In the present study, a high-surface area activated carbon was prepared by chemical activation of lemon peel with H3PO4 as the active agent. Then, the adsorption behavior of Malachite green dye and Pb(II) ions on the produced activated carbon was studied. Batch process was employed for sorption kinetics and equilibrium studies. Experimental data were �tted to various isotherm models. According to the Langmuir model, the maximum adsorption capacities of Malachite green dye and Pb(II) ions were found to be 66.67 and 90.91 mg g-1, respectively, at room temperature. Kinetic studies showed the adsorption process followed a pseudo second-order rate model. The sorption kinetics were controlled by intra-particle diffusion. The results indicated that the produced activated carbon can be economically and effectively used as an adsorbent for the removal of Malachite green dye and Pb(II) ions from wastewaters.

Uma abordagem rápida e sem solvente envolvendo a exposição de reagentes puros a radiação de micro-ondas em conjunto com o uso dos catalisadores clinopetilolita, H3PW12O40 e nanopartículas de Fe2O3 é descrita. Neste trabalho, a condensação de cloridrato de hidroxilamina, acetato de sódio, acetoacetato ou benzoilacetato de etila e aldeídos apropriados pelo emprego dos catalisadores forneceu 5(4H)-isoxazolona em etapa única. A quantidade de catalisador, efeito de temperatura e reutilização dos catalisadores foram monitorados. Entre os catalisadores, o catalisador de nanopartículas de Fe2O3 apresentou melhor desempenho que os demais do ponto de vista de rendimento e tempo de reação. Os presentes protocolos oferecem várias vantagens, tais como tempo de reação curto, rendimento razoável, condição de reação suave e fácil reciclagem dos catalisadores.

A quick and solvent-free approach involving the exposure of neat reactants to microwave irradiation in conjunction with the use of clinoptilolite, H3PW12O40 and Fe2O3 nanoparticle catalysts is described. In this work, condensation of hydroxylamine hydrochloride, sodium acetate, acetoacetic or benzoyl acetic ethyl ester and appropriate aldehydes by employing catalysts gave 5(4H)-isoxazolone only in one step. Catalyst amount, temperature effects and catalysts reusability were monitored. Among the catalysts, Fe2O3 nanoparticles had better performance than other catalysts from viewpoint of yield and reaction time. The present protocol offers several advantages, such as short reaction time, reasonable yield, mild reaction condition and recycling catalysts with a very easy workup.