water distribution system in Oslo

2001 ◽  
Vol 1 (3) ◽  
pp. 91-96 ◽  
Author(s):  
L.J. Hem ◽  
E.A. Vik ◽  
A. Bjørnson-Langen
Keyword(s):  
Water Treatment ◽  
Corrosion Rate ◽  
Distribution System ◽  
Water Distribution ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Corrosion Monitoring ◽  
Copper Corrosion ◽  
Iron Corrosion ◽  
Internal Corrosion

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.

Cost-effective water treatment of polluted surface water by using direct filtration and granular activated carbon filtration

2002 ◽  
Vol 2 (1) ◽  
pp. 233-240 ◽  
Author(s):  
J. Cromphout ◽  
W. Rougge
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Process ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Direct Filtration ◽  
Carbon Filtration ◽  
Effective Water

In Harelbeke a Water Treatment Plant with a capacity of 15,000 m3/day, using Schelde river water has been in operation since April 1995. The treatment process comprises nitrification, dephosphatation by direct filtration, storage into a reservoir, direct filtration, granular activated carbon filtration and disinfection. The design of the three-layer direct filters was based on pilot experiments. The performance of the plant during the five years of operation is discussed. It was found that the removal of atrazin by activated carbon depends on the water temperature.

scholarly journals Research on improving water quality using two experimental statistical methods

2018 ◽  
Vol 178 ◽  
pp. 08014
Author(s):  
Mihail Aurel Ţîţu ◽  
Andrei Victor Sandu ◽  
Costel Ceocea ◽  
Alina Bianca Pop ◽  
Ştefan Ţîţu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Process ◽  
Treatment Plant ◽  
Scientific Paper ◽  
Taguchi’S Method ◽  
Water Treatment Process ◽  
Experiment Method ◽  
Points Of View

This scientific paper addresses the importance of water treatment process until it becomes drinkable, studying the treatment process from different points of view that are considered to be relevant. The choice of this subject was motivated by the water consumption importance for the entire population, the scientific paper proposing to study in what way this water treatment process could be improved, using for analysis two methods of experimental statistical modeling, namely the Taguchi's method and the factorial experiment method. The purpose of this scientific paper was to identify the deficiencies of the water treatment process after it entered the treatment plant and analyze is carried out using the two mentioned methods above, were continued by finding optimization solutions for the process. These solutions are intended to avoid the situations in which the treatment plant may be unable to cover the required volume of drinking water and to ensure the quality of the drinking water supplied to consumers according to the legislation to date. The knowledge benefit of this research consists in the realization of the research intentions formulated and the practical applicability of the results.

Study on Phosphorus and Bacterial Regrowth in Drinking Water

2012 ◽  
Vol 461 ◽  
pp. 466-469
Author(s):  
Deng Ling Jiang ◽  
Yu Min Zhang ◽  
Ning Zheng
Keyword(s):  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Treatment Process ◽  
Water Distribution System ◽  
Phosphorus Concentration ◽  
Available Phosphorus ◽  
Source Water ◽  
Bacterial Regrowth ◽  
Water Treatment Process

Phosphorus limitation on bacterial regrowth was studied in source water, water treatment process and water distribution system of J Water Supply Plant in T city, by modified AOC method and MAP analysis. Based on the study, the follows can be concluded: ① MAP(Microbially Available Phosphorus) concentration was higher in source water and water treatment process, which was 5～38µg PO43－-P/L. However in water distribution, MAP concentration was lower, which was less than 5µg PO43--P/L. ②Coagulation and sedimentation can remove MAP efficiently. 31%～68% of MAP can be removed in these process. ③ In source water and water treatment process, there was no evident difference between AOCpotential, AOCp and AOCnative. So assimilable organic carbon (AOC) was the most important factor of bacterial regrowth. In water distribution system, the concentration of AOCpotential and AOCp were 2～8.7 times of the concentration of AOCnative. So phosphorus limited bacterial regrowth.

Specific Fluorescent Fingerprint of Organic Matter in Advanced Water Treatment and its Molecular Weight

2013 ◽  
Vol 448-453 ◽  
pp. 317-321 ◽  
Author(s):  
Jing Wen Cao ◽  
Shao Wei Liao ◽  
Chung Yi Chung ◽  
Hwa Sheng Gau ◽  
Chun Yen Chiu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Water Treatment ◽  
High Performance ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Excitation Wavelength ◽  
Source Water ◽  
Fluorescent Intensity ◽  
Treated Water

In this research, the UV absorbance values of wavelength at 210 and 254 nm, excitation emission fluorescent matrix were measured for source water and treated water in CCL (Cheng Ching Lake) water treatment plant during five months. The whole data produced from EEFM was analyzed by PARAFAC operated in MATLAB software. The variation of molecular weight for organic matter was measured by HPLC (high performance liquid chromatography) with UV and fluorescent detectors. Observed from the variation of UV210/UV254, high value in treated water compared with source water was found. More molecular weight less than 5 k Da was formed in the treated water with relative to source water. Also, both major components in source water were located at wavelengths of excitation/emission of 250/410 nm and 230/330 nm and those in treated water were 240/410 nm and 220/290 nm. Also, the fluorescent intensity, long excitation wavelength was higher than short excitation wavelength in source water. This phenomena was opposite with treated water.

Removal of cyanobacteria, cyanotoxins, heterotrophic bacteria and endotoxins at an operating surface water treatment plant

2006 ◽  
Vol 54 (3) ◽  
pp. 23-28 ◽  
Author(s):  
J. Rapala ◽  
M. Niemelä ◽  
K.A. Berg ◽  
L. Lepistö ◽  
K. Lahti
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Treatment Process ◽  
Heterotrophic Bacteria ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Bacterial Isolates ◽  
Sand Filtration ◽  
Surface Water Treatment ◽  
Guide Value

The removal of cyanobacteria, hepatotoxins produced by them (microcystins), phytoplankton, heterotrophic bacteria and endotoxins were monitored at a surface water treatment plant with coagulation, clarification, sand filtration, ozonation, slow sand filtration and chlorination as the treatment process. Coagulation–sand filtration reduced microcystins by 1.2–2.4, and endotoxins by 0.72–2.0 log10 units. Ozonation effectively removed the residual microcystins. The treatment process reduced phytoplankton biomass by 2.2–4.6 and heterotrophic bacteria by 2.0–5.0 log10 units. In treated water, the concentration of microcystins never exceeded the WHO guide value (1 μg/L), but picoplankton and monad cells were often detected in high numbers. The heterotrophic bacterial isolates from the treated waters belonged to genera Sphingomonas, Pseudomonas, Bacillus, Herbaspirillum and Bosea.

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