4. Conclusions
Biochars derived from agricultural/forestry wastes were proven to be a promising adsorbent of H2S with distinctive properties. The breakthrough capacities and removal rate of SR was superior to those of SB, SC, and AC because SR possessed a higher pH value. The biochar samples were basic with higher quantities of oxygen-containing functional groups than commercial AC. The FTIR spectra of the biochars provide evidence of the presence of some surface structures such as OH, COO, and C@O. Further research is needed to apply biochars derived from other wastes in the removal of H2S.