Five adsorbents based on fly ash treated with NaOH for the adsorption of cadmium ion from aqueous solutions were investigated. The materials were characterized using scanning electron microscopy ...(SEM), Fourier transform infrared spectroscopy (FTIR) and the Brunauer-Emmett-Teller (BET) surface area methods. The results demonstrated that the specific surface area of fly ash was improved after NaOH treatment, and that the adsorption of cadmium by the new adsorbents reached equilibrium in less than 120 min. The results also confirmed that the materials treated with NaOH solution by direct activation had a higher adsorption capacity than untreated fly ash. The maximum adsorption capacities obtained were in the range of 9.18–48.5 mg/g. Also, SEM/EDS and FT-IR results of Cd(II) loaded adsorbents were performed. The obtained experimental data were used for kinetics determination using three model equations: a pseudo first-order model, a pseudo second-order model, and the intraparticle diffusion model. Was found that the adsorption of cadmium ions onto the adsorbents studied follows the pseudo second-order model. The adsorption isotherms of the adsorbent synthesized by direct activation for 15 h using 5 M NaOH at 90 °C with a ratio of 1:3 fly ash: NaOH (A5) was assessed in terms of the Langmuir (four types of linearization), Freundlich, Temkin, Harkin-Jura, and Halsey models. The effectiveness of the adsorbents was evaluated using the toxicity characteristic leaching (TCLP) procedure. Accordingly, the proposed methods in this study are recommended for advanced capitalization of fly ash, particularly as a potential adsorbent for the removal of cadmium ions from wastewater.
Display omitted
•The new adsorbents were synthesized by alkali activation of power plant fly ash.•An efficient and cost-effective approach for capitalization of fly ash was proposed.•The cadmium ions were successfully adsorbed by synthesized materials.•The experimental data were processed using different adsorption isotherms.
The initial characteristics of Romanian fly ash from the CET II Holboca power plant show the feasibility of its application for the production of a new material with applicability in environmental ...decontamination. The material obtained was characterized using standard techniques: scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), instrumental neutron activation analysis (INAA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), the Brunauer–Emmett–Teller (BET) surface area, and thermogravimetric differential thermal analysis (TG-DTA). The adsorption capacity of the obtained material was evaluated in batch systems with different values of the initial Cu(II) ion concentration, pH, adsorbent dose, and contact time in order to optimize the adsorption process. According to the experimental data presented in this study, the adsorbent synthesized has a high adsorption capacity for copper ions (qmax = 27.32–58.48 mg/g). The alkali treatment of fly ash with NaOH improved the adsorption capacity of the obtained material compared to that of the untreated fly ash. Based on the kinetics results, the adsorption of copper ions onto synthesized material indicated the chemisorption mechanism. Notably, fly ash can be considered an important beginning in obtaining new materials with applicability to wastewater treatment.
Hyponatremia and Fractures: Findings From the MrOS Study Jamal, Sophie A; Arampatzis, Spyridon; Harrison, Stephanie Litwack ...
Journal of bone and mineral research,
June 2015, 2015-Jun, 2015-06-01, 20150601, Letnik:
30, Številka:
6
Journal Article
Biochar and zeolite, due to their porous structure, are supposed to be appropriate soil amendments especially in agricultural areas with a lack of water or unsuitable soils with coarse texture. Two ...soil additions that are intended to assist an increase soil water content (AWC) are biochar and zeolite. With this aim, the effects of biochar and zeolite at two levels of 5 and 10 t ha−1 (known as B5, B10, Z5, and Z10) on soil hydrological properties and consequently corn growth were investigated in this study. The results showed that the application of B5 and B10 significantly improved AWC by 76% and 48% due to increasing soil micro- and meso-pores. The application of Z5 and Z10, associated with an increase of macro-pores in soil, enhanced saturated hydraulic conductivity (Ks) up to 174% and 303% and caused losses. The highest specific surface area and mean weight diameter in soil obtained from B10 had an increase of 171% and 197% over the control. Biochar treatments considerably affected plant growth features and shoot nutrient content, whilst zeolite treatments had an impact that is much less apparent than that of biochar. Observations indicate that biochar greatly boosted nutrient availability and water retention in the soil by raising the share of micro- and mezzo-pores, respectively, and as a result, has benefited plant growth. Increasing the level of biochar application from 5 to 10% would have more positive effects on the water available in the soil and on plant root systems. In contrast, the high rate of application of zeolite particles due to coarseness and adding Na+ ions to the soil caused the dispersion of soil particles, the destruction of soil structure, increasing Ks and water loss and consequently a reduction in plant growth.
Organic nitrates uncouple bone turnover, improve bone mineral density, and improve trabecular and cortical components of bone. These changes in turnover, strength and geometry may translate into an ...important reduction in fractures. However, before proceeding with a large fracture trial, there is a need to identify the nitrate formulation that has both the greatest efficacy (with regards to bone turnover markers) and gives the fewest headaches. Ascertaining which nitrate formulation this may be is the purpose of the current study.
This will be an open-label randomized, controlled trial conducted at Women's College Hospital comparing five formulations of nitrates for their effects on bone turnover markers and headache. We will recruit postmenopausal women age 50 years or older with no contraindications to nitroglycerin. Our trial will consist of a run-in phase and a treatment phase. We will enroll 420 women in the run-in phase, each to receive all of the 5 potential treatments in random order for 2 days, each with a 2-day washout period between treatments. Those who tolerate all formulations will enter the 12-week treatment phase and be randomly assigned to one of five groups: 0.3 mg sublingual nitroglycerin tablet, 0.6 mg of the sublingual tablet, a 20 mg tablet of isosorbide mononitrate, a 160 mg nitroglycerin transdermal patch (used for 8 h), and 15 mg of nitroglycerin ointment as used in a previous trial by our group. We will continue enrolment until we have randomized 210 women or 35 women per group. Concentrations of bone formation (bone-specific alkaline phosphatase and procollagen type I N-terminal propeptide) and bone resorption (C-telopeptides of collagen crosslinks and N-terminal crosslinks of collagen) agents will be measured in samples taken at study entry (the start of the run in phase) and 12 weeks. Subjects will record the frequency and severity of headaches daily during the run-in phase and then monthly after that. We will use the 'multiple comparisons with the best' approach for data analyses, as this strategy allows practical considerations of ease of use and tolerability to guide selection of the preparation for future studies.
Data from this protocol will be used to develop a randomized, controlled trial of nitrates to prevent osteoporotic fractures.
ClinicalTrials.gov Identifier: NCT01387672. Controlled-Trials.com: ISRCTN08860742.
Soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cellular adhesion molecule-1 (sVCAM-1) were measured alongside flow-mediated vasodilation (FMD) in 34 patients with intermittent ...claudication and 14 control subjects. Patients with plasma sICAM-1 >253 ng/mL (median value) showed lower FMD than those with sICAM-1 < 253 ng/mL (5.6 +/- 1.8% vs 9.6 +/- 4.2%, p < 0.01). Similarly, in the 17 patients with plasma sVCAM-1 > 414 ng/mL, FMD was lower than in the remaining 17 patients (6.1 +/- 1.9% vs 9.2 +/- 4.5%, p < 0.05). Additionally, when endothelial dysfunction was defined as FMD < or = 5.5%, patients with FMD below this value had higher plasma concentrations of sICAM-1 and sVCAM-1 than those with FMD > 5.5%. Therefore, our findings indicate a close association between elevated plasma levels of adhesion molecules and endothelial dysfunction. As impaired endothelial function is one of the first steps in atherogenesis, our findings have clinical relevance since they serve as the basis for further evaluation of sICAM-1 and sVCAM-1 as potential plasma markers for progression of atherosclerosis in a population at high risk.
The influence of coal fly ash and glass fiber waste on the tensile strength of cement concrete was studied using central composite design. Coal fly ash was used to replace 10% of the cement in the ...concrete mix. Glass fiber was added to improve the tensile properties of the concrete in different dosages and lengths. In total, 14 mixes were investigated, one only with 10% coal fly ash replacement of cement and the other thirteen were determined by the experimental design. Using analysis of variance, the order of importance of the variables was established for each property (flexural strength and split tensile strength). From the nonlinear response surfaces, it was found that higher values of flexural strength were obtained for fibers longer than 12 mm and at a dosage of 1-2%. For split tensile strength, higher values were obtained for fibers with a length of 19–28 mm and at a dosage of 1–1.5%.
The meaning of technological progress is to produce economic development and to increase the level of personal comfort. Sustainability can only be achieved if, at the microsystem level as well as at ...the macrosystem level, the secondary effects of the activities undertaken by people on the environment are in a state of neutrality compared to the impact they can produce on natural conditions. This neutrality can be intrinsic or can be achieved through coercive and compensatory measures. If we take into account the production of carbon dioxide that accompanies a product from the stages of conceptualisation, design, procurement of materials, execution, operation, maintenance, decommissioning and recycling the waste produced at the end of use, then nothing can be sustainable in pure form. Nevertheless, there are products whose production, both as a raw material and as a technological process, can be neutral in terms of carbon emissions. Moreover, they can even become carbon negative over time. This is also the case with eco-sustainable hemp concrete, whose capacity to absorb carbon dioxide starts from the growth phase of the plant from which the raw material is obtained and continues throughout the existence of the constructed buildings. Not only does it absorb carbon dioxide, but it also stores it for a period of at least 50 years as long as the construction is guaranteed, being at the same time completely recyclable. However, in order to obtain an optimal mixture from the point of view of raw material consumption, represented by industrial hemp wood chips and the binder based on lime and cement, multiple experiments are necessary. The study presented in this work is based on the use of an advanced method of experimental planning (design of experiments method), which makes possible the correlation between the values obtained experimentally and the algorithm that generated the matrix arrangement of the quantities of materials used in the recipes. This approach helps to create the necessary framework for parametric optimisation with a small number of trials. Thus, it is possible to obtain the mathematical law valid within the minimum and maximum limits of the studied domain that defines the characteristics of the material and allows the achievement of optimisation. The material is thus designed to satisfy the maximum thermal insulation requirements that it can achieve depending on a certain minimum admissible compressive strength.
PDF
