The Using of Nanoparticles of Microalgae in Remediation of Toxic Dye from Industrial Wastewater: Kinetic and Isotherm Studies

Batch adsorption experiments were carried out to study the removal of the toxic Methylene Blue Dye (MBD) from synthetic aqueous solutions using the nanoparticles form of Arthrospira platensis NIOF17/003. The adsorption capacity of the adsorbent for MBD was investigated using different amounts of A. platensis nanoparticles at different contact times, temperatures, pH, and MBD initial concentrations in the synthetic aqueous solution. In addition, A. platensis nanoparticles were characterized using Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier Transform Infrared (FTIR), and Ultraviolet spectra (UV) techniques. The optimum removal of MBD was found at a concentration of 0.4 g A. platensis nanoparticles. A. platensis nanoparticles remove 93% of MBD in 5 min (under agitation conditions at 150 rpm). The highest adsorption capacity was found by the Langmuir model to be 58.8 mg g⁻¹. It is an endothermic process with spontaneity increasing with temperature. The probable mechanism for the adsorption is chemisorption via surface-active charges in the initial phase, which is followed by physical sorption by occupying pores of A. platensis. MBD adsorption by A. platensis follows pseudo-second-order kinetics. The Freundlich and Langmuir models fit well with the experimental data. The adsorption experiments suggested that the regeneration of the adsorbents was possible for repeated use, especially regarding MBD up to 65.8% after three cycles, which proves it can be easily recycled. In conclusion, the nanoparticles of A. platensis have a significant adsorption potential in the removal of MBD from effluent wastewater.     

Green Synthesis of Zinc Oxide Nanoparticles Using Red Seaweed for the Elimination of Organic Toxic Dye from an Aqueous Solution

This study aims to produce green zinc oxide nanoparticles (ZnO-NPs) derived from red seaweed (Pterocladia Capillacea) and evaluate their potential to absorb Ismate violet 2R (IV2R) ions from an aqueous solution. UV-vis spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and a Brunauer–Emmett–Teller surface area analysis (BET) were used to analyze the structural, morphological, and optical features of the synthesized nanoparticles. The change in color of the chemical solution revealed the formation of zinc oxide nanoparticles. The FTIR examination confirmed the synthesis of both Zn and ZnO nanoparticle powder, with a BET surface area of 113.751 m² g⁻¹ and an average pore size of 2.527 nm for the synthesized adsorbent. Furthermore, the maximum removal effectiveness of IV2R was 99% when 0.08 g ZnO-NPs was applied at a pH of 6, a temperature of 55 °C, and a contact time of 120 min. The dye adsorption capacity of the ZnO-NPs was 72.24 mg g⁻¹. The adsorption process was also controlled by the Freundlich adsorption model and pseudo-second-order reaction kinetics. The adsorption of IV2R ions onto the ZnO-NPs could be represented as a nonideal and reversible sorption process of a nonuniform surface, according to Freundlich adsorption isotherms. In addition, the constant values of the model parameters were determined using various nonlinear regression error functions. Moreover, thermodynamic parameters such as entropy change, enthalpy change, and free energy change were investigated; the adsorption process was spontaneous and endothermic. The high capacity of the ZnO-NPs synthesized by red seaweed promotes them as promising substances for applications in water treatment for the removal of IV2R dye from aqueous systems.     

继发于前额粘液囊肿的眼眶脓肿1例

目的:报告1例继发于前额粘液囊肿的左眼眶脓肿患者。方法:病例报告。结果:1例30岁马来西亚妇女,表现为左眼疼痛、肿胀3d,伴视力下降和上眼睑下垂。CT报告左额窦粘液囊肿蔓延至左眶内。手术引流治疗,视力和上眼睑下垂很快改善。结论:眼眶脓肿可继发于前额粘液囊肿,而且患者可无鼻旁窦既往病史。     

Apparent induction of microsomal carboxylesterase activities in tissues of clofibrate-fed mice and rats

Treatment with 0.5% (w/w) dietary clofibrate, a peroxisome proliferator, for 14 days induced microsomal carboxylesterase activities for five substrates including malathion, clofibrate, diethylsuccinate, diethylphthalate, and p-nitrophenylacetate in liver and kidney of male Swiss-Webster mice and Sprague-Dawley rats. The induction was substrate, tissue, and species dependent. The carboxylesterase activity was induced in mouse from 1.2- to 2.2-fold (liver) and from 1.1- to 1.7-fold (kidney) depending upon substrate used. Analogous values from rat ranged from 1.0- to 1.4-fold (liver) and from 1.1- to 1.8-fold (kidney). Enzyme activities were either decreased or not affected in testes of treated mice and rats. Substituted trifluoroketones ("transition-state" inhibitors of carboxylesterase) were found to be very potent inhibitors of clofibrate-metabolizing carboxylesterase(s) and to be potentially useful in distinguishing among isozymes. The inhibition data suggested that changes in carboxylesterase activity following clofibrate treatment were both qualitative and quantitative.