Influence of preparation method on structural,optical, magnetic,and adsorption properties of nano-NiFe2O4

Nickel ferrite (NiFe₂O₄) nanoparticles are prepared through different routes (microwave, co-precipitation, and pyrolysis) and tested for water purification applications through adsorption removal of an acid red dye B as a model organic pollutant. The characterizations of the prepared samples were done using XRD, FT-IR, SEM, TEM, BET, UV-Vis absorbance, Raman spectrum, and vibrating sample magnetometer (VSM). All samples showed an inverse spinel crystal structure. The obtained results pointed out to the effect of the synthetic route on the morphology, particle size, optical, and magnetic properties of the prepared ferrites. Magnetic measurements showed super-paramagnetic behavior for all samples. The magnetic saturation (M_s) of the sample prepared by pyrolysis, was found to possess the highest saturation value, 34.8 emu/g. Adsorption experiments were performed under the change in several parameters, such as pH, adsorbent dosage, and initial dye concentration. A dye removal percentage of 99% was reached under the optimum state. The isothermal adsorption of the acid red dye was investigated using several models, in which the experimental data could be best described by the Freundlich model. Several kinetic and equilibrium models were inspected by linear regression analysis and showed best fitting for the adsorption data through pseudo-second-order model. The calculated thermodynamic parameters indicated that the adsorption of acid red dye onto all the ferrite samples is a spontaneous and endothermic physical adsorption process.

     

Chitosan-polypropylene imine dendrimer hybrid: a new ecological biomordant for cochineal dyeing of wool

The classical use of synthetic dyes is causing issues of environmental pollution and heath risk. As a consequence natural dyes are gaining interest, but the use of natural dyes still includes toxic reagents such as metals as mordants and acids to enhance color and yield. Therefore, we designed a new chitosan-polypropylene imine dendrimer hybrid at 0–2000 mg/L to treat wool before dyeing with cochineal. We compared dye exhaustion, color depth, color characteristics, and color fastness of the new process with dyed pristine and metal mordanted wool. Results show that wool pretreatment improved dye exhaustion from 48 to 88 %, shifted saturation point toward lower dye concentration from 3000 to 1000 mg/L, and improved color depth from 13.68 for pristine wool and 15.17 for metal mordanted wool to 23.89 for the new process.     

Increased Levels of serum Pentraxin 3 in Critical Coronavirus Disease-2019 Patients

Environmental Science and Pollution Research - Pentraxin 3 (PTX3) and ficolin are the plasma phase of pattern recognition receptors (PRRs) and can activate complement through classical and lectin...     

Removal of dinitrotoluenes from water via reduction with iron and peroxidase-catalyzed oxidative polymerization: a comparison between Arthromyces ramosus peroxidase and soybean peroxidase

A two-step process for the removal of dinitrotoluene from water is presented: zero-valent iron reduction is coupled with peroxidase-catalyzed polymerization of the resulting diaminotoluenes (DAT). The effect of pH was examined in the reduction step: at pH 6 the reaction occurred much more rapidly than at pH 8. In the second step, optimal pH and substrate ratio, minimal enzyme concentration and effect of polyethylene glycol (PEG) as an additive for greater than 95% conversion of DAT, over a 3h reaction period were determined using high performance liquid chromatography. Two enzymes were investigated and compared: Arthromyces ramosus peroxidase (ARP) and soybean peroxidase (SBP). The optimal pH values were 5.4 and 5.2 for ARP and SBP, respectively, but SBP was more resistant to mild acid whereas ARP was more stable in neutral solutions. SBP was found to have a greater hydrogen peroxide demand (optimal peroxide/DAT molar ratio for SBP: 2.0 and 3.0 for 2,4-diaminotoluene (2,4-DAT) and 2,6-diaminotoluene (2,6-DAT), respectively; for ARP: 1.5 and 2.75 for 2,4-DAT and 2,6-DAT, respectively) but required significantly less enzyme (0.01 and 0.1 U ml(-1) for 2,4-DAT and 2,6-DAT, respectively) to convert the DAT than ARP (0.4 and 1.5 U ml(-1) for 2,4-DAT and 2,6-DAT, respectively). PEG was shown to have no effect upon the degree of substrate conversion for either enzyme.     

Preparation of lactic acid modified cellulose nanoparticles by microwave heating for preconcentration of copper from blood and food samples

In this study, nano-sized cellulose modified with lactic acid (MW-Ce-LA) was prepared with the assistant of microwave then used for the adsorption of Cu²⁺ from real samples. This modified cellulose was characterized by means of FTIR, TEM, XRD, and elemental analysis. ICP-OES was used for determination of Cu²⁺. The effect of pH, adsorption times, temperature, sorbent dose, and initial adsorbate concentration were studied to detect the ideal adsorption condition. Langmuir model proved to be the best to fit the adsorption isotherm experiments with maximum adsorption capacity of 90.3 mg g^?1 Cu²⁺. Calculated thermodynamic parameters (ΔG° and ΔH°) for adsorption of Cu²⁺ on MW-Ce-LA suggested exothermic and nonspontaneous character of the adsorption process. The reusability tests indicated regeneration of the prepared adsorbent simply using 1 mol L^?1 of HCl. The examined method was used effectively to preconcentrate Cu²⁺ from water, blood, and food samples.

     

Exposure to ionizing radiations and changes in blood cells and interleukin-6 in radiation workers

Environmental Science and Pollution Research - Long-term exposure to ionizing radiation (IR) can cause dire health consequences even less than the dose limits. Previous biomonitoring studies have...     

Mineral reserves under price uncertainty

National reporting organizations and regulatory bodies for the minerals and mining sector are requiring publicly reported Ore-Reserve estimates to take account of uncertainties. Whilst methodologies that account for physical uncertainty appear relatively well developed, methodologies which can take account of economic uncertainty appear much less so. To counter this shortfall, we present an efficient and general methodology which can quantify the effect of price uncertainty within reserve estimates, providing both the expected reserve size and the associated distribution (box whisker plot). This statistical information can be used by interested parties to understand precisely where the reserve risks lie, which we highlight in a worked example.     

Experimental investigation of gamma-ray attenuation in Jordanian building materials using HPGe-spectrometer

The capabilities of some building materials used in Jordan to attenuate gamma radiation were tested. Measurements of the attenuation coefficients of limestone, bricks and concrete have been carried out using a HPGe-spectrometer. Narrow beam technique was used, with a multiple gamma radiation source of different energy lines. Results indicate that variations in the attenuation coefficient for all limestone samples, at the same energy line, are within the experimental uncertainties. On the basis of the results achieved, an empirical formula mu(m)=AE(-0.44) was proposed to calculate attenuation at various incident energies. Limestone of average thickness 7cm was found to stop 75% of a gamma beam of energy 662keV. Meanwhile a brick of effective thickness 7cm was found to stop 60% of the same beam. The total attenuation coefficient of concrete calculated at 1333keV was 11.2m(-1), which is less than that of limestone and bricks.