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[en] Whereas energy and agricultural prospective scenarios aiming at limiting global warming rely on a significant mobilization of agricultural biomass for the deployment of methanization, this publication highlights conditions according to which it will be a lever for energy transition. It proposes an overview of scientific knowledge, and an identification of research axes. Thus, after a discussion of the role of agricultural methanisation in energy and agriculture transitions, and of opportunities for the development of methanization in France, this publication presents a participatory approach to the identification of sustainability stakes for this sector, to the sharing of scientific knowledge and agricultural practices, and to the formulation of recommendations. Three sustainability conditions are then formulated and discussed. The use of intermediate crops for energy valorization (Chive) and digestate valorization are then addressed and discussed in terms of sustainability. Stakes are then identified and recommendations are made for agricultural methanization 'scale-up'
[en] Highlights: • MIBK/H2O pretreatment with biphasic system was applied to treat Eucalyptus. • Treatment condition had obvious effect on yield of furfural and glucose conversion. • Optimum condition was obtained (VMIBK:VH2O = 5:5, 150 °C, 60 min, 0.3 M HCl). • MIBK/H2O pretreatment was effective for production of clean energy and biochemical. - Abstract: Forest wood biomass can be a sustainable and cost-effective feedstock for the biorefinery industries, but the rigid and compact structure of plant cell is a major barrier for production of clean energy and biochemical. In this case, the MIBK/H2O pretreatment with biphasic system was applied to treat Eucalyptus and then systematically evaluated pretreatment conditions (e.g., MIBK/H2O ratio, reaction temperature and time, NaCl concentration, and HCl dosage) on the effect of furfural yield. The resulting solid fraction obtained from the optimum pretreatment condition for furfural yield was to produce fermentable glucose by enzymatic hydrolysis. Study on enzymatic hydrolysis of the raw material and resulting solid fraction obtained by single aqueous system was also contrastively investigated. The furfural yield was 65.9% and the recovery of residue was 46.9% under an optimal reaction condition (VMIBK:VH2O = 5:5, 150 °C, 60 min, 0.3 M HCl). Meanwhile, the yield of glucose of cellulose was improved after the pretreatments with different systems and a maximum value was up to 60.2% by the MIBK/H2O pretreatment. The effective fermentable glucose production was mainly affected by the significant removal of hemicelluloses, change of CrI, and destruction of surface morphology of Eucalyptus. The MIBK/H2O pretreatment can be considered as a potential approach for efficient conversion of Eucalyptus to clean energy and biochemicals.
[en] The relationship between diversity and productivity of plant community under plant invasion has been not well known up to now. Here, we investigated the relationship between diversity and productivity under plant invasion and studied the response of species level plant mass to species richness in native and invaded communities. A field experiment from 2008 to 2013 and a pot experiment in 2014 were conducted to study the effects of plant invasion on the relationship between diversity and productivity and the response of species level plant mass to species richness in native and invaded communities. The community level biomass was negatively correlated to plant species richness in invaded communities while the same relationship was positive in native communities. The species level plant mass of individual species responded differently to overall plant species richness in the native and invaded communities, namely, most of the species’ plant mass increased in native communities, but decreased in invaded communities with increasing species richness. The complementarity or selection effects might dominate in native communities while competition effects might dominate in invaded communities. Accordingly, the negative relationship between diversity and productivity under plant invasion is highlighted in our experiments.
[en] This study is concerned with the sorption behavior of natural radionuclides (226Ra, 210Po, 228Th - originated from TENORM waste associated with petroleum industry) onto silica/olive pomace nanocomposite. Initially, nanocomposites of extracted silica and olive pomace are prepared and characterized by physicochemical techniques. In the batch technique, 60% SiO2 40% olive pomace (AM3) nanocomposite showed a considerable group sorption for 226Ra and 210Po larger than 228Th in 1M HNO3 and HClO4 solutions. In case of sorption by the compacted disc, sorption of 226Ra was similar to batch method, sorption of 228Th increased slightly to ∼ 17%, while sorption of 210Po was decreased to 77%. Thus, AM3 nanocomposite can be considered as an efficient nano-adsorbent for sorption and separation of Ra-isotopes and 210Po-radionuclides from 226Ra-210Po-228Th admixture associated with nuclear and non-nuclear industries. (author)
[en] Various approaches can minimize biomass accumulation in biotricking filters (BTF), which can be classified as: (1) physical, (2) chemical and (3) biological. Other approaches include (4) improvement of the bioreactor design and (5) modification of the mode and operational parameters. All of these methods involve either reduction in biomass growth or removal of excess biomass and each method has unique advantages and disadvantages as far as biomass reduction capability, sustainability and ease of integration to the system are concerned, which are compared and contrasted in this review. A careful comparison and analysis of these methods is a requisite to an optimum operation of a BTF system.
[en] Stillage is an abundant wastewater from the sugarcane ethanol industry. It is rich in fermentable substrates and presents low-nutrient content, constituting a promising substrate for polyhydroxyalkanoate (PHA) production by mixed microbial cultures (MMC). This work assessed the enrichment of a PHA-accumulating MMC from acidified sugarcane stillage in a sequencing batch reactor under increasing organic loading rates (OLR) and no external nutrient supplementation. The OLR was increased from 1.0 to 7.1 kg COD m−3 day−1 in four steps. A PHA-producing MMC with high storage response was selected in all experimental conditions. The volumetric biomass productivity and the maximal PHA storage capacity increased continuously with the OLR, reaching 0.061 g VSS L−1 h−1 and 0.49 g PHA g VSS−1, respectively. The highest observed PHA storage yield (0.60 g CODPHA g COD.t−1) and specific PHA storage rate (0.169 g CODPHA g of CODX h−1) were obtained for the OLR of 4.5 kg COD m−3 day−1. The PHA produced was a co-polymer of 3-hydroxybutyrate (86–77%mol) and 3-hydroxyvalerate (14–23%mol). The performance of the biomass enrichment was comparable to those attained with other agro-industrial wastewaters, indicating the potential of acidified sugarcane stillage as a feedstock for MMC PHA production.
[en] We evaluated variation in root turnover across five root orders in sugar maple (Acer saccharum Marsh.) saplings growing in a northern hardwood forest in central New York, USA. We used a stable isotope approach in which root systems were labeled with 13C and root structural C sequentially sampled for 13C enrichment. Turnover of first- and second-order roots was apparently rapid with only about 5% of the 13C retained in living roots after two growing seasons. Although third- to fifth-order roots appeared to persist longer, differences among root orders were not statistically significant, probably mostly because of highly nonuniform initial labeling. This nonuniform labeling constrains the precision of root turnover quantification using this approach. (author)
[en] Highlights: • Characterisation of different types sewage sludge for pyrolytic properties. • Developed analytical procedure to categorise and quantify composition of sludge. • Observed qualitative similarity and quantitative variation on properties of sludge. • Correlated organic components with thermochemical properties of sludge. • Coupled model compounds selection and composition analysis for simulation study. - Abstract: Pyrolytic behaviour of sludge is highly complex and obscure because of its heterogeneous and diverse composition. Therefore, an analytical procedure is proposed to categorise and quantify the main constituents in sludge. In addition, a simulation study of sludge characteristics is carried out to complement the composition analysis and to improve our understanding on the relationship between composition of sludge and its corresponding properties. Different types of sludge samples were collected at different treatment stages from four Water Reclamation Plants in Singapore in two separate batches. Model compounds are selected to represent components identified and are used in simulation of pyrolytic properties of sludge. Constituents of sludge are adequately categorised, quantified and characterised in this study. Qualitative similarities and quantitative variations on characteristics of different sludge samples were identified. Comparison among the samples collected with the simulation provided insights on how differences in organic composition of sludge affected its properties.
[en] Metal hyperaccumulation can increase plant resistance to herbivory, but tolerance as an herbivore defense has been little investigated. This study explored the interaction between Ni hyperaccumulation and herbivory tolerance using Streptanthus polygaloides. Plants were grown in one of two potting soil Ni treatments: Ni-amended (800 µg g−1 added Ni) or unamended (0 µg g−1 added Ni). One-month-old plants were arbitrarily assigned one of four levels of artificial herbivory damage applied to the leaves. Response variables included aboveground dry biomass and Ni concentration, total leaf number, final plant height, and total number of flowers, and were analyzed by two-way ANOVA. We found no consistent soil Ni effect, artificial herbivory effect, or interaction between soil Ni and artificial herbivory treatments for total leaf number or final plant height. However, there was a soil Ni effect for biomass, flower production, and Ni concentrations: all were greater for plants grown in Ni-amended soil when compared to plants grown in unamended soil. There was also a significant interaction between treatments for number of flowers produced (reflecting plant fitness) as well as for aboveground biomass. Plants of S. polygaloides receiving greater damage produced significantly more flowers, and had greater biomass, when grown in Ni-amended soil than plants in unamended soil. We conclude that Ni hyperaccumulation is associated with herbivory tolerance of S. polygaloides, increasing plant fitness when herbivory damage is severe. Herbivory tolerance provides an additional dimension to elemental defenses that can supplement the defense trait of herbivory resistance.