Determination of Au(III) and Pd(II) ions by flame atomic absorption spectrometry in some environmental samples after solid phase extraction

A simple and sensitive solid phase extraction method was developed for simultaneous separation and preconcentration of gold and palladium ions with N-(4-methylphenyl)-2-{[(4-phenyl-5-pyridine-4-yl-4H-1,2,4-triazol-3-yl)thio]acetyl}hydrazine carbo thioamide complex on Amberlite XAD-1180 resin before their determination by flame atomic absorption spectrometry. Some analytical parameters such as HNO₃ concentration of the sample solution, amount of complexing agent, sample volume, eluent type and volume, effects of foreign ions and adsorption capacity of the resin were investigated for quantitative recovery of gold and palladium ions. The effects of some anions and cations were also examined. Under optimum conditions, the detection limits for gold and palladium ions were found to be 0.29 and 0.19 μg L^?1, respectively. The preconcentration factor for gold and palladium was 250. After being validated by standard addition and analysis of standard reference material, the procedure was successfully applied to the analysis of sea and stream water, anodic slime, gold ore, soil and electronic waste.     

Preparation and characterization of calcium alginate-based composite adsorbents for the removal of Cd,Hg, and Pb ions from aqueous solution

Composite adsorbent materials containing calcium alginate, clinoptilolite, and coal-derived humic acid were prepared. Humic acid (HA), clinoptilolite (CL), alginate (AL), alginate-entrapped humic acid (AL/HA), clinoptilolite (AL/CL), and humic acid/clinoptilolite (AL/HA/CL) samples were characterized. The effectiveness of the samples as adsorbents for the removal of cadmium (Cd), mercury (Hg), and lead (Pb) were studied in a series of batch-adsorption experiments. For the AL, AL/HA, AL/CL, and AL/HA/CL adsorbents, uptake versus time data were evaluated using two kinetic models, a linear and a non-linear pseudo-first-order and a pseudo-second-order model. The data for each metal ion on all adsorbents showed good correspondence with the pseudo-second-order kinetic model. The equilibrium data were fitted to Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin isotherm models. The results show that a non-linear method seems more appropriate for obtaining isotherm parameters. The non-linear Freundlich and Langmuir models for Pb and Hg produced a best fit with high R ² value (0.99). For HA adsorbent, the equilibrium data for Cd removal better fit to the non-linear Dubinin–Radushkevich isotherm.     

Evaluating sustainable land use for the Değirmendere valley: A case study from northeastern Turkey

Regional land-use development projects are undertaken to protect water resources necessary for agriculture, energy and sustaining human life. The De?irmendere valley, in the province of Trabzon in the Black Sea region of Turkey, provides clean water to the city of Trabzon. The valley is part of the Silk Road from Asia to the Black Sea and contains historical monasteries such as Sumela, Kustul and Vazelon. However, over the years, misuse of the valley has caused freshwater, sea and environmental pollution. In an attempt to overcome these problems, a multilateral project, De?irmendere Vadisi Çevre Düzenlemesi (DEVAÇED), was launched in the region. This paper aims to provide information necessary for engineering projects within the region. Six villages, on both sides of the valley, were selected for this research and evaluated in terms of river basin utilization, topography, cadastral survey of property and ownership, and land readjustment improvements. The study found illegal and improper urbanization, including industrial facilities within the valley causing water pollution. Current cadastral base maps are not sufficiently accurate for engineering projects, and in some places buildings have been constructed on unstable soils that are susceptible to landslides. The research results have helped to generate important recommendations for rehabilitation of the river basin.