How long does it take to produce gas under anaerobic conditions?
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For food wastewater, 15 g/L of sludge from the sewage treatment plant after filtration was added anaerobically. It has been soaking for three days now, with an internal circulation pump in operation; there are very small, discontinuous bubbles in the water, which are likely resulting from hydrolysis. How long does it usually take to produce methane? Also, if methane is not produced in the short term and the removal efficiency is low, should water be added gradually to increase the load?
Based on circular analysis, after adding 20 kilograms of heavy metal scavenger, it is recommended to add a certain amount of polyaluminum chloride as well. Improve the sedimentation properties of sludge.
Please reply after carefully analyzing the original poster’s question. Thank you
The initial stage is the methanogen cultivation phase; the bubbles present now are likely CO2 generated by acidification, and they should contain a small amount of methane as well. It’s hard to say exactly how long it takes to produce methane; it depends on the anaerobic activity of the sludge. If the activity is high and the environment is suitable, anaerobic bacteria will multiply in large numbers, allowing biogas to be produced quite quickly. If methane is not produced in the short term, there’s no need to increase the load; increasing the load only suppresses the growth of methanogens, leading to acidification, and it will be more difficult to restart operations after that. It is recommended to continue monitoring, with frequent measurements of pH, VFA, and alkalinity. For reference.