residential domestic sewage treatment plant

Package MBR Sewage Treatment Plant

MBR Introduction

Membrane bio-reactor is a kind of new type sewage treatment technique which combine high efficient membrane separation technique and activated sludge manner, it inherit membrane separation technique and biochemical treatment technique feature and intensify biochemical treatment effect, it can used in high organic content municipal or industrial sewage treatment.

2.1 Compare to traditional activated sludge, MBR has the following advantage:

1)  0.05 micro membrane filtering outlet water, the effluent water suspended solid and turbidity can close to zero, can be reuse directly

2)  Compare to traditional treatment system, it can save 50% land usable area;

3)  Due to membrane high efficient intercept action, micro organism fully intercept in reactor , realize reactor hydraulic retention time and sludge age fully separation, to make operation control more flexible and steady;

4)  The micro-organism concentration in bio-reactor can reach 5000-8000 mg/L, with high biochemistry efficiency, strong impact resistance;

5)   Long sludge age, in favor of slowly accretion nitrobacteriaIntercepting growth and breed, system nitration efficiency increase;

6)   Reactor is operate in high volume loading,low sludge loading,long sludge age condition , surplus sludge discharge volume.

7)   Membrane separation to make the big molecule difficult degrade into bioreactor has enough retention time, greatly improve difficult organism degrade efficiency;

8)   System with high automation degree, adopt PLC control, can realize whole automatic control;

9)   Modular design, compact structure, small occupy area ,low operation cost

After many years of sewage treatment project experience, start MBR sewage treatment technique has the following feature:

1)    Membrane material is polyvinylidene fluoride, strong stain resistance, easy to washing, suitable for sewage treatment; chemical properties stable, strong oxidation resistance, it can adopt common oxidability agentia washing.

2)    Membrane flux higher than other material (such as PP or PE) similar product, adopt periodically,chemical backwashing and chemical washing process guarantee membrane module water output ability and membrane flux.

3)    Low trans-membrane pressure, usually is 0.01~0.06 Mpa, it can adopt siphon principle and no need suction power can output water, low operation cost.

4)    MBR technology adopt anoxia and aerobic combining form, sewage enter into anoxia zone, make the big molecular weight long chain organism resolve into easy biological organism, then enter into aerobic area to make organism biological degrade , at the same time, to make biology nitration reaction, and make denitrificationreaction, and by backflow to anoxia area to make   denitrification, finish denitrification function.

2.2 MBR process description

MBR is a kind of new type sewage treatment technique which combine activated sludge manner and integrated immersed membrane separation system, this process can be widely used in municipal and industrial sewage treatment area, which contain water resource reuse,community development, park scenic water source reuse etc.

It is a new kind of sewage treatment technique, MBR has widely apply in all over the world sewage treatment plant.

Typical MBR system process can be described as following:

  The sewage enter into equalize tank pass by 1-2mm bar screen, used to equalize water quality and volume. The intercept impurity need clear up in regular. Next, the sewage in equalize tank will pump to MBR system,  in MBR system realize mirco-organism resolve reduction ,which contain aerobic and anoxia reaction area, the can’t degrade impurity and activated sludge will intercept in the membrane tank , the membrane filtering output water will reach standard reuse or discharge.

2.2.1Membrane module description

MBR system use hollow fiber membrane to make solid-liquid separation. The NL series immersed hollow fiber membrane is special developed membrane module. It has higher filtering efficiency, it can effective remove bacteria,suspended particles and impurity, thus get the superior filtering water. In additional, due to each unit membrane module filtering area big, small membrane installation occupy volume, decrease reactor volume and occupy area.

2.2.2Application scope:
* Hotel,restaurant,community etc domestic sewage treatment recycle
* Industrial and mining enterprises,remote village,sentry ,tourist area etc domestic sewage recycle.
* Each kind of industrial sewage (similar to domestic sewage) :such as hospital sewage,pharmaceutical sewage ,washing sewage,food sewage etc

2.3 Influent and effluent water quality

2.4 Feature:
*  This system with containerized package function: make the anoxia tank,MBR bio-reaction tank,sludge tank,cleaning water tank and operation room integrated into a big tank body, compact structure, process concise, small occupy area ( only traditional process 1/3-1/2) ,increment expansion convenient, high automatic degree, operating maintenance conciseness, it can move at anytime and anywhere, it can move to treatment goal location, direct large-scale to make proceed treatment, no need make twice construction.
*  Gather sewage treatment and water purification process into one system, it shallow buried underground or ground; the treatment basic no sludge generate, hasn’t influence to surrounding; better operation effect,high reliability,effluent water quality steady,little operation cost.
*  In treating municipal sewage, impact resistance,high remove efficiency to pollutant, strong nitration ability, it can make nitration,denitrification, both nitrogen and phosphorus removal function, suitable for treat municipal sewage,distributed sewage, the effluent can be reuse or can be discharge after reach standard, it can meet different users of different water quality.
*  cleaning disinfection tank equip with packing which made of new type environmental protection active ion material, it has disinfection function and can effective remove the heavy metal ion in water, it can overcome medication washing disinfect caused secondary pollution and reduce the heavy metal content in effluent, greatly improve the recycle water quality.
*  The aeration pipeline of membrane bio-reactor divide two parts, 1 part is make aeration to surrounding activated sludge , another part is make aeration to membrane module.

Its advantage is to make the membrane module mutual flap by aeration membrane module produce scour force, thus it can shake off the calcified sludge adsorb in the membrane fenestra surface, make the membrane flux greatly extend the membrane service life, thus reduce operation cost.

2.5 MBR treatment process:

  The sewage first pass by bar screen (mechanical bar screen or manual bar screen), bar space is 3mm, used to gain big particle suspended solid and impurity, then flow into equalize tank interior, to make the water quality,volume in equalize tank, then lift the sewage into anoxia tank by sewage lift pump, after hydrolytic acidify by anoxia tank, enter into MBR biochemical treatment system.  Whole set of bio-chemical treatment system is composed of front pretreatment and reaction tank, according to influent water quality and effluent water quality requirements, which decide if need and design leading treatment end. In reaction tank equipment immersed plain film, constitute MBR- aerobic running mode.

MBR reaction tank effluent water direct enter into PE recycle tank, discharge or pump into reclaimed water pipe network to recycle.

2.5.1Main treatment unit
(1) Front pretreatment tank:

In front of this device is anoxia tank, in one end of anoxia tank set water inlet, another side top set water weir tank and outlet water, can make the sewage stable nature flow into membrane reaction tank, equip floating packing and anoxia sludge, the sludge in anoxia tank HRT is 3-8h, give oxygen by interval, to make acidify,nitration and denitrification function, make the organism gradate translate into inorganics remove. 
(2)MBR bio-reaction tank:

It has set water inlet in one side, and the immersed flat membrane module set in reaction tank, accommodate activated sludge, around aeration and membrane unit aeration pipeline connect with air blower, the matched collecting pipe in membrane module connect with suction pump, the untreated sewage enter into MBR biochemical reaction tank by water inlet, sewage HRT is 5h in reaction tank.  After degrade by activated sludge in reaction tank, by resistance pollutant flat membrane module, then enter into cleaning water disinfection tank by suction pump. There set sludge lifting pump in aeration, it can lift the surplus sludge to sludge digestion tank interior; there has overflow in reaction tank top, it can make the sewage backflow into tank outside equalize tank; in below side open vent , in order to convenient for tank interior maintenance, cleaning.
(3) Sludge tank:

there are set sludge collecting hopper and sludge pipeline in sludge tank bottom, in order to convenient for sludge concentration, set weir water tank in top, there open mud discharge inlet in bottom, rely on static pressure automatic discharge mud.
  (4)Cleaning water tank:

  (5) Operation room:

 It set 2 pcs air blower in operation room, operate 12h automatic shift 1 time, air blower equip with silencer damping measures; suction pump 2pcs, electric control cabinet 1pc, lighting system; in the top, equip with rain-proof air vent and ventilate convection device.

The above treatment unit integrated in a tank body, electric control cabinet automatic control each power plant operation.

2.6 MBR plant selection
1,before chose this MBR plant, first make clear of sewage nature, the influent water quality and volume required treatment standard. Each industrial sewage, the PH of sewage must be control 6.8-9, it shouldn’t contain the excess element which hamper microbial growth.

2,Equalize tank should supplied or construct by user, it is concrete tank body usually, its volume should confirm according to drainage period ,production process etc factor , its volume is water flow rate 4-10 times.
3,The MBR plant can design vertical and buried two types, it can lay on the ground according to client requirements, or buried below the earth’s surface. 
4,If plant use in cold region, it need make antifreezing treatment to guarantee equipment normal operation in winter.