With economic and population growth, nature pollution was more and more valued by people, based on summarizing domestic sewage treatment plant operating experience at home and abroad ,combine our company's scientific achievements and engineering practice, designed one whole set organic wastewater treatment plant which can be buried underground or ground, it was adopt carbon steel lining with anti-corrosion painting main material compact sewage treatment plant, its main purpose is make domestic sewage and similar industrial organic sewage to achieve user's emissions standards after treatment by this plant, its mainly used in treating domestic sewage in Residential area (including villa district) , senior hotel,complex office and various of public hospital buildings, final cleaning water quality can achieve national emission standard after treatment. The whole set plant can be buried underground or lay on the ground, so it is known as "compact sewage treatment plant." it adopt international advanced biological treatment processes, set removing BOD5, COD, NH3-N together, with the advantage of Technical performance stable and reliable, good treatment effect, save investment, small occupy area, and easy maintenance.
1. 1 Feature:
1. 11 Its installation manner can be underground or ground, the surface above plant can be used as green or other land, no housing and heating, insulation.
1. 12 The contact oxidation process adopt plug-flow bio-contact oxidation, treatment effect better than completely mixed or two grade series completely mixed biological contact oxidation pool. And smaller than activated sludge tank, strong adaptability to water quality , resistance to shock loading performance, effluent water quality stability, it won't produce sludge bulking. Tank body equip new flexible three-dimensional biological carrier , large surface area, microbial easy to hang film and stripping, in same organic load condition, high removal rate of organic matter, improve oxygen solubility in water.
1. 13 The biochemical tank adopt biological contact oxidation, its biological carrier
volume loading relatively low volume , microbial stay in self-oxidation section, less sludge production, only each three months or more days discharge one time sludge, (using suction truck or dehydration cake transport away).
1. 14 control manner have PLC fully automatic control and manual control , electric parts setting failure alarm, safe and reliable operation, usually no need special expert management generally, only timely maintenance small parts of plant.
1.2 Scope ofApplication
1.21 Hotels, restaurants, nursing homes, hospitals.
1.22 Residential areas, village, town ,Villa,shelter etc
1.23 Stations, airports, port terminals and ship.
1.24 Factories, mines, tourist, scenic.
1.25 All kinds of industrial wastewater similar with domestic sewage.
2 Design scope and Design water quality and quantity
This design mainly for wastewater treatment process, structure and related equipment to carry on the design.
2. 1 Design water quantity
The wastewater treatment engineering design for the hotel sewage, the treatment of processing water is10m3 /d, sewage treatment , The sewage treatment process has the,capability of shock load resistance.
2.2 Design the water quality of influent and effluent
Influent water quality designed according to the following table:
Table 1- 1: Influent water quality
Unit :mg/L
Influent |
A&G |
BOD5 |
SST |
Ammomia
nitrogen |
Total phosphorus |
| Concentration |
150 |
300 |
300 |
60 |
15 |
Effluent water quality standard,as follows:
3 Process selection and brief introduction
3. 1 Scheme outlined
Traditional sewage treatment process can divide into biological membrane manner and activated sludge manner, biological membrane suitable to small wa ter volume, steady water quality, low concentration sewage water quality, better
system commission. Steady back operation, better operability. Sewage water q uality set as traditional routine: CODCr ≤ 620mg/l ,BOD5 ≤536mg/l,BOD5/CO Dcr >0.5, better biodegradability, due to ammonia nitrogen and organism conte nt is high, especially organic nitrogen, when biological degradation organism, t he organic nitrogen will be express in the form of ammonia nitrogen, ammonia
nitrogen is a key pollution control index, so such sewage treatment adopt ano xia oxic A/O biological contact oxidation process, so the biochemical tank divi de into A grade anoxia tank and O grade oxidation tank two parts.
The sewage will first pass screen channel.In this channel,part of floating s olid and suspended matter will be removed.Then flow into Equalize Tank, due
to the sewage flow rate was different in each day, it has peaking time, so w e set equalize tank to balance the quality and flow rate of water. Then sewage
will uniform lifting into compact sewage treatment plant by pump; there are s et 2 pcs of submersible sewage pump in equalize tank.
The compact sewage treatment plant includes primary setting tank,anoxia t ank, oxidation tank, secondary settling tank ,cleaning water tank and control ro om etc six parts.
First enter into primary settling tank, it used to primary remove the settlin g matter and floats, it can relieve the following loading. Then sewage enter int o anoxia tank, due to sewage organism content is high, microorganism in anox ia condition, now the microorganism is facultative, they will transform the orga nic nitrogen into ammonia nitrogen, at the same time, using organic carbon so urce as electron donor, to make the NO2-N ,NO3-N translate into N2, and usi ng part of carbon source and ammonia nitrogen synthesis new cellular material.
so anoxia tank has certain function of organic matter removal, relieve the org anic load of follow-up oxidation tank, to benefit to nitrification, and rely on hi gh concentration organism in sewage, to finish denitrification, finally eliminate the nitrogen eutrophication pollution. By anoxia tank biochemical action, the se wage still contain some organism and higher ammonia nitrogen, in order to ma ke organism further oxic degradation, at the same time, when carbonization ten d to finish, nitrification can smoothly going on, thus set O grade oxidation tan k.
The outlet water from anoxia tank will flow into oxidation tank, the oxic biochemical treatment rely on autotrophic bacteria finish, they utilize organism resolve generate inorganic carbon or carbon dioxide in air as nutrients source, to make the ammonia nitrogen translate into NO2-N, NO3-N, a part of oxic ta nk outlet water enter into secondary settling tank to sediment, another part ba ckflow to anoxia tank to proceed anoxic tank to proceed internal recycle, to re alize nitrifying purpose. All equip with padding in anoxic tank and oxic tank, the whole biochemical treatment process all rely on many kinds of microorgani sm to finish.
The dissolved oxygen is control about 0.5mg/l in anoxia tank, above 2.0m g/l oxic tank, air water ratio 12:1; part of outlet water in oxic tank backflow t o anoxic tank, reflux ratio is 200%; part flow into secondary settling tank, to make solid liquid separation; the outlet water in settling tank after solid liquid separation, it will flow into cleaning water tank,the fianl water will discharge a fter make disinfection by uv-sterilzier. The settling sludge in settling tank will pump to sludge concentration tank, the concentrated sludge transport out as far ming fertilizer.
Compact sewage treatment plant structure:
( 1) Primary settling tank:
It can initial remove the sediment and floating matter in waste water, as pretre atment unit;
(2) Anoxic tank
In order to control the dissolved oxygen in A grade biochemical tank about 0. 5mg/l, adopting interval aeration. The padding in A grade biochemical tank ad opting new type elastic padding, height is 2.0m. such padding with the advanta
ge of no easy blocking, light weight, big specific surface area, treatment effect steady etc, easy to maintenance;
(3) Oxidation tank with MBR
The O grade biochemical tank equip with columnar biology carrier padding, thi s padding specific surface area is big, is 16-20 times comparing with common
biological padding, keep higher biomass, to reach the purpose of removing or ganic pollutant, aeration device adopting air blower and micropore aerator, the oxygen utilization rate is above 30, effective save operation cost. air water rati o about 12:1.
(4) Secondary settling tank
The sewage still contain large number of suspended solid after treated by O gr ade biochemical, in order to make the effluent water SS meet up discharge sta ndard, adopting vertical settling tank to make solid liquid separation, 1 set , su
rface load 1.0m3/m2·hr. the settling tank sludge adopt air lifting device lift to sludge tank, at the same time, according to actual condition to make part of sl udge lifting to A grade biochemical tank to proceed sludge backflow, increase the sludge concentration in O grade, improve removal efficiency.
(5) control room
Air blower set in the air blower room, equip with silencer.
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