a modified constructed wetland system for greywater...
TRANSCRIPT
A modified constructed wetland system for greywater treatment and reuse
Jhonatan B. da Silva, Paulo J.A. Oliveira, Marc Á. BonczPaula L. Paulo
Contains chemicals and hardly any nutrients
High solids concentration (even light gw (hair and lint)
Due to (among others):
• dynamics and behaviour of individuals, sanitary standards, age, lifestyle, eating habits, water use and availability, choice on personal care and household products
2
Composition and volume /person highly variable
BackgroundGreywater (gw)
choice – some points to be considered
• required quality of the effluent (reuse applicable?)
• Sustainability of household or small scale system:• Cost• Operation and maintenance requirements• Odour nuisance• Health risks
BackgroundGreywater treatment (small scale)
3
Natural treatment systems
• Good visual impact• Landscaping: total integration with ndividual gardens
or common areas (condominial)• May promote water conservation by the direct reuse of
GW• Increase of green sites in urban areas – expected
contribution to an improvement of microclimate.
Background Greywater treatment
4
Constructed wetlands
• Most common system for small scale greywater treatment (peri-urban, rural areas)
• Simplified and low-cost treatment system • Clog easily depending on substrate type and influent
characteristics• Requires a pre-treatment unit (e.g. septic or sed tank)
How to adapt for the use in urban area?
Background Greywater treatment
5
high variationComposition and volume
High impactHousehold or swws
soil and plants based system
• Inbuilt AnC (car tires)• Layers of different substrates• Fast growing, high water
consumption plants• Effluent percolates upwards
through the layers
BackgroundEvapotranspiration tank (Tevap)
6
• AnC replaces a pre-treatment unit• retaining solids • equalising the inflows
• avoiding clogging• improving the stability of the
system • low maintenance
BackgroundHypothesis
7
CEvaTAnC
• Combination of CEvaT + HSSF-CW• Main focus: direct reuse of gw for
gardening using the system itself
BackgroundEvaTAC
8
CEvaTHSSF-CW
EVaTAC
greywater
BackgroundEvaTAC
9
CEvaTZero discharge
HSSF-CW
Combination of units: depends on final use (if any)
CEvaT + HSSF-CWTreated GW
GW
CEvaT
CEvaTCEvaT
• To propose a modified design of a cw system for GW - EvaTAC
• To better understand the capacity of the AnC to equalise the daily variation of flow and organic load in the EvaTAC.
• real scale EvaTAC system
• 24 hours and 8 days monitoring profiles
10
Objectives
Dimensions
CEvaT: 2.0 m × 1 m × 1.05 m (level exit - 0.74 m)
HSSF-CW: 2.0 m × 1 m × 0.60 m (level exit - 0.4 m)
Material
Masonry, lined with Fiberglass
Full scale - 3 persons household
3 years in operation, Light greywater
Ornamental Plants
White ginger, Caladium, Canna x generalis
(beri), heliconia pisittacorum (parrot´s peak)11
Material & MethodsExperimental setup - EvaTAC
Material & MethodsExperimental setup - EvaTAC
12
gravel n 4
gravel n 2
soil
fine gravel
grav
el n
2
grav
el n
2
HSSF-CW
CEvaTAnC
piezometersFiberglassD=0.5 m
• Filtering material
• Gravel (different particle sizes)
• Soil
• Geotextile blanket
• Bottom slope: 1%
13
Material & Methodsmonitoring profiles
.
P1P2
P3
P4
Profile A24 h, sinks and showersProfile B24h , sinks, showers and laundry (washingmachine)Profile C 8 days, same as B
PZ
• Greywater characterisation (routine simulation)
• Interviews• Questionnaires (filled during the profiles)
Material & MethodsMonitoring profiles
Quantitativecharacterisation
• Flow meters (generationpoints)
• P4 - Ultrasonic flow meter
• Levellogers (piezometers– closest to the exit in both units)
• Meteorological station(hidrological conditions)
Qualitativecharacterisation
• grab or composite samples - depending on situation
• Parameters
• CODtotal, CODsoluble, Solids, turbidity, pH
• Sensors: temperature, conductivity, redox potential.
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ResultsProfile B - Flow patterns and level
15
0
2
4
6
8
10
12
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Q (
L.m
in-1
)
Q - P1 Q - P3 Q - P4
bath 1 bath 2 washing
rinsing
73
74
75
76
77
78
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Lev
el C
Ev
aT
(cm
)
35
36
37
38
39
40
Lev
el H
SS
F-C
W (
cm)
Level CEvaT Level HSSF-CW
DAYNIGHT NIGHT
ResultsProfile B - Flow patterns and level
16
0
2
4
6
8
10
12
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Q (
L.m
in-1
)
Q - P1 Q - P3 Q - P4
bath 1 bath 2 washing
rinsing
73
74
75
76
77
78
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Lev
el C
Ev
aT
(cm
)
35
36
37
38
39
40
Lev
el H
SS
F-C
W (
cm)
Level CEvaT Level HSSF-CW
DAYNIGHT NIGHT
ResultsProfile B - Flow patterns and level
17
0
2
4
6
8
10
12
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Q (
L.m
in-1
)
Q - P1 Q - P3 Q - P4
bath 1 bath 2 washing
rinsing
73
74
75
76
77
78
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Lev
el C
Ev
aT
(cm
)
35
36
37
38
39
40
Lev
el H
SS
F-C
W (
cm)
Level CEvaT Level HSSF-CW
DAYNIGHT NIGHT
Level CW
Level CEvaT
ResultsProfile B - Flow patterns and level
18
0
2
4
6
8
10
12
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Q (
L.m
in-1
)
Q - P1 Q - P3 Q - P4
bath 1 bath 2 washing
rinsing
73
74
75
76
77
78
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time (d)
Lev
el C
Ev
aT
(cm
)
35
36
37
38
39
40
Lev
el H
SS
F-C
W (
cm)
Level CEvaT Level HSSF-CW
DAYNIGHT NIGHT
Level CW
Level CEvaT
evapotranspiration
19
A
ResultsProfiles A, B and C
Inflow volume and Evapotranspiration
B C A B C
20
A
ResultsEvapotranspiration – Profiles A, B and C
B C A B C
CEvAT HSSF-CW
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CEvaT – higher potential for evapotranspiration (soil, plants density)
About 4 times the Evap in the HSSF-CW
A
ResultsEvapotranspiration – Profiles A, B and C
B C A B C
CEvAT HSSF-CW
22
Profile B (1 d) Profile C (8 d)
QP1 = 8.3 L.min-1 QP1 = 6.6 ± 2.2(36) L.min-1
sampling
pointP1 P2 P3 P4 P1 P2 P3 P4
CODt(mg.L-1)
290 113 55 41 307 ± 190(8) 147 ± 67(8) 118 ± 21(8) 73 ± 16(8)
T(NTU)
60 35 40 9.3 56 ± 17(8) 45 ± 17(8) 43 ± 12(8) 10 ± 1.5(8)
Resultsqualitative - Profiles B and C
COD and Turbidity to illustrate behaviour
No means to assess removal efficiency
23
Profile B (1 d) Profile C (8 d)
QP1 = 8.3 L.min-1 QP1 = 6.6 ± 2.2(36) L.min-1
sampling
pointP1 P2 P3 P4 P1 P2 P3 P4
CODt(mg.L-1)
290 113 55 41 307 ± 190(8) 147 ± 67(8) 118 ± 21(8) 73 ± 16(8)
T(NTU)
60 35 40 9.3 56 ± 17(8) 45 ± 17(8) 43 ± 12(8) 10 ± 1.5(8)
Resultsqualitative - Profiles B and C
Turbidity
Low variation between AnC and CevAT (P2 - P3)
Most retained in HSSF-CW (P4)
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Profile B (1 d) Profile C (8 d)
QP1 = 8.3 L.min-1 QP1 = 6.6 ± 2.2(36) L.min-1
sampling
pointP1 P2 P3 P4 P1 P2 P3 P4
CODt(mg.L-1)
290 113 55 41 307 ± 190(8) 147 ± 67(8) 118 ± 21(8) 73 ± 16(8)
T(NTU)
60 35 40 9.3 56 ± 17(8) 45 ± 17(8) 43 ± 12(8) 10 ± 1.5(8)
Resultsqualitative - Profiles B and C
Profiles B and C higher variation than Profile AP1 - CODtotal as high as 900 mg.L-1
HRT (average)CEvaT – 3 to 6 daysHSSF-CW – 1.8 to 2 days
EVaTAC - 5 to 8 days
Does not reflect in final effluent (Profile C – 8d)
Resultsqualitative - Profile B
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0
100
200
300
400
500
600
700
P1-1 P1-2 P1-3 P2-1 P2-2 P2-3 P2-4 P3-1 P3-2 P3-3 P4-1 P4-2 P4-3
CO
D (
mg
.L-1
)
CODtotal CODdissolved
Variation of COD (total and dissolved) along P1 to P4
Inlet
AnC
outletCEvaT
Resultsqualitative - Profile B
26
0
100
200
300
400
500
600
700
P1-1 P1-2 P1-3 P2-1 P2-2 P2-3 P2-4 P3-1 P3-2 P3-3 P4-1 P4-2 P4-3
CO
D (
mg
.L-1
)
CODtotal CODdissolvedAnaerobic chamber
Indicates mixture in the AnC –mixed flow reator?
Variation of COD (total and dissolved) along P1 to P4W
ash
ing
mac
hin
e
sho
we
r
Bef
ore
wm
Aft
er
wm
Stable valuesfor COD in P4 along Profiles
B and C
outlet
Conclusions
• Monitoring profiles - appropriate tool to better understand the capacity of the AnC to equalise the daily variation of flow and organic load in the EvaTAC .
• For low flows (sinks and showers) no mixing observed in the. For higher flows (e.g. washing machine) the AnC attenuates the peak load and stabilises the system.
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• AnC replaces a pre-treatment unit.
• The HSSF-CW operates as an efficient polishing unit.
• CEvaT and HSSF-CW complement each other.
• 3 years of operation: no sludge withdrawal, no maintenance in the distribution pipe (inlet) of the HSSF-CW.
• householders routine undisturbed, rendering a green site totally integrated into the garden, without the use of potable water for irrigation.
28
Conclusions
29
During the experiments (2015)
Present days (2016)
Thanks for the attention!
AcknowledgmentsFINEP – project nº.01.10.0507.00
Fundect- MS – project nº 021/11 and PhD grant