Economic efficiency of microalgae carbon sequestration coordinating with ecological restoration technology for coal mines

The economic viability of integrating microalgae carbon sequestration with coal mine ecological restoration technologies is investigated.It begins by delineating the current environmental damages caused by mining activities, particularly to water bodies, and outlines the ecological restoration needs in key regions such as Inner Mongolia and Shaanxi Province. Relevant national and local policy frameworks and legal requirements are reviewed. Through an analysis of the technological pathway for microalgae-based carbon sequestration and ecological restoration, and drawing on the practical case study of the Guoneng Baorixile Project - where pit drainage water was utilized to cultivate microalgae for restoring a 50,000 m² waste dump - the study demonstrates the technology's effectiveness. The project led to a 42% increase in soil organic matter and a 28% enhancement in vegetation biomass, thereby validating its technical feasibility. A cost-benefit techno-economic assessment model is constructed, evaluating the economics per mu (Chinese unit of area) of restored land. The analysis indicates a net annual profit of 0.14 million RMB per mu, confirming the project's economic viability. Finally, targeted policy recommendations and future prospects are proposed. Suggestions include government support through special subsidies, tax incentives, and the establishment of technical standards to foster technology dissemination. The integration of this approach with agriculture and photovoltaic-based desert control is also envisioned. This research aims to provide theoretical underpinnings and decision-making references for the broad application and sustainable advancement of microalgae carbon sequestration technology in mine site restoration.