Centralized Control on Decentralized Wastewater Treatment: The ...

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Centralized Control on Decentralized Wastewater Treatment. Influent. Effluent. MBR System. What is Membrane Bioreactor (MBR) ? • Combination of 2 basic ...
Centralized Control on Decentralized Wastewater Treatment: The Emerging Role of Membrane Bio-reactors New Horizons in Biotechnology November 22-25, 2015, Trivandrum, India

C. Visvanathan and P. Jacob

Environmental Engineering and Management Program Asian Institute of Technology, Thailand Email: [email protected] http://faculty.ait.ac.th/visu

What is Membrane Bioreactor (MBR) ? • Combination of 2 basic processes  Biological degradation  Membrane separation • MBR is a single process where SS and microorganisms responsible for biodegradation are separated from treated water by a membrane separation unit instead of gravity settlement.

MBR System

Influent

+ Effluent

C .Visvanathan

Centralized Control on Decentralized Wastewater Treatment

History

How it Began – WWT For solid liquid separation

History

1829 - Smith Slow Sand Filtration Water Purification 1899 - Trickling Filter Activated Sludge Sewage treatment C .Visvanathan

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Membrane Separation Bioreactor Principles: Dissolved organic materials converted to: Microbial biomass:  Suspended solids  entrained in some way Gases:  Mineralization  end products of respiratory metabolism  aerobic systems- CO2, H2O  Anaerobic systems - CO2 , CH4 C .Visvanathan

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Conventional WWT Approach

Filtration/ Adsorption

Activated Sludge Process Return Sludge

Sedimentation

Tertiary Treatment

Disadvantages:

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Need for close operational control (SS Removal)



Separation depends on floc characteristics



The large amount of waste sludge Centralized Control on Decentralized Wastewater Treatment

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Technology Evolution- Telephone

Not only a Telephone Anymore C .Visvanathan

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Development of MBR Conventional Approach

Membrane Technology for Tertiary Treatment

Energy Saving Options in Membrane Bioreactor

Tertiary treatment

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Submerged Membrane

Membrane Bioreactor (Crossflow membrane filtration)

Decentralized Wastewater Treatment

Air

Plunging Liquid Jet Aeration

Membrane as Solid/Liquid Separator & Air Diffuser Air

Centralized Control on Decentralized Wastewater Treatment

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Centralized Control on Decentralized Wastewater Treatment

We are already Connected

C .Visvanathan

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Internet of Things (IoT) • Internet of Things (IoT) is a scenario in which objects, devices are provided with a unique identifiers. • Thus ability to transfer data over a network without requiring human-tohuman or human-to-computer interaction. • An ability to learn by constant feedback from centralized servers • Ex. Self learning thermostats. • Ex. Google Nest

Source : http://www.tweaktown.com/news/41530/internet-of-things-market-is-growing-with-industry-deals-accelerating/index.html

C .Visvanathan

https://nest.com/ Centralized Control on Decentralized Wastewater Treatment

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What are decentralized WWT and MBR’s Role • Decentralized WTP are so called due to their location away from main wastewater treatment facility • They are located close to source, such as homes and businesses. • Currently trends in WWT moving towards Decentralized WTP.

• Small conventional WTP cannot be used as decentralized system • Membrane based bioreactors with its ability to retain 2-4 times the MLSS can treat onsite WW effectively. • Thus source treatment increasing the chances of water reuse. C .Visvanathan

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Centralized Control on Decentralized Wastewater Treatment



Decentralized MBR send and receiving data from central control system through internet.



Centralized operation control unit can observe and operate individual plants.



Operators and technicians will be informed if any, technical issue.

Centralized Control

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Case Study - Gas Station Wastewater Management

Gas Station Overview

Slope

Slope

Slope

Slope

Slope

Slope

Slope

Slope

Slope

Slope

8

3 5

7

4

Slope

Slope

Slope

Slope

Slope

Slope

Slope

6

Slope

Slope

Slope

Slope

Slope

Slope

Slope

9 2

Slope

1

Slope

Slope Slope

Slope

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Premium Gas Station 1 Gas station 2 Toilet 1 3 Office 4 Food court 5 Noodle restaurant 6 Coffee shop 7 Toilet 2 8 MBR system 9 KFC restaurant 10 Convenience store 11 Effluent sump 1 12 Effluent sump 2 Fixed film tank Water pump station Septic tank

12 Slope

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Slope

Slope

Slope

Slope

Slope

Slope

Slope

Slope

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Major Wastewater Source- Gas Station Coffee shop, 3%

~60 m3/month KFC, 10%

~ 180 m3/month

Toilet, 66%

~ 1,200 m3/month

Food Court, 17%

~ 300 m3/month

Noodle Restaurant, 3% ~ 60 m3/month Coffee shop C .Visvanathan

KFC

Food Court

Noodle Restaurant

Toilet Centralized Control on Decentralized Wastewater Treatment

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Wastewater Characterization Parameter

Unit

KFC restaurant

Coffee shop

Noodle restaurant

Food court

Toilet

COD

mg/L

797 ± 48

2448 ± 48

715 ± 35

1578 ± 170

245 ± 5

TKN

mg/L

53 ± 3

31 ± 3

91 ± 21

30 ± 5

182 ± 14

TP

mg/L

10 ± 0.5

8 ± 0.1

6 ± 0.1

7 ± 0.1

15 ± 4

100

100

100

100

100

COD : N : P Ratio

COD

N

100

100 80

P

75 50 25 5 0

1

Suitable ratio

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7

13 1

KFC restaurant

2

0.4

Coffee shop

1 Noodle restaurant

2

6

0.4

Food court

Toilet

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Emerging Issues: Social Concerns Affecting WWT • Gas stations toilets wastewater contained ~1-2 condom/ (Per transfer (5m3)) • In our research: Solids and condoms were skimmed before entering storage units @ 50 C

• Condoms are polymer based material that can easily clog pipes, screens, basic (fixed film) and advance WW (MBR’s) treatment units. • This is a social issue that will severely affect decentralized WWTP’s in automated operations. • Potential for research ? Social Issues affection Environmental Protection C .Visvanathan

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Pilot Scale MBR System

PLC Controller

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PLC Controller on Computer Centralized Control on Decentralized Wastewater Treatment

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Schematic Diagram of Pilot Scale MBR System PG

AB

V4

Influent

V2

V3

P5

V P AB PG FI

Chemical Tank

FI

Wastewater Flow Air Flow Waster Backwash Flow Chemical Flow Valve Pump Air Blower Pressure Gauge Flow Meter

V1 P3

Anoxic Tank

P2

MBR Tank Drainage P4

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Permeate Tank

• Pumps, Pressure gauge, flow meters are connected to computerized control system. • System can control and observe over the internet.

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Flux and TMP Interaction over the MBR Study

20

40

15

30 10 20 10

Flux (LMH)

5

TMP (kPa)

0

TMP (kPa)

Permeate Flux (LMH)

50

0 1

3

5

7

9 11 13 1

SWW (6)

3

5

7

9 11 13 15 17 19 21 23 1 RWW (6)

3

5

7

9 11 13 15 17 19 21 23 RWW (8)

TIME (D)

• Trends of flux and TMP were stable at 32 LMH and 13 kPa. • Membrane fouling has low affected to TMP and permeate flux because of backwash system. C .Visvanathan

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Colour for Acceptable Reuse

Color (CU) in permeate of;  AIT MBR vs. Gas station’s MBR 60 vs. 131  Tap Water vs. AIT MBR 28 vs. 60

200

Color (Color Unit))

Treating RWW; • At HRT 6, color in permeate was 111 ± 17 CU. • At HRT 8, color in permeate was 104 ± 12 CU.

150

 At HRT 8 with RWW, FeCl3 was add anoxic tank.  Color in permeate reduced to 60 ± 6 CU.

100

50

0 2 TW

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GS

6

10

SWW (6)

14

2

6

10

RWW (6)

14

4

6

8

RWW (6-pH) Time (d)

10

2

6

10

RWW (8)

14

2

6

8

10

RWW (8-FeCl3)

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Performances of this MBR study with literatures

This study AIT HRT Wastewater Type MLSS (g/L) Flux (LMH) % COD removal % TKN removal % TP removal Coloreff (CU)

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6h SWW

25 - 36 91 ± 2 82 ± 3 43 ± 5 35 ± 6

8h RWW

RWW

8 - 10 27 - 42 24 - 37 85 ± 4 84 ± 3 81 ± 19 99.4 ± 0.3 9±3 6±4 173 ± 41 104 ± 12

RWW – FeCl3 28 - 38 94 ± 1 99.5 87 ± 8 60 ± 6

Gas Station 4h Toilet Wastewate r 0.6 – 1.1 20 58 83 20 131

21 h

(Abdel-Shafy and El-Khateeb, 2011) 2.4 d

Blackwater

Blackwater

6.3 96 49 -

2-4 92 95

(Hocaoglu et al., 2011)

-

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Energy Consumption Others 22%

Aeration Energy consumption 78%

Synthetic Wastewater (HRT 6)

Others 21%

Others 17%

Aeration Energy consumption 83%

Aeration Energy consumption 79%

Real Wastewater (HRT 6)

Real Wastewater (HRT 8)

 Major energy consumption was the aeration  The percentages of energy consumption distribution at different HRT were approximately 78, 79 and 83% of total energy consumption. C .Visvanathan

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Concept: Centralized Control Over Decentralized WWTP

Gas station 1

Central Controller Gas station 2

Online data storage Gas station n

Data exchange and analysis

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Concept: Centralized Control Over Decentralized WWTP

Gas Station 1

Gas Station 3

Central Control

Gas Station 2

Gas Station 4

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Concept: Centralized Control Over Decentralized WWTP

MBR Tank C .Visvanathan

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Potential of Decentralized and Automated control : E.g. MBR 45

50

40

40

Stable flux

35

45

Stable

Stable flux

40

30 35 25 30 20

Flux (LHM)

15

TMP (kPa)

25 20

10

TMP Increases

5

Stable TMP

TMP Increases

15

0

10

1

3

5

7

9

11

13

15

17

19

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25

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31

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37

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45

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53

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63

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67

Time (Min)



Sudden flux decline, TMP rises → 40 kPa



System automatically back wash to solve problem.



During backwash TMP and Flux = 0



Stable Flux achieved for few minutes.



2nd time sudden flux decline- System sends message to controller and operator fixes problem



Problem due to clogging and leak

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TMP ()kPa)

Flux (L/m2.h)

ALERT OPERATOR

AUTOMATIC SYSTEM BACKWASH

Thank You!

C .Visvanathan

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