TY  - JOUR
A1  - Reza, M. Toufiq
A1  - Rottler, Erwin
A1  - Herklotz, Laureen
A1  - Wirth, Benjamin
T1  - Hydrothermal carbonization (HTC) of wheat straw: Influence of feedwater pH prepared by acetic acid and potassium hydroxide
JF  - Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformation, production technologies
N2  - In this study, influence of feedwater pH (2-12) was studied for hydrothermal carbonization (HTC) of wheat straw at 200 and 260 degrees C. Acetic acid and KOH were used as acidic and basic medium, respectively. Hydrochars were characterized by elemental and fiber analyses, SEM, surface area, pore volume and size, and ATR-FTIR, while HTC process liquids were analyzed by HPLC and GC. Both hydrochar and HTC process liquid qualities vary with feedwater pH. At acidic pH, cellulose and elemental carbon increase in hydrochar, while hemicellulose and pseudo-lignin decrease. Hydrochars produced at pH 2 feedwater has 2.7 times larger surface area than that produced at pH 12. It also has the largest pore volume (1.1 x 10(-1) ml g(-1)) and pore size (20.2 nm). Organic acids were increasing, while sugars were decreasing in case of basic feedwater, however, phenolic compounds were present only at 260 degrees C and their concentrations were increasing in basic feedwater. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Hydrothermal carbonization
KW  - HTC biochar
KW  - pH
KW  - Fiber analysis
KW  - Pore analysis
Y1  - 2015
U6  - https://doi.org/10.1016/j.biortech.2015.02.024
SN  - 0960-8524
SN  - 1873-2976
VL  - 182
SP  - 336
EP  - 344
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Rudolph-Mohr, Nicole
A1  - Gottfried, Sebastian
A1  - Lamshöft, Marc
A1  - Zühlke, Sebastian
A1  - Oswald, Sascha
A1  - Spiteller, Michael
T1  - Non-invasive imaging techniques to study O-2 micro-patterns around pesticide treated lupine roots
JF  - Geoderma : an international journal of soil science
N2  - The soil root interface is a highly heterogeneous system, e.g. in terms of O-2 and pH distribution. The destructive character of conventional methods disturbs the natural conditions of those biogeochemical gradients. Therefore, experiments aiming to control these influences and study pesticide kinetics under given O-2 and pH conditions suffer from a large uncertainty of the "real" O-2/pH at a certain position. Our approach with two different imaging techniques will examine the soil-root interface as well as the dissipation of the applied pesticide at a high spatial resolution.
 The obtained outcomes show directly that the pH has an influence on enantioselective dissipation of the acetanilide fungicide metalaxyl. In areas with high pH from an applied racemic mixture, the R-enantiomer dissipates faster than the S-enantiomer. Moreover, we found significantly reduced oxygen values in the bulk soil and vicinity of metalaxyl treated roots compared to control plant roots. The combination of matrix-assisted laser desorption/ionization mass spectrometry (MALDI) and fluorescence imaging indicated the oxygen-dependent behavior of metalaxyl at the root surface.
 The results presented here underline the great potential of combining different imaging methods to examine the soil-root interfaces as well as the dissipation of organic pollutants in small soil compartments. (C) 2014 Elsevier B.V. All rights reserved.
KW  - MALDI imaging
KW  - Fluorescence imaging
KW  - pH
KW  - O-2
KW  - Rhizosphere
KW  - Rac-metalaxyl
Y1  - 2015
U6  - https://doi.org/10.1016/j.geoderma.2014.10.022
SN  - 0016-7061
SN  - 1872-6259
VL  - 239
SP  - 257
EP  - 264
PB  - Elsevier
CY  - Amsterdam
ER  -