Opportunity Windows and Added Value of Gentle Remediation Options for Contaminated Land Management

Doctoral thesis, 2024

Well-functioning, healthy soils are increasingly recognized as vital to human well-being, but soil contamination impairs the capacity of soils to perform their essential functions and provide humans with ecosystem services (ES). Contaminated land poses risks to human health and the environment, which must be managed, but also constitute an important and underutilized land and soil resource for providing ES in urban areas through phytomanagement with gentle remediation options (GRO) – nature-based solutions using plants, fungi, bacteria, and soil amendments to manage risks at contaminated sites while also improving soil functionality. The overall aim of this thesis is to explore the opportunity windows and added value of using GRO for contaminated land management and develop applied knowledge and methods for practitioners to support a broader use of GRO in practice. Five studies were carried out to achieve the overall aim and specific objectives, containing both conceptual and empirical work, with a field experiment performed at the Kolleberga tree nursery. Specific contributions from the studies include: considering GRO applications for sustainable remediation and development (Paper I); developing a risk management framework for GRO (Paper II); investigating the costs and benefits and social profitability of GRO compared to conventional alternatives (Paper III); estimating time requirements for phytoextraction (Paper IV); and evaluating the effects of GRO on soil health (Paper V). Results from the studies in this Ph.D.-thesis are considered within the unifying concept of opportunity windows to explore the wider application and added value of GRO for contaminated land management and are connected to the generic workflow for contaminated land management in Sweden to facilitate communication with stakeholders and inclusion in the decision-making process. The applied knowledge and methods developed in this Ph.D.-thesis support the wider application of GRO for contaminated land management by exploring the opportunity windows for feasible use of GRO and demonstrating their added value.