Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
This paper presents a comparative review of arsenite (As(III)), arsenate (As(V)), and fluoride (FâË?â??) for a better understanding of\nthe conditions and factors during their adsorption with focus on (i) the isotherm adsorption models, (ii) effects of pH, (iii) effects\nof ionic strength, and (iv) effects of coexisting substances such as anions, cations, and natural organics matter. It provides an indepth\nanalysis of various methods of arsenite (As(III)), arsenate (As(V)), and fluoride (FâË?â??) removal by adsorption and the anionsââ?¬â?¢\ncharacteristics during the adsorption process. The surface area of the adsorbents does not contribute to the adsorption capacity of\nthese anions but rather a combination of other physical and chemical properties.Theadsorption capacity for the anions depends on\nthe combination of all the factors: pH, ionic strength, coexisting substances, pore volume and particles size, surface modification,\npretreatment of the adsorbents, and so forth. Extreme higher adsorption capacity can be obtained by the modification of the\nadsorbents. In general, pH has a greater influence on adsorption capacity at large, since it affects the ionic strength, coexisting\nanions such as bicarbonate, sulfate, and silica, the surface charges of the adsorbents, and the ionic species which can be present in\nthe solution....
Alkalinity determination is of crucial significance for the applications of basic ionic liquids with imidazolyl. In this work, the\nionization constant p...
Theaimof this study was to develop an inexpensive apparatus for fabricating microspheres, based on chitosan, for 5-fluorouracil (5-\nFU) controlled release. Chitosan microspheres were prepared by precipitationmethod and the effects ofmanufacturing parameters\n(injection and airflow rates) on size distribution microspheres were analyzed by optical and scanning electron microscopy. The\nresults show that the manufacturing parameters, injection and airflow rates, determine the microsphere size distribution. By\nmodulating these parameters, it was possible to produce chitosan microspheres as small as 437 �± 44 ...
Pyrolysis properties and kinetic analysis of lake sediment, as well as evolution characteristics of the gaseous products at 5âË?Ë?C/min,\n10âË?Ë?C/min, and 20âË?Ë?C/min, were investigated by TG-FTIR. Comparison to the TG and DTG curves at different heating rates, the\npyrolysis process at 10âË?Ë?C/min could describe the sediment pyrolysis characteristics better than at 5âË?Ë?C/min and 20âË?Ë?C/min; thus the\nprocess of sediment pyrolysis could be considered as four stages. Fromthe kinetics analysis, the nth-order chemical reactionmodel\nwas suitable to describe the sediment pyrolysis reaction well. The values of n were within 2.55ââ?¬â??3.42 and activation energy ...
Over the past few years, great attention is paid to syngas production processes from\ndifferent resources especially from abundant sources, such as methane. This review of the literature\nis intended for syngas production from methane through the dry reforming (DRM) and the steam\nreforming of methane (SRM). The catalyst development for DRM and SRM represents the key factor\nto realize a commercial application through the utilization of more efficient catalytic systems. Due to\nthe enormous amount of published literature in this field, the current work is mainly dedicated to\nthe most recent achievements in the metal-oxide catalyst development for DRM and SRM in the\npast five years. Ni-based supported catalysts are considered the most widely used catalysts for\nDRM and SRM, which are commercially available; hence, this review has focused on the recent\nadvancements achieved in Ni catalysts with special focus on the various attempts to address the\ncatalyst deactivation challenge in both DRM and SRM applications. Furthermore, other catalytic\nsystems, including Co-based catalysts, noble metals (Pt, Rh, Ru, and Ir), and bimetallic systems have\nbeen included in this literature review to understand the observed improvements in the catalytic\nactivities and coke suppression property of these catalysts...
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