CN101659491A

CN101659491A - System and method for treating urban sewage

Info

Publication number: CN101659491A
Application number: CN200810118942A
Authority: CN
Inventors: 王强
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-08-27
Filing date: 2008-08-27
Publication date: 2010-03-03

Abstract

The invention belongs to the technical field of environmental protection, and in particular relates to a system and a method for treating urban sewage. The invention provides the system and the methodfor treating the urban sewage, which are simple in operation, good in treatment effect, simple in process and strong in adaptation to water quality and water amount and of which the effluent meets the discharge standard. The technical scheme is as follows: by adopting a treatment process of an anaerobic tank and an oxidation ditch, big and small suspended matters are substantially removed after the sewage passes through a middle bar screen and a fine bar screen; the effluent enters an aeration desilting basin so that inorganic particles with a big grain size, such as sands, gravels and coal slag, are precipitated; the effluent enters the anaerobic tank and the oxidation ditch, wherein in the oxidation ditch, the mixed liquid of the wastewater and activated sludge continuously and circularly flows under the action of an externally added driving force, organic substances are degraded under the functions of microorganisms, and the nitrogen and phosphor are well removed; the effluent enters a secondary settling tank; after the sludge and water in the effluent are separated, the sterilized and filtered effluent can be discharged after reaching the standard; and the left sludge is condensed, dehydrated and carried away.

Description

A kind of urban sewage treatment system and method

Technical field

The invention belongs to environmental technology field, particularly a kind of urban sewage treatment system and method.

Background technology

Along with the quickening of process of industrialization, environmental problem becomes increasingly conspicuous, especially the deterioration of Urban Water Environment, aggravated the shortage of water resources, many areas and urban water resource water shortage affect the people's physical and mental health, have become the serious restraining factors of urban sustainable development.China's municipal sewage treatment is started late with respect to developed countries.Over nearly 200 years, municipal sewage treatment from primary handle naturally, simple one-level handles to develop into and utilizes various modern techniquies, deeply treating wastewater, and reuse.Method for the treatment of city waste water has AB method, SBR method, A ²/ O method etc.AB method technology is divided the secondary oxygen supply to the aeration tank by high and low load, A stage load height, and aeration time is short, and it is big to produce sludge quantity, and sludge loading is more than 2.5kgBOD/ (kgMLSSd), and pool volume is loaded at 6kgBOD/ (m ³D) more than; The B stage load is low, and sludge age is longer.A level and B inter-stage are established the intermediate sedimentation pond.The secondary pond F/M ratio of microbial biomass (amount of pollutant with) is different, forms different microbial populations.Although the AB method has energy-saving advantages, be not suitable for lower concentration water quality.The SBR method was developed as far back as 20 beginnings of the century, this method collection water inlet, aeration, precipitation, water outlet are finished in a pond, Chang Yousan or four ponds constitute one group, running in turn, the ground intermittent operation of one pond, one pond, so claim sequencing batch active sludge, but this method not too is suitable for large-scale municipal sewage treatment.A ²/ O method is the technology of anaerobic-anoxic-aerobic composition, utilizes the biological treatment denitrogenation dephosphorizing, can obtain the high-quality water outlet, is a kind of degree of depth second-stage treatment technology.

Summary of the invention

The invention provides a kind of easy and simple to handle, but treatment effect good, technology is simple, the urban sewage treatment system and the method for, water outlet qualified discharge strong to water quality and quantity adaptability.

The invention provides a kind of urban sewage treatment system and method, its technical scheme is as follows:

The present invention adopts the treatment process of anaerobic pond+oxidation ditch.Sewage through in behind grid and the fine fack, the big suspended substance with little is removed basically, water outlet enters aerated grit chamber then, make oarse-grained sand grains, stone, inorganic particle sedimentations such as cinder, water outlet enters anaerobic pond and oxidation ditch again, in oxidation ditch, the mixed solution of sewage and active sludge is under the effect of additionaling power, that does not stop circulates, organism obtains degraded, nitrogen under action of microorganisms, phosphorus is also well removed, and water outlet enters second pond, but the water outlet after the mud-water separation is through qualified discharge after sterilizing, and excess sludge is transported through after the thickening.

The present invention has following beneficial effect: needn't establish preliminary sedimentation tank, technology is simple, and is easy and simple to handle, and oxidation ditch has unique waterpower flow feature, helps the biological flocculation and precipitation effect of active sludge, and denitrification effect is good, and is strong to water quality and quantity adaptability.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Embodiment

The present invention adopts the Process for Treating Municipal of anaerobic pond+oxidation ditch, and influent quality sees Table 1, and its concrete steps are:

(1) during waste water is introduced into, fine fack, middle grid adopts mechanical scarfing cinder, the grizzly bar gap is 20mm, fine fack grizzly bar gap is 6mm, sewage is crossed grid current speed and is 0.8m/s, the setting angle of grid is 70 °;

(2) water outlet enters aerated grit chamber again, removes inorganic particle, by regulating aeration rate may command sewage rotation flow velocity, make it to do swirling motion, produce centrifugal force, remove silt particle, the silt particle of eliminating comparatively cleans, deal with more convenient, and it is little that it is influenced by fluctuations in discharge, and it is stable to remove sand coarse aggregate ratio, simultaneously, sewage is also played the preaeration effect, and horizontal flow velocity is 0.1m/s;

(3) water outlet enters anaerobic pond and oxidation ditch, and the hydraulic detention time of anaerobic pond is 0.8h, in oxidation ditch, the mixed solution of sewage and active sludge is under the effect of additionaling power, that does not stop circulates, and organism obtains degraded under action of microorganisms, and nitrogen, phosphorus are also well removed;

(4) water outlet enters second pond, carries out mud-water separation, adopts machinery to inhale the circular radial-flow sedimentation tank of radial inflow of mud, water inlet employing center water inlet peripheral effluent, and the water outlet of second pond sterile-processed back discharging, excess sludge is transported through after the thickening.

Discharge water reaches emission request after treatment, and effluent quality sees Table 2.

Table 1 raw water quality

	??COD	??BOD ₅	??P	??NH ₃-N	??SS
	??COD	??BOD ₅	??P	??NH ₃-N	??SS	??390	??180	??6	??40	??180
Unit	??mg/L	??mg/L	??mg/L	??mg/L	??mg/L	??390	??180	??6	??40	??180

Table 2 effluent quality

	??COD	??BOD ₅	??P	??NH ₃-N	??SS
	??COD	??BOD ₅	??P	??NH ₃-N	??SS	??89	??15.5	??0.6	??10.8	??16.3
Unit	??mg/L	??mg/L	??mg/L	??mg/L	??mg/L	??89	??15.5	??0.6	??10.8	??16.3

Claims

1. urban sewage treatment system and method, its technical scheme is as follows:

The present invention adopts the treatment process of anaerobic pond+oxidation ditch, sewage through in behind grid and the fine fack, the big suspended substance with little is removed basically, water outlet enters aerated grit chamber then, make oarse-grained sand grains, stone, inorganic particle sedimentations such as cinder, water outlet enters anaerobic pond and oxidation ditch again, in oxidation ditch, the mixed solution of sewage and active sludge is under the effect of additionaling power, and that does not stop circulates, and organism obtains degraded under action of microorganisms, nitrogen, phosphorus is also well removed, water outlet enters second pond, but the water outlet after the mud-water separation is transported after the thickening of excess sludge process through qualified discharge after sterilizing.

2. a kind of urban sewage treatment system according to claim 1 and method is characterized in that: grid grizzly bar gap is 20mm in described, and fine fack grizzly bar gap is 6mm, and sewage is crossed grid current speed and is 0.8m/s, and the setting angle of grid is 70 °.

3. a kind of urban sewage treatment system according to claim 1 and method is characterized in that: the hydraulic detention time of described anaerobic pond is 0.8h.