Properties of biochar obtained from pyrolysis of bamboo shoot shell

• Agricultural by-product bamboo shoot shell (BSS) was used to produce biochar.
• Biochar derived at 400 °C had the best properties.
• Pyrolysis of BSS was a method to fixate carbon from biomass.
• Improvements in soil properties were occurred upon biochar additions.

Production of biochar from bamboo (Dendrocalamus latiflorus Munro) shoot shell (BSS) was performed as a function of the temperature (ranging from 300 °C to 500 °C) under N2 flow. The yields, physical and chemical characteristics of biochar from BSS (BSSBC) and its potential uses in soil amendment were studied. All of the biochar obtained was low in density, but high in pH value, carbon content, nitrogen content, surface functional group content, iodine adsorption value and inorganic nutrients. Biochar derived at 400 °C had the best properties in terms of the contents of C, H, O, N, P and K were 67.2%, 3.89%, 24.4%, 3.10%, 0.41% and 1.07%, respectively, the pH value was 10.2, its iodine sorption value was 1254 mg g−1 and its total functional groups content was 3.784 mmol g−1. Four different dosages from 2.5 to 10 wt% of biochar produced at 400 °C were added to soil samples to investigate the improvement of soil water holding capacity, bulk density, iodine sorption and metal adsorption, respectively. Soil adsorption capacities of Pb(II), Cr(III) and Cd(II) were improved by approximately 27%, 21% and 29% with addition of 2.5 wt% BSSBC. Biochar had properties that could improve soil properties such as density, acidity, moisture retention and heavy metal ions stability in soils. The findings support the potential to prepare soil ameliorant from BSS by pyrolysis.