Preparation of Mn modified waste dander biochar and its effect on soil carbon sequestration

Abstract

In order to reduce the mineralization of soil organic carbon (SOC) and enhance the ability of soil carbon sequestration. Mn-modified waste dander biochar (Mn-BC) was successfully prepared via impregnation and pyrolysis, and MnSO₄ was formed on its surface. Mn-BC increases the carbon retention and reduces the emissions of CO₂ and SO₂ in way of forming CO, Mn-O-C bond and MnSO₄. At the same time, the stability of the original biochar was reserved due to forming a conjugated structure (CC and pyridine-N bond), and the carbon sequestration content was increased to 25.63%. Importantly, the application of Mn-BC can directly regulate the transformation of microbial bacterial community and lead to create stable carbon dominant bacteria (Firmicutes). And the mineralization rate of SOC is reduced to 0.48 mg CO₂/(g·d), together with an increased content of TOC (48.16%), thus the purpose of efficient carbon sequestration is achieved in soil.

Keywords: Biochar; Firmicutes; Microbial bacterial community; Pyrolysis; Soil organic carbon.