Treatment process and system of sludge from wastewater treatment plant

Abstract

The invention discloses a treatment process of sludge from a wastewater treatment plant, and the treatment process comprises the following steps: firstly carrying out gravity sedimentation on sludge; sequentially carrying out aerobic digestion on the obtained concentrated sludge and sedimentation treatment on the digested sludge; after the digested sludge is settled, obtaining digested sludge anddigestion tail water; discharging the digested sludge; and carrying out aquatic plant purification treatment on the digestion tail water. The invention also discloses a system for realizing the process. After the digestion treatment of the concentrated sludge, the stabilization degree of the sludge is greatly improved; and the digestion tail water enters an aquatic plant purification system, nutrient elements in water are absorbed and utilized by the plants, and the nutrient elements are not transferred to the discharged water from the sludge, so that the sludge reduction and tail water purification are simultaneously achieved.

Description

technical field [0001] The invention relates to a sludge treatment process and system of a sewage treatment plant, including the system combination of sludge reduction and tail water plant purification. Background technique [0002] With the popularization of urban sewage treatment facilities in China, the improvement of treatment rate and the deepening of treatment degree, the sludge generation of sewage treatment plants has increased rapidly. According to the data of the Ministry of Housing and Urban-Rural Development, by the end of 2009, 1,992 urban sewage treatment plants had been put into operation nationwide, and the urban sewage treatment capacity reached 28 billion m 3 , the production of wet sludge (80% moisture content) has exceeded 20 million tons, and the annual sludge discharge of urban sewage treatment plants in my country is still growing at a rate of more than 10% per year. The sludge of urban sewage treatment plants is mainly biochemical residual sludge. Th...

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Problems solved by technology

The degree of sludge stabilization treatment is relatively low. An important reason is that for sewage treatment plants, the cost of building a separate sludge digestion treatment system is high (especially for anaerobic digestion process), the effect is not obvious, the benefit is not significant, and the operation management inconvenient

[0005] For sludge from urban sewage treatment plants, concentration and digestion technologies are more suitable, but due to the lack of systematic research and coupling of this technology in China, there are not many cases of joint application in engineering, and the effect is not obvious, so further in-depth research and optimization are still needed ;

[0006] The second category is sludge disposal technology, such as landfill, incineration, composting and land utilization, etc. As far as the second category of disposal technology is concerned, these technologies face many difficulties in the actual application process

For landfill, first, it consumes a lot of land resources, and it is difficult for many cities and towns to find new landfills; second, it produces a large amount of leachate, which affects the normal operation of landfills due to the high moisture content of sludge, and aggravates the waste The landfill leachate is polluted, and most of the mixed landfill landfills have the phenomenon of rejecting sludge; third, there are few landfills that use the gas generated by the landfill as a resource, and the waste gas generated by the landfill is not only Pollution of the environment and potential safety hazards

For incineration, it has the advantages of small footprint, fast processing, wide consumption channels, significant volume reduction rate, and high resource utilization rate. Assessment, higher environmental requirements for flue gas treatment

For land use, the cost is relatively low and the resource utilization rate is high, but the method has high requirements on the original mud, the treatment land is relatively large, and the use of greening is limited by the season; in addition, for some treatment processes, due to the addition of The polymer flocculant does not effectively break the shell, which is easy to cause soil compaction

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