Temperature requirements for anaerobic treatment of domestic sewage treatment

It is generally believed that high-temperature digestion is about twice as high as that of medium-temperature digestion. The temperature level not only affects the production of biogas, but also affects the content of methane in biogas and the nature of anaerobic digestion sludge, and has different effects on pollutants of different natures. In a certain temperature range, the temperature is increased, the organic matter removal rate is increased, and the gas production amount is increased.

The suitable temperature for anaerobic digestion sometimes varies to some extent due to other process conditions. For example, a higher sludge concentration in the reactor, that is, a higher concentration of microbial enzymes, makes the influence of temperature less likely to be revealed.

In general, the temperature rises by 10 for all other process conditions. C, the reaction rate is increased by about 2 to 4 times. Therefore, high temperature digestion takes less time than medium temperature digestion.

In domestic sewage treatment, rapid changes in temperature and fluctuations in the upper and lower limits are not conducive to the anaerobic digestion process. The temperature rises and falls within a short time. C, biogas production has dropped significantly, and when the fluctuation is too large, gas production is even stopped. Temperature fluctuations not only affect biogas production, but also affect methane content in biogas, especially high temperature digestion is more sensitive to temperature changes.

Therefore, when designing the digester, it is often necessary to take certain temperature control measures to make the digester run at a constant temperature as much as possible, and the temperature change range does not exceed 2. C/h-3. C/h. However, a temporary sudden drop in temperature does not cause a fundamental damage to the anaerobic digestion system. Once the temperature returns to the original level, the treatment efficiency and gas production will also recover, but the time required for recovery will be extended accordingly.