A Circular Economy Approach to Restoring Soil Substrate Ameliorated by Sewage Sludge with Amendments

Abstract

This study examined the use of an artificial soil substrate in a mine waste reclamation area and its effect on plant metabolic functions. Research was conducted by determining the relationship between the plants’ biochemical features and the properties of plant growth medium derived from post-flotation coal waste, sewage sludge, crushed stone and fly ash on the surface of the mine waste disposal area. Trees and shrubs were established on the material and allowed to grow for eight years. The study determined that the applied plants and the naturally occurring Taraxacum officinale were suitable for physio-biochemical assessment, identification of derelict areas and reclamation purposes. An evaluation of a soil substrate applied to post-mining areas indicated that it was beneficial for plant growth since it activated the metabolic functions of herbaceous plants, shrubs, and trees. The study showed that soil substrate can be targeted to improve plant stress tolerance to potentially toxic elements (PTEs). These data suggest the potential for growth and slower susceptible response to Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. It is possible that the constructed soil-substitute substrate (biosolid material) would be an effective reclamation treatment in areas where natural soil materials are polluted by PTEs. This observation may reflect a more efficient use of soil substrate released from the cycling of organic biogene pools, in accordance with the circular economy approach. In further studies related to land reclamation using sewage sludge amendments, it would be necessary to extend the research to other stress factors, such as salinity or water deficiency.

Critical assessment and recommendations for sewage sludge management in Poland

“…Research in this field focuses on assessing the effec-tiveness of sewage sludge use in various environmental protection processes and assessing their impact on soil, water, and air quality (Joniec et al, 2019a). For example, Halecki et al (2022) examined the use of artificial soil substrate in the reclamation of mining waste and its impact on plant metabolic functions. The research was carried out to determine the relationship between the biochemical characteristics of plants and the properties of the plant growth substrate derived from post-flotation coal waste, sewage sludge, crushed stone, and fly ash on the surface of the mine waste landfill.…”

Biofertilizers from wastewater treatment as a potential source of mineral nutrients for growth of amaranth plants

“…Several studies have been conducted in order to verify the benefits of biosolid application on several crops' growth and biochemical parameters [14][15][16]. In addition, the application of biosolid in areas undergoing reclamation can effectively improve the performance of introduced vegetation and the tolerance to potentially toxic elements [17] thus serving as a key tool for farm utilization [18]. The conventional sewage treatment processes have proven effective in managing sewage sludge but often present issues such as high energy consumption and the generation of residual sludge with environmental concerns.…”