Physical Sciences and Mathematics Commons^™

Chromium Speciation In Water Using Magnetic Polyaniline Nanoparticles Coupled With Microsampling Injection-Flame Atomic Absorption Spectroscopy, Osman Çaylak

Turkish Journal of Chemistry

The chromium speciation procedure was optimized using magnetic polyaniline nanoparticles (Fe3O4@PANI NPs) solid-phase extraction coupled with microsampling injection-flame atomic absorption spectrometry (MIS-FAAS). Chromium speciation was successfully achieved by Fe3O4@PANI NPs at pH 8.0. The recoveries obtained for Cr(III) and Cr(VI) were above 95% and under 5%, respectively. Recoveries of over 95% for Cr(III) from 40.0 mL of the sample were obtained using 25 mg Fe3O4@PANI NPs and 500 µL of 0.2% (w/v) thiourea (TU) solution prepared in 2 mol L–1 HCl as eluent. Total chromium as Cr(III) was extracted quantitatively after reducing the Cr(VI) to Cr(III). The linear range, detection …

Environmental Impact Assessment (Eia) Of As, Se, Sn, And Hg In Water And Sediments From The Egyptian Red Sea Ports, Lamiaa I. Mohamedein, Khalid M. El-Moselhy, Mohamed A. El-Sawy

Blue Economy

Background: Pollution monitoring is an important tool to protect the marine ecosystems where ports had been seen as a source of contamination affecting the public wellbeing. Methods: Therefore, in the present study, surface seawater and surficial sediment samples were collected from 19 stations covering six ports of the Egyptian Red Sea during summer 2017 and winter 2018. The concentrations of As, Se, Sn, and Hg were determined using the Hydride system MH10 coupled with atomic absorption spectrophotometer. Results: The obtained data revealed that mean values of AS, Se, Sn and Hg for water samples were ranged between …

A Scarcity Of Biospheric Values In Local And Regional Reporting Of Water Issues: Media Coverage In The Floridan Aquifer Region, Sadie Hundemer, Debbie Treise, Martha Monroe

Journal of Applied Communications

The values invoked by journalists in the reporting of water issues influence public support for water policy and the assessment of water tradeoffs. This qualitative framing analysis of water coverage from six newspapers in the Floridan aquifer region from 2010 to 2018 reveals the values used to stimulate reader engagement on a range of water challenges including weather, residential behavior, agriculture, algae, industry, springs, energy, municipalities, and fecal matter. Results reveal a hierarchy of value frames that prioritizes economics and human health, thereby attending primarily to the motivations of egoistic and social-altruistic individuals. The ecosystem implications of deteriorated water conditions, …

Generating The Power Of Microbes How Microbial Metabolism May Solve Water And Energy Shortages, Anna Vietmeier

D.U.Quark

No abstract provided.

Schiff Base Functionalized Silica Gel For Simultaneous Separation And Preconcentration Of Cu(Ii), Ni(Ii), And Cd(Ii) In Pharmaceuticals And Water Samples, Feyzullah Tokay, Sema Bağdat

Turkish Journal of Chemistry

A method for separation and preconcentration of Cu(II), Ni(II), and Cd(II) using N-N'-bis(5-methoxsalicylidene)-2-hydroxy-1,3-propanediamine modified silica gel was improved for aqueous samples and pharmaceuticals. Determination of the analytes was achieved by inductively coupled plasma optic emission spectrometry. The experimental conditions including pH value, sample volume, eluent type and volume, sorbent mass, sample, and eluent flow rates were optimized with univariate and multivariate optimization tools. The relative standard deviations of the method were 2.9% for Cu(II), 3.0% for Ni(II), and 3.3% for Cd(II) with recovery values between 98.8 ± 3.2-101.5 ± 3.0%. The limits of detection were found to be 62.4, 39.5, …

Supramolecular Solvent-Based Microextraction For The Preconcentration Of Pb2+ Andcd2+ Prior To Spectrophotometric Detection, Huma Zafar, Faheem Shah, Rafaqat Ali Khan, Asad Muhammad Khan, Jan Nisar, Bushra Ismail

Turkish Journal of Chemistry

Supramolecular solvent-based dispersive liquid-liquid microextraction technique has been developed as a preconcentration tool for the determination of trace level of Pb2+ and Cd2+. Dodecanol dispersed in tetrahydrofuran has been utilized as a supramolecular-solvent system for the extraction of analytes prior to their quantitative determination with graphite furnace atomic absorption spectrophotometer. Both Pb2+ and Cd2+, which were efficiently extracted by supramolecular solvent system, were complexed with dithizone followed by the addition of supramolecular solvent. The experimental variables that could possibly influence the extraction efficiency, i.e. pH value, temperature, sample volume, centrifugation time, rate of centrifugation, ionic strength, etc. were subjected to …

Physical And Chemical Properties Of Soil, Water And Air Around Ukawu Pb-Zn Mine, Southeastern Nigeria, Nwachukwu Arthur Nwachukwu, Sikakwe Gregory Udie, Eluwa Ndidiamaka Nchedo, Uwa Clementina Ukamaka, Oluwatoyin Oluwatosin Olaosebikan

Makara Journal of Science

In this study, analysis of water, and soil samples, air quality, and noise levels in Ukawu Pb-Zn mine were examined. The pH of the water samples, at 6.7, exceeded permissible levels for potable water established by the National Environmental Standard Regulatory Agency (NESREA), European Union, and World Health Organization (i.e., 7.0-8.5). The soil pH was 5.2, which indicates acidity due to acid mine drainage. Low soil pH is evidence of acid mine drainage. All cations detected in water and soil were below standard limits considered harmful by the NESREA. Measurements of precursor gases, such as O₃, NO_{2 …}

Uncertainties Associated With The Use Of Erosional Cave Scallop Lengths To Calculate Stream Discharges, Gregory S. Springer, Andrew Hall

International Journal of Speleology

Scallops are extremely valuable indicators of past water flows in caves because they often record events that cannot be safely witnessed nor measured. Qualitatively, the inverse relationship between their lengths and formative water velocities is useful for determining how flow changes along a cave passage, but they are most valuable because they can be used to directly estimate actual water velocities and discharges. We explore the effects of sample size, measurement choices, and other methods commonly applied to the use of cave scallops in estimating cave stream velocities and discharges. We measured 100 scallops on a cave wall and find …

Kentucky's Environmental Future, Fall/Winter 2004, Issue 9

Sustain Magazine

No abstract provided.

Spatial Patterns Of Particulate Organic Carbon Concentrations And Isotopic Signatures Across A Salinity Gradient In A River Dominated Estuary, Lauren E. Alvaro, John C. Lehrter, Mai Fung

Gulf and Caribbean Research

No abstract provided.

Urban Lawn Microclimates Affect Reference Evapotranspiration, Kenton W. Peterson, Dale J. Bremer, Jack D. Fry

Kansas Agricultural Experiment Station Research Reports

Grass reference evapotranspiration (ET_o) obtained from weather stations in open locations is often used to estimate irrigation requirements of turfgrass in local or regional urban lawns. However, the environments of urban lawns are often altered by surrounding buildings, trees, etc., to form various microclimates that may alter evapotranspiration (ET). Our research, which placed weather stations in urban lawns and nearby open swards of turfgrass, revealed ET_o was 41% lower in residential lawn microclimates than in nearby open turfgrass swards. Less ET within urban lawns than in nearby open swards suggests using standard historical weather data to estimate …

Spectrophotometric Detection Of Rhodamine B In Tap Water, Lipstick, Rouge, And Nail Polish Samples After Supramolecular Solvent Microextraction, Nebi̇ye Özkantar, Mustafa Soylak, Mustafa Tüzen

Turkish Journal of Chemistry

A simple and sensitive supramolecular solvent-based dispersive liquid--liquid microextraction method was described for the separation/preconcentration and spectrophotometric detection of rhodamine B. The microextraction method, which was realized at ambient temperature for the detection of rhodamine B, was carried out by using supramolecular solvents such as tetrahydrofuran and decanoic acid. The method was based on analyses of rhodamine B by using UV-Vis spectrophotometry at 558 nm. The influences of some parameters such as pH, sample volume, eluent solutions, centrifugation time, and ultrasonic bath time were optimized. The effects of various matrix ions were also investigated. Moreover, the limit of detection and …

Drop By Drop

SIGNED: The Magazine of The Hong Kong Design Institute

In October 2013 Yale University professor Sheila Levrant de Bretteville began exploring the water's edge at four Hong Kong harbours with an interdisciplinary group of students from HKDI. The issues that captured their attention formed the basis of some vivid and emotionally compelling work.

Developing A Sustainable Water Supply In The American West: The Case Of Rio Rancho, New Mexico, Hubert B. Stroud, Mary K. Kilmer

Suburban Sustainability

Suburban and urban communities in the American West are challenged by rapid population growth combined with limited natural resources. Supporting sustainable development is of great concern in this region and in similar regions throughout the world. This research examines the sustainability of the water supply within a rapidly growing suburban city in the American West. The city, Rio Rancho, New Mexico, began as an interstate land sales operation and rapidly became a “boom” town, in part because of its location near metropolitan Albuquerque.

Because of a very limited water supply and an increasing demand for water associated with population growth, …

Barays, Boeungs And Bassins: Reservoirs And The Capacity For Life And Change In Cambodia, Kevin D. Curry

Bridgewater Review

No abstract provided.

Simple And Rapid Voltammetric Determination Of Boron In Water And Steel Samples Using A Pencil Graphite Electrode, Lokman Li̇v, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This paper presents a simple, rapid, and accurate voltammetric method for determination of boron in water and steel samples using a disposable pencil graphite electrode. The oxidation of Tiron in the boron-Tiron complex in phosphate buffer at pH 7.5 was measured as a response. Type and concentration of supporting electrolyte, pH, ionic strength, Tiron concentration, scan rate, step amplitude, pulse amplitude, and pencil grade were investigated as the parameters affecting the peak current. The limit of detection (3s) was estimated as 84 $\mu $g/L. The relative standard deviation of the method was 4.6 for 1 mg B/L (N = 7). …

Palladium-Catalyzed Ligand-Free And Efficient Suzuki--Miyaura Reaction Of $N$-Methyliminodiacetic Acid Boronates In Water, Chun Liu, Xinmin Li, Xinnan Wang, Jieshan Qiu

Turkish Journal of Chemistry

A green and efficient protocol has been developed for the Pd(OAc)$_{2}$-catalyzed ligand-free Suzuki--Miyaura reaction of $N$-methyliminodiacetic acid (MIDA) boronates in water. In the presence of Pd(OAc)$_{2}$ as a catalyst and ($i$-Pr)$_{2}$NH as a base, the cross-coupling reactions of aryl bromides with aryl MIDA boronates proceeded smoothly in water without any surfactant, and various functional groups were tolerated under the optimized conditions.

Vernal Pool: A Participatory Art Project About Place + Precipitation, Karen Miranda Abel, Jessica Marion Barr

The Goose

Produced by Karen Miranda Abel with Jessica Marion Barr, Vernal Pool is an immersive, elemental water installation created as a participatory, contemplative inquiry into our transitory interrelationships with water and landscape. From November 2013 to April 2014, 114 individuals across Canada and abroad gathered snow samples as a form of extrinsic artistic practice about place and precipitation. With the arrival of spring, the reservoir of melted snow was convened for four days at Toronto’s historic Gladstone Hotel to create Vernal Pool.

Agriculture In A Water Scarce World, Allison Roberts, Amjad Assi, Bassel Daher, Men Li

Student Papers in Public Policy

According to the McKinsey report (2009), the world is facing a water scarcity challenge where agriculture is its predominant consumer. It accounts for approximately 3100 billion m³, or 71 percent of global water withdrawals today, and is expected to increase to 4500 billion m³ by 2030. This increase is due to a number of factors: growing population and the ever growing necessity to cater for its food needs, economic growth, the variability of precipitation trends and increase in global temperatures. In addition to the increase in water scarcity, the agricultural sector faces an enormous challenge of producing …

Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi

Turkish Journal of Chemistry

Reactions of isocyanides with thioacids in water proceeded smoothly at room temperature and in neutral conditions to afford thioformylamide and thioformamide derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed.

Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This paper describes a sensitive and accurate adsorptive catalytic stripping voltammetric method for the determination of zineb (zinc ethylene-bis- dithiocarbamate) in tap water and tomato samples. The method is based on the reduction of adsorbed zineb at a hanging mercury drop electrode following its catalytic oxidation using peroxydisulfate as an oxidizing reagent. Chemical and instrumental parameters of the process were optimized. The catalytic mechanism of the reduction of zineb is discussed as well. The limits of detection (3 s) and quantification (10 s) and linear range of the method for accumulation time of 60 s were calculated as 8.1 nM, …

Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

Palladium-catalyzed Heck coupling reactions of styrene with bromoarene derivatives are carried out under aerobic conditions in water using water-soluble N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine (EdteH_4) and ethylenediaminetetraacetic acid disodium salt (Na_2EDTA) as ligands. The effect of different bases, catalyst loading, and additives is also monitored. The olefination of bromoarenes with styrene affords the desired products in high yields. The Na_2PdCl_4-Na_2EDTA precatalyst system is also used for the preparative scale (50.0 mmol) synthesis of 4-acetyl-trans-stilbene and 4-styrylbenzaldehyde without a noticeable decrease in the activity. Recycling studies on the Na_2PdCl_4 - Na_2EDTA precatalyst system are also tested in the coupling of 4-bromoacetophenone with styrene.

Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Denitrification in metalimnetic water was examined under different conditions to determine how addition of nitrate (NO3 -) and particulate carbon (PC), aeration, and concentrations of nitrate affect denitrification. In the first experiment, water samples from a metalimnion were treated with different combinations of NO3 - and PC. Changes in excess N2 -N concentration for 10 days were measured using membrane inlet mass spectrometry (MIMS). The second experiment used the same treatments as the first experiment after aeration of water. Besides excess N2 -N concentrations, O2 concentrations were measured for 16 days. The third experiment examined how different initial concentrations of …

Comparative Microbial Sampling From Eutrophic Caves In Slovenia And Slovakia Using Rida ®Count Test Kits, Janez Mulec, Václav Krištůfek, Alica Chroňáková

International Journal of Speleology

RIDA®COUNT test plates were used as an easy-to-handle and rapid indicator of microbial counts in karst ecosystems of several caves in Slovakia and Slovenia. All of the caves had a high organic input from water streams, tourists, roosting bat colonies or terrestrial surroundings. We sampled swabs, water and air samples to test robustness and universality of the RIDA®COUNT test kit (R-Biopharm AG, Germany, http://www.r-biopharm.com/) for quantification of total bacteria, coliforms, yeast and mold. Using data from swabs (colony-forming units per cm²) we proposed a scale for description of biocontamination level or superficial microbial load of cave niches. Based …

Climate. Renewables: Old Problem, New Answers, Michael Eckhart

New England Journal of Public Policy

The article offers information on the first Agricultural Renewable Energy Forum to be held in New York on December 3, 2008.

Water. World Water, A Crisis Of Global Governance?, Robert Weiner

New England Journal of Public Policy

In a global world, how can water, a necessary and increasingly scarce resource, be managed? We understand that water is a basic need. Do we also share the belief that water is a basic right? Does the international community share beliefs about water that may be the foundation of an international regime or system of global governance for the equitable implementation of global water policy? And finally, what international body or bodies might handle the disputes that arise as our population and need for water increase? The author tackles these questions and looks at models to guide us.

Water. Global Water Outlook To 2025: Averting An Impending Crisis, Mark W. Rosegrant, Ximing Cai, Sarah A. Cline

New England Journal of Public Policy

IFPRI and IWMI's report uses computer modeling to project water demand and availability through to 2025 and predicts the likely impact of changes in water policy and investment, making specific recommendations for specific locations around the globe. The report argues that if current water policies continue, farmers will find it difficult to meet the world’s food needs. Hardest hit will be the world’s poorest people. The authors call for: International commitment to sustainable use of water, through appropriate policies and investments; Wider application of existing water saving technologies; The removal of inappropriate incentives and reform of institutions which hinder effective …

Water. Commons Or Commodity?: The Future Of Water, Marcia Brewster

New England Journal of Public Policy

This article by Marcia Brewster is taken from the proceedings of the EPIIC Symposium at Tufts University in February 2005.

Water. The Geopolitics Of Water, Paul Michael Wihbey, Ilan Berman

New England Journal of Public Policy

In the great geo-strategic game known as the Middle East, peace politics get much of the press and the attention of policy leaders. On occasion, oil takes center stage but often for the wrong reason (see, e.g., "The End of the Oil Era and the Price of Oil"). What is important to understand is that water is in fact the key strategic resource in the region and if you follow the flow of water, you'll follow the politics and policy machinations that lie at the heart of the Israeli-Syrian dialogue. IASPS Fellow in Strategy Paul Michael Wihbey co-authored an analysis …

Preconcentration Of Trace Elements On Amberlite Xad-4 Resin Functionalised With 1,2-Bis (O-Aminophenylthio) Ethane And Their Determination By Faas In Environmental Samples, Ömer Dalman, Volkan Numan Bulut, İsmai̇l Deği̇rmenci̇oğlu, Mehmet Tüfekçi̇

Turkish Journal of Chemistry

The use of chemically modified XAD-4-1,2-bis (o-aminophenylthio) ethane chelating resin for preconcentrating Cr^{6+}, Mn^{2+}, Fe^{3+}, Co^{2+}, Cu^{2+}, Cd^{2+}, Zn^{2+}, Pb^{2+}, and Ni^{2+} was studied using flame atomic absorption spectrometry (FAAS) for metal monitoring in environmental samples. Cd^{2+}, Zn^{2+}, Pb^{2+}, and Ni^{2+} ions were quantitatively recovered at the rate of 96.0%, 101.0%, 101.0%, and 95.0%, respectively (RSD < 5%), from the studied solutions. The procedure is based on the retention of analytes on a short column of 1,2-bis (o-aminophenylthio) ethane-XAD-4 chelating resin from a buffered sample solution and subsequent elution with 1 M HNO_3. Various parameters, such as pH, eluent type, and concentration, flow rate of sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of the above-mentioned metal ions was about 6. The adsorption and batch capacity of adsorbent and loading half time (t_{1/2}) for Ni^{2+}, Zn^{2+}, Cd^{2+}, and Pb^{2+} were established. The limit of detection was 3.0 \mu g L^{-1} for Pb^{2+} and Ni^{2+}, 0.6 \mu g L^{-1} for Cd^{2+}, and 0.3 \mu g L^{-1} for Zn^{2+}. The validation of the procedure was carried out by analysis of certified reference materials and standard addition. The proposed enrichment method was applied to environmental samples from Trabzon.