Factors Affecting the Genotoxicity of Drinking Water

2012 ◽  
Vol 518-523 ◽  
pp. 922-927
Author(s):  
Zhi Zhen Xu ◽  
Dong Sheng Wang ◽  
Rong Zhang ◽  
Shi Chuan Tang
Keyword(s):  
Drinking Water ◽  
Sample Preparation ◽  
Acid Solution ◽  
Aquatic Ecosystem ◽  
Ammonia Nitrogen ◽  
Solution Ph ◽  
Factors Affecting ◽  
Chlorine Disinfection ◽  
Umu Test ◽  
Genotoxic Compounds

The genotoxicity of drinking water have received increased attention in recent years to assess aquatic ecosystem safety. The factors affecting the genotoxicity of drinking water, including sample preparation, the concentration of bromide and ammonia nitrogen (NH3-N), were investigated using umu test. The result showed that sample preparation and bromide could significantly influence the genotoxicity of drinking water. During sample preparation, 1 and 2 L waters concentrated were suitable for umu test and the highest yield for genotoxic compounds was obtained from acid solution (pH 2) when ethyl acetate served as the eluant. Bromide could substantially increase the genotoxicity of drinking water after chlorine disinfection. The genotoxicity of drinking water could not be increased with increasing NH3-N concentration.

Application of Automated FIB for TEM Sample Preparation in Semiconductor Failure Analysis

2014 ◽  
Author(s):  
Jie Zhu ◽  
Soo Sien Seah ◽  
Irene Tee ◽  
Bing Hai Liu ◽  
Eddie Er ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Success Rate ◽  
Protective Layer ◽  
Factors Affecting ◽  
Dual Beam ◽  
Lamella Thickness ◽  
Surface Patterns ◽  
Working Parameters ◽  
Practical Factors ◽  
High Flexibility

Abstract In this paper, we describe automated FIB for TEM sample preparation using iFast software on a Helios 450HP dual-beam system. A robust iFast automation recipe needs to consider as many variables as possible in order to ensure consistent sample quality and high success rate. Variations mainly come from samples of different materials, structures, surface patterns, surface topography and surface charging. The recipe also needs to be user-friendly and provide high flexibility by allowing users to choose preferable working parameters for specific types of samples, such as: grounding, protective layer coating, milling steps, and final TEM lamella thickness/width. In addition to the iFast recipe, other practical factors affecting automation success rate are also discussed and highlighted.

Trace Metal Soil Quality Criteria to Protect Ground Water

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2327-2329
Author(s):  
J. Lee ◽  
B. Chen ◽  
H. E. Allen ◽  
C. P. Huang ◽  
D. L. Sparks ◽  
...  
Keyword(s):  
Drinking Water ◽  
Quality Criteria ◽  
Maximum Level ◽  
Inorganic Materials ◽  
Decision Making Process ◽  
Water Quality Standards ◽  
Solution Ph ◽  
Drinking Water Standard ◽  
Cadmium And Lead ◽  
Adsorption Desorption

A major problem in site remediation is frequently the lack of appropriate standards for pollutants in soil. Lack of standards for an exposure route can result in subjective judgments regarding the extent of remediation needed. These problems are particularly important when considering the potential for groundwater contamination by inorganic materials. The partitioning of trace metals is highly dependent on the nature of the soil and on the solution pH. The maximum level of metal in soil for which the equilibrium soluble metal does not exceed the drinking water standard can be computed, at any pH, from the measured partition coefficient for any metal and soil. The sorption of cadmium and lead onto major types of New Jersey soil has been determined as a function of pH. As the pH decreased, the amount of adsorbed metal decreased. As is conventionally done, we have transformed these data into sorption coefficients (Kd) which are a function of pH. To apply such data in the decision making process, it is necessary to use the Kd and appropriate conditions of soil/groundwater in the environment. The calculation determines the maximum concentration of metal which will not result in exceedence of water quality standards. Thesecriteria can be used as a soil standard which will be protective of groundwater quality. We developed adsorption/desorption relationships in the form of a mathematical model and computed the maximum level of metal in soil for which the equilibrium soluble metal will not exceed the drinking water standards.

Thermodynamic Simulation of Sulphide Mineral Leaching

2009 ◽  
Vol 71-73 ◽  
pp. 437-440
Author(s):  
Lasse Ahonen ◽  
Pauliina Nurmi ◽  
Olli H. Tuovinen
Keyword(s):  
Acid Solution ◽  
Ferric Iron ◽  
Geochemical Modeling ◽  
Thermodynamic Simulation ◽  
Sulphide Mineral ◽  
Solution Ph ◽  
Dissolved Iron ◽  
Iron Precipitation ◽  
Oxidative Leaching ◽  
Mineral Leaching

Geochemical modeling program PHREEQC was used to simulate generic bioleaching processes. Carbonate minerals (e.g., calcite) dissolve in acid solution, increasing the solution pH and Ca concentration while the concentration of CO2 may be controlled by the equilibrium with the atmospheric CO2. Non-oxidative dissolution of Fe-monosulphides was demonstrated to release H2S and increase the pH. In the absence of ferric iron precipitation (goethite), the oxidation of pyrite decreased the solution pH from 2 to ~1.4, while the oxidation of Fe-monosulphide and chalcopyrite increased the solution pH to ~3.2-3.4. Assuming equilibrium precipitation of goethite, oxidative leaching decreased the solution pH for all three minerals from pH ~2 to ~0.9-1.2. Adjustment of the solution pH to 1.8 or 2.0 with KOH with concurrent equilibrium precipitation of K-jarosite resulted in low dissolved iron concentrations.

scholarly journals A Novel and Efficient Metal Oxide Fluoride Absorbent for Drinking Water Safety and Sustainable Development

2021 ◽  
Vol 13 (2) ◽  
pp. 883
Author(s):  
Changjuan Dong ◽  
Xiaomei Wu ◽  
Zhanyi Gao ◽  
Peiling Yang ◽  
Mohd Yawar Ali Khan
Keyword(s):  
Sustainable Development ◽  
Drinking Water ◽  
Metal Oxide ◽  
Environmental Sustainability ◽  
Environmentally Friendly ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Low Carbon ◽  
Water Safety ◽  
Solution Ph

Inefficient and non-environmentally friendly absorbent production can lead to much resource waste and go against low carbon and sustainable development. A novel and efficient Mg-Fe-Ce (MFC) complex metal oxide absorbent of fluoride ion (F−) removal was proposed for safe, environmentally friendly, and sustainable drinking water management. A series of optimization and preparation processes for the adsorbent and batch experiments (e.g., effects of solution pH, adsorption kinetics, adsorption isotherms, effects of coexisting anions, as well as surface properties tests) were carried out to analyze the characteristics of the adsorbent. The results indicated that optimum removal of F− occurred in a pH range of 4–5.5, and higher adsorption performances also happened under neutral pH conditions. The kinetic data under 10 and 50 mg·g−1 were found to be suitable for the pseudo-second-order adsorption rate model, and the two-site Langmuir model was ideal for adsorption isotherm data as compared to the one-site Langmuir model. According to the two-site Langmuir model, the maximum adsorption capacity calculated at pH 7.0 ± 0.2 was 204 mg·g−1. The adsorption of F− was not affected by the presence of sulfate (SO42−), nitrate (NO3−), and chloride (Cl−), which was suitable for practical applications in drinking water with high F− concentration. The MFC adsorbent has an amorphous structure, and there was an exchange reaction between OH− and F−. The novel MFC adsorbent was proven to have higher efficiency, better economy, and environmental sustainability, and be more environmentally friendly.

scholarly journals Green synthesis of the innovative super paramagnetic nanoparticles from the leaves extract of Fraxinus chinensis Roxb and their application for the decolourisation of toxic dyes

2019 ◽  
Vol 8 (1) ◽  
pp. 256-271 ◽  
Author(s):  
Imran Ali ◽  
Changsheng Peng ◽  
Dichu Lin ◽  
Iffat Naz
Keyword(s):  
Environmental Remediation ◽  
Degradation Mechanism ◽  
Pseudo First Order Reaction ◽  
Solution Ph ◽  
Factors Affecting ◽  
Toxic Dyes ◽  
Degradation Of Dyes ◽  
Stability Structure ◽  
Ft Ir ◽  
Fraxinus Chinensis

Abstract The leaves extract of Fraxinus chinensis Roxb was used for the synthesis of the innovative phytogenic magnetic nanoparticles (PMNPs) without adding toxic surfactants. The formation, morphology, elemental composition, size, thermal stability, structure and magnetic properties of these PMNPs were examined by UV-visible spectrophotometry, FT-IR, XRD, SEM, EDX, TEM, VSM, XPS, BET and TGA. The reactivity of the obtained PMNPs against decolourising toxic dyes, namely, malachite green (MG), crystal violet (CV) and methylene blue (MB), were investigated by UV-vis spectrophotometry. Further, the factors affecting the removal of dyes, including solution pH, adsorbent dosages, initial concentration of dyes, reaction temperature and contact time, were also investigated. The results revealed the decolourisation of 99.12% of MG and 98.23% of CV within 60 min, and 97.52% of MB within 200 min by the PMNPs using dyes concentration of 25 mg/l at pH 6.5 and 298.15 K. The kinetics outcome indicated that the degradation of dyes matched well to the pseudo first-order reaction kinetics model. Furthermore, the probable degradation mechanism of dyes by the PMNPs, including the adsorption of cationic dye molecules onto the negatively charged surface of adsorbent and the oxidation of the Fe° in the solution, were discussed. Thus, the PMNPs can be produced by the bulk and have great potential to be employed for biomedical/environmental remediation.

scholarly journals Factors Affecting Spermatozoa Motility Analysis using CASA

2019 ◽  
Vol 29 (3) ◽  
pp. 145
Author(s):  
Dian Ratnawati ◽  
N Isnaini ◽  
T Susilawati
Keyword(s):  
Sample Preparation ◽  
Influencing Factors ◽  
Frame Rate ◽  
Analysis Time ◽  
Factors Affecting ◽  
Spermatozoa Motility ◽  
Fast Implementation ◽  
Concentration Chamber

Motility is a very important parameter to determine the quality of semen. Spermatozoa motility assessment can be done manually (subjectively) or with CASA. The superiority of motility assessment using CASA compared to manually is more objective, accurate, fast, efficient and able to provide detailed motility of spermatozoa. However, in implementation, assessments with CASA produce varied data. So far, there has not been a spermatozoa motility standard with CASA, except by minimizing variations in the factors that influence the results of analysis with CASA. The purpose of this paper is to describe factors that affecting spermatozoa motility analysis using CASA to reach optimal motility analysis. Some influencing factors include: CASA settings, semen diluent, spermatozoa concentration, chamber, analyst, sample preparation and analysis time. Recommendation standard motility assessments using CASA include: experienced and consistent analysts, sample preparation properly (mixing, pipeting and sampling), spermatozoa concentration of 20 million / ml, consistent in chamber type (conditioned 37°C), semen diluents and CASA settings (frame rate of 60 Hz and frame per field 30) and fast implementation of analysis (<2 minutes).

scholarly journals Risk Assessment for the Selected Surface Water Intake

2020 ◽  
Vol 50 (4) ◽  
pp. 147-163
Author(s):  
Dawid Szpak ◽  
Janusz R. Rak ◽  
Krzysztof Boryczko ◽  
Izabela Piegdoń ◽  
Jakub Żywiec
Keyword(s):  
Water Quality ◽  
Risk Assessment ◽  
Drinking Water ◽  
Surface Water ◽  
Water Intake ◽  
Security Measures ◽  
Efficient System ◽  
Factors Affecting ◽  
Risk Definition ◽  
Water Supply Company

AbstractThe purpose of the work is to analyze the risk for surface water intake, taking into account factors affecting the water quality. A three-parameter risk definition was proposed. It was found that the analyzed water intake has an efficient system that protects consumers against drinking water of inadequate quality (multibarier system). The task of the water supply company is to maintain its security measures (including a caution and warning station, biomonitoring) in a state of efficiency.

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