scholarly journals A systematic approach to determine herbicide removals in constructed wetlands using time integrated passive samplers

2011 ◽  
Vol 1 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Declan W. Page ◽  
Stuart J. Khan ◽  
Konrad Miotlinski
Keyword(s):  
Water Treatment ◽  
Constructed Wetlands ◽  
Systematic Approach ◽  
Passive Samplers ◽  
Stormwater Quality ◽  
Natural Wetland ◽  
Process Validation ◽  
Treatment Processes ◽  
Wide Range ◽  
Wetland System

Natural water treatment systems such as wetlands are increasingly being recognised for their role as part of a multi-barrier system for water recycling. Natural wetland systems have the ability to provide effective treatment for a wide range of organic chemicals. However, techniques are required to validate the performance of these treatment processes in the field. This paper provides a new method for evaluating wetland systems using passive samplers and applies a statistical method for use in advanced water treatment processes. Three years of stormwater quality passive sampler data for diuron, simazine and atrazine is provided to determine herbicide removal between the inlet and outlet regions of a constructed wetland. Mean removal rates over the three year period for diuron, simazine and atrazine were 43, 54 and 50% respectively. The results show that this method coupled with passive samplers is amenable to wetland system barrier characterisation where opportunities for process validation is not feasible.

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.

scholarly journals INCREASING THE EFFICIENCY OF MEMBRANE TECHNOLOGIES IN WATER TREATMENT PROCESSES

2021 ◽  
pp. 1-3
Author(s):  
Kuvardina Elena Mikhailovna
Keyword(s):  
Water Treatment ◽  
Rapid Development ◽  
Chemical Properties ◽  
First Century ◽  
Industrial Enterprises ◽  
Treatment Processes ◽  
Wide Range ◽  
Save Energy ◽  
Increasing Trends ◽  
Modern Technologies

The twenty-first century is the century of the rapid development of nanotechnologies, which determine the successful dynamics of the country's economy, save energy resources, and ensure a safe ecological level of the environment. Membrane processes have rightfully occupied their niche in various areas of a number of industries. Modern technologies have made it possible to create a wide range of membranes with good mechanical, thermal and chemical properties. The range of membrane devices and installations is also diverse, which are more and more improved from year to year. Water treatment of boiler houses is a necessary process that ensures successful commissioning of technological equipment of industrial enterprises, as well as heating systems. Water treatment systems are high-cost technologies, and these costs increase annually due to annually increasing trends: an increase in tariffs for water use, deterioration of water quality indicators in sources suitable for industrial use, stricter standards for quantitative and qualitative indicators for discharged effluents, increasing quality requirements treated water used in the technological cycle.

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.

Stirring and aeration system for the upgrading of small waste water treatment plants

1994 ◽  
Vol 29 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Marcus Höfken ◽  
Katharina Zähringer ◽  
Franz Bischof
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Large Scale ◽  
Waste Water Treatment ◽  
Water Treatment Plants ◽  
Waste Water Treatment Plants ◽  
Basic Fluid ◽  
Aeration System ◽  
Technical Realization ◽  
Wide Range

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications. This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.

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.

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.

A four-year mass balance for a natural wetland system receiving domestic wastewater

1994 ◽  
Vol 30 (8) ◽  
pp. 235-244 ◽  
Author(s):  
M. Hosomi ◽  
A. Murakami ◽  
R. Sudo
Keyword(s):  
Organic Matter ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Residential Area ◽  
Flowing Water ◽  
Natural Wetland ◽  
N Release ◽  
Main Factors ◽  
Wetland System ◽  
Natural Purification

In order to clarify the natural purification potential of a natural wetland having free-flowing water, we performed a four-year study on such a wetland system which had been receiving for 12 years the domestic wastewater discharged from a residential area comprised of 45 households. The wetland's removal rate of organic matter throughout the four years ranged from 80% for COD to 95% for BOD, whereas the corresponding nitrogen removal rate was comparatively lower. Results indicate that NH4-N release from the bottom sediment and repression of nitrification are the main factors responsible for the wetland's low removal rate of nitrogen during winter. The wetland purification performance even in winter was determined as follows (g m−2 d−1): 2.2 BOD, 0.81 COD, 1.1 TOC, 0.10 T-N, and 0.023 T-P.

scholarly journals Nanometals-Containing Polymeric Membranes for Purification Processes

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 513
Author(s):  
Anna Rabajczyk ◽  
Maria Zielecka ◽  
Krzysztof Cygańczuk ◽  
Łukasz Pastuszka ◽  
Leszek Jurecki
Keyword(s):  
Synergistic Effects ◽  
Membrane Surface ◽  
Antibacterial Properties ◽  
Polymeric Membranes ◽  
Treatment Processes ◽  
Wide Range ◽  
Different Types ◽  
Type Size ◽  
Titanium Zinc ◽  
Membrane Surface Charge

A recent trend in the field of membrane research is the incorporation of nanoparticles into polymeric membranes, which could produce synergistic effects when using different types of materials. This paper discusses the effect of the introduction of different nanometals such as silver, iron, silica, aluminum, titanium, zinc, and copper and their oxides on the permeability, selectivity, hydrophilicity, conductivity, mechanical strength, thermal stability, and antiviral and antibacterial properties of polymeric membranes. The effects of nanoparticle physicochemical properties, type, size, and concentration on a membrane’s intrinsic properties such as pore morphology, porosity, pore size, hydrophilicity/hydrophobicity, membrane surface charge, and roughness are discussed, and the performance of nanocomposite membranes in terms of flux permeation, contaminant rejection, and antifouling capability are reviewed. The wide range of nanocomposite membrane applications including desalination and removal of various contaminants in water-treatment processes are discussed.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

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