Embedding constructed wetland into sequencing batch reactor for - - PowerPoint PPT Presentation

Embedding constructed wetland into sequencing batch reactor for enhancing nutrients removal: Green Bio-adsorption Reactor

UCD Dooge Centre for Water Resource Research School of Civil Engineering University College Dublin Ireland

Ranbin Liu, Yaqian Zhao

16/9/2016

liu.ranbin@ucdconnect.ie; yaqian.zhao@ucd.ie

[From online]

Content

• Conclusion and further work
• Background
• Methods
• Highlights
• Background

Eutrophication Algae bloom Oxygen depletion undesirable odor Point source pollution from WWTPs ~12% contribution to eutrophication P N

Upgrading or stabilizing the nutrients removal in biological unit

Conventional methods

Biological unit External carbon Carriers addition Multivalent metal ions Phosphorus precipitation

Promising denitrification Increasing nitrifier Enhancing P removal

Robust P adsorption capacity 14.5 mg-P/g

Alum sludge holds the potential taking functions in activated sludge system

CW

Alum sludge Aerobic tank

Integrating these two technology?

Air

P adsorption Carriers for bacteria Saving organic

Three tech-functions In One solution

Aeration Tank

Alum sludge holds the potential taking function in activated sludge system

External carbon Carriers addition

Multivalent metal ions

Phosphorus precipitation

Green Bio-adsorption Reactor

Source of odor Aesthetic value

Wastewater treatment “PARK”

[From online]

Wastewater treatment PLANT

and potential carbon sink

CO2

CO2

CO2

CO2

[From online]

Content

• Conclusion and further work
• Background
• Methods
• Highlights
• Methods

Configuration of reactor Wastewater Piggery wastewater from a farmland COD: 400±80 mg·L-1 NH4

+-N

30±9 mg·L-1 P 15±4 mg·L-1

Operating in SBR mode for 3 months initially

Parameter Value Parameter Value Cycle time (h) 24 DO (mg·L-1) 2.5-4 HLR (m3·m-3·d-1) 0.6 SS (mg·L-1) 1,500-2,000 OLR (g·m-3·d-1) 242±178 Exchange ratio 0.6 Inflow Aeration Anoxic Settling Outflow

Time distribution in one cycle

No anaerobic stage

[From online]

Content

• Conclusion and further work
• Background
• Methods
• Highlights
• Highlights

Averagely 96% BOD removal

Satisfied P removal at the beginning

Deterioration of P removal performance Day 0 Day 30 Day 90

The suspended sludge filled and reduced the active alum sludge surface

50~96% TN removal

The removal performance also deteriorated at the end because of decreased SND induced by suspended sludge blockage

Robust SND process

SND process contributes to the TN removal

DB AOB HB

Organics NH4

+

O2 N2 NO3

• Liquid phase

Biofilm

NO2

• DB

HB

N2 Suspended sludge

AOB

O2 NH4

+

Organics NO3

• NO2
• NO3
• Biofilm

Alum sludge Alum sludge

(a) (b)

Comparison of SND with biofilm only (a) and with biofilm/suspended sludge together (b)

Potential carbon-sink of Green Bio-adsorption Reactor (GBR)

Electricity CO2 CO2 Conventional WWTP Present GBR Electricity CO2 CO2

[From online]

Content

• Conclusion and further work
• Background
• Methods
• Highlights
• Conclusion and further work

Conclusions

• As P-adsorptive material, alum sludge could

enhance nutrients removal effectively

• The high aesthetic value of GBR makes it

advantageous

• Carbon-sink property induces sustainability

Further work

• The impact of alum sludge on EBPR
• the optimal placement of alum sludge

Thanks!

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