Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 60 for “"As (V)"”.
-
Adsorption Properties of Roxarsone and Arsenate on Goethite and Kaolinite
… and kaolinite showed a dependence on pH for both As(V) and roxarsone. This pattern can be explained by the pH-dependent changes in the mineral surface charge and protonation of the aqueous arsenic species. Isotherms for As(V) and roxarsone on goethite and kaolinite show surface saturation for …
-
Arsenic Adsorption on Iron Oxides in the Presence of Soluble Organic Carbon and the Influence of Arsenic on Radish and Lettuce Development
… is available on the survival, uptake, and dry mass production of vegetable seedlings and maturing plants in arsenic enriched environments. Such information is however very important to many vegetable growers in areas of subsistent agricultural like Bangladesh or home-gardeners in closer …
-
The adsorption of arsenic (V) by iron (Fe2O3) and aluminum (Al2O3) oxides
<p>Arsenic(As), one of most toxic contaminants found in water, is well known to have adverse effects on human health, such as skin cancer. The consumption of arsenic contaminated water has led to human health crises in many countries such as Bangladesh, China and even the western USA. The new EPA …
-
Application of phosphate and surfactant-modified zeolite for remediation/attenuation of trace elements in soil and coal fly ash
… trace element contamination sourced by coal fly ash and arsenic trioxide herbicide. Both alkaline and acidic fly ash samples were found to contain significant concentrations of environmentally available trace elements. The treatment of fly ash leachate with surfactant-modified zeolite (SMZ) …
-
Characterization of Arsenic by High Performance Liquid Chromatography and Inductively Coupled Plasma Mass Spectrometry of Algal Extracts and Water in Evaporation Ponds
… method to accurately determine the concentration as well as the speciation of arsenic in highly complex evaporation pond water and algae will be discussed. Interestingly, microorganisms are thriving in evaporation ponds that have high levels of arsenic, which is unusual for their survival. This …
-
Synthesis and potential application of Fe3+/Mn2+ bimetal and hexadecyltrimethylammonium bromide (HDTMA-Br) modified clayey soils for arsenic removal in groundwater
The presence of arsenic in groundwater has drawn worldwide attention from researchers and public health officials due to its effects on human health such as, cancer, skin thickening, neurological disorders, muscular weakness, loss of appetite and nausea. World Health Organisation (WHO) has set the …
-
Microbial Oxidation of Arsenite in Anoxic Environments: Impacts on Arsenic Mobility
AbstractArsenic (As) contamination of groundwater and surface water is a worldwide problem. Exposure to arsenic in drinking water is an important current public health issue. Arsenic is well known for its carcinogenic and teratogenic effects. The U.S. Environmental Protection Agency (USEPA) has …
-
Arsenic speciation by ion-exchange chromatography with on- line determination by hydride generation: electronic modification of the D.C. plasma by photon counting
… for the determination of arsenous acid (As(III)), arsenic acid (As(V)), monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) by hydride generation was demonstrated. The instrument used was a d.c. plasma atomic emission spectrometer (OCP-AES). Complete recovery was reported for …
-
The transport and reaction behavior of arsenic in groundwater : experiments and case studies
… but less is know about the reduction and release of arsenic. A continuous injection tracer test was conducted at the USGS Cape Cod research site (Mass.,USA) in order to investigate natural reduction of As(V) to As(III) in an iron reducing environment. As(V) reduction was observed to take place …
-
Novel treatment technologies for arsenic removal from water
… on the environment. Arsenic pollution in water has been found in many parts of the world, especially in developing countries such as Bangladesh, India, Nepal, and Vietnam. It is also detected in some areas of Australia. In rural area of Victoria, arsenic concentrations of up to 8 μg/L and 220 …
-
Sorptions- und Redoxprozesse von Arsen an oxidischen Oberflächen : experimentelle Untersuchungen
… der anorganischen Arsenspezies (As(III) und As(V)) hat einen entscheidenden Einfluss auf die Toxizität und Mobilität des Elements. Im Grundwasserleiter finden eine Vielzahl von Sorptions- und Redoxreaktionen zwischen Feststoffen und den gelösten Arsenspezies statt. Manganoxide und …
-
Coupled arsenic, iron, and nitrogen cycling in arsenic-contaminated Upper Mystic Lake
… addresses the mechanisms controlling arsenic (As) remobilization and cycling in the hypolimnion of As-contaminated Upper Mystic Lake (UML; Winchester, MA). We conducted field and laboratory studies, and applied mass balance, surface complexation, and thermodynamic modeling to explore As cycling …
-
The Effect of Speciation and Form on the Bioavailability of Arsenic: Insight into the Behavior of Arsenic in Natural Waters
… water supplies contaminated with arsenic (As), a toxin and carcinogen, adversely impact the health of millions of people worldwide. Previous work has documented that different inorganic and organic As species vary with respect to their toxicities. It is, however, currently not well …
-
Bindungsformen und Mobilität von Arsen in Moorböden
… der Umwelt vorkommt. Moorböden bilden Senken für As, obwohl sie zumeist anoxische Bedingungen aufweisen, unter denen As eher mobil sein sollte als unter oxischen Bedingungen. Arsen besitzt eine Affinität zu oxidischen Oberflächen, aber die Bedeutung der organischen Substanz für die Bindung von As …
-
Application of Mixed Iron Oxides in Subsurface Remediation Technologies
… metal contamination of soil and groundwater has been a concern in water supply and public health in many countries where the water supply system draws primarily from groundwater. In the present study, mixed maghemite-magnetite nanoparticles have been used as adsorbents for Cr(VI), As and …
-
Quantifying the Expansion of an Invasive Plant Species, Dog-strangling Vine (Vincetoxicum rossicum), in Environmental and Geographic Space Over the Past 130 Years
Invasive plant species are an increasing global threat to native biodiversity. Effective management depends on accurate predictions of their spread. However, modelling the geographic distribution of invasive species, particularly with methods like correlative species distribution models (SDMs), is …
-
Studies of the NAD metabolism of Haemophilus influenzae
Haemophilus influenzae, as well as other members of the genus which require V-factor, display a unique growth requirement for intact NAD. This organism, the primary cause of bacterial meningitis, is incapable of synthesis of pyridine nucleotides from the usual precursors. An externally directed …
-
Nuclear quadrupole resonance of Na23 in NaBrO3
… Na<sup>23</sup> in NaBrO<sub>3</sub> have been measured, The quadrupole frequency is found to range from 886 kHz. at 4.1 °K to 849 kHz. at 300 °K at atmospheric pressure. The pressure dependences were determined at 196, 273 and 298 °K. From the pressure dependences and the compressibility the …
-
Attempted asymmetric synthesis of Lactobacillic acid / |nFawzy F. Z. Georges. -- 260 St. Catharines, Ont. : [s. n.],
This research work has been planned with the intention of proving the absolute configuration of lactobacillc acid. During the course of this work, attempts have been made to synthesize cis-2-carboxycyclopropane- l-.acetic acid as,v,a suitable resolvable material. As the results were not …
-
Colorimetric determination and speciation of arsenic with silver diethyldithiocarbamate
… the improved procedure is 5 {dollar}\mu{dollar}g As/L (0.5 {dollar}\mu{dollar}g As). Due to the varied toxicity of arsenic compounds and oxidation states in the environment, speciation techniques are important. A review of the literature regarding the determination of individual arsenic species is …
Page 1 of 3