16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
a NSF Engineering Research Center ReNUWIt,
Colorado School of Mines
Department of Civil and
Environmental Engineering,
Golden, CO, USA
b Aqua-Aerobic Systems Inc.,
Rockford, IL, USA
Jan Benecke
Cand. Ing. (TU Berlin)
WASTEWATER REUSE FOR URBAN IRRIGATION
Tailored Nitrogen Removal in a Full-Scale
Decentralized Hybrid SBR-MBR
Jan Benecke, J. Henkel, D. Vuono,
T. Y. Cath, J. E. Drewes a
L. W. Johnson, T. Reid b
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Introduction
Arising Water Management Challenges
Historic Water Management:
import of freshwater to cities
single usage
transportation & treatment
discharge
Arising Challenges
population growth
urbanization
climate change
local supply shortages
require
local water reuse
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Introduction
Wastewater Reuse for Urban Irrigation
Local Reuse of Water + Nitrogen
saves freshwater
sources
replaces inorganic
N-fertilizer
Control of N-Removal
prevent nitrification
control SRT
limit denitrification
control O2
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Season H2O N c(N)
[mm/d] [mg/(d·m²)] [mg/L]
Spring 8 40 – 80 5 – 10
Summer 12 80 – 160 7 – 14
Winter 0 0 *
* discharge requirements
Introduction
Tailored Nitrogen Removal
according to Carrow et al. 2002. Turfgrass Soil Fertility & Chemical Problems: Assessment and Management.
Seasonal Variation of
plant growth
water requirements
nitrogen requirements
Jan Dec Jul
Growth Rate + N Demand
Tailored N Removal
seasonal control of c(N)
prevent ion of over-
or under fertilization
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
SBR-MBR
Site Location – Golden, CO, USA
Colorado School of Mines
Student Housing
SBR-MBR
Field
Laboratory
Green
House
Parking Water Reuse
Test Areas
Process Unit
Treatment Areas
Raised Plots
Photo
Bioreactors
Sustainable Water
System Site
Google Earth
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
SBR-MBR
Process Flow Diagram
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Flow (Q)
=
≈
24 d-1 x 1.14 m³
27.3 m³/d
140 PE
Volume (V) 23.9 m³
VER (VF/VT) 10 %
SRT ≈ 35 d
MLSS ≈ 6 g/L
Treatment Time
=
1 h Fill
1 h Draw
2 h Total
Membrane Module PURON® (KMS)
Surface Area (A) 2 x 30.6 m²
Net Flux (J) 19 L/(m²·h)
SBR-MBR
Select Process Parameters
www.filtsep.com
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Results
Research Objectives
Modify system operation to tailor effluent nitrate
concentrations
Investigate reversibility of operational modifications
Assess energy demand for tailored nitrogen removal
Investigate impacts on system robustness
(membrane performance, maintenance)
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Results
SBR-MBR Nutrient Removal Performance
Influent Effluent Removal [%]
SUMMER
BREAK
2011
COD [mg COD/L] 354 12 96
T-N [mg N/L] 38.5 4.4 88
T-P [mg P/L] 4.7 2.8 40
3 month operation (n = 8)
FALL
TERM
2011
COD [mg COD/L] 471 18 96
T-N [mg N/L] 57.6 4.2 93
T-P [mg P/L] 6.8 2.3 (< 0.2) 66 (98)
1.5 month operation (n = 8)
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Results
Tailored N Removal - SBR Treatment Cycle
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 20 40 60 80 100 120
Nit
roge
n [
mg
N/L
]
Time [min] NO3-N NH3-N
ANOXIC OXIC ANOXIC OXIC ANOXIC
INFLUENT
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Results
Tailored N Removal – Aeration Setup
0
10
20
30
25 32 39 46 53 60
[NO
3-N
] ein
mg/
L
Time [d]
NO3 (lab)[NO3-N]e (lab)
3F 6F FDFD
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Results
Tailored N Removal – Aeration Setup (2)
0
10
20
30
58 65 72 79 86 93
[NO
3-N
] ein
mg/
L
Time [d]
NO3 (lab)[NO3-N]e (lab)
9 6 FDFD FD
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Conclusion
Results
Nitrogen-removal can be tailored as a function of
season or irrigation needs
Tailored effluent nitrate concentrations are achieved
quickly
Operational modifications are reversible
(full denitrification recovered after a few days)
Energy consumption to retain NO3-N in effluent is
competitive to fertilizer production
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Conclusion
Further Studies
Characterize bacterial/archaeal communities during
tailored N removal (reversibility)
Long term experiments (robustness) + urban landscape
irrigation
Assessment of health risks
Detailed analysis of environmental and economical
impacts (LCA)
16th International EWA Symposium “Sustainable Wastewater Management – New solutions for new problems”
Munich, Germany, 8-9 May 2012
Acknowledgements
Special thanks to:
Aqua-Aerobic Systems, Inc. for their generous support
Hach Company for providing an online nitrate probe