Physicochemical Characteristics of Activated Biochar Derived from Different Sources

An experiment was carried out to study the characteristics of biochar made from rice husk, rice straw, Toria stover and bamboo leaves. Biochar was produced by slow pyrolysis system (300 – 4000C). Locally available bio-wastes viz. rice husk, rice straw, toria stover and bamboo leaves were used as raw materials to produce chars. Two samples of feedstock each from 5 development blocks of Jorhat district of Assam were collected, dried and pyrolysed for production of char for their physicochemical properties. Per cent moisture and ash content, bulk density, particle density and porosity of biochars ranged from 3.26 to 4.91%, 3.70 to 24.97%, 0.178 to 0.729 g/cm3, 0.85 to 2.02 g/cm3 and 61.54 to 78.90%, respectively. Pore volume, particle size and specific surface area ranged from 0.83 to 1.15 ml, 310×147 to 350×209 μm2 and 89.40 to 184.75 m2/g, whereas pH ,EC, CEC, total Carbon varied from 7.74 to 9.46, 0.272 to 1.005 dsm-1, 12.74 to16.68 c mol (p+)/kg and 36.63 to 49.424%, respectively. Porosity maintained significant and positive correlation with pore volume (0.715**) and specific surface area (0.614**). CEC had significant positive correlations with total C (0.583**), total N (0.587**), total K (0.443**) and IAN (0.766**).Percent total N, P, K, and S had their value ranged from 47.27 to 60.07, 0.017 to 0.032, 0.237 to 0.453 and 0.083 to 0.099; while, Ca and Mg, Fe, Zn, Cu and Iodine adsorption number ranged from 1.11 to 5.23 and 0.148 to 1.326 c mol (p+)/kg, 16.65 to 2.91, 30 to 162, 8.6 to 43 mg/kg and 186.64 to 489.77 mg/g of biochar.