The WEOC concentration of the filtrate was determined with a Multi N/C 3100 analyzer (Jena, Germany), while the UV absorbance characteristic at 280 nm was measured by UV/VIS-2450 to evaluate the aromaticity of biochar WEOC content (Weishaar et al.
Change of biochar WEOC content and the UV absorbance
At beginning, the WEOC content of biochar samples varied from 359.
Before incubation, the UV absorbance values of WEOC varied from 0.
Biochar pH and WEOC were positively correlated with axis of RDA 1, while TN, TP were negatively related to RDA1.
Though the WEOC fraction accounts for a small proportion, as shown only 0.
The OC concentration of the WEOC extracts was determined after dichromate digestion by titrating with 0.
The WEOC sorption data were analysed by 2-way ANOVA with WEOC concentration and clay subsoil as fixed factors.
All soils released WEOC when shaken with water (no WEOC added; Fig.
To determine which soil properties influence WEOC sorption at, or close to, the maximum sorption capacity, correlations between WEOC sorption at 9 g WEOC [kg.
The batch sorption experiment showed that the WEOC sorption capacity of clay subsoils differed and was related to soil properties.