The effects of soil properties and temperature on the adsorption isotherms of lead on some temperate and semiarid surface soils of Iran

Sorption of metal ions by soil and clay minerals is a complex process involving different mechanisms, and controlled by different variables that can interact. The aim of this work was to study the retention mechanisms of Pb ions on different soil samples. Surface soils were sampled from Guilan and Hamadan provinces in north and northwest of Iran with temperate and semiarid climates. The adsorption isotherms of Pb on the soils have been studied at 15, 27 and 37°C. The adsorption data for different soils were fitted into Langmuir and Freundlich models. Temperate soil samples had higher clay content, cation exchange capacity, dichromate (oxidable) organic carbon, total Kjeldahl-nitrogen, biological activity, amorphous and crystalline Fe and Al, but semiarid soil samples had higher sand content, pH, equivalent calcium carbonate, available P and K. Lead adsorption data obtained from semiarid soils against those obtained from temperate soils were better fitted in both Langmuir and Freundlich models. Langmuir constants Q ₀ for Pb adsorption in semiarid soils were considerably lower than those for Pb adsorption in temperate soils. However, the binding energy (K _L) of Pb and Freundlich constant n were higher for data of semiarid soils. The effect of temperature on the Pb adsorption was positive especially in temperate soils; however, soil properties had higher effects on Pb adsorption.     

Cloud point extraction–atomic absorption spectrometry for pre-concentration and determination of cadmium in cigarette samples

A new complexing agent, 2-((2-((1H-benzo[d]imidazole-2yl)methoxy)phenoxy)methyl)-1H-benzo[d]imidazole (BIMPI), was used in cloud point extraction and applied for selective pre-concentration of trace amounts of cadmium in cigarette samples. Cadmium was complexed with BIMPI in a buffer solution (pH?=?10) using Triton X-114 as surfactant and quantitatively extracted into a small volume of the surfactant-rich phase after centrifugation. Under optimized conditions (pH?=?10.0, 0.8?×?10^?4?mol?L^?1 BIMPI and 0.08 % (w/v) Triton X-114), calibration graph was linear in the range of 34.0–1,670.0 μg?L^?1. The proposed method was applied to the determination of Cd in various cigarette (tobacco) samples which gave satisfactory results.     

DRASTIC framework improvement using Stepwise Weight Assessment Ratio Analysis (SWARA) and combination of Genetic Algorithm and Entropy

Environmental Science and Pollution Research - Hybrid and integrated techniques can be used to investigate intrinsic uncertainties of the overlay and index groundwater vulnerability assessment...     

Application of Artificial Neural Networks to Predict Total Dissolved Solids at the Karaj Dam

We applied multilayer perceptron (MLP) and radial basis function (RBF) neural networks using data from two water quality monitoring stations at the Karaj Dam in Iran. Input data were calcium ions (Ca²⁺), magnesium ions (Mg²⁺), sodium ions (Na⁺), chloride ions (Cl^?), sulfate (), and pH, and the output data were total dissolved solids (TDS). An MLP with one hidden layer containing eight neurons was selected for the upstream water quality station using normalized input data. We developed a second MLP neural network for the downstream station with one hidden layer containing 10 neurons in the hidden layer using normalized input data. Considering applying normalized input data and one hidden layer, the coefficient of determination (R ²) and index of agreement (IA) between the observed and the predicted data for the upstream and downstream monitoring stations using the MLP neural networks were 0.985, 0.84, 0.99, and 0.92, respectively. The RBF neural network with 100 neurons in its hidden layer reached the minimum errors between the observed and the predicted results in upstream and downstream stations. The R ² between observed and predicted data for upstream and downstream monitoring stations for the RBF was 0.999 and 0.998, respectively. Data normalization improved the performance of the MLP neural networks. Sensitivity analysis indicated that magnesium is the most effective water quality parameter for predicting TDS, and sulfate is the second most effective water quality parameter affecting TDS prediction at the Karaj Dam.     

Minimum quantity lubrication in grinding: effects of abrasive and coolant–lubricant types

This research has been conducted to study the influence of the abrasive and coolant–lubricant types on the minimum quantity lubrication (MQL) grinding performance. One type of CBN and three types of conventional wheels (corundum) have been tested. The tests have been performed in presence of fluid, air jet and eleven types of coolant–lubricants, as well as, in dry condition. The results indicate that the finest surface quality and lower grinding forces could be obtained while grinding with CBN wheel. In case of conventional wheels, the coarser and high porosity wheels induce much proper grinding results. Furthermore, grinding when utilizing MQL with oil results in higher grinding performance.     

GIS aided prediction of CO2 emission dispersion from geothermal electricity production

CO₂ is the dominant constituent of non-condensable gases in the steam phase of most geothermal fluids. This paper attempts to present the results of a study conducted to develop prediction modeling of CO₂ dispersion in the surrounding atmosphere from a planned 50 MWe geothermal power plant prior to its production. Dispersion models are widely used for predicting future concentrations of environmental emissions on a range of geographic scales. The dispersion type for gases and their average removal rate depends on the meteorological conditions such as wind direction, wind speed, precipitation, atmospheric stability, and surface roughness and topography. Geographic Information System (GIS) capabilities were used for quality visualization of the model outputs and presenting an accurate numerical copy of the study area. The results by the prediction model show that the natural transfer of CO₂ will be from the power plant toward east and northeast and CO₂ concentration trends after the power plant utilization will be similar to the background conditions with minor changes. This dispersion test was carried out to validate and field test the GIS aided dispersion modeling approach described in the paper and the procedure may be applicable for other studies assessing the emission dispersion of pollutants from a point source.     

Which crop production system is more efficient in energy use: wheat or barley?

Efficient use of energy helps to achieve increased production and productivity and contributes to the economy, profitability, and competitiveness of agricultural sustainability of rural communities. Evaluation of wheat and barley production systems in view of energy balance was conducted in Khorasan Razavi Province, Iran. Data were collected by using a face-to-face questionnaire from wheat and barley fields in 2011. Results revealed that total energy input for wheat was 51,040 MJ ha^?1 and for barley 44,866; in wheat and barley systems, renewable energy was consumed by 25.43 and 23.53 %, while non-renewable energy was consumed by 74.57 and 76.47 %, respectively. Energy use efficiency, energy productivity, and net energy were 1.7 kg MJ^?1, 0.088 kg MJ^?1, and 35,987 MJ ha^?1 in wheat system and 1.83 kg MJ^?1, 0.092 kg MJ^?1, and 33,833 MJ ha^?1 in barley system, respectively. Energy intensiveness in wheat fields (61.84 MJ $^?1) was higher than in barley fields (58.71 MJ $^?1). Also, benefit-to-cost ratio in wheat system (1.59) was higher than in barley system (1.35). In general, production in barley fields was more sustainable than wheat production because, in view of ecological indices such as amount of energy use and renewable energy consumption, it was more environment-friendly production.     

Characterization and Optimization of Persian Gum/Whey Protein Bionanocomposite Films Containing Betanin Nanoliposomes for Food Packaging Utilization

Journal of Polymers and the Environment - In this study, composite packaging films were produced from relatively inexpensive materials including Whey protein isolate (WPI) and Persian gum (PG),...