Invited Talk: Green and Sustainable Remediation Using Nature Based Solutions with Biological Waste Derived Materials

Land contamination at many thousands of sites around the world pose a severe hazard to public health. Traditional physical and chemical remediation solutions will often require high energy with secondary pollution emission, high resource input and waste production, and can result in loss of soil functionality. Therefore, the ‘Green and Sustainable Remediation’ (GSR) concept has been put forward to facilitate prudent holistic land remediation decision making. The emphasis of GSR is placed on maximizing net environmental benefit, rather than health risk assessment alone. This provides a framework where the recycling of waste materials is afforded greater value than the use of virgin materials, and nature based solutions (NBS) are valued over traditional thermal or chemical based remediation. As such, GSR provides the incentive to develop and promote new remediation technologies that are aligned well to these values. This departs from the traditional driving forces for developing new remediation technologies, which has been to develop the best available technology in terms of efficiency of reducing the risk of soil contaminants. In the context of NBS, contaminant stabilization may be achieved by reagents that derive from biological waste, such as biochar. Biochar is produced by the combustion of biomass under a limited supply of oxygen in a controlled environment. The main purpose in contaminated land application is to reduce contaminant bioavailability, as well as enhancing soil structure and fertility. Biochar has the potential be widely used as a low-cost in situ stabilization agent for the remediation of pollution-degraded land. The growth of GSR in the remediation industry should proceed hand-in-hand with the development of new nature based solutions like biochar.