The gas outlet in the top cap of the reactor was connected by a flexible pipeline to a gas burette (cylinders with diameter 85 mm with scale). The burette was filled with saturated NaCl solution. A valve was placed at the top of the burette for the removal of the accumulated gas and the collection of samples for analysis. High concentrations of NaCl in the burette limited dissolution of the biogas components. The second outlet in the top cap of the reactor was combined with a recycled water storage tank to simulate rainfall. At the bottom of each reactor was placed a 0.15-m gravel layer. Thermocouples were mounted in the walls of the reactors. In each reactor, 10 kg of waste shredded to a grain size of