The potential of raw pine-cone (PC) biochar and its modified form (Zn-loaded biochar) was evaluated for the removal of trivalent arsenic [As(III)] from the aqueous solution. The influence of treatment of PC biochar with Zn(NO3)2 on the physico-chemical properties of biochar was examined using elemental analyzer, surface area analyzer, thermo-gravimetric analyzer, fourier transform-infrared spectroscopy, and scanning electron microscopy. Experimental results revealed that the removal of As(III) was almost consistent (66.08±3.94% and 87.62±3.88% on raw and Zn-loaded biochar, respectively) over an acidic pH range of 2-4 as a consequence of high affinity between the positively charged biochar surface and the predominant arsenic species (H3AsO3 and H2AsO4-), followed by which a decrease in removal was observed with increase in solution pH (in the range of 4-12). Langmuir isotherm model was well fitted to the experimental equilibrium data (R2 = 0.93) rendering the maximum adsorption capacity of 5.7 µg/g and 7.0 µg/g on raw and Zn-loaded PC biochar, respectively. The adsorption of As(III) was well represented by pseudo-second order with reaction rate constant (k2) of 0.040 mg/g.min and 0.282 mg/g.min on raw and Zinc-loaded PC biochar, respectively, and was mainly controlled by boundary layer diffusion followed by some extent of intra-particle diffusion. The adsorption process was spontaneous with Gibb's free energy (G0, -4.42±0.72 kJ/mol and -11.86±1.78 kJ/mol) and exothermic in nature with enthalpy (H0, 13.25 kJ/mol and 31.10 kJ/mol) and entropy (S0, 0.058 kJ/mol/K and 0.141 kJ/mol/K) for raw and Zinc-loaded adsorbent, respectively.