Rice husk templated water treatment sludge as low cost dye and metal adsorbent

AbstractThe preparation of adsorbents at low cost as alternatives to the expensive ones in the treatment processes of water and wastewater is the interest of the researchers worldwide. Here, a novel cheap mesoporous adsorbent was prepared via the recycling of wastes namely water treatment sludge and rice husk (RH) as textural modifier. Surface area and pore dimensions were optimized against RH ratio. The mesoporous sludge was employed in adsorption of rosaniline dye, Pb2+, Ni2+ and chlorine from aqueous solutions under dynamic experimental conditions. It was found that the initial dye concentration and textural structure of the adsorbent played important roles in adsorption capacity. The reusability test shows the ease desorption of dye with slightly alkaline water (pH=8) indicating the stability and reusability of the ceramic adsorbent for several times. For metallic cations, the characteristics (ionic radius and ΔHhyd) of ions affect the adsorption affinity. Chlorine adsorption is controlled by the cation exchange capacity(CEC)

Efficient Catalytic Production Of Biodiesel Using Nano-sized Sugar Beet Agro-industrial Waste

This paper addresses the use of agro-industrial residue as a promising heterogeneous catalyst for the efficient production of biodiesel. That is, CaO-rich Sugarbeet agro-industrial waste (smashed down to nano-size) shows superb catalytic activity for biodiesel production via transesterification process employing sunflower oil and methanol. Physicochemical properties of the proposed catalyst are probed by TGA–DTG, XRF, XRD, FT-IR, SEM, BET, and CO2-TPD techniques. Biodiesel conversion (%) of Ca. 93% is achieved under the optimal conditions (catalyst loading of 1 wt%, methanol/oil molar ratio of 4.5:1, refluxed at 75 °C for 60 min). The relatively short reaction time indicates the enhanced kinetics of the process using the proposed agro-industrial residue which imparts its economic feasibility. Also, the proposed CaO-rich residue can be reused twice while retaining its catalytic activity. The thus-produced biodiesel fuel compiles the ASTM D6751 and EN-14214 specifications

Historical and Archaeological Study of Nefer-Seshem-Ptah and šḫntíw Tomb at Saqqara Necropolis

This study reports the first analytical study conducted on samples of bedrock, and plaster layers, and also painting techniques employed by the ancient craftsmen. Collected from Nefer-Seshem-Ptah and šḫntíw tomb, the unique construction at Saqqara necropolis in Egypt, the samples, which comprise the microscopic particularities, were assessed by digital optical microscope, while the petrographic analysis was performed by polarized light microscope. An X-ray diffractometer was used to analyze the bedrock and plaster layers samples. Further, the molecular and vibrational attributions of some fragments and pigment grains were recognized using Fourier Transform Infrared Spectrometer and Raman Micro Spectrometer (μ-Raman). As a result, the studied bedrock indicates that calcite and quartz are the main minerals, whereas halite is revealed in other samples. In addition, assemblages were identified as clay mineral including montmorillonite and kaolinite. Further, the thin-section observation revealed a clayey fossiliferous and micrite. The observation on the plaster layers formed of coarse gypsumincludes little amount of limestone powder, together with fine sand, while the second layer weas composed mainly of a clay plaster with straw plants. The cross-sectional observation on the plaster layers defined three layers, which are mainly made up of calcium carbonate (calcite), quartz and clay. Minerals were identified in varying proportions. Likely, Fourier Transforms Infrared Spectroscopy analysis of the samples disclosed that the craftsmen used animal glue as media to decorate the tomb, which means the “Tempera” Technique was used to decorate Nefer-Seshem-Ptah and šḫntíw tomb.šḫntíwのšとíは、チェコ語のšとíを代用している

Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate

<p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr^III(HIDA)(IDA)(H₂O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO₄^-] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr^III(IDA)(Val)(H₂O)₂] and [Cr^III(IDA)(Arg)(H₂O)₂] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃(1.82 × 10^-3s^-1), is greater than the value of <it>k</it>₁(1.22 × 10^-3s^-1) for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺at 45.0°C and <it>I </it>= 0.20 mol dm^-3. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO₄^-to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃, is greater than the value of <it>k</it>₁for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p

Novel Zirconia Surface Treatments for Enhanced Osseointegration: Laboratory Characterization

Purpose. The aim of this study was to evaluate three novel surface treatments intended to improve osseointegration of zirconia implants: selective infiltration etching treatment (SIE), fusion sputtering (FS), and low pressure particle abrasion (LPPA). The effects of surface treatments on roughness, topography, hardness, and porosity of implants were also assessed. Materials and Methods. 45 zirconia discs (19 mm in diameter × 3 mm in thickness) received 3 different surface treatments: selective infiltration etching, low pressure particle abrasion with 30 µm alumina, and fusion sputtering while nontreated surface served as control. Surface roughness was evaluated quantitatively using profilometery, porosity was evaluated using mercury prosimetry, and Vickers microhardness was used to assess surface hardness. Surface topography was analyzed using scanning and atomic force microscopy (α=0.05). Results. There were significant differences between all groups regarding surface roughness (F=1678, P<0.001), porosity (F=3278, P<0.001), and hardness (F=1106.158, P<0.001). Scanning and atomic force microscopy revealed a nanoporous surface characteristic of SIE, and FS resulted in the creation of surface microbeads, while LPPA resulted in limited abrasion of the surface. Conclusion. Within the limitations of the study, changes in surface characteristics and topography of zirconia implants have been observed after different surface treatment approaches. Thus possibilities for enhanced osseointegration could be additionally offered

Impact of Clinical Pilates Exercise on Pain, Cardiorespiratory Fitness, Functional Ability, and Quality of Life in Children with Polyarticular Juvenile Idiopathic Arthritis

Objective: This study intended to examine the effects of Pilates exercise on pain, cardiorespiratory fitness, functional ability, and quality of life in children with polyarticular juvenile idiopathic arthritis. Methods: Forty children with polyarticular JIA aged 10&ndash;14 years old were randomly allocated into two groups: the control group (n = 20) received conventional physical therapy (CPT), and the experimental group (n = 20) received clinical Pilates exercises combined with CPT. Patients in both groups received their program three times/week for 3 months. Pain, cardiorespiratory fitness, functional ability, and quality of life were assessed through the visual analogue scale, cardiopulmonary exercise test, 6 min walk test, and PedsQL scale, respectively, just before and after treatment. Results: Pain (p = 0.001), cardiorespiratory markers (all p &lt; 0.05), functional ability (p = 0.002), and overall quality of life (p = 0.007) improved significantly in the experimental groups compared to the control group. Conclusion: Incorporating Pilates exercises into CPT is likely more effective for decreasing pain intensity, improving cardiorespiratory fitness, augmenting functional ability, and promoting quality of life in children with JIA than CPT alone