Conventional Treatment Processes for Removal of HAB Cells and Toxins from Drinking Water

2014 ◽  
pp. 96-123
Author(s):  
Fengxun Tan ◽  
Haihan Chen ◽  
Daoji Wu ◽  
Nan Lu ◽  
Zhimin Gao

Abstract2-methylisoborneol (2-MIB) is a common odor-causing compound in drinking water with a low odor threshold (10 ng/L). Since conventional treatment processes cannot effectively remove it, this study investigated an advanced oxidation technology: UV/H


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.


2011 ◽  
Vol 255-260 ◽  
pp. 2731-2735
Author(s):  
Hua Fang ◽  
De Fu Xu ◽  
Xiao Ru Fu ◽  
Yuan Wang ◽  
Ji Lai Lu

Levels of organic matters in raw water from Huangpu River and treated water from different processes have been investigated. Dissolved organic carbon (DOC) and assimilable organic carbon (AOC) have been determined on ultrafiltrate (UF) (MW cut-off of 1K and 10K Daltons) samples. The organics in raw water are majority of lower MW (<1K Daltons) fractions. The conventional treatment processes are effective in removing higher MW (>10K Daltons) organics, while granular activated carbon (GAC) adsorption can reduce organics with lower MW significantly. The lower MW fractions correspond to 60%~70% of the AOC in raw and treated waters, and much higher than other MW fractions. This indicates that the AOC is mainly related to organics with lower MW. In order to decrease AOC level to achieve biostability in drinking water, the processes which can reduce lower MW organics effectively must be employed.


1985 ◽  
Vol 17 (10) ◽  
pp. 97-103 ◽  
Author(s):  
P. Payment ◽  
M. Trudel

During the last decade, with the amelioration of the detection methods and the increasing number of studies on the subject, the isolation of viruses in treated drinking water has been reported more frequently than ever. These reports have in common the very low number of viruses isolated and these viruses are usually found only after concentration procedures involving several hundred liters of water. Our own studies have shown that during the conventional treatment of drinking water 99.998% of the indigenous viruses are removed. The residual viral fraction does not exceed 10 viruses per 1 000 liters of water. Using a probabilistic approach this viral concentration in drinking water is well below any dangerous level of enteric viruses in water and the presence of these viruses should not be considered as a health problem but more as the limit of the water treatment methodology.


1983 ◽  
Vol 15 (S2) ◽  
pp. 95-101 ◽  
Author(s):  
E T Gjessing

For several reasons the surface waters in cold climate areas are coloured due to humic substances. There are two major objections against humus in drinking water, the first is concerned with aesthetical and practical problems and the second is due to indirect negative health effects. There are essentially three different methods in use today for the removal or reduction of humus colour in water: (1) Addition of chemicals with the intention of reducing the “solubility”, (2) Addition of chemicals in order to bleach or mineralize the humus, and (3) Filtration with the intention of removal of coloured particles and some of the “soluble” colour. The treatment processes are discussed.


2014 ◽  
Vol 884-885 ◽  
pp. 91-95
Author(s):  
Shang Chao Yue ◽  
Le Jun Zhao ◽  
Xiu Duo Wang ◽  
Qi Shan Wang ◽  
Feng Hua He

The objectives of this study were to investigate impact of preoxidation on disinfection by-product (DBP) precursors in drinking water via two different preoxidation methods. The full-scale study was conducted on surface river water in a water supply plant in Tianjin, China. Two treatment trains were performed, with prechlorination and preozonation as preoxidation methods, respectively. The water samples were collected on different stages along the treatment processes and analyzed by following organic parameters: dissolved organic carbon (DOC), UV254 and specific ultraviolet absorbance (SUVA). The results indicated that Train 2 with preozonation was more effective to reduce DBP precursors. Preozonation possessed an excellent ability in the removal of UV254 and SUVA, the removal efficiencies were 25.14% and 18.77%, respectively, comparing to the removal rates of 6.66% and 5.64% during prechlorination, separately.


2021 ◽  
Vol 02 ◽  
Author(s):  
Joanna Kisała ◽  
Jakub Goclon ◽  
Dariusz Pogocki

: In this mini-review, the problem of effective elimination of perfluorinated organic micropollutants from aquatic environment has been touched. The extraordinary chemical stability of common perfluorinated organic surfactants results in unsatisfactory efficiency of conventional treatment processes, which opens perspectives for photocatalytic methods - especially for reductive-dehalogenation. To tackle this challenge by photocatalysis one have to be aware of objective, physical limits set by very nature of the reduction process, electronic structure chemical stability, and formulation of the catalyst as well as emission characteristic of the light source. The paper provides some clues for rational design of reductive-dehalogenation oriented photolytic systems, which are derived on the basis of physical principles, and, rather sparse, experimental examples.


2004 ◽  
Vol 49 (9) ◽  
pp. 289-295 ◽  
Author(s):  
S.-W. Jung ◽  
K.-H. Baek ◽  
M.-J. Yu

Massive blooms of blue-green algae in reservoirs produce the musty-earthy taste and odor, which are caused by compounds such as 2-MIB and geosmin. 2-MIB and geosmin are rarely removed by conventional water treatment. Their presence in the drinking water, even at low levels (ng/L), can be detected and it creates consumer complaints. So those concentrations have to be controlled as low as possible in the drinking water. The removals by oxidation (O3, Cl2, ClO2) and adsorption (PAC, filter/adsorber) were studied at laboratory and pilot plant (50 m3/d) to select suitable 2-MIB and geosmin treatment processes. The following conclusions were derived from the study. Both of the threshold odor levels for 2-MIB and geosmin appeared to be 30 ng/L as a consequence of a lab test. For any given PAC dosage in a jar-test, removal efficiencies of 2-MIB and geosmin were increased in proportion to PAC dosage and were independent of their initial concentration in raw water for the tested PAC dosages. In comparison of geosmin with 2-MIB, the adsorption efficiency of geosmin by PAC was superior to that of 2-MIB. The required PAC dosages to control below the threshold odor level were 30 mg /L for geosmin and 50 mg/L for 2-MIB at 100 ng/L of initial concentration. Removal efficiencies of odor materials by Cl2, ClO2, and O3 were very weak under the limited dosage (1.5 mg/L), however increased ozone dosage (3.8 mg O3/L) showed high removal efficiency (84.8% for 2-MIB) at contact time 6.4 minutes. According to the initial concentrations of 2-MIB and geosmin, their removal efficiencies by filter/adsorber differed from 25.7% to 88.4%. For all those, however, remaining concentrations of target materials in finished waters were maintained below 30 ng/L. The longer run-time given for the filter/adsorber, the higher the effluent concentration generated. So it is necessary that the run-time of the filter/adsorber be decreased, when 2-MIB or geosmin occurs in raw water.


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