Removal of Co by carbonaceous material obtained through solution combustion of tamarind shell

New carbonaceous materials were obtained through solution combustion process of tamarind shell in the presence of urea and ammonium nitrate, and all of them were tested for Co removal. The effect of temperature (from 600 to 1000°C) and water volume on surface texture of carbonaceous material and its adsorptive capacity was evaluated. Scanning electron microscope, Fourier transform infrared spectroscopy, X-ray powder diffraction, and Brunauer–Emmett–Teller (BET) model were used to characterize the obtained carbonaceous material before applying for the removal of cobalt. The point of zero charge was also determined. The results indicate that BET-specific surface areas ranged from 6.40 to 216.72 m²g^?1 for the carbonaceous materials obtained at 600, 700, 800, 900, and 1000°C. The one obtained at 900°C (CombTSF₉₀₀) was found to be the most effective adsorbent for the removal of Co(II) ions from aqueous solutions, with a maximum sorption capacity (Q_max) of 43.56 mg/g. Carbonaceous material obtained through the solution combustion process improves morphological characteristics of adsorbent in a short time, and could be used as an alternative method for the removal of cobalt.     

Novel 13C enrichment technique reveals early turnover of DHA in peripheral tissues

The brain is rich in DHA, which plays important roles in regulating neuronal function. Recently, using compound-specific isotope analysis that takes advantage of natural differences in carbon-13 content (¹³C/¹²C ratio or δ¹³C) of the food supply, we determined the brain DHA half-life. However, because of methodological limitations, we were unable to capture DHA turnover rates in peripheral tissues. In the current study, we applied compound-specific isotope analysis via high-precision GC combustion isotope ratio mass spectrometry to determine half-lives of brain, liver, and plasma DHA in mice following a dietary switch experiment. To model DHA tissue turnover rates in peripheral tissues, we added earlier time points within the diet switch study and took advantage of natural variations in the δ¹³C-DHA of algal and fish DHA sources to maintain DHA pool sizes and used an enriched (uniformly labeled ¹³C) DHA treatment. Mice were fed a fish-DHA diet (control) for 3 months, then switched to an algal-DHA treatment diet, the ¹³C enriched-DHA treatment diet, or they stayed on the control diet for the remainder of the study time course. In mice fed the algal and ¹³C enriched-DHA diets, the brain DHA half-life was 47 and 46 days, the liver half-life was 5.6 and 7.2 days, and the plasma half-life was 4.7 and 6.4 days, respectively. By using improved methodologies, we calculated DHA turnover rates in the liver and plasma, and our study for the first time, by using an enriched DHA source (very high δ¹³C), validated its utility in diet switch studies.     

Effect of (Ce,Dy) co-doping on the microstructural,optical, and photoluminescence characteristics of solution combustion synthesized ZnO nanoparticles

Solution combustion synthesized ZnO nanoparticles that were Ce doped, Dy doped or co-doped at varying dopant concentrations were characterized for their microstructural, optical, and photoluminescence (PL) characteristics. The synthesized nanoparticles matched the standard hexagonal wurtzite structure of ZnO. The lattice fringes in the high-resolution transmission electron micrographs and the bright spotty rings in the selected area electron diffraction patterns authenticated the high crystallinity of the nanoparticles. The diffuse reflectance spectroscopy resolved the energy bandgap for the undoped ZnO as 3.18 eV, which decreased upon doping and co-doping. A sharp narrow ultraviolet emission peak at ~398 nm that originated from excitonic recombination was found in the PL spectra of the nanoparticles. The visible emission peaks in the PL spectra were assigned to the f–d and f–f electron transitions of Ce³⁺ and Dy³⁺ ions, respectively, in addition to different native defects in ZnO. The visible emissions (blue, yellow, and red) improved upon (Ce, Dy) co-doping, therefore (Ce, Dy) co-doped ZnO nanoparticles can be considered a promising luminescent material for the development of energy-saving light sources.     

How to manage plant biomass originated from phytotechnologies? Gathering perceptions from end-users

A questionnaire survey was carried out in four European countries to gather end-user's perceptions of using plants from phytotechnologies in combustion and anaerobic digestion (AD). Nine actors of the wood energy sector from France, Germany, and Sweden, and eleven AD platform operators from France, Germany, and Austria were interviewed. Questions related to installation, input materials, performed analyses, phytostabilization, and phytoextraction were asked. Although the majority of respondents did not know phytotechnologies, results suggested that plant biomass from phytomanaged areas could be used in AD and combustion, under certain conditions. As a potential benefit, phytomanaged plants would not compete with plants grown on agricultural lands, contaminated lands being not suitable for agriculture production. Main limitations would be related to additional controls in process' inputs and end-products and installations that might generate additional costs. In most cases, the price of phytotechnologies biomass was mentioned as a driver to potentially use plants from metal-contaminated soils. Plants used in phytostabilization or phytoexclusion were thought to be less risky and, consequently, benefited from a better theoretical acceptance than those issued from phytoextraction. Results were discussed according to national regulations. One issue was related to the regulatory gap concerning the status of the plant biomass produced on contaminated land.     

Product specific emissions from municipal solid waste landfills

For the inventory analysis of environmental impacts associated with products in Life Cycle Assessment (LCA) there is a great need for estimates of emissions from waste products disposed at municipal solid waste landfills (product specific emissions). Since product specific emissions can not be calculated or measured directly at the landfills, they must be estimated by modeling of landfill processes. This paper presents a landfill model based on a large number of assumptions and approximations concerning landfill properties, waste product properties and characteristics of various kinds of environmental protection systems (e.g. landfill gas combustion units and leachate treatment units). The model is useful for estimation of emissions from waste products disposed in landfills and it has been made operational in the computer tool LCA-LAND presented in a following paper. In the model, waste products are subdivided into five groups of components: general organic matter (e.g. paper), specific organic compounds (e.g. organic solvents), inert components (e.g. PVC), metals (e.g. cadmium), and inorganic non-metals (e.g. chlorine,) which are considered individually. The assumptions and approximations used in the model are to the extent possible scientifically based, but where scientific information has been missing, qualified estimates have been made to fulfill the aim of a complete tool for estimation of emissions. Due to several rough simplifications and missing links in our present understanding of landfills, the uncertainty associated with the model is relatively high.     

Low temperature-synthesized MgAl2O4:Eu3+ nanophosphors and their structural validations using density functional theory: photoluminescence,photocatalytic, and electrochemical properties for multifunctional applications

A low temperature-assisted and oxalyl dihydrazide fuel-induced combustion synthesized series of uncalcined MgAl₂O₄:Eu³⁺ nanophosphors showed an average crystallite size of ~20 nm, and bandgap energy (E_g) of 4.50–5.15 eV, and were validated using density functional theory and found to match closely with the experimental values. The photoluminescence characteristic emission peaks of Eu³⁺ ions were recorded between 480 and 680 nm. The nanophosphors excited at 392 nm showed f–f transitions assigned as ⁵D₀→⁷F_J (J = 0, 1, 2, and 3). The optimized MgAl₂O₄ phosphors had Commission Internationale de l'Eclairage coordinates in the red region, a correlated colour temperature of 2060 K, and a colour purity of 98.83%. The estimated luminescence quantum efficiency ( $\eta$) was observed to be ~63% using Judd–Ofelt analysis. Electrochemical and photocatalytic performance were explored and indicated its multifunctional applications. Therefore, MgAl₂O₄:Eu³⁺ nanophosphors could be used for the fabrication of light-emitting diodes, industrial dye degradation, and as electrodes for supercapacitor applications.     

Alkali Soil Reclamation with Flue Gas Desulfurization Gypsum in China and Assessment of Metal Content in Corn Grains

Flue gas desulfurization gypsum (FGDG), the by-product of wet and semi-dry desulfurization processes, has been used as an alkali soil amendment in China. We evaluated the change in soil properties, agricultural production and the safety of FGDG as a soil amendment. As a result, soil pH and ESP (exchangeable sodium percentage) decreased and corn production increased in FGDG-treated plots. The metal (B, Cr, Mn, Ni, Cu, As, Cd, Pb) contents in soil, FGDG, and corn grains were quantified by ICP-MS. Consequently, the contents of almost all metals in FGDG were lower than in soil. Moreover, the contents of almost all of the metals in the corn grains in the FGDG-treated plots were almost the same or lower than those in the control plot. Statistical analysis indicated that there was no effect of gypsum application on the metal content in the corn grains. Almost all of the metal contents were lower than the standard values set by FAO/WHO for human intake. The results showed that the FGDG from wet and semi-dry FGD processes is suitable as an alkali soil amendment.     

Photoluminescence characteristics of novel Sm3+ ions-doped La1.4Al22.6O36 phosphor for n-UV w-LED

The combustion procedure was used to synthesize La_1.4Al_22.6O₃₆:Sm³⁺ phosphors. The X-ray diffraction (XRD) patterns and morphological and photoluminescence properties were investigated. The XRD patterns consisted of a hexagonal crystal structure. At 405 nm, the maximum excitation intensity was obtained. Following 405 nm excitation, three different emission peaks at 573, 604, and 651 nm were seen. Concentration quenching occurred at 1.5 mol% Sm³⁺ ions. The Commission Internationale de l'éclairage coordinates for the La_1.4Al_22.6O₃₆ phosphor with Sm³⁺ doping were 604 nm (x = 0.644, y = 0.355) falling in the red region. The findings implied that the prepared phosphor may be used to develop w-light-emitting diodes.     

Human Risks from the Combustion of SRM-Derived Tallow in Ireland

The identification of meat and bone meal (MBM) as a significant factor in the spread of bovine spongiform encephalopathy (BSE) has resulted in the introduction of restrictions on the use and movement of MBM and tallow. This has led to a requirement for alternative uses for these products. This paper reports on a risk assessment performed on the use of tallow as a fuel oil extender in diesel engines. With up to 4000 tonnes of tallow being produced each year in Ireland, combustion with energy recovery represents a viable, cost-efficient utilization route. A stochastic (Latin Hypercube sampling) simulation model was developed to assess the infectiv-ity risk to humans associated with potential airborne exposure to the combustion products when using tallow as a combustion fuel in diesel engines. The model simulates the potential infectivity pathways that tallow follows, including its production from animals with potentially subclinical BSE and processing the tallow with segregation and heat treatments. The model uses probability distributions for the most important input parameters. The assessment takes into account a number of epidemiological parameters that include tissue infectivity, species barrier, disease incidence, and heat inactivation. Two scenarios, reflecting the infectivity risk in different animal tissues defined by the European Commissions Scientific Steering Committee (SSC), were performed. It is seen from the model results that the risk of a human contracting variant Creutzfeldt-Jakob Disease (vCJD) from potential airborne exposure to BSE, resulting from the combustion of tallow, is extremely small even when model uncertainty is taken into account (mean individual risk values ranging from 10^-11.43 to 10^-7.23 per year/person). The risks are a number of orders of magnitude less than the sporadic annual incidence level of Creutzfeldt-Jakob Disease 9CJD) in Europe (approximately 10^-6)