A multi-objective closed-loop supply chain network design problem under parameter uncertainty: comparison of exact methods

Environment, Development and Sustainability - Forward and reverse supply chains are one of the most important issues in supply chain management. These kinds of supply chain networks include a...     

Magnetic Cr(VI) Ion Imprinted Polymer for the Fast Selective Adsorption of Cr(VI) from Aqueous Solution

In this study, a novel magnetic Cr(VI) ion imprinted polymer (Cr(VI)-MIIP) was successfully synthesized and used as a selective sorbent for the adsorption of Cr(VI) ions from aqueous solution. It can be synthesized through the combination of an imprinting polymer and magnetic nanoparticles. The high selectivity achieved using MIIP is due to the specific recognition cavities for Cr(VI) ions created in Cr(VI)-MIIP. Also, the magnetic properties that could be obtained using magnetic nanoparticles, helps to separate adsorbent with an external magnetic field without either additional centrifugation or filtration procedures. The magnetic Fe₃O₄ nanoparticles (MNPs) were synthesized using an improved co-precipitation method and modified with tetraethylorthosilicate (TEOS) before imprinting. The magnetic Cr(VI) ion imprinted polymer was prepared through precipitation copolymerization of 4-vinylpyridine as the complexing monomer, 2-hydroxyethyl methacrylate as a co-monomer, the Cr⁶⁺ anion as a template, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker in the presence of modified magnetite nanoparticles. This novel synthesized sorbent was characterized using different techniques. Batch adsorption experiments were performed to evaluate the adsorption conditions, selectivity, and reusability. The results showed that the maximum adsorption capacity was 39.3 mg g^?1, which was observed at pH 3 and at 25?°C. The equilibrium time was 20 min, and the amount of adsorbent which gave the maximum adsorption capacity was 1.7 g L^?1. Isotherm studies showed that the adsorption equilibrium data were fitted well with the Langmuir adsorption isotherm model and the theoretical maximum adsorption capacity was 44.86 mg g^?1. The selectivity studies indicated that the synthesized sorbent had a high single selectivity sorption for the Cr(VI) ions in the presence of competing ions. Thermodynamic studies revealed that the adsorption process was exothermic (\(\Delta H\)?<?0) and spontaneous (\(\Delta G\)?<?0). In addition, the spent MIIP can be regenerated up to five cycles without a significant decrease in adsorption capacity.     

Contaminants of emerging concern: a review of new approach in AOP technologies

The presence of contaminants of emerging concern (CECs) such as pharmaceuticals and personal care products (PPCPs), endocrine-disrupting compounds (EDCs), flame retardants (FRs), pesticides, and artificial sweeteners (ASWs) in the aquatic environments remains a major challenge to the environment and human health. In this review, the classification and occurrence of emerging contaminants in aquatic environments were discussed in detail. It is well documented that CECs are susceptible to poor removal during the conventional wastewater treatment plants, which introduce them back to the environment ranging from nanogram per liter (e.g., carbamazepine) up to milligram per liter (e.g., acesulfame) concentration level. Meanwhile, a deep insight into the application of advanced oxidation processes (AOPs) on mitigation of the CECs from aquatic environment was presented. In this regard, the utilization of various treatment technologies based on AOPs including ozonation, Fenton processes, sonochemical, and TiO₂ heterogeneous photocatalysis was reviewed. Additionally, some innovations (e.g., visible light heterogeneous photocatalysis, electro-Fenton) concerning the AOPs and the combined utilization of AOPs (e.g., sono-Fenton) were documented.     

Multivariate statistical techniques for the assessment of seasonal variations in surface water quality of pasture ecosystems

This study investigates the applicability of multivariate statistical techniques including cluster analysis (CA), discriminant analysis (DA), and factor analysis (FA) for the assessment of seasonal variations in the surface water quality of tropical pastures. The study was carried out in the TPU catchment, Kuala Lumpur, Malaysia. The dataset consisted of 1-year monitoring of 14 parameters at six sampling sites. The CA yielded two groups of similarity between the sampling sites, i.e., less polluted (LP) and moderately polluted (MP) at temporal scale. Fecal coliform (FC), NO₃, DO, and pH were significantly related to the stream grouping in the dry season, whereas NH₃, BOD, Escherichia coli, and FC were significantly related to the stream grouping in the rainy season. The best predictors for distinguishing clusters in temporal scale were FC, NH₃, and E. coli, respectively. FC, E. coli, and BOD with strong positive loadings were introduced as the first varifactors in the dry season which indicates the biological source of variability. EC with a strong positive loading and DO with a strong negative loading were introduced as the first varifactors in the rainy season, which represents the physiochemical source of variability. Multivariate statistical techniques were effective analytical techniques for classification and processing of large datasets of water quality and the identification of major sources of water pollution in tropical pastures.     

Reclaimed rockwool fibers for thermally stable palm oil-based polyurethane foam

Journal of Material Cycles and Waste Management - Due to its non-existent recyclability, industrial rockwool fiber wastes have caused environmental and waste management issues, which, therefore,...     

The analysis and probabilistic health risk assessment of polycyclic aromatic hydrocarbons in cereal products

Environmental Science and Pollution Research - The analysis and probabilistic health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in cereal products were done by using magnetic...     

Determination of the effect of operating cost uncertainty on mining project evaluation

Mining projects are complex businesses that demand constant risk assessment. This is because several kinds of uncertainties influence the value of a mine project, typically. These uncertainties may be classified as exploration uncertainties, economic uncertainties and engineering uncertainties. The evaluation of a mine project under these uncertainties is a complicated job, which may lead to making a wrong decision by managers and stockholders. Therefore, at first, the engineers must recognize the mining uncertainties before carrying out the project evaluation. The economic uncertainties are the most important factors, which may affect the project evaluation. Among the mentioned uncertainties, the operating cost uncertainty is an important and effective factor, which is ignored to a certain extent.     

An approach for land suitability evaluation using geostatistics, remote sensing, and geographic information system in arid and semiarid ecosystems

This study was undertaken to incorporate geostatistics, remote sensing, and geographic information system (GIS) technologies to improve the qualitative land suitability assessment in arid and semiarid ecosystems of Arsanjan plain, southern Iran. The primary data were obtained from 85 soil samples collected from tree depths (0–30, 30–60, and 60–90 cm); the secondary information was acquired from the remotely sensed data from the linear imaging self-scanner (LISS-III) receiver of the IRS-P6 satellite. Ordinary kriging and simple kriging with varying local means (SKVLM) methods were used to identify the spatial dependency of soil important parameters. It was observed that using the data collected from the spectral values of band 1 of the LISS-III receiver as the secondary variable applying the SKVLM method resulted in the lowest mean square error for mapping the pH and electrical conductivity (ECe) in the 0–30-cm depth. On the other hand, the ordinary kriging method resulted in a reliable accuracy for the other soil properties with moderate to strong spatial dependency in the study area for interpolation in the unstamped points. The parametric land suitability evaluation method was applied on the density points (150 × 150 m²) instead of applying on the limited representative profiles conventionally, which were obtained by the kriging or SKVLM methods. Overlaying the information layers of the data was used with the GIS for preparing the final land suitability evaluation. Therefore, changes in land characteristics could be identified in the same soil uniform mapping units over a very short distance. In general, this new method can easily present the squares and limitation factors of the different land suitability classes with considerable accuracy in arbitrary land indices.     

Optimization of decolorization of palm oil mill effluent (POME) by growing cultures of Aspergillus fumigatus using response surface methodology

The conventional treatment process of palm oil mill effluent (POME) produces a highly colored effluent. Colored compounds in POME cause reduction in photosynthetic activities, produce carcinogenic by-products in drinking water, chelate with metal ions, and are toxic to aquatic biota. Thus, failure of conventional treatment methods to decolorize POME has become an important problem to be addressed as color has emerged as a critical water quality parameter for many countries such as Malaysia. Aspergillus fumigatus isolated from POME sludge was successfully grown in POME supplemented with glucose. Statistical optimization studies were conducted to evaluate the effects of the types and concentrations of carbon and nitrogen sources, pH, temperature, and size of the inoculum. Characterization of the fungus was performed using scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and Brunauer, Emmet, and Teller surface area analysis. Optimum conditions using response surface methods at pH 5.7, 35 °C, and 0.57 % w/v glucose with 2.5 % v/v inoculum size resulted in a successful removal of 71 % of the color (initial ADMI of 3,260); chemical oxygen demand, 71 %; ammoniacal nitrogen, 35 %; total polyphenolic compounds, 50 %; and lignin, 54 % after 5 days of treatment. The decolorization process was contributed mainly by biosorption involving pseudo-first-order kinetics. FTIR analysis revealed that the presence of hydroxyl, C–H alkane, amide carbonyl, nitro, and amine groups could combine intensively with the colored compounds in POME. This is the first reported work on the application of A. fumigatus for the decolorization of POME. The present investigation suggested that growing cultures of A. fumigatus has potential applications for the decolorization of POME through the biosorption and biodegradation processes.