Effect of Aging Process on Physical and Chemical Properties of Rice Husk Biochar
The nature of biochar is stable, but it is not invariable. Its physical and chemical properties will change slowly over time, then impact its function. In order to clarify the influence of aging process on physical and chemical properties of biochar and its mechanism, rice husk biochar was used as the material, Using PVC column, 25 cycles of freeze-thaw cycles(30 ℃/10 d,-25 ℃/10 d)to simulate the biochar aging in climatic cabinet. The apparent structure, element composition, oxidation degree, adsorption capacity, pH value and carbonate content of biochar were analyzed. Results showed that aging damaged the biochar apparent structure, increase the surface pore with the cycles. Carbon element and the C/H ratio did not changed significantly, but the ratio of C/N, available P and N was decreased and then steady, available K from 7917 mg·kg-1 drop down to 917 mg·kg-1 decreased significantly. At the initial stage of aging treatment, the surface O/C ratio of biochar increased rapidly, after the 7th cycle, it began to decrease, and reached to stable after the 15th cycle. It was showed that the surface oxidation of biochar was rapidly in early aging, the latter tended to stable. During the 25 cycles of aging, the adsorption capacity of biochar for hydroquinone increased from 5.93 mg·g-1 to 11.73 mg·g-1. So aging treatment increased the adsorption capacity of biochar. The pH value was decreased and then increased, tends to be stable. Finally there was no significant difference with the original biochar. The carbonate content showed a downward trend and tended to be stable in 20 cycles. Comprehensive analysis showed that aging treatment had affected physical and chemical properties of biochar, and had significant influences on its available nutrients and adsorption capacity.
rice husk biocharagingphysical and chemical properties
国家科技期刊平台
NSTL
万方数据
维普
