1. JDS International Seminar, Tsukuba, Japan
Impact of Intermittent Aeration Strategy on Aerobic Granular Sequencing Batch Reactor for Domestic Wastewater Treatment
Presented By
Saha Pankaj Kumar
ID#
Supervisor: Prof. Lei Zhongfang
Date: January 22, 2019

2. Contents Introduction
Materials and Methods Results and Discussion Conclusion
Future work 2

3. 1. Introduction
Wastewater is an inevitable byproduct of human consumption and it’s treatment efficiency is related with the income level of a country.
Wastewater treatment in developing countries like Bangladesh needs to be more efficient in the context of resource requirement and energy consumption.
Types of WW treatment
Chemical
Physiochemical
Biological
Activated Sludge
Aerobic granular sludge (AGS) 8%
28%
High Income
Upper middle income Lower middle income Low income
70%
38%
Figure 1: Wastewater treatment percentage with income level of the country (UN World Water Development Report 2017) 3

4. 1. Introduction Advantage of AGS over CAS Excellent settleability
High nutrient removal efficiency
High biomass retention
After five minutes settling, AGS(right), CAS(left)
Ability to withstand at high organic loading
Aerobic granular sludge (AGS)
Tolerance to toxicity
Adav et.al. (2008)
Source: Nereda® Garmerwolde WWTP (Netherlands). 4

5. Aerobic granular Sludge (AGS)
1. Introduction
layered structure of aerobic granules and presence of key microorganisms, AGS can remove nitrogen and phosphorus simultaneously (Nancharaiah et al., 2018).
Factors affecting AGS
DO & aeration; Granular size; Substrate composition, pH, Temperature, Reactor configuration etc.
Aerobic granular Sludge (AGS)
IA operation strategy is efficient for nitrogen removal from wastewater due to alternating nitrification and denitrification (Wang et al. 2015). This alternating oxic/anoxic process has the potential for minimizing energy requirement.
Factors affecting IA
O/A duration, Chemical oxygen demand (COD)
Intermittent aeration
Combination of AGS and IA has the potential of better nutrient removal from wastewater and reduce energy requirement 5

6. 1. Introduction Specific objective of the study
To evaluate the effect of IA on the granular stability
To investigate the impact of IA in reactor performance (TOC removal, TIN & TP)
To establish the relationship between the microbial community and the removal performance by microbial community analysis 6

7. 2. Materials and methods RIA RC 7 HRT= Hydraulic retention time
Air pump
Effluent
Influent RC
RIA 7
HRT= Hydraulic retention time

8. 2. Materials and methods 8

9. 3. Results and discussion
Granular Stability 7 6 5 4
1.0 70
RC RIA 60
MLSS & MLVSS (g/L)
0.8
SVI5 (mL/g-MLSS) 50
MLVSS/MLSS
0.6 40 3
RC-MLSS RC-MLVSS RIA-MLSS RIA-MLVSS
RC-MLVSS/MLSS RIA-MLVSS/MLSS
22 29
0.4 30 2 20
0.2 1 10
0.0 7 14 7 14 22 29
IA-1
IA-2
IA-1
IA-2
Operational Duration (Day)
Operational Duration (Day)
MLSS increased up to 4.52 g/L for RC and 4.61 g/L for RIA
MLVSS/MLSS ratio increased up to 0.78 for RC and 0.79 for RIA
Settleability for RIA (SVI5=54.23 mL/g)) compared to RC (SVI5=59.67 mL/g)
MLSS= Mixed liquor suspended solids, MLVSS= Mixed liquor volatile suspended solids 9

10. 3. Results and discussion
Granular Stability
Total EPS content was higher in AGS of RIA ( mg/g) than RC ( mg/g)
AGS under IA-1 strategy also showed significant increase in PN (65.77mg/g)and PS(16.20 mg/g) content with respect to its initial condition (PN=46.42 mg/g, PS= mg/g)
Intermittent change of oxic/anoxic condition is probably the major reason of higher EPS secretion in RIA
120 5
PN PS
100
PN & PS (mg/g-MLVSS)
PN/PS 4 80 3 60 2 40 1 20 RC
RIA RC
RIA RC
RIA 14
IA-1 29
IA-2
Operational duration (day)
Extracellular polymeric substance(EPS)= Protein (PN)+Polysaccharide (PS) 10

11. 3. Results and discussion
Granular Size
RIA (Average Diameter 0.81 mm)
RC (Average Diameter mm) 11

12. 3. Results and discussion Reactor performance80
100 80
RIA RC
RIA Removal % RC Removal % 2 5 7 10 12 15 17 20 22 25 27 30
IA-1
IA-2
RC RIA 80 60 60
TOC (mg/L)
TOC (mg/L)
Removal % 60 40 40 40 20 20 20 15 30 45 60 75 90
105
115
130
145
160
170
185
200
215
225
on off on off
Aeration
on off
Non-aeration
Operational duration (day)
IA-1
Cycle time (min)
100 80 60 40 20
RIA
TOC (mg/L)
AGS in RIA underIA-2 showed better TOC removal (68.99%) than IA-1 (61.05%) but lower than those RC (75.93%)
Cycle test data showed that residual TOC from RIA in IA-1 and IA-2 were mg/L and mg/L, respectively 15 30 45 60 75 90
100
115
130
145
155
170
185
200
210
225
on off on off
Aeration
on off
Non-aeration
TOC= Total organic carbon
IA-2
Cycle time (min) 12

13. 3. Results and discussion
Reactor performance 35 30 25 20 15 10 5 6 5 4 3 2 1
RIA (NH₄⁺-N) RC (NH₄⁺-N)
RC RIA
NH₄⁺-N (mg/L)
NH₄⁺-N (mg/L)
IA-2 15 30 45 60 75 90
105
115
130
145
160
170
185
200
215
225
on off on off
Aeration
IA-1
on off
Operational duration (day)
Non-aeration 35 30 25 20 15 10 5
IA-1
Cycle time (min)
NH₄⁺-N (mg/L)
RIA (NH₄⁺-N)
RIA under IA-2 strategy showed better NH₄⁺-N removal than that under IA-1 strategy possibly due to its longer aeration duration
RC showed efficient NH₄⁺-N removal throughout the whole operation 15 30 45 60 75 90
100
115
130
145
155
170
185
200
210
225
on off on off
Aeration
on off
Non-aeration
IA-2
Cycle time (min) 13

14. 3. Results and discussion
Reactor performance 30 25 20 15 10 5 30 25 20 15 10 5
RC (NO₂⁻-N) 25 25
NO₂⁻-N (mg/L)
NO₃⁻-N (mg/L)
RIA (NO₂⁻- N) 20 20
NO₃⁻-N (mg/L) 15 15
NO₂⁻-N (mg/L) 10
RC (NO₂⁻-N) RC (NO₃⁻-N) RIA (NO₂⁻-N) RIA(NO₃⁻-N) 10 5 5 15 30 45 60 75 90
105
115
130
145
160
170
185
200
215
225
on off on off
Aeration
on off
Non-aeration
IA-1 IA-2
Operational duration (day)
IA-1
Cycle time (min) 16 20
RIA (NO₂⁻- N)
NO₃⁻-N (mg/L)
During IA-1 strategy, NO₂⁻-N and NO₃⁻-N concentration in the effluent from RIA were 9.01 mg/L and 9.75 mg/L respectively
Under IA-2 Strategy, increased NO₃⁻-N concentration up to
16.42 mg/L was detected in the effluent from RIA probably due to longer aeration, but significantly lower than RC (22.69 mg/L)
RIA under IA-2 strategy showed better denitrification efficiency than RC
NO₂⁻-N (mg/L) 12 15 8 10 4 5 15 30 45 60 75 90
100
115
130
145
155
170
185
200
210
225
on off on off
Aeration
on off
Non-aeration
IA-2
Cycle time (min) 14

15. 3. Results and discussion
Reactor performance 40 80
IA-2 strategy enhance TIN removal (68%) significantly than IA-1 (58.29%) and RC (54.62%)
Higher aeration enhance the nitrification and anoxic phase of IA strategy reduced nitrogen concentration through denitrification 35 30 60 25
TIN(mg/L)
Removal % 20 40 15
RC RIA
RC Removal% RIA Removal %
IA-1 IA-2 10 20 5
Operational duration (mg/L)
Total inorganic nitrogen (TIN)= NH₄⁺-N+NO₂⁻-N +NO₃⁻-N 15

16. 3. Results and discussion
Reactor performance 7 6 5 4 3 2 1
5.0
100
RC RIA
PO₄3⁻-P (mg/L)
4.0 80
PO₄3⁻-P (mg/L)
Removal %
3.0
RC RIA
RC Removal %
RIA Removal % 60
2.0 40
1.0 20 15 30 45 60 75 90
105
115
130
145
160
170
185
200
215
225
on off on off
Aeration
0.0
on off
IA-2
Non-aeration
IA-1
IA-1
Cycle time (min)
Operation duration (day) 8
PO₄3⁻-P (mg/L)
RIA 6
PO₄3⁻-P removal was consistent for both the reactor. 4
RIA under IA-2 strategy showed better PO₄3⁻-P removal ( mg/L) than RC (77.16 mg/L) and RIA under IA-1 (74.77 mg/L)
Higher residual TOC for the next cycle and better nitrogen removal in RIA under IA-2 reduced the competition for organic carbon and thus enhance P-removal 2 15 30 45 60 75 90
100
115
130
145
155
170
185
200
210
225
on off on off
Aeration
on off
Non-aeration
IA-2
Cycle time (min) 16

17. 3. Results and discussion
Reactor performance (DO, ORP & pH)
20 200 20
180
150
120 90 60 30
IA-2 RC 16
DO (mg/L) & pH
16 160
DO (mg/L) & pH 12
ORP (mV)
12 120
8 80
ORP (mV) 8 DO pH
ORP DO 4 40 4
pH ORP 60
100
170
210 10 20 30 40 50 70 80 90
110
120
130
140
150
160
180
190
200
220 15 30 45 60 75 90
105
120
135
150
165
180
195
210
225
on off on off
Aeration
on off on
off on
off on
off
Non-aeration
Non-aeration Aeration
RC & RIA under IA-2 strategy showed clear indication of complete nitrification where RIA under IA-1 did not show any significant ORP change with respect to pH and DO 18 15 12 9 6 3
180
150
120 90 60 30
IA-1
DO (mg/L) & pH DO pH
ORP
ORP (mV)
It indicates that, nitrification was inhibited in RIA under IA-1 strategy which affect the nutrient removal performance in comparison to IA-2 and RC 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
170
180
190
200
210
220
on off on off
Aeration
on off 17
Non-aeration

18. 3. Results and discussion
Energy consumption 30
RIA under IA-2 Strategy can save energy % for per g-N removal and 3.04% for per g-TOC removal where as RIA under IA-1 can save 22.84% for per g-P removal with respect to RC
RIA under IA-1 strategy can save up to 19.84% energy per m3 of treated effluent discharge with respect to R
% Saving energy with respect to RC 20
IA-1 IA-2 10
-10
% Saving energy/g-N removal
% Saving energy/g-P removal
% Saving energy/g-TOC removal
% Saving energy/m3 effluent discharge 14 12 10 8 6 4 2
Types of fuel
gCO₂e/kW-hr
Nuclear 66
Natural gas
443
Coal
960 C
kgCO₂e/m3 of discharge
IA-1 IA-2
In terms of GHG gas emission, RIA under IA-1 strategy can reduce 0.8, 5.9 and kgCO₂e/m3 of treated effluent discharge if the electricity is generated by nuclear, natural gas and coal respectively
(Sovacool,2008)
Nuclear Natural gas Coal with scrubbing
Types of fuel used in electricity generation 18

19. 4. Conclusion
RIA under IA-2 strategy exhibited enhanced TIN removal (68%)
Higher TOC removal was achieved in RC (75.93%) than RIA (68.99%)
RIA showed better PO₄3⁻-P removal (81.55%) than RC (77.16%)
AGS from RIA shows higher PN( mg/g) concentration than RC ( mg/g)
RIA under IA-1 strategy can reduce 12.8 kgCO₂e GHG gas per m3 discharge if the electricity is generated by coal 19

20. Future Work Continue experiment with IA-3 strategy
Analyze microbial community to shed light on the relationship of microbes in the nutrient removal performance 20

21. References
Adav S.S., Lee D.J., Show K.Y., Tay J.H. (2008). Aerobic granular sludge: Recent advances Biotechnol. Adv. 26,
APHA, Standard Methods for the Examination of Water and Wastewater. American Public Health Association/American Water Work Association/Water environment Federation, Washington, D.C., USA.
B. K. Sovacool, “Valuing the Greenhouse Gas Emissions from Nuclear Power: A Critical Survey,” Energy Policy, Vol. 36, No. 8, 2008, pp
Nancharaiah Y.V., Reddy G. K.K., (2018). Aerobic granular sludge technology: Mechanisms of granulation and biotechnological applications. Bioresour. Technol. 247,
United Nations World Water Development Report (2017). Wastewater the untapped resource.
Wang H., Guan Y., Li L., Wu G. (2015). Characteristics of biological nitrogen removal in a multiple anoxic and aerobic biological nutrient removal process. Biomed. Res. Int., 2015: 21

22. Thank you 22