Abstract:
Sorption capacity of two different biochar (saw dust and rice straw) was evaluated in
the recovery of arsenic from aqueous solutions. Biochar from rice straw and saw dust
were obtained from pyrolysis of biomass at 400◦
C. The optimum sorption conditions
were studied for different concentrated monometallic system. Sorption studies were
performed at different pH, contracting time and different initial metal ion concentration
in the batch mode. The optimum pH was 3 for recovery of As(III) and kinetic studies
yielded an optimum equilibrium time of 50-60 minutes with an adsorbent dose of
1 g/L and initial concentration ∼20 mg/L for As(III) ions. As(III) ions in aqueous
solution were transported to biochar surface through adsorption and intra-particle
diffusion process. Experimental data for As(III) ions was fitted a Langmuir model
with R2 value for As(III) 0.969, 0.879 for saw dust and rice straw respectively. The
Freundlich constant, KF values for removal of As(III) ions by saw dust and rice straw
were 0.9127, 0.8951 respectively. The 1/n value for arsenic ions obtained from saw
dust and rice straw were 0.209, 028 and indicate the normal sorption of As(III). The
values indicated the affinity of the sorbent towards the uptake of As(III) ions were
favorable and rice straw and saw dust biomass can be used to remove Arsenic(III)
ions from aqueous phase.
