100 years of biological wastewater treatment practice: a

Chuan-hong XINGMarch 11, 2008

100 Years of Biological 100 Years of Biological Wastewater Treatment Practice: Wastewater Treatment Practice:

A PerspectiveA Perspective

■Re-look at WWTPs on an 100-year scale

The OutlineThe Outline

■Current biological wastewater treatment

■ Promising R&D focus

■ Future R&D directions: a shift in concept ?

■Concluding remarks

■ Re-look at WWTPs worldwide

In ancient Rome…

■ Fixed film Nature■ Re-look at WWTPs worldwide


IMAGE CREDITS: Henry Aldrich Email: [email protected]

■ Fixed film Nature

■ Re-look at WWTPs worldwide■May 1914, Ardern and Lockett introduced a recycle of

suspension (activated sludge).

* Arden, E. and W. T. Lockett (1914) Experiments on the oxidation of sewage without the aid of filters. J. of Soc. Chem. Ind. Vol. 33, pp. 523-539

Aeration Basin

SecondaryClarifier

Screening

Degritting Primary Clarifier

Start Here

dPdP

dNdN

DisinfectionDischarge

Tertiary Treatment

Na2(SO3)NaClO

Biosolids Final

Disposal

Polyer

Belt Thickener

Blend Tank

Gas Generator

Centrifuge

Polyer Boiler Flare



Wastewater

Point Source Non-point Source

DomesticIndustrial AgriculturalOther>80% 100% 100%>80%


Wastewateras mgCOD/L

Low strengthe.g. <1000 mgCOD/L

High strengthe.g. >1000 mgCOD/L

Aerobic *

Anaerobic++ Aerobic

Major breakthrough:Major breakthrough:

■Membrane bioreactor


For aerobic processes:For aerobic processes:

■ Demand of oxygen Energy high

■ Excess sludge Disposal difficult

< 50,000 m< 50,000 m33/d/d < 144,000 m< 144,000 m33/d/d

< 50,000 m< 50,000 m33/d/d < 50,000 m< 50,000 m33/d/d


< 50,000 m< 50,000 m33/d/d

< 50,000 m< 50,000 m33/d/d

< 50,000 m< 50,000 m33/d/d

and more . . .


G 2

*Smith, C.V.Jr., D.Di Gregorio (1969) The use of ultrafioltration membrane for activated sludge separation. In: proceedings of the 24th annual Purdue industrial waste conference. West Lafayette, Indiana, 1300-1310

G 1

G 3 ?


* * Yamamoto k., M.Yamamoto k., M.HiasaHiasa, M. , M. MahmoodMahmood and T. Matsuo (1989) Direct solidand T. Matsuo (1989) Direct solid--liquid liquid separation using hollow fiber membrane in an activated sludge aeseparation using hollow fiber membrane in an activated sludge aeration tank. ration tank. Water Water Science and TechnologyScience and Technology 21(4/5):4321(4/5):43--5454

Mitsubishi Rayon PE membrane 0.1micronMitsubishi Rayon PE membrane 0.1micron


■MBR G3

√√ Significantly reduced energy consumption

√√ Integrated N & P removals

√√ Minimized excess sludge production

√ Extended filtration time


0

5

1 0

1 5

2 0

2 5

3 0

3 5

4 0

4 5

0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0

S R T , d

MLV

SS, g

/L

H R T , h

2

4

6

81 0

1 61 2

2 0

⎟⎠⎞

⎜⎝⎛ −

=∞→ HRT

CCkYMLVSSLim ei

dSRT

When SRT→∝ ,


Zero excess sludge MBR≡

MBR at , gMLVSS/L⎟⎠⎞

⎜⎝⎛ −

HRTCC

kY ei

d


The highest MLSS in practice

■ Japan recommendations: 10g/L~20g/L

* Building Research Institute, Ministry of Construction (1998) Design and management guidelines for the development of advanced onsite domestic wastewater treatment facilities using membrane filtration. Water and Waste 40(3):241-252.

■ 5-Year Dutch MBR experience (2000-2005): preferably up to 10g/L while 20g/L unfavorable


Yamamoto and Xing (2005)Zero Excess Sludge MBR, US Patent No. 11/070,134


12.6mg/L92.1%COD

1.3 as mgNH3-N/L 93%Nitrification

0.01NTU99.9%Turbidity

8.86 as mgTN/L71.7% at R=300%deNitrification*

Permeate AverageRemoval Average, %


Case I: Tanzhou WWTP, Beijing (45,000m3/d in operation)


Case II: Wenyuhe Reclamation Plant, Beijing(100,000m3/d)


Major breakthrough:Major breakthrough:

■ IC Reactor

For anaerobic processes:For anaerobic processes:

■ Insufficient mixing

■ Limited 3-phase separation

Sludge digester= G1Sludge digester= G1


UASB= G2UASB= G2 IC= G3IC= G3



IC ReactorIC Reactor

Membrane (PP) Membrane (PP) Pukang Lincomycin Wastewater Treatment, Nanyang China (4,500m3/d)

COD6000~10000mg/L

COD1200~2500mg/L

COD<300mg/L

■ Promising R&D focuses

UASB (G2)UASB (G2)

IC (G3)IC (G3)

(G4)(G4) ??

+MBR (G1)MBR (G1)

MBR (G2)MBR (G2)

MBRMBR (G3) (G3) ??

Digester(G1)Digester(G1)


Anaerobic Anaerobic ReactorReactor (G4)(G4)

1. Enhanced mixing

2. Improved 3-phase separation

3. Lowered influent strength ?


MBRMBR (G3)(G3)

1. Significantly reduced kWh/m3 treated

2. Preferably zero excess sludge

3. Integrated N and P removals

4. Extended filtration time

Biogas, O2 depleted air

Fouling control

Mixing effect

Anaerobic MBR (II) ?


■ Future R&D : a shift in concept ?

Currently, ■ Nutrient removals ( i.e.N、P)

■ Excess sludge disposal

■Water reclamation & Reuse

Future, ■ Energy recovery

■ Sludge production

■Water-mining

■ Future R&D : a shift in concept ?

Wastewater

Water mining

Anaerobic Reactor

Biogas mining

Concentrator Aerobic Reactor

Sludge mining

Watermining

Membrane 2

Membrane 1

Dual Membrane bioreactor ?

■ Concluding remarks

UASB (G2)UASB (G2)

IC (G3)IC (G3)

(G4)(G4)

+MBR (G1)MBR (G1)

MBR (G2)MBR (G2)

MBRMBR (G3)(G3)

Digester(G1)Digester(G1)

100 years of biological wastewater treatment practice: a

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