This study investigated the impact of spent brewery grains and spent mushroom compost on the development of phenanthrene biodegradation in soil. Two aspects were considered: (i) the influence of increasing waste-to-soil ratios (1:10, 1:5, 1:2, 1:1 & 2:1) and (ii) the impact of soil-PAH contact time (1–100 d). Biodegradation was quantified by measuring changes in the lag phase, the fastest rates and extents of mineralization of 14C-phenanthrene, as well as changes in the number of total heterotrophic and phenanthrene degrading bacteria and fungi. The amendment of smaller amounts of the wastes (1:10 & 1:5) resulted in greatest levels of biodegradation. Microbial numbers increased in all of the amended soils but phenanthrene-degrading numbers in most amended soils did not correlate with the rates and extents of 14C-phenanthrene mineralization. This investigation highlighted the value of waste organic materials as nutrient sources to stimulate microbial degradation of contaminants in soil.
This is the author’s version of a work that was accepted for publication in International Biodeterioration and Biodegradation. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Biodeterioration and Biodegradation, 151, 2020 DOI: 10.1016/j.ibiod.2020.104991
