Abstract: The resource utilization of municipal sewage plant sludge is an important initiative to achieve the synergistic targets of pollution reduction and carbon emission mitigation in the sewage treatment industry for the goal of building a beautiful China. Converting sewage sludge to sewage sludge derived biochars (SSBCs) with pyrolysis techniques is a promising way to achieve resource utilization of sewage sludge. SSBCs have excellent properties of high aromaticity, high stability, rich pore structure, large specific surface area and strong adsorption capacity, making them highly applicable for soil quality improvement and carbon sequestration. However, there is a lack of summary on the preparation methods, modification technologies, and soil improvement research progress of SSBCs, which greatly limits the improvement of the performance and application of SSBCs. We reviewed the advantages and disadvantages of the current preparation methods and modification technology of SSBCs, as well as the future development trend, and summarized the application and possible mechanisms of SSBCs in soil quality improvement and pollution remediation. Finally, we summarized the problems in the preparation and application of SSBCs, and put forward the prospects for the application mode in soil improvement, particularly in salt-affected soil. This review will provide a theoretical basis for the development of soil improvement and remediation technologies based on carbon sequestration materials SSBCs, and contribute to the synergy of pollution reduction and carbon emission reduction in the sewage treatment industry.

Key words: modified biochar, soil amendment, salt-affected soil, soil carbon sequestration