Abstract <p>The combustion behavior of a wet mixture of sludge from a pulp and paper plant and municipal waste was analyzed through complementary experiments. The collected mixed sludge was first naturally dried to decrease its initial moisture percentage to 5–9%. Pure water with mass proportions between 30 and 60% was added to the naturally dried samples to analyze their combustion behavior. Thermogravimetric experiments were carried out with the dried and humidified samples under air and at heating rates between 5 and 100 K/min. The thermogravimetric profiles and the heat flows of the dried and humidified samples were compared. The emissions of CO, CO₂, and total hydrocarbons were measured during further combustion experiments carried out at isothermal temperatures of 600, 700, 800, and 900°C.</p>