1, the role of anaerobic digesters
Anaerobic digesters is mainly used in the treatment of municipal sewage sludge, but also can be applied to the treatment of organic wastewater with high concentration of organic wastewater;
Its main function is:
A portion of the organic matter in the sludge is converted to methane;
In the sludge, a part of the organic matter is converted into a stable humus;
To improve the dewatering performance of sludge;
It makes the volume of the sludge is reduced by more than 1/2;
The pathogenic microbial sludge in a certain degree
Inactivation, which is conducive to the further treatment and utilization of sludge.
2, the characteristics of anaerobic digesters
Closed, anaerobic, wastewater by the storage tank into the pool, in a certain reaction temperature, anaerobic digestion, the production of methane from the top of the gas cover output, as fuel or chemical raw materials. Access to the material is intermittent, the storage gas equipment to balance the gas and gas, but also to balance the pressure inside the pool, to prevent the formation of negative pressure suction air, thereby destroying the anaerobic environment.
3, the principle of anaerobic digesters
The process of producing methane by liquefaction, acid fermentation and alkaline fermentation in three stages.
4, the advantages of anaerobic digestion
Organic wastewater which is suitable for high concentration wastewater and aerobic degradation. (aerobic: medium and low concentration) low energy consumption: ASP 1/10.
Load height: good oxygen 2 - D - 4KgBOD/M3, anaerobic 2 - 10, can be as high as 50. Less sludge: easy to concentrate, easy to dehydration, the amount of sludge is ASP 5% - 20%. P, N need less: good oxygen 100:5:1 for BOD:N:P, anaerobic 100:2.5:0.5,
The lack of N, P lack of industrial wastewater need to add the nutrients. There is a certain bactericidal action (waste water, sludge in the parasite eggs, bacteria, viruses, etc.). Production flexibility and adaptability: seasonal, intermittent operation. Can produce valuable by-products: such as biogas.
5, the shortcomings of anaerobic digestion
Slow growth and propagation of anaerobic microorganisms, equipment, processing time is long. The effluent water quality is not up to the discharge standard, which need to be further processed by aerobic treatment. Operating control factors are more complex.