Biosparging primarily promotes:
Principal benefit of biosparging lies in stimulating rapid aerobic biodegradation within otherwise anaerobic groundwater by resolving oxygen limitation that constrains metabolic energetics. Most petroleum hydrocarbon catabolic routes depend on iron-containing monooxygenases and Rieske dioxygenases inserting molecular oxygen into inert C-H bonds of alkanes forming alcohols and aromatic rings forming catechols, reactions impossible without O2 as cosubstrate. Products funneled via beta-oxidation and ortho cleavage into TCA cycle generating high ATP yield. Under anoxia, degradation relies on slower anaerobic activation like fumarate addition to toluene by benzylsuccinate synthase coupled to nitrate or sulfate reduction with lower energy and half-lives years. Oxygen injection raises dissolved oxygen to 6 to 10 mg per L, redox to plus 100 to 200 mV, supports aerobes with low oxygen half-saturation 0.1 mg per L, accelerates mineralization 5 to 20 fold versus natural attenuation, documented by in situ microcosm measuring oxygen utilization, carbon dioxide production and decrease in BTEX half-life from years to months without chemical oxidants.
Ref: Vidali Bioremediation review 2001 aerobic pathways; EPA Biosparging enhances aerobic degradation; PubMed PMID 14767740 rates.