Cooperative remediation mechanism and key technologies for pollution reduction and carbon sequestration in coal mining subsidence areas of the eastern plain

Abstract

The serious water pollution of coal mining subsidence areas in the eastern plains, greatly restricted the wetland self-purification and the formation of carbon sink functions. Therefore, this study starts from the causes of hydrops pollution in the coal mining subsidence areas in eastern plain, to elaborate the practical demands for collaborative remediation of pollution reduction and carbon sequestration. Meanwhile, the study provides a fascinating insight into the key processes and carbon sink formation mechanism of new formed wetland for pollution reduction and carbon sequestration, and estimate the potential of collaborative remediation, as well as put forward the adaptive managerial approach and crucial technical system for collaborative remediation. The results show that: ① Complex water supply, diverse pollution sources, and unstable ecosystem transformation are the primary causes of pollution in newborn wetlands in the eastern plain mining areas. The collaborative remediation of pollution reduction and carbon fixation can be achieved during the procedure of nitrogen, phosphorus, and organic matter degradation, as well as heavy metal detachment. The essential processes such as photosynthetic carbon fixation, carbon distribution, carbon deposition, and carbon loss, affect the carbon sink in the newly formed wetlands. ② The carbon pool stability of newly formed wetland shows significant relationships with plant root exudates, plant dead residues, wetland hydrological processes, active organic carbon components, and microbial community structure. ③ The existing carbon sink potential of the newly formed wetland in the eastern mining subsidence areas is about 4.43×106 t/a, which could reach 3.27×107 t/a up to 2060. After artificial restoration, the remediation capacity nitrogen and phosphorus pollution of newly formed wetlands can be elevated by 32.7 and 42.5 times, respectively. ④ Establishing the standing navigation mark of resources and protection, and the adaptive management strategies for synergistic and dynamic adjustment of pollution control and carbon fixation effects and schemes, is an important guarantee for implementing coordinated remediation of carbon sequestration and pollution reduction in the eastern coal mining subsidence plain. ⑤ In the future, it is necessary to gradually form a key technology system for enhancing microbial restoration of environmental materials, screening of advantageous vegetation and/or functional bacteria, and targeted proliferation of carbon fixing microorganisms, providing scientific support for ecological restoration, farmland protection, and high-quality development in coal mining subsidence areas of the eastern plain, China.

Keywords

• coal mining subsidence
• pollution reduction and carbon sequestration
• collaborative remediation
• ecological carbon sink
• adaptive management