This brief gives a summary of the soluble bio-based substances (SBO) field. Urban bio-wastes of differing compositions and ageing conditions represent a promising source of soluble bio-based substances (SBO), potentially able to perform as chemical auxiliaries for applications in the chemical industry and in environmental remediation. In particular, SBO process development, characterization and scale-up is described and bioassay studies discussed. This brief also discusses the use of SBOs in wastewater treatment in the context of 'green' processes, their role as humic-like substances, and...