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Infrared and 13C solid state nuclear magnetic resonance spectroscopies and benzene polycarboxylic acids (BPCA) analysis were used to characterize the structural changes occurring during slow pyrolysis of corncob and Miscanthus at different temperatures from 235°C to 800°C. In the case of corncob, a char sample obtained from flash carbonization was also investigated. Spectroscopic techniques gave detailed information on the transformations of the different biomass components, whereas BPCA analysis allowed the amount of aromatic structures present in the different chars and the degree of aromatic condensation to be determined. The results showed that above 500°C both corncob and Miscanthus give polyaromatic solid residues with similar degree of aromatic condensation but with differences in the structure. On the other hand, at lower temperatures, char composition was observed to depend on the different cellulose/hemicellulose/lignin ratios in the feedstocks. Flash carbonization was found to mainly affect the degree of aromatic condensation.

This paper in a uniform manner examines temporal trends in phosphorus (P) concentrations and losses from small and well-monitored agricultural catchments in the Nordic and Baltic countries. Thirty-four catchments (range 0.1-33 km 2 ) in Norway (8), Denmark (5), Sweden (8), Finland (4), Estonia (3), Latvia (3) and Lithuania (3) were selected for the study. The time series ranged from 10 (2002-2011) to 21 years . The monthly P concentration and loss time series were tested for significant monotone trends (p < 0.05; two-sided test) using the partial Mann-Kendall test with stream discharge as an explanatory variable. The results show a large variation in concentrations and losses of total phosphorus (TP) among the 34 studied catchments, where the long-term mean annual losses varied from 0.09 to 7.5 kg TP ha −1 . In addition, a large interannual variability in losses within catchments was found with up to a factor of 23 between years within the same catchment. Six catchments showed downward temporal trends in the TP loss time series. One upward trend in TP losses was detected in a catchment in south-west Sweden. Eight downward trends were detected in the TP concentration time series. Overall, our results show (1) a huge variability in mean P losses and concentrations among catchments, (2) a huge temporal variability in losses within catchments and (3) few detectable changes in P losses and concentrations over the study period. The results showcase the need for implementation of mitigation strategies towards reduced P losses from agricultural landscapes in the Nordic/Baltic Sea region in order to improve P water quality and ecology in surface waters.

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