METHANE PRODUCTION IN THE CO-DIGESTION OF LANDFILL LEACHATE WITH DOMESTIC SEWAGE AND THE METHANOGENIC ACTIVITY OF FULL-SCALE UASB REACTORS

Abstract

The study aimed to individually assess the specific methanogenic activity of the sludge of 10 UASB reactors from a full-scale domestic sewage treatment plant (STP) and the sludge behavior under conditions of anaerobic co-digestion of leachate with domestic sewage in dilutions (v/v) of 0.1%, 1.0%, 2.5%, 5.0%, 10.0%, 25.0%, 50.0%, 75.0% and 100%. In order to compare the influence of the activity on co-digestion sludge, a parallel test was performed with sludge coming from the treatment of swine wastewater under the same conditions as the test with STP sludge. Specific methanogenic activity results showed the difference between STP sludge conversion capacities at each reactor, as well as preponderant conversion routes, which can have several origins within the mesh of factors that affect the units. Co-digestion analyses pointed out a better adaptation of piggery sludge to higher organic loads, such as the viability of up to 50% of leachate in relation to treated sewage volume, while the STP sludge showed a more delayed response in methane production. The best co-digestion condition was 10% leachate. The study highlights the possibility of increased leachate fractions in the co-digestion with domestic sewage with methane production potential, with incorporation of sludge from agro-industrial wastewater treatment.