The sustainable management of hazardous wastes and contaminated land is a fundamental aim of EU and UK environmental legislation. Stabilisation/ Solidification (S/S) has emerged as a cost-effective and fast method for the treatment of certain hazardous wastes and contaminated land. S/S can involve a wide range of materials such as binders and sorbents with technologies based on both chemical and physical processes. Binders in common use include Portland cement, pozzolans, lime and other special cements, whilst common sorbents include pulverised-fuel ash, carbon and clays. In addition, novel binders and processes are being developed. The mix design criteria used with each binder will depend on the application, which could be landfilling, redevelopment of a contaminated site or reuse as aggregate for construction. Implementation methods have included in-situ and ex-situ techniques, carried out both on and away from the site. S/S is accepted in the USA as an established treatment technology, however, its use in the UK has been limited to date. Further knowledge of the underlying scientific and engineering principles and long-term performance will promote acceptance and widespread use of the technology.
An EPSRC funded Engineering Network on Stabilisation/Solidification Treatment and Remediation, has been established and includes leading UK scientists and engineers, organisations and regulators involved with S/S technologies.
The key scientific and technical issues for S/S technologies addressed by the Network include:
(a) binder selection
(b) technology selection
(c) testing and performance level
(d) long-term performance and environmental impact
(e) quality assurance and quality control issues
(f) good practice guidance documents