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Lignocellulosic biomass represents one of the most important feedstocks for future biorefineries, being a precursor of valuable bio-products, obtainable through both chemical and biological conversion routes. Lignocellulosic biomass has a complex matrix, which requires the careful development of multi-step approaches for its complete exploitation to value-added compounds. Based on this perspective, the present work focuses on the valorization of hemicellulose and cellulose fractionsof giant reed (Arundo donax L.) to give second-generation sugars, minimizing the formation of reaction by-products. The conversion of hemicellulose to xylose was undertaken in the presence of the heterogeneous acid catalyst Amberlyst-70 under microwave irradiation. The effect of the main reaction parameters, such as temperature, reaction time, catalyst, and biomass loadings on sugars yield was studied, developing a high gravity approach. Under the optimised reaction conditions (17 wt% Arundo donax L. loading, 160 °C, Amberlyst-70/Arundo donax L. weight ratio 0.2 wt/wt), the xylose yield was 96.3 mol%. In the second step, the cellulose-rich solid residue was exploited through the chemical or enzymatic route, obtaining glucose yields of 32.5 and 56.2 mol%, respectively. This work proves the efficiency of this innovative combination of chemical and biological catalytic approaches, for the selective conversion of hemicellulose and cellulose fractions of Arundo donax L. to versatile platform products. [ABSTRACT FROM AUTHOR]

• MW-assisted hydrolysis of Arundo donax L. was investigated. • Two-steps hydrolysis catalysed by FeCl 3 was optimized. • The highest xylose yield was 98.2 mol% respect to xylan. • The highest levulinic acid yield was 57.6 mol% respect to glucan. • This cascade approach allowed the extensive valorisation of carbohydrates. The present work aimed to investigate and optimize the selective exploitation of hemicellulose and cellulose fractions of the energy crop Arundo donax L. (giant reed), to give xylose and levulinic acid, respectively. In order to improve the sustainability of this process, a microwave-assisted hydrolysis in the presence of FeCl 3 was implemented using as substrate the raw biomass without any pretreatment process. The effects of the hydrolysis reaction conditions, such as temperature, reaction time, salt amount and biomass loading, on giant reed exploitation were investigated. In the first step, under the optimized conditions (150 °C, 2.5 min and 1.6 wt% FeCl 3), the xylose yield reached 98.2 mol%. In the second step, under the best conditions (190 °C, 30 min and 2.4 wt% FeCl 3), the levulinic acid yield was 57.6 mol%. This novel cascade approach ensured an extensive exploitation of giant reed polysaccharides working in the respect of Green Chemistry principles. [ABSTRACT FROM AUTHOR]

Constructed wetland systems for wastewater treatment represent an excellent opportunity for the recovery of water resources in those areas subject to prolonged periods of water shortage. This paper presents a study of the efficiency of a pilot horizontal subsurface flow system using pre-treated urban wastewater from a small town in the West of Sicily. The pilot system had a total surface area of 100 m² with two units. Unit A was planted with Arundo donax L. and unit B with Cyperus alternifolius L. The HLR was 10cm d-1. The main objectives of research were to evaluate the growth and biomass yield of two macrophytes and to determine the removal efficiency of physical-chemical and microbiological parameters. The results showed excellent organic pollutant removal (BOD5 70-72%, COD 61-67%), whilst macronutrient removal was found to be lower (TKN 47-50%, TP 43-45%). Pathogen load removal was found to be approximately 90%, but Escherichia coli concentrations at outflow were not within Italian legislative limits. Giant reed showed higher nitrogen content in the biomass (an average 28.9 ± 1.8 g m-2 year-1 and 63.8 ± 1.8 g m-2 year-1 for the aboveground and belowground parts, respectively) than umbrella sedge. The treated wastewater was used to irrigate parkland areas. [ABSTRACT FROM AUTHOR]

Arundo donax L., common name giant cane or giant reed, is a plant that grows spontaneously in different kinds of environments and that it is widespread in temperate and hot areas all over the world. Plant adaptability to different kinds of environment, soils and growing conditions, in combination with the high biomass production and the low input required for its cultivation, give to A. donax many advantages when compared to other energy crops. A. donax can be used in the production of biofuels/bioenergy not only by biological fermentation, i.e. biogas and bio-ethanol, but also, by direct biomass combustion. Both its industrial uses and the extraction of chemical compounds are largely proved, so that A. donax can be proposed as the feedstock to develop a bio-refinery. Nowadays, the use of this non-food plant in both biofuel/bioenergy and bio-based compound production is just beginning, with great possibilities for expanding its cultivation in the future. To this end, this review highlights the potential of using A. donax for energy and bio-compound production, by collecting and critically discussing the data available on these first applications for the crop., (Copyright © 2014 Elsevier Inc. All rights reserved.)