Method and device for reduction treatment of residual sludge

Abstract

The invention discloses a method and a method for reduction treatment of residual sludge. After entering an aerobic biochemical reaction basin for aeration and mixing, a mixture of sludge and sewage is led to a settlement basin for settling, and supernate is extracted; the sludge in the settlement basin is periodically drawn into an anaerobic reaction basin for reacting and static settling; equivalent statically-settled supernate in the anaerobic reaction basin is drawn out to flow back to the aerobic biochemical reaction basin; and equivalent sludge in the anaerobic reaction basin is drawn out every three days to flow back to the aerobic biochemical reaction basin, so as to accomplish circulated exchange and flow of the sludge among settlement equipment, anaerobic equipment, aerobic equipment and the settlement equipment. The method of statically settling the supernate in the backflow anaerobic reaction basin is adopted, the concentration of the sludge in the anaerobic reaction basin is increased, the sludge reduction effect is good and stable, and the denitrogenation ability of a process system is improved; in addition, as the concentration of the sludge in the anaerobic reaction basin is increased, and the volume of the anaerobic reaction basin is reduced, constructing and transforming are easy, no reaction devices and equipments are required to be added, the construction cost is low, and the method and the device have a long-term economic benefit.

Description

technical field [0001] The invention relates to the field of sewage treatment, in particular to a method and device for waste sludge reduction treatment. Background technique [0002] Municipal sludge is a by-product produced in the process of urban sewage treatment. As far as the nature of municipal sludge in my country is concerned, the content of organic matter in sludge exceeds 50%, and contains a large amount of nutrients such as N and P (N content of which is 1.5% to 7.0 %, P content 0.8% to 3%). According to the figures provided by the State Environmental Protection Administration of China, China currently discharges about 40.1 billion m of sewage every year. 3 , there are more than 400 urban sewage treatment plants that have been built and operated, with a daily treatment capacity of 25.34 million m 3 . Based on the calculation that the sludge output accounts for 0.3% to 0.5% of the treated water (calculated with a water content of 97%), the sludge output of China'...

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Problems solved by technology

[0005] However, the current OSA process itself still has certain defects.

Since the OSA process is equivalent to inserting an anaerobic reaction tank in the aerobic sludge return section of the traditional activated sludge method, the sludge discharged from the sedimentation tank is treated in an anaerobic tank and then returned to the aeration tank, which substantially changes The living environment of microorganisms is changed, and the microbial population structure and sludge properties in the original aerobic activated sludge are also changed to a certain extent. This not only brings sludge reduction effect to the system, but also affects the system sludge Activity will bring adverse results to sewage treatment, such as the reduction of sludge yield, resulting in the reduction of part of the nitrogen and phosphorus in the sludge into the water phase, which increases the burden of nitrogen and phosphorus pollutants in the process system, thus making the effluent Total nitrogen and total phosphorus increase

At the same time, the reflux ratio of the traditional OSA process is about 10%, the volume of the anaerobic reaction tank is large, the cost is high, and the management is difficult, while the OSA process has a great potential for sludge reduction, so the OSA process is continuously optimized and improved. The performance of all aspects of the process, giving full play to the effect of OSA sludge reduction, is of great significance to the promotion of the application of OSA and the treatment of surplus sludge in my country

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