To evaluate the biodegradation of polluted soil from the Burgan oil field in Kuwait, a novel combination of GC-MS & Pyrolysis-GC-MS fingerprinting approaches and metagenomic profiling of microbial populations was utilised. To assess the viability of this material for bioremediation, the soil was treated with (sludge) compost in microcosms. The most successful trial revealed a > 80% reduction in TPH, demonstrating high potential for widescale deployment utilising a technology that is both affordable and in keeping with the circular economy's guiding principles. The microbiological investigation revealed that adding compost improved the soil's organic matter and nutritional content Compost additions act as a biostimulation rather than a bio augmentation strategy since the microorganisms in the compost did not appear to play a significant role in bioremediation. Although heavy fractions are typically thought to be recalcitrant to biodegradation, we observed incipient degradation of the asphaltene fraction by means of double-shot thermodesorption and pyrolysis. The chemical study of the various oil fractions revealed rapidly biodegradable compounds (alkanes, alkyl-aromatics, etc.) and others that were much more refractory of note. The treated soil also included some of the substances found in the compost, such as coprostanol, cholesterol, and plant sterols, according to chemical fingerprinting results. This finding would be in favour of using these substances as proxy to track the effects of compost and modify dosages throughout large-scale bioremediation procedures
