Effects of Environmental Conditions on the Adsorption of NH4+-N by Rice-straw Biochar

Rice-straw biochar was prepared with rice straw as raw material at 400℃, 600℃ and 800℃. Grinding biochar through 10 mesh sieve (1.91mm aperture) and 40 mesh sieve (0.38mm aperture). By means of adsorption to research the effects of the adsorption time, environmental pH, NH4+-N concentration gradient and biochar quantity of environmental conditions on the adsorption of NH4+-N. The results show that the amount of NH4+-N adsorption increased with the increase of the adsorption time and the concentration of NH4+-N in the rice straw. 40 mg/ml biomass was most beneficial to the adsorption of NH4+-N at 400℃. The adsorption amount of NH4+-N on rice straw biochar was significantly higher than that of 400℃ and 800℃ under the same pH condition. The effect of the adsorption of NH4+-N on rice-straw-biochar in 40 mesh was better than that in 10 mesh. We recommended contact time was 12h and the initial pH value was 8.We also recommended that we should use smaller biochar particle size, more addition of biochar and higher initial NH4+-N concentration.