Synthetic organic dyes are widely used in various industrial sectors but are also among the most harmful water pollutants. In the last decade, significant efforts have been made to develop improved materials for the removal of dyes from water, in particular, on nanostructured adsorbent materials. Metal organic frameworks (MOFs) are an attractive class of hybrid nanostructured materials with an extremely wide range of applications including adsorption. In the present work, an iron-based Fe-BTC MOF, prepared according to a rapid, aqueous-based procedure, was used as an adsorbent for the removal of alizarin red S (ARS) and malachite green (MG) dyes from water. The synthesized material was characterized in detail, while the adsorption of the dyes was monitored by UV-Vis spectroscopy. An optimal adsorption pH of 4, likely due to the establishment of favorable interactions between dyes and Fe-BTC, was found. At this pH and at a temperature of 298 K, adsorption equilibrium was reached in less than 30 min following a pseudo-second order kinetics, with k″ of 4.29 × 10−3 and 3.98 × 10−2 g∙mg−1 min−1 for ARS and MG, respectively. The adsorption isotherm followed the Langmuir model with maximal adsorption capacities of 80 mg∙g−1 (ARS) and 177 mg∙g−1 (MG), and KL of 9.30·103 L∙mg−1 (ARS) and 51.56·103 L∙mg−1 (MG).

Biofuels could be defined as the fuels of the future, although much work is still required before they will replace fossil fuels. In this review, lignocellulosic biomass based on straw and related crops and wastes is described concerning its lignin contents, structure, and properties, and an overview on the means of current and predictable delignification protocols is presented. The discussion is focused on herbaceous monocot materials and their available pretreatments (physical, chemical, and enzymatic), with special emphasis on fungal ligninolytic enzymes and the most recent findings and developments in their current application, issues, and perspectives.

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