Abstract

A pilot-scale Hybrid Membrane Bioreactor (HMBR) containing both suspended biomass and biofilm was tested for the treatment of a low strength municipal wastewater. The wastewater fed was characterized by a high variability throughout the day, low BOD5/TN ratio and low alkalinity (302 ± 52 mgCaCO3/L). For limiting membrane fouling, an innovative abrasive granular material has been proven in the Microdyn-Nadir membrane. Permeability ranged from 126 to 291 L/(h m2 bar) during the operational period, achieving a maximum flux of 24 L/(m2 h). A low BOD5/TN ratio of the raw wastewater, led to insufficient denitrification, with an average nitrogen removal of 49%. This fact, in turn, caused a decrease in the pH due to the lack of alkalinity. This study underlined that wastewaters characterized by high variability throughout the day, low BOD5/TN ratio and/or low alkalinity content require carefully design of the MBR systems. It was shown that a low pH in the HMBR led to a strong membrane fouling increasing cake resistances.

https://doi.org/10.1016/j.scitotenv.2017.09.278

Abstract

Life Cycle Assessment (LCA) methodology was used to estimate the environmental impacts and identify the most critical stages (hotspots) of cultivation of three cereal crops typically used for animal feed purposes – barley, rye and sorghum – in the Lombardy region, the most productive crop and livestock area in Northern Italy. The crop variety (out of 3 and 4 varieties of barley and rye, respectively) and cultivation regime (single vs. double cropping of sorghum) with the lowest impacts per kg of crude protein (mass-based functional unit) were identified. Environmental impact categories reported by ReCiPe method were used. According to the results, both Reni and Dank Nowe were the varieties with the lowest environmental impacts for barley and rye varieties, respectively; single cropping of sorghum had lower impacts than double cropping. Impact hotspots included field emissions, agricultural activities and agrochemical (fertilisers and herbicides) production regardless the cropping system considered. Moreover, among the cereals studies, rye was identified as the best environmental alternative. Use of land-based and economic functional units did not change the ranking of systems according to their impacts.

https://www.sciencedirect.com/science/article/pii/S0964830517308399 DOI: 10.1016/j.ibiod.2017.10.010

http://dx.doi.org/10.1080/10242422.2017.1316489

Abstract

This paper assesses the environmental profile of the biscuit supply chain for producing high quality gluten-free biscuits. Three different types of biscuits were considered. The assessment followed a cradle-to-grave approach applying the ISO standards in compliance with the Product Category Rules (PCR) defined within EPD (Environmental Product Declaration) for bakery products. Analogous environmental profiles were implemented for assessing the products: It was found that the main hotspot in all impact categories was ingredients production with the range contribution from 22.2% to 84.9%, followed by transportation. Initial hypotheses for ingredients origin and waste management practices were demonstrated to have a key influence on the environmental results: higher packaging recycling rates and local ingredients usage led to improved environmental results (up to 5.5%) while direct food waste disposal was responsible for slightly unfavourable performance relative to base case (below 1%). Additionally, healthier ingredients such as xylitol and fructose were used to evaluate their potential benefits from an environmental perspective. It was found that only the use of fructose was a suitable alternative sweetener for more sustainable production.

http://dx.doi.org/10.1080/10242422.2017.1315411

Abstract

Nonisothermal autohydrolysis treatments of vine shoots were used as a method for hemicellulose solubilization and xylooligosaccharides (XOS) production. The proposed kinetic model allowed the selection of the operational conditions that maximize the oligosaccharides content and minimize the generation of undesired compounds such as monosaccharides and sugar-decomposition products. In this sense, the maximum value of XOS (9.9 g/100 g raw material) was obtained at 200 °C. The liquid fraction containing oligosaccharides was highly stable against heat and pH (degradation below 10%), demonstrating its potential as functional food ingredients. On the other hand, the cellulose-enriched solid fraction was subjected to enzymatic digestibility, obtaining 49.5% of total glucan hydrolysis after 96 h. In this work, the holistic use of wine shoots following a biorefinery concept has been proposed. However, a delignification step of the cellulose-enriched solid fraction should be included in order to increase the enzymatic digestibility, and hence allow the integral use of this byproduct.