Optimization of metal bio-acid leaching from mobile phone printed circuit boards using natural organic acids and H2O2

Journal of Material Cycles and Waste Management - With increased popularity and technological innovation, more and more electric and electronic equipment wastes (e-wastes) are being generated....     

Design and optimization of new La1−xCexNi1−yFeyO3 (x,y = 0–0.4) nano catalysts in dry reforming of methane

The paper reports the production of syngas from dry reforming of methane (DRM) over La_1?xCe_xNi_1?yFe_yO₃ (x, y = 0–0.4) perovskites. A series of La_1?xCe_xNi_1?yFe_yO₃ were designed by central composite design (CCD) and synthesized by a sol–gel auto combustion method. Artificial neural network (ANN) approach was used to determine the relationship between preparation and operational parameters on the performance of the catalysts in the DRM process. Nickel mole fraction, lanthanum mole fraction, calcination temperature, and reaction temperature were considered as input variables, and conversion of methane was considered as the output variable. An ANN model with nine neurons in the hidden layer was the suitable in predicting conversion of methane. The genetic algorithm (GA) was subsequently used to determine the optimal preparation condition for enhancing the conversion of methane. La_0.6Ce_0.4Ni_0.99Fe_0.01O₃ catalyst, calcined at 756°C was obtained to be the most active catalyst owing to the optimal composition of nickel and lanthanum in the catalyst formulation.     

Comparative phytotoxicity of ZnO nanoparticles,ZnO microparticles,and Zn2+ on rapeseed (Brassica napus L.): investigating a wide range of concentrations

The effects of ZnO nanoparticles (NPs), ZnO microparticles (MPs), and zinc ions (Zn²⁺) on some growth parameters of rapeseed (Brassica napus) seedlings have been studied. The growth inhibition by ZnO NPs was not stronger than that by ZnO MPs while treatment with Zn²⁺ inhibition was clearly stronger.     

Simultaneous Cr (VI) reduction and diazinon oxidation with organometallic sludge formation under photolysis: kinetics,degradation pathways,and mechanism

Environmental Science and Pollution Research - In this study, simultaneous removal of an organic matter (diazinon, DIZ) and an inorganic substance (chromium, Cr) was used. Breaking down of organic...     

Hospital admissions in Iran for cardiovascular and respiratory diseases attributed to the Middle Eastern Dust storms

Environmental Science and Pollution Research - The main objective of this study was to assess the possible effects of airborne particulate matter less than 10 μm in diameter (PM10)...     

Biological nutrient recovery from culturing of pearl gourami (Trichogaster leerii ) by cherry tomato (Solanum lycopersicum) in aquaponic system

Environmental Science and Pollution Research - The possibility of using different densities of cherry tomato as a bio-filter in a simple media-based aquaponic system to recycle nutrients from pearl...     

Indigenous knowledge on use values of Karvan district plants,Iran

Traditional and indigenous knowledge on plants usage is a valuable source of information from cultural and natural perspectives, reflecting society’s complicated and close relationship with the environment. Communities have a valuable source of traditional knowledge on the utilization of natural resources, and it is worth to be documented and preserved for current and future applications. We conducted this research to collect and identify plant species of Karvan District and document the traditional knowledge on their use and consumption values. Regarding the results, 150 plant species are used by local communities, more than 30 % of which are directly consumed as food, 24 % (37 species) are used as medicinal plants, and 16.3 % are applied for decoration purposes; 58.6 % of the species are consumed in the raw form, and the remaining is processed before consumption. Leaves (35 %), seeds (21 %) and flowers (21 %) are the most frequent parts of the plants that are used. High number of young emigrants to industrialized areas in seek of job opportunities is threatening this precious source of indigenous knowledge. Attempts to preserve this empirical source of information by encouraging trans-generational knowledge transmission would help to maintain it for future applications.     

Fate of metolachlor under subirrigation in a sandy soil: A lysimeter study

Abstract

A three‐year field lysimeter study was conducted to investigate the role of subirrigation systems in reducing the risk of water pollution from metolachlor (2‐chloro‐N‐(2‐ethyl‐6‐methlphenyl)‐N‐(2‐methoxy‐l‐methylethyl)acetamide). Nine large PVC lysimeters, 1 m long x 0.45 m diameter, were packed with a sandy soil. Three water table management treatments, i.e. two subirrigation treatments with constant water table depths of 0.4 and 0.8 m, respectively, and a free drainage treatment in a completely randomized design with three replicates were used. Corn (Zea mays L.) was grown in each lysimeter, and at the beginning of summer of each year metolachlor was applied, at the locally recommended rate of 2.75 kg a.i./ha. Soil and water samples were collected at different time intervals after each natural or simulated rainfall event. Metolachlor was extracted from these samples and analyzed using Gas Chromatography.

Results obtained in this three year study, (1993–1995), lead to the conclusion that metolachlor is quite mobile since it leached to a depth of 0.85 m below the soil surface quite early in the growing season. Metolachlor concentrations decreased with depth as well as with time. The shallower water table in the 0.4 m subirrigation treatment showed less residues in the soil solution than that of other treatments. However, a mass balance study, supported by an independent laboratory investigation, shows that water table management, statistically, has no significant effect on the reduction of metolachlor residues in sandy soils.