scholarly journals Parallel study on removal efficiency of pharmaceuticals and PFASs in advanced water treatment processes: Ozonation, GAC adsorption, and RO processes

2020 ◽  
Vol 27 (1) ◽  
pp. 200509-0
Author(s):  
Hyun-Seok Choe ◽  
Ki Yong Kim ◽  
Jeong-Eun Oh ◽  
Jae-Hyuk Kim
Keyword(s):  
Water Treatment ◽  
Operating Conditions ◽  
Membrane Processes ◽  
Chemical Structures ◽  
Treatment Processes ◽  
Stable Chemical ◽  
Adsorption Processes ◽  
Ro Membrane ◽  
Physical Treatments ◽  
Gac Adsorption

We aimed to assess the removal efficiencies of four pharmaceuticals (carbamazepine, crotamiton, metformin, and sulfamethoxazole) and four poly- and perfluoroalkyl substances (PFASs) (PFHxA, PFHxS, PFOA, and PFOS) by lab-scale ozonation, granular activated carbon (GAC) adsorption, and reverse osmosis (RO) membrane processes under varying operating conditions. Ozonation and GAC adsorption processes were conducted at two temperatures (5 and 25°C) and three pH conditions (3, 7, and 11). The membrane process was performed using an unstirred cell with two different RO membranes. The most pharmaceuticals were effectively removed by ozonation, whereas metformin and PFASs were unaffected due to their stable chemical structures. In the GAC process, metformin was hardly removed under acidic conditions but it was enhanced by over 90%. PFASs were effectively removed by GAC adsorption and RO membrane processes. The RO membrane for brackish water treatment showed higher rejection than that for residential water treatment. Moreover, the rejection of PFAS increased as the molecular weight increased. A strategy was found to effectively remove the remaining metformin in most advanced water treatment processes. Chemically persistent PFASs were hardly removed by the ozonation process but were effectively removed by physical treatments such as GAC adsorption and RO membrane processes.

scholarly journals Water Treatment in Hybrid Connection of Coagulation, Ozonation, UV Irradiation and Adsorption Processes

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1748
Author(s):  
Beata Karwowska ◽  
Elżbieta Sperczyńska ◽  
Lidia Dąbrowska
Keyword(s):  
Water Treatment ◽  
Metal Ions ◽  
Uv Irradiation ◽  
Uv Absorbance ◽  
Treatment Processes ◽  
Coagulation Process ◽  
Organic Pollutants Removal ◽  
Adsorption Processes ◽  
Pollutants Removal ◽  
Ozonation Process

In recent years, conventional water treatment systems have been supported by ozonation or UV irradiation processes. The efficiency of four hybrid processes: (1) coagulation and adsorption, (2) ozonation and coagulation, (3) ozonation, coagulation and adsorption, (4) ozonation, UV irradiation, coagulation and adsorption of inorganic and organic pollutants removal was analysed. In the presented study, the content of organic matter in natural water was evaluated as colour, oxidisability (OXI), total and dissolved organic carbon (TOC and DOC) content and UV absorbance at the wavelength of 254 nm for natural and modified water. Additionally, removal of Ni2+, Cd2+and Pb2+ ions during the treatment processes was analysed. The coagulation process with the use of polyaluminium chloride removed 45% of colour and 39, 26% and 45% of OXI, TOC and UV absorbance, respectively. Using the ozonation before coagulation increased efficiency of colour and UV254 absorbance reduction by 33% and 25%, respectively. Coagulation with both UV irradiation and adsorption had insignificant results on the analysed factors value. The coagulation process was the most efficient for metal ions removal (40–78%). The ozonation process before coagulation increased removal up to 55–85%. Additional irradiation with UV or using of the adsorbent during coagulation of initially ozonated water had an insignificant impact on metal ions concentration in water.

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.

Particle counters as tools for managing Cryptosporidium risk in water treatment

1997 ◽  
Vol 36 (4) ◽  
pp. 143-149 ◽  
Author(s):  
Tom Hall ◽  
Brian Croll
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Operating Conditions ◽  
Water Supplies ◽  
Treatment Processes ◽  
Particle Counting ◽  
Particle Counts ◽  
The Uk ◽  
And Control

Outbreaks of waterborne cryptosporidiosis have been a major concern for the Water Industry in the UK and US over the past ten years. Management of risk from Cryptosporidium in water supplies relies heavily upon operation and control of water treatment processes to maximise oocyst removal. Difficulties in measuring oocyst concentrations in water supplies have led to evaluation of surrogate parameters with which to assess oocyst removal by treatment. Whilst turbidity measurement can give an indication of the risk of oocyst breakthrough from filters, a more sensitive indicator appears to be particle counts in filtered water. The paper gives a demonstration of the potential for particle counting as a tool for managing Cryptosporidium risk, and describe ways in which particle counting can be used for monitoring and controlling water treatment plant operation. With the present level of knowledge, the most suitable application for particle counting is as a diagnostic tool for the identification of operating conditions which reduce or minimise particle counts in filtered water at individual sites.

Scenario-based quantitative microbial risk assessment to evaluate the robustness of a drinking water treatment plant

2016 ◽  
Vol 51 (2) ◽  
pp. 81-96 ◽  
Author(s):  
Mohamed A. Hamouda ◽  
William B. Anderson ◽  
Michele I. Van Dyke ◽  
Ian P. Douglas ◽  
Stéphanie D. McFadyen ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Operating Conditions ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Treatment Processes

While traditional application of quantitative microbial risk assessment (QMRA) models usually stops at analyzing the microbial risk under typical operating conditions, this paper proposes the use of scenario-based risk assessment to predict the impact of potential challenges on the expected risk. This study used a QMRA model developed by Health Canada to compare 14 scenarios created to assess the increase in risk due to potential treatment failures and unexpected variations in water quality and operating parameters of a water treatment plant. Under regular operating conditions, the annual risk of illness was found to be substantially lower than the acceptable limit. Scenario-based QMRA was shown to be useful in demonstrating which hypothetical treatment failures would be the most critical, resulting in an increased risk of illness. The analysis demonstrated that scenarios incorporating considerable failure in treatment processes resulted in risk levels surpassing the acceptable limit. This reiterates the importance of robust treatment processes and the multi-barrier approach voiced in drinking water safety studies. Knowing the probability of failure, and the risk involved, allows designers and operators to make effective plans for response to treatment failures and/or recovery actions involving potential exposures. This ensures the appropriate allocation of financial and human resources.

The control of disinfection by-products precursors by advanced methods of water treatment

2018 ◽  
Vol 18 (6) ◽  
pp. 1906-1914
Author(s):  
Mariola Rajca ◽  
Agnieszka Włodyka-Bergier ◽  
Michał Bodzek
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Membrane Processes ◽  
Lower Affinity ◽  
Treatment Processes ◽  
Hydrophilic Fraction ◽  
Specific Potential ◽  
Hydrophobic Fraction ◽  
By Products

Abstract In the article, the results of the research on reactivity of natural organic matter in regard to disinfection by-products, specifically trihalomethanes (THM) formation, with the use of model waters, are discussed. Additionally, the evaluation of different processes used in water treatment, i.e. photocatalysis, MIEX®DOC and membrane processes, is made. It was found that the affinity of particular natural organic matter compounds to form chlorination by-products could be arranged in a series: hydrophobic fraction (HA) > hydrophilic fraction (FA). The applied treatment processes efficiently decreased the concentration of disinfection by-products (DBPs) precursors and characterized with different removal mechanisms. Water treated by means of photocatalysis (specific potential of ∑THM was 30 μg/mg dissolved organic carbon (DOC) for HA and 12 μg/mg DOC for FA) revealed lower affinity to form chlorination by-products in comparison with water undergone to MIEX®DOC process (specific potential of ∑THM was 38 μg/mg DOC for HA and 29 μg/mg DOC for FA). Moreover, combination of those methods with membrane processes efficiently reduced DBPs formation potential. In nanofiltration effluents DBPs potential were very low and equalled to 50 μg/L for HA and 15 μg/L for FA.

Recent Development of Membrane Processes for Water and Waste Water Treatment

1993 ◽  
Vol 27 (10) ◽  
pp. 141-149 ◽  
Author(s):  
R. Ben Aim ◽  
M. G. Liu ◽  
S. Vigneswaran
Keyword(s):  
Waste Water ◽  
Experimental Study ◽  
Water Treatment ◽  
Waste Water Treatment ◽  
Operating Conditions ◽  
Water Disinfection ◽  
Simultaneous Optimization ◽  
Membrane Processes ◽  
The Relationship

Membranes are presently used at industrial scale for water and waste water treatment, but still for limited production. More knowledge of hydrodynamic phenomena has recently resulted in significant technical improvements (backflush, unsteady flow). However an experimental study performed at lab scale in a rotating membrane device has shown the complexity of the relationship between operating conditions, rejection and filtrate flux. The need for bettering the quality of the water (low turbidity) and waster water (disinfection) may be in favour of the development of membrane processes if efficient models allowing simultaneous optimization of quality and productivity are made available (as was done years ago for deep bed filtration).

Water Treatment Considerations–Aquatic Humus

1983 ◽  
Vol 15 (S2) ◽  
pp. 95-101 ◽  
Author(s):  
E T Gjessing
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Health Effects ◽  
Surface Waters ◽  
Cold Climate ◽  
Treatment Processes ◽  
Aquatic Humus ◽  
Treatment Considerations

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.

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.

Studies of microbial acclimation to hard chemicals on the basis of respiratory quinone profiles and kinetic analyses

1996 ◽  
Vol 34 (5-6) ◽  
pp. 249-256 ◽  
Author(s):  
Hong-Ying Hu ◽  
Mamie Nozawa ◽  
Koichi Fujie ◽  
Tsuyoshi Makabe ◽  
Kohei Urano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Population Dynamics ◽  
Volatile Substance ◽  
Operating Conditions ◽  
Biological Wastewater Treatment ◽  
Basic Information ◽  
Optimal Operating ◽  
Respiratory Quinone ◽  
Treatment Processes ◽  
Quinone Profile

The population dynamics of microbes in the biological wastewater treatment processes such as a submerged biofilter was investigated to obtain basic information to determine the optimal operating conditions. The effects of coexistence of biodegradable substances such as glucose and peptone on the acclimation of microbes in the biofilm to hard chemicals such as acrylonitrile (AN), which is poorly biodegradable and a volatile substance, was investigated on the basis of the respiratory quinone profile. Kinetic study of the removal of AN in the course of acclimation of microbes was investigated using a laboratory-scale submerged biofilter as well. It was ascertained that the acclimation of the microbes to AN was accelerated by coexistence of biodegradable substances, and the microbial phase after acclimation differed from those with the coexistence of glucose and peptone. The quinone profiles in the acclimation showed that Brevibacterium sp. and Pseudomonas aeruginosa, of which the predominant quinone of the respiratory chain is menaquinone-8(H2) and ubiquinone-9, respectively, multiplied selectively in the acclimation course without and with the coexistence of glucose and peptone, respectively. It was also made clear that there were few kinds and number of protozoa and metazoa in the biofilter treating the wastewater containing AN.

Removal of sulphite-reducing clostridia spores by full-scale water treatment processes as a surrogate for protozoan (oo)cysts removal

2000 ◽  
Vol 41 (7) ◽  
pp. 165-171 ◽  
Author(s):  
W. A. Hijnen ◽  
J. Willemsen-Zwaagstra ◽  
P. Hiemstra ◽  
G. J. Medema ◽  
D. van der Kooij
Keyword(s):  
Water Treatment ◽  
Removal Efficiency ◽  
Water Quality Monitoring ◽  
Full Scale ◽  
Process Conditions ◽  
Safe Drinking Water ◽  
Unit Process ◽  
Treatment Processes ◽  
Scale Unit ◽  
Micro Organisms

At eight full-scale water treatment plants in the Netherlands the removal of spores of sulphite-reducing clostridia (SSRC) was determined. By sampling and processing large volumes of water (1 up to 500 litres) SSRC were detected after each stage of the treatment. This enabled the assessment of the removal efficiency of the full-scale unit processes for persistent micro-organisms. A comparison with literature data on the removal of Cryptosporidium and Giardia by the same type of processes revealed that SSRC can be considered as a potential surrogate. The average Decimal Elimination Capacity (DEC) of the overall treatment plants ranged from 1.3–4.3 log. The observed actual log removal of SSRC by the unit processes and the overall treatment at one of the studied locations showed that the level of variation in removal efficiency was approximately 2 log. Moreover, from the actual log removal values it was observed that a low SSRC removal by one unit process is partly compensated by a higher removal by subsequent unit processes at this location. SSRC can be used for identification of the process conditions that cause variation in micro-organism removal which may lead to process optimization. Further research is necessary to determine the optimal use of SSRC in water quality monitoring for the production of microbiologically safe drinking water.

Sign in / Sign up

Export Citation Format

Share Document