Start up of anaerobic bioreactor landfills in cold climates by intermittent air injection.

摘要

Intermittent air injection may be one of the most economical solution to enhance waste temperature without toxicity to methanogenesis. Waste placed in landfill at lower temperatures may remain at lower temperature, leading to slow startup of anaerobic digestion process in biodegradation in landfills. In this study, waste placed at ambient temperature of 3.2+/-0.3°C (range between -30°C to +30°C), was subjected to leachate injection to increase waste moisture content. This has resulted in waste temperature of 10.4+/-1.3°C. After leachate injection, the was subjected to intermittent horizontal air injection increasing the temperature by 10.2+/-2.6°C over the entire cell using 2.5hp compressor.; The objectives of this study were to quantify the relationship between amount of heat consumed and amount of heat production (known as heat generation factor), to determine Point oxygen consumption rates (i.e., that is oxygen consumption rate at particular location in the landfill not normalized to the waste mass), and to evaluate the impact of air injection on methanogenesis process.; The average heat generation factor under field conditions was 341+/-84 kJ/mole, using dynamic calorimetric method. First order POCR averaged 0.0867+/-0.0422 h-1 after 15 days of air injection and increased to 0.2450+/-0.0843 h-1 after 21 days of air injection.; This study demonstrated that air injection is key to a successful startup of anaerobic digestion of bioreactor landfills in colder climates. The average rate of increase in percent methane at all locations exposed to air in the landfill increased significantly from 0.15+/-0.042°C day-1 to 0.68+/-0.15°C day-1. This was accompanied by a decrease in the median of hydrogen concentration from 4,085 ppm to 953 ppm. The lag time also decreased from 137 days to 15 days, in response to air injection.