Biodegradability assessment of complex chemical mixtures using a carbon balance approach

Abstract

The assessment of complex mixture biodegradability can be limited by technical issues and/or difficulties to rule on ready or inherent biodegradability. This work is composed of three different studies to introduce and improve Ultimately Transformed Organic Carbon (UTOC) as a quantification tool for biodegradation. The UTOC includes the inorganic carbon resulting from respiration and the carbon assimilated by microorganisms. The UTOC is correlated with dissolved organic carbon removal and can be a robust alternative for non-soluble substance evaluation. The UTOC was evaluated using a complex mixture of soluble and non-soluble substances and verified with an UVCB (vegetal extract). The advantages of UTOC are clear; it is an appropriate method to quantify the initial raw material converted into an inert product by the action of microorganisms and to determine the ready biodegradability of an unknown substance such as a vegetal extract.