Photoremediation of natural leachate from a municipal solid waste site in a pilot-scale bubble column reactor

An 18-litre pilot-scale bubble column photoreactor has been used to carry out the mineralisation of a municipal solid waste dirty brown leachate. Rate data collected at 300 K and atmospheric pressure with titania particles suspended in upward flowing oxidising air through a stationary liquid phase suggested that the mineralisation of humic compounds was accompanied by a parallel hydrolytic photodecomposition of nitrogenous matter to NH4+ ions. The total organic carbon (TOC) reduction rate followed a Langmuir–Hinshelwood kinetics, while NH4+ ions production is competitively inhibited at high TOC concentration (>35 mM). Photoremediation was also attended by significant (50–70%) decolourisation. The treated leachate may be recycled for agricultural use.