Biochar : a promising step towards environmental protection and sustainable agriculture

Abstract

In this study, mandarine peels, pistachio shells, and apple juice waste underwent slow pyrolysis to produce biochar at temperatures of 300 ℃, 350 ℃, and 400 ℃, with an heating rate of 40 ℃/min and residence time of 4 hr. The produced biochars were characterized in terms of physicochemical properties (pH, moisture, ash, and volatile content). Analytical techniques such as CHNS, ICP-OES, and FTIR analysis were also carried out to determine the elemental composition of biochars and identify surface functional groups present in the biochar. The maximum iodine number, which is a measure of a sorbent ability to adsorb iodine, was obtained for all biochars produced at 400 ℃, although pistachio shells biochar at 350 ℃ was found to have a high iodine number. These aforementioned biochars were utilized for sulphur dioxide sorption test. Apple juice waste biochar at 400 ℃ demonstrated the highest sulphur content of biochar after SO2 sorption at 0.107%, compared to mandarine peels biochar at 0.101% and pistachio shells biochar at 0.074%. Pot experiments performed on mandarine peels, pistachio shells and apple juice waste sulphur-enriched biochars proved that these soil additives increased the growth of plant; that is length and dry weight of plants including increasing the chlorophyll content in leaves. The data obtained in this research work indicates that sulphur-enriched biochar can be effectively utilized as a soil additive for plant development. The results of the Master Thesis showed that waste biomass can be used to produce biochar, which has potential applications in environmental protection and agriculture.