Biodegradation of haloacetic acids in water treatment processes

2009 ◽  
Vol 9 (5) ◽  
pp. 557-564 ◽  
Author(s):  
G. S. Wang ◽  
S. P. Lai ◽  
Y. T. Huang
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Haloacetic Acids ◽  
Biological Degradation ◽  
Major Mechanism ◽  
Sand Surface ◽  
Treatment Processes ◽  
Tai Lake ◽  
Coagulation And Filtration

Formation and degradation of haloacetic acids (HAAs) in Tai Lake Water Treatment Plant (WTP) in Kin-Men County, Taiwan, were evaluated in this study. The results showed that formation of HAAs after chlorination is a fast process. Owing to the presence of fairly high organic precursors in the raw water, a large amount of HAAs (up to 80 μg/L in summer) was formed after addition of the pre-chlorine, and only a small portion of the HAAs was removed during the coagulation, flotation, and rapid filtration units. However, more than 80% of HAAs were removed in slow sand filtration (SSF) unit. Laboratory batch filtration tests showed that the HAAs can not be effectively removed by conventional coagulation and filtration treatments. However, the HAAs in water was effectively removed by biodegradation in batch biodegradation tests using filter sands taken from the top of the SSF unit in Tai Lake WTP. For comparison with the results obtained in batch experiments, simulated SSF systems were also installed in laboratory to evaluate the effects of biodegradation for HAAs removal in filter columns. Results of parallel laboratory SSF column tests showed that HAAs was quickly degraded when the simulated SSFs have been operated for a suitable time to allow the microbial growth on the sand surface. In both batch and simulated SSF biodegradation treatments, the biodegradation rates for HAAs decreased as the number of halogen atoms increased. The results in this study demonstrated that biological degradation is the major mechanism responsible for HAAs removal in the SSF units.

Practical Guide to Determine the Impact of Radon and Other Radionuclides on Water Treatment Processes

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Packed Tower ◽  
Treatment Processes ◽  
Radioactivity Exposure ◽  
The Impact ◽  
Percent Removal

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.

Model-based pH monitor for sensor assessment

2009 ◽  
Vol 60 (3) ◽  
pp. 709-715 ◽  
Author(s):  
Kim van Schagen ◽  
Luuk Rietveld ◽  
Alex Veersma ◽  
Robert Babuška
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Mathematical Models ◽  
A Priori ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Treatment Processes ◽  
Online Measurements ◽  
Measurement Devices

Owing to the nature of the treatment processes, monitoring the processes based on individual online measurements is difficult or even impossible. However, the measurements (online and laboratory) can be combined with a priori process knowledge, using mathematical models, to objectively monitor the treatment processes and measurement devices. The pH measurement is a commonly used measurement at different stages in the drinking water treatment plant, although it is a unreliable instrument, requiring significant maintenance. It is shown that, using a grey-box model, it is possible to assess the measurement devices effectively, even if detailed information of the specific processes is unknown.

Quantifying human exposure to contaminants for multiple-barrier water reuse systems

2010 ◽  
Vol 61 (1) ◽  
pp. 77-83 ◽  
Author(s):  
S. J. Khan ◽  
J. A. McDonald
Keyword(s):  
Water Treatment ◽  
Water Reuse ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Disinfection Byproducts ◽  
Plant Performance ◽  
Advanced Treatment ◽  
Safe Drinking Water ◽  
Treatment Processes ◽  
Wide Range

Reliance upon advanced water treatment processes to provide safe drinking water from relatively compromised sources is rapidly increasing in Australia and other parts of the world. Advanced treatment processes such as reverse osmosis have the ability to provide very effective treatment for a wide range of chemicals when operated under optimal conditions. However, techniques are required to comprehensively validate the performance of these treatment processes in the field. This paper provides a discussion and demonstration of some effective statistical techniques for the assessment and description of advanced water treatment plant performance. New data is provided, focusing on disinfection byproducts including trihalomethanes and N-nitrosamines from a recent comprehensive quantitative exposure assessment for an advanced water recycling scheme in Australia.

Reagentless-Continuous Flow Method for Determination of Aqueous Ozone with Thin Film Semiconductor and Application to an Advanced Water Treatment Plant

1991 ◽  
Vol 23 (10-12) ◽  
pp. 1961-1968 ◽  
Author(s):  
T. Aoki ◽  
H. Oguro ◽  
K. Fujiyoshi ◽  
M. Yamamoto
Keyword(s):  
Thin Film ◽  
Water Treatment ◽  
Treatment Plant ◽  
Glass Tube ◽  
Water Treatment Plant ◽  
Treatment Processes ◽  
Relative Standard ◽  
Clean Air ◽  
Ultra Trace

A method without any reagent for the determination of ultra-trace aqueous ozone, utilizing a glass tube-separation process and a thin film semiconductor, is proposed. The glass tube was used as the separator to transfer ozone from water into a gas phase. Ozone was transferred into clean air flowing in the tube and then was continuously monitored at the thin film semiconductor. Signals were proportional to concentration of aqueous ozone more than 5 µ g/L. The relative standard deviation (n = 7) las 3.8 % at 7.6 µ g/L. The interference from hydrogen peroxide, mono-chloramine, and dichloramine, was completely eliminated. The present method was applied to an advanced water treatment pilot-plant incorporating two parallel treatment trains and was examined for its potential for monitoring aqueous ozone in treatment processes.

Algal Removal Studies on a Pilot Scale Water Treatment Plant at Loch Leven, Kinross

1974 ◽  
Vol 74 ◽  
pp. 183-194 ◽  
Author(s):  
D. Johnson ◽  
M. R. Farley ◽  
R. E. Youngman
Keyword(s):  
Water Treatment ◽  
Potable Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Chemical Quality ◽  
Treatment Processes ◽  
Loch Leven ◽  
Large Numbers ◽  
Removal Studies

SynopsisDuring 1970 a pilot-scale water treatment plant was operated at Loch Leven to investigate the feasibility of producing a potable water from such a source.The study showed that while no particular problems were encountered in producing a water of satisfactory chemical quality it was rarely possible to produce a water of satisfactory biological quality. This was due to the fact that the water treatment processes investigated were unable to retain sufficiently large numbers of the small algae so characteristic of Loch Leven and as a consequence the finished water nearly always contained unacceptably high numbers of algae.

scholarly journals Optimizing NOM Removal: Impact of Calcium Chloride

2021 ◽  
Vol 13 (11) ◽  
pp. 6338
Author(s):  
Alfredo Gonzalez-Perez ◽  
Kristofer Hägg ◽  
Fabrice Duteil
Keyword(s):  
Water Treatment ◽  
Calcium Chloride ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Adverse Health Effects ◽  
Surface Water Treatment ◽  
Treatment Processes ◽  
Aluminum Sulphate ◽  
Adsorption Processes ◽  
Sedimentation Processes

Understanding the character of natural organic matter (NOM) and assessing its impact on water quality is paramount for managers of catchments and water utilities. For drinking-water producers, NOM affects disinfectant demand and the formation of by-products which can have adverse health effects. NOM content in raw waters also has an impact on water treatment processes by increasing required coagulant dosages, reducing the effectiveness of adsorption processes and fouling membrane systems. This study investigated the effects of calcium chloride (CaCl2) as a co-coagulant in Al3+ and Fe3+ assisted coagulation, flocculation and sedimentation processes for NOM-removal from raw water collected from Lake Bolmen, in southern Sweden. Jar tests were conducted at Ringsjö Water Works (WW), a surface water treatment plant (WTP), to investigate the potential reduction in primary coagulants aluminum sulphate (Al2(SO4)3) and ferric chloride (FeCl3). This work shows that CaCl2 can, in certain situations, reduce the need for primary coagulants, which would reduce the environmental impact and costs associated with primary coagulant consumption.

scholarly journals Investigation of the Efficiency of the Conventional Water Treatment Processes Employed to Eliminate TOC in Jalaliyeh Water Treatment Plant, Tehran

Health Scope ◽  
2017 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Hossein Kiashemshaki ◽  
Amir Hossein Mahvi ◽  
Ali Asghar Najafpoor ◽  
Ahmad Hosseinzadeh
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Treatment Processes

scholarly journals Investigating the fate of natural organic matter at a drinking water treatment plant in South Africa using optical spectroscopy and chemometric analysis

Water SA ◽  
2020 ◽  
Vol 46 (1 January) ◽  
Author(s):  
Welldone Moyo ◽  
Nhamo Chaukura ◽  
Machawe M Motsa ◽  
Titus AM Msagati ◽  
Bhekie B Mamba ◽  
...  
Keyword(s):  
South Africa ◽  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Chemometric Analysis ◽  
Relative Distribution ◽  
Two Dimensional ◽  
Treatment Processes

The removal dynamics of biodegradable dissolved organic carbon (BDOC) and natural organic matter (NOM) polarity fractions at a water treatment plant (WTP) in South Africa was studied using UV-Vis absorbance, fluorescence excitation-emission matrix, and two-dimensional synchronous fluorescence spectroscopy (SFS). This study gave insights into the transformation of NOM due to treatment processes. The objectives of the study were: (i) to use chemometric analysis and two-dimensional SFS correlations to investigate the evolution of NOM arising from treatment processes, and (ii) to access the chemical profile dynamics of polarity and BDOC fractions throughout the treatment train. The UV254 absorbance, which indicates aromaticity, reduced by 45%  along the WTP. Gaussian fitting of UV-Vis data showed a decreasing trend in intensity and number of bands along the treatment process. The removal efficiency of NOM components followed the order: humic-like (HL) > tyrosine-like (TYL) > fulvic-like (FL) > tryptophan-like (TPL) > microbial-like (MBL).  At the source, the relative distribution of the hydrophobic (HPO), hydrophilic (HPI), and transphilic (TPI) fractions was 45%, 31%, and 24%, respectively. The HPI was recalcitrant to treatment, and the TYL component of the HPI fraction was conjectured to be a disinfection byproduct limiting reagent. The HL and FL components of the BDOC fraction were the major substrates for bacterial growth. According to two-dimensional-SFS correlation, TYL, TPL, and MBL varied concurrently across the treatment stages. Used for the first time in South Africa, the robustness of a multi-dimensional approach of optical methods coupled with chemometric tools for the assessment of the fate of NOM along the treatment processes was revealed by this study.

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