Degrading a mixture of three textile dyes using photo-assisted electrochemical process with BDD anode and O2–diffusion cathode

In this paper, degradation of a mixture of three azo dyes was studied by the photo-assisted electrochemical process using an O₂-diffusion cathode containing carbon nanotubes and boron-doped diamond (BDD) anode. The concentration of three textile dyes (C.I. Acid Orange 8 (AO8), C.I. Acid Orange 10 (AO10), and C.I. Acid Orange 12 (AO12)) was determined simultaneously despite the severe overlap of their spectra. For this purpose, partial least square (PLS), as a multivariate calibration method, was utilized based on recording UV–Vis spectra during the decolorization process. Moreover, the central composite design was used for the modeling of photo-assisted electrochemical decolorization of the aqueous solutions containing three dyes. The investigated parameters were the initial concentration of three dyes, applied current and reaction time. Analysis of variance (ANOVA) revealed that the obtained regression models match the experimental results well with R (Khataee et al. 2010, Clean-Soil Air Water 38 (1):96–103, 2010) of 0.972, 0.971, and 0.957 for AO8, AO10, and AO12, respectively. Three-dimensional surface and contour plots were applied to describe the relation between experimental conditions and the observed response. The results of TOC analysis confirmed good ability of proposed photo-assisted electrochemical process for degradation and mineralization of textile industry wastewater.     

An integrated approach for improving energy efficiency of manufacturing process chains

The rising energy prices and increasingly imposing regulations have drawn attention for improving the energy efficiency of manufacturing processes. Over the past decade, different approaches have been developed to target from individual unit processes to entire manufacturing systems. However, each model or approach has limitations in terms of the efficiency improvement. Thus, an integrated approach is proposed to overcome these limitations combining unit process energy consumption models with production system simulation. The outcome potentially leads to a more energy-efficient production and process planning, which considers the dynamics of individual processes as well as the entire system. Two case studies are presented to demonstrate the approach and its benefits.     

A ternary CdS/AgBr/Ag3PO4 nanocomposite: characterization and the kinetics of its photocatalytic activity

Environmental Science and Pollution Research - A ternary CdS/AgBr/Ag3PO4 coupled system was prepared, characterized by different techniques, and used for the photodegradation of methylene blue...     

Subnational exposure to secondhand smoke in Iran from 1990 to 2013: a systematic review

Environmental Science and Pollution Research - Every year, almost eight million people die from tobacco-related diseases, among which around 1.2 million die from secondhand smoke (SHS) exposure....     

Lemon Balm (Melissa officinalis) Stalk: Chemical Composition and Fiber Morphology

This work investigates the potentials of lemon balm (Melissa officinalis L.) stalk (LBS), a massive waste part of medicinal plant, for pulp and papermaking by assessing its fiber characteristics and chemical composition. In addition, LBS properties were compared with some important agro-residues such as bagasse stalk (BS), cotton stalk (CS) and tobacco stalk (TS). There is no information about suitability of the LBS in the open literature. Chemically, LBS fibers contain a relatively high percentage of alpha-cellulose (32.7%), but a low percentage of lignin (25%), which benefits pulping and bleaching. The hemicelluloses in LBS are mainly glucose and xylose. Ash content was about 6%, superior to the average value corresponding to woods, which makes pulping difficult. It was verified that the chemical compositions of the studied agro-residues vary significantly. Morphologically, the LBS fibers are comparable to those of hardwoods. Rather a significant amount of parenchyma cells was found in LBS. The TS has the highest average fiber length, while the LBS has the least, and the lengths of BS and CS fibers fall in between. In general, based on the results of this study, some propositions can be made about the possible applications of LBS as a non-wood renewable source of natural products for use in the production of pulp and paper.     

Adaptation of maize to climate change impacts in Iran

Adaptation is a key factor for reducing the future vulnerability of climate change impacts on crop production. The objectives of this study were to simulate the climate change effects on growth and grain yield of maize (Zea mays L.) and to evaluate the possibilities of employing various cultivar of maize in three classes (long, medium and short maturity) as an adaptation option for mitigating the climate change impacts on maize production in Khorasan Razavi province of Iran. For this purpose, we employed two types of General Circulation Models (GCMs) and three scenarios (A1B, A2 and B1). Daily climatic parameters as one stochastic growing season for each projection period were generated by Long Ashton Research Station-Weather Generator (LARS?WG). Also, crop growth under projected climate conditions was simulated based on the Cropping System Model (CSM)-CERES-Maize. LARS-WG had appropriate prediction for climatic parameters. The predicted results showed that the day to anthesis (DTA) and anthesis period (AP) of various cultivars of maize were shortened in response to climate change impacts in all scenarios and GCMs models; ranging between 0.5 % to 17.5 % for DTA and 5 % to 33 % for AP. The simulated grain yields of different cultivars was gradually decreased across all the scenarios by 6.4 % to 42.15 % during the future 100 years compared to the present climate conditions. The short and medium season cultivars were faced with the lowest and highest reduction of the traits, respectively. It means that for the short maturing cultivars, the impacts of high temperature stress could be much less compared with medium and long maturity cultivars. Based on our findings, it can be concluded that cultivation of early maturing cultivars of maize can be considered as the effective approach to mitigate the adverse effects of climate.     

Optimization of Xanthan Gum/Poly(acrylic acid)/Cloisite 15A Semi-IPN Hydrogels for Heavy Metals Removal

Journal of Polymers and the Environment - Semi-interpenetrating networks (semi-IPNs) of Xanthan gum/poly (acrylic acid) containing Cloisite 15A were prepared via radical polymerization using a...     

Bio-based composites from waste agricultural residues

The main objective of this research was to study the potential of waste agricultural residues such as sunflower stalk, corn stalk and bagasse fibers as reinforcement for thermoplastics as an alternative to wood fibers. The effects of two grades (Eastman G-3003 and G-3216) of coupling agents on the mechanical properties were also studied. In the sample preparation, one level of fiber loading (30 wt.%) and three levels of coupling agent content (0, 1.5 and 2.5 wt.%) were used. For overall trend, with addition of both grades of the coupling agents, tensile, flexural and impact properties of the composites significantly improved, as compared with untreated samples. In addition, morphological study revealed that the positive effect of coupling agent on interfacial bonding. The composites treated with G-3216 gave better results in comparison with G-3003. This could be caused by the high melt viscosity of G-3003. In general, bagasse fiber showed superior mechanical properties due to its chemical characteristics.