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Non-condensable volatile organic compounds (VOCs) in the gases from pyrolysis of the three main lignocellulosic biomass components were studied. Cellulose, lignin and hemicellulose, the last replaced by xylan, were pyrolysed at a temperature up to 900oC. Atmosphere Pressure - Temperature Programmed (AP-TP) equipment for analytical pyrolysis coupled "off-line" with TD-GC/MS technique was used. Quantitative information for the composition of compounds emitted as non-condensable VOCs and PAHs in pyrolysis gas was obtained. Total amounts of noncondensable VOCs from pyrolysis of a cellulose and xylan were comparable, 3141 - 3409 µg/g, but considerable lower for lignin, 667 µg/g. PAHs amounts were 105 µg/g for cellulose, 168 µg/g for xylan, and 27 µg/g for lignin, respectively. Their identification and quantification is important, especially in the cases of industrial pyrolysis where tons of biomass are converted into "value-added" products, i.e. bio-gas and bio-oil, besides char. In addition, non-condensable volatiles produced during biomass pyrolysis and emitted in the atmosphere are of environmental importance and should be tracked and validated. [ABSTRACT FROM AUTHOR]

Comprehending the decomposition process is crucial for our understanding of the mechanisms of carbon (C) sequestration in soils. The decomposition of plant biomass has been extensively studied. It revealed that extrinsic biomass properties that restrict its access to decomposers influence decomposition more than intrinsic ones that are only related to its chemical structure. Fungal biomass has been much less investigated, even though it contributes to a large extent to soil organic matter, and is characterized by specific biochemical properties. In this study, we investigated the extent to which decomposition of heathland fungal biomass was affected by its hydrophobicity (extrinsic property) and melanin content (intrinsic property). We hypothesized that, as for plant biomass, hydrophobicity would have a greater impact on decomposition than melanin content. Mineralization was determined as the mineralization of soil organic carbon (SOC) into CO2 by headspace GC/MS after inoculation by a heathland soil microbial community. Results show that decomposition was not affected by hydrophobicity, but was negatively correlated with melanin content. We argue that it may indicate that either melanin content is both an intrinsic and extrinsic property, or that some soil decomposers evolved the ability to use surfactants to access to hydrophobic biomass. In the latter case, biomass hydrophobicity should not be considered as a crucial extrinsic factor. We also explored the ecology of decomposition, melanin content, and hydrophobicity, among heathland soil fungal guilds. Ascomycete black yeasts had the highest melanin content, and hyaline Basidiomycete yeasts the lowest. Hydrophobicity was an all-or-nothing trait, with most isolates being hydrophobic. [ABSTRACT FROM AUTHOR]

Soil metal pollution can trigger evolutionary adaptation in soil-borne organisms. An in vitro screening test showed cadmium adaptation in populations of Suillus luteus (L.: Fr.) Roussel, an ectomycorrhizal fungus of pine trees. Cadmium stress was subsequently investigated in Scots pine (Pinus sylvestris L.) seedlings inoculated with a Cd-tolerant S. luteus, isolated from a heavy metal contaminated site, and compared to plants inoculated with a Cd-sensitive isolate from a non-polluted area. A dose–response experiment with mycorrhizal pines showed better plant protection by a Cd-adapted fungus: more fungal biomass and a higher nutrient uptake at high Cd exposure. In addition, less Cd was transferred to aboveground plant parts. Because of the key role of the ectomycorrhizal symbiosis for tree fitness, the evolution of Cd tolerance in an ectomycorrhizal partner such as S. luteus can be of major importance for the establishment of pine forests on Cd-contaminated soils. [Copyright &y& Elsevier]

Two Salix genotypes ( Salix alba , clone LUC-31—genotype I and Salix viminalis , clone STOTT—genotype II) were grown hydroponically for 14 d at increasing concentrations of cadmium (Cd) (0, 5, 10, and 15 μM) in order to study both Cd accumulation and genotype tolerance. Growth responses, photosynthetic performance, activities of metal-responsive enzymes, and changes in some nutrients content were used as evaluation criteria. The Genotype II assimilated more Cd (maximum leaf concentration 47.8± 2.9 mg Cd kg -1 DW) compared with the Genotype I and, based on both morphological (root length, total biomass) and metabolic indicators (photosynthetic performance, activities of metal-responsive enzymes, changes in several nutrients), was classified as less tolerant to this heavy metal. However, it is considered to be more suitable for Cd phytoextraction, as it would compensate for its somewhat lower tolerance with its higher Cd accumulation, as well as its higher productivity under field conditions. [ABSTRACT FROM AUTHOR]

Abstract: Treatment and/or disposal of metal contaminated biomass are still an unsolved problem. Knowledge of the metal distribution is of prime importance concerning the application of pyrolysis product streams. Sorghum bicolor (L.) Moench was cultivated in a semi-hydroponic system to assess its potential use in phytoremediation and biomass production. Plants were grown in a greenhouse using perlite as substrate, half-strength Hoagland's solution as control (CTR) and the same solution supplemented with a mixture of Ni and Zn (CTM; 10 g m−3 each). Shoot and root biomass were determined and analyzed for their metals content. Flash and slow pyrolysis were performed on S. bicolor shoots at 450 °C. Biomass and pyrolysis products were analyzed focusing on metal distribution. Mass and energy balances were determined. S. bicolor delivered good shoot biomass with relatively moderate concentrations of Ni and Zn. Metal concentrations in the pyrolysis oils were below detection limits and almost all metals accumulated in the char. In fact, 99% of Ni and 98% of Zn were recovered in the char when a slow pyrolysis process was applied, while in flash pyrolysis conditions both metals were found back in the char and in the heating transfer medium. Furthermore, the percentages of char and oil were higher in slow pyrolysis compared to flash pyrolysis. Energy recovery in the char from slow pyrolysis was higher than flash pyrolysis. Flash and slow pyrolysis can likely offer a valuable processing method for metal contaminated biomass, thus limiting the waste disposal problem associated with phytoremediation of metals. [Copyright &y& Elsevier]