Preparation And Characterization Of Biochar Derived From Bamboo Shoot Shell And Its Application In Soil Amendment

Biomass has attracted researchers’ interests because of its features of huge amount of raw material, environment-friendly and renewable. As a common biomass, most of bamboo shoot shell is discarded or burned directly, causes not only environmental pollution, but also a great waste of resources. Soil is a kind of important natural resoucre. Due to ’three industrial wastes’ direct emissions, excessive use of fertilizers and pesticides, sewage water irrigation, the soil is seriously polluted. In this context, this dissertation aims to study the pyrolysis of agricultural waste bamboo shoot shell to obtain biochar for improving soil.Firstly, the main components and characterization of bamboo shoot shell were conducted. Nitric acid-ethanol method,72%concentrated sulfuric acid and sodium chlorite method was used to determine the contents of cellulose, lignin and holocellulose (the total amount of cellulose and hemicellulose) of bamboo shoot shell, respectively. The result was that bamboo shoot shell contains38.81%of cellulose,20.37%of lignin and77.96%of holocellulose. And hemicellulose content was calculated of39.12%. The element contents of bamboo shoot shell were determined to have44.33%of C,5.265%of H and2.073%of N. The ash content of bamboo shoot shell was4.40%. The high content of C illustrated that it could be used to produce biochar. The higher content of cellulose and hemicellulose indicated that the bamboo shoot shell might be made utilization through the method of pyrolysis. And TG analysis results showed that the pyrolysis temperature of bamboo shooot shell could be lower than400℃Secondly, the preperation and characterization of biochar were researched. Pyrolysis temperature of400℃and residence time of15min were considered as the optimal pyrolysis conditions based on the yield and properties of biochar produced. At this pyrolysis condition, the biochar had the content of C67.17%, H3.885%, N3.102%, P0.14%and K1.20%. The pH value was10.17, the idione sorption value was1254.09mg/g, and the surface acidic and basic functional groups content were2.187mmol/g and1.597mmol/g. These results indicated that biochar had high carbon content, pH value and adsorption ability.Finally, the soil properties were studied with the addition of biochars produced. Biochar was added to soil at different mass fractions of0%,2.5%,5%,7.5%and10%respectively to make the experiment samples. The experiment results indicated that:the bulk density of soil decreased, while the pH value increased with the increasing of biochar mass fraction. Biochar also could afford some fertilizer for soil because of its containing of N, P and K. Heavy metal ions in soil were efficiently adsorbed by biochar added in the soil. Water holding capacity and nutrient preserving capability of soil were improved obviously with the increasing of biochar mass fraction in soil.Combining the preparation of biochar from bamboo shoot shell and utilization of biochar as soil amendment can reduce the environment pollutions. Furthermore, the method will make the use of the agricultural by-pruducts such as bamboo shoot shell more effective. So the research provides a way for sustainable development of agriculture.