ground source heat pumps installation within permeable pavement systems for wastewater quality...

IIE Internal Seminar

January 2008 Permeable Pavement Systems with integrated Ground Source Heating

Pumps

Piotr Grabowiecki

Contents


January 2008

Introduction- Sustainable Drainage Systems- Permeable Pavement Systems- Research Objectives

Materials and Methods- Construction of Systems- Experimental Setup- Inside Rig- Outside Rig- Schematic Layout- Operational Conditions- Analytical Methods

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Contents


January 2008

Results- Water Quality- Carbon Dioxide Collection Points- Carbon Dioxide- Microbiology- Summary Statistics (Inside Rig)- Summary Statistics (Outside Rig)

Discussion

Conclusions

Future Research

Acknowledgements

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Introduction:Sustainable Drainage Systems


January 2008

Traditional systems capture storm runoff, and subsequently distribute it to nearby watercourses orsewer systems.

Some of these expensive systems have becomeineffective and inefficient.

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January 2008

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Source: http://www.floodline.gov.uk



January 2008

Instead of focussing on ‘end-of-pipe’ treatment, sustainable (urban) drainage systems (SUDS) challenge the traditional approach of wastewater treatment by optimising the resource utilisation and development of novel and more productive ‘at source’ technologies.

Apart from swales, filter strips, ponds and wetlands, permeable pavement systems (PPS) can be used.

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Introduction:Permeable Pavement Systems


January 2008

• Reduce runoff

• Recharge groundwater

• Save water by recycling

• Prevent against water pollution

• Reduce suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD) and ammonia concentrations

• Low requirement for maintenanceCOVENTRY UNIVERSITY



January 2008

• Are effective in-situ bioreactors

• Can be designed as tanked or infiltration systems

• Hydrocarbon decomposition and low evaporation, if composite geotextiles are applied

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January 20082007

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Introduction:Ground Source Heating Pumps


January 20082007

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Source: http://www.waterfurnace.com

Introduction:Research Objectives


January 2008

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• To evaluate the efficiency of PPS with novel Ground Source Heating Pumps (GSHP)

• To assess the potential transfer of pathogens

• To characterise microbial activities under different temperature patterns

• To assess the water quality within different tanked systems

• To prepare Health and Safety, and Risk Assessment guidelines


January 2008

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• Systems were designed and constructed in spring 2006

• One rig containing six experimental systems outside

• One rig containing six experimental systems inside

• Both mirror each other; therefore, the comparison is effective and scientifically sound

• Coolers or heaters provide operational control

• One Institution of Civil Engineers briefing article and one journal review paper (Building and Environment) covering the subject have already been published.

Materials and Methods:Construction of Systems


January 2008

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Materials and Methods:Experimental Setup

Inside rig Outside rig

Feature 1 2 3 4 5 6 1 2 3 4 5 6

Inbitex composite √ √ √ √ √ √

Inbitex geotextile √ √ √ √ √ √

Cooling or heating √ √ √ √ √ √ √ √

Animal feaces √ √ √ √

Air thermometers √ √ √ √ √ √

Vessel thermometers √ √ √ √

Carbon dioxide sampling

√ √ √ √


January 2008

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Materials and Methods: Inside Rig


January 2008

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Materials and Methods: Outside Rig


January 2008

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Materials and Methods:Schematic Layout

pump

Titan cooler

bin water level

bin sub-basebin

heater

paving blocks

tubing coils

vessel

mains 230 V


January 2008

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Materials and Methods:Operational Conditions

• Systems are operating 24/7

• Two main patterns of operation for the first year:

Heating PPS during winter season

Cooling PPS during summer season

For the second year, these patterns will be reversed (i.e. cooling during winter and heating during summer)

• Water circulation provides adequate temperature

distribution

• All systems are tanked and the flow regime simulation

is performed manually.


January 2008

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Materials and Methods:Operational Conditions

• Main pollutants used:

Gully pot liquor – simulates urban runoff

Animal faeces (i.e. dog droppings) – main pathogen source


January 2008

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• Nutrients such as nitrate-nitrogen (N-NO3),

ammonia-nitrogen (NH4) and

ortho-phosphate-phosphorus (PO4) are analysed

using a flow injection analyser.

• Standard water quality indicators: total dissolved solids

(TDS), SS, BOD, conductivity, pH, dissolved oxygen

(DO) and the redox potential.

• Microbes are analysed for Salonellae, Enterococci and

total heterotrophic bacteria using plate count

techniques.

Materials and Methods:Analytical Methods


January 2008

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• Temperature is monitored with various thermometers

installed within the system.

Data is being analysed using standard methods including MS Excel, SPSS, Self Organising Maps and Minitab.

Materials and Methods:Analytical Methods


January 2008

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Results: Water Quality

0

50

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450

500

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Jul-06 Aug-06 Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Mar-07

Am

mo

nia-

nitr

og

en, i

nflo

ws

(mg

/l)

Am

mo

nia-

nitr

og

en, s

yste

ms

(mg

/l)

Date

1

2

3

4

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6

IN

IN+P

Ammonia-nitrate for the inside and outside systems


January 2008

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Results: Water QualityOrtophosphate-phosphorus for the inside and outside systems

0

5

10

15

20

25

30

35

40

0.0

0.5

1.0

1.5

2.0

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3.5

Jul-06 Aug-06 Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Mar-07

Ort

ho-p

hosp

hate

-p

hosp

horu

s, in

flo

ws

(mg

/l)

Ort

ho-p

hosp

hate

-p

hosp

horu

s, s

yste

ms

(mg

/l)

Date

123456ININ+P

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400

0.0

0.2

0.4

0.6

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1.0

1.2

1.4

1.6

1.8

Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Feb-07

Ort

ho

-ph

os

ph

ate

-ph

osph

oru

s, in

flow

s (m

g/l

)

Ort

ho

-ho

sp

ha

te-p

ho

spho

rus,

sy

ste

ms

(m

g/l

)

Date

1

2

3

4

5

6

IN

IN+P


January 2008

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Results: Water QualityNitrate-nitrogen for the inside and outside systems

0

2

4

6

8

10

12

May-06 Jul-06 Aug-06 Oct-06 Nov-06 Jan-07 Mar-07 Apr-07

Nitr

ate-

nitr

og

en (

mg

/l)

Date

1

2

3

4

5

6

IN

IN+P

0

1

2

3

4

5

6

7

Oct-06 Nov-06 Dec-06 Jan-07 Feb-07

Nit

rate

-nit

rog

en

(mg/

l)

Date

1

2

3

4

5

6

IN

IN+P


January 2008

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upper part of lowersub-base (0.1-6.3 cm

aggregates)

lower part of lowersub-base

(0.1-6.3 cm aggregates)

upper sub-base(0.5-2 cm aggregates)

0.5 cm clean stone 5 cm width

25 cm width

10 cm width

25 cm width

Results:Carbon Dioxide Collection Points


January 2008

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Results: Carbon DioxideCarbon dioxide for the inside and outside systems

0

500

1000

1500

2000

2500

Aug-06 Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Feb-07

Ca

rbo

n d

iox

ide

(p

pm)

Date

Point 1Point 2Point 3Point 4Point 5Point 6Point 7Point 8Air

0

200

400

600

800

1000

1200

1400

1600

1800

Oct-06 Nov-06 Dec-06 Jan-07 Feb-07 Mar-07

Ca

rbo

n d

iox

ide

(p

pm)

Date

Point 9Point 10Point 11Point 12Point 13Point 14Point 15Point 16Air


January 2008

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Results: Microbiology

Microbiology: colony forming units (CFU) per 100ml of the samlpe

Rig location

CFU per 100 ml Bin number 1 2 3 4

Inside Shigellae; Salmonellae 498 441 260 195 Enterococci 173 215 68 578 Total Heterotrophs 121000 56750 38500 74000 Outside Shigellae; Salmonellae 8931 368 598 371 Enterococci 704 251 370 198 Total Heterotrophs 51500 100833 180000 129800 Rig location

CFU per 100 ml Bin number Inflow 5 6 - P + P

Inside Shigellae; Salmonellae 198 68 636 920 Enterococci 59 185 883 3900 Total Heterotrophs 63500 78750 101250 7605000 Outside Shigellae; Salmonellae 708 485 160 78 Enterococci 95 98 178 598 Total Heterotrophs 77667 76833 171750 378250


January 2008

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Results:Summary Statistics (Inside System)

Variable Statistics Bin numbers 1 2 3 4 5 6

BOD (mg/l)

Mean 0.7 1.0 1.2 1.2 1.1 1.1 SD 0.30 0.67 0.70 0.67 0.32 0.30

SS (mg/l)

Mean 166.7 199.0 260.0 131.1 138.2 174.2 SD 179.98 269.09 256.73 136.42 166.32 179.77

TDS (mg/l)

Mean 202 213 187 217 201 202 SD 19.0 20.1 29.9 12.8 17.5 29.8

DO (mg/l)

Mean 5.0 5.3 6.5 5.4 4.6 5.6 SD 1.52 1.71 2.20 1.34 1.38 2.08

pH (-) Mean 7.4 7.5 7.5 7.5 7.4 7.5 SD 0.26 0.21 0.26 0.28 0.21 0.22

Cond (S)

Mean 403 428 374 435 403 416 SD 38.4 40.7 59.5 25.4 35.1 80.4

AN (mg/l)

Mean 0.15 0.11 0.11 0.13 0.10 0.11 SD 0.219 0.146 0.123 0.154 0.102 0.114

NN (mg/l)

Mean 3.2 1.0 2.7 1.4 0.4 2.2 SD 3.69 1.35 3.10 1.35 0.49 2.78

OPP (mg/l)

Mean 0.89 0.48 0.47 0.82 0.43 0.47 SD 0.460 0.481 0.491 0.559 0.549 0.502


January 2008

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Results:Summary Statistics (Outside System)

Variable Statistics Bin numbers 1 2 3 4 5 6

BOD (mg/l)

Mean 1.2 0.1 0.3 0.1 0.3 0.4 SD 1.72 0.30 0.65 0.30 0.65 0.67

SS (mg/l)

Mean 90.0 77.3 130.0 71.3 96.0 42.0 SD 112.03 146.70 275.56 97.02 208.44 78.00

TDS (mg/l)

Mean 202 213 187 217 201 202 SD 19.0 20.1 29.9 12.8 17.5 29.8

DO (mg/l)

Mean 5.1 6.1 6.8 5.5 6.4 7.3 SD 1.15 0.90 1.17 0.87 0.81 1.41

pH (-) Mean 7.2 7.4 7.5 7.4 7.5 7.5 SD 0.28 0.14 0.15 0.16 0.12 0.15

Cond (S)

Mean 403 428 374 435 403 416 SD 38.4 40.7 59.5 25.4 35.1 80.4

AN (mg/l)

Mean 0.14 0.03 0.03 0.04 0.03 0.03 SD 0.103 0.027 0.022 0.036 0.020 0.027

NN (mg/l)

Mean 1.7 0.3 2.6 1.0 0.7 1.8 SD 2.27 0.25 1.26 1.56 0.72 0.99

OPP (mg/l)

Mean 0.35 0.22 0.22 0.60 0.14 0.23 SD 0.428 0.336 0.253 0.298 0.120 0.236


January 2008

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Discussion

Biological Oxygen Demand:

Values vary between 0.3 – 1.1 mg/l, very satisfactory

result as for the bottom of the system level with the

reduction of inflow values up to 99%

Suspended Solids:

High variability between outside and inside systems, with

maximum standard deviation of 275.56 mg/l.

Result of sediment pump out while sample collection –

sum of all acumulated elements and compounds

Varied properties of gully pot mixture.


January 2008

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Discussion

Nitrate Nitrogen:

Maximum values of 3.2 and 2.7 mg/l for inside system and

2.6 mg/l for outside system, caused by either system

imperfections or accumulation of nitrate form ammonia

transformation.


January 2008

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• Ortho-phosphate-phosphorus removal rate of 95%

• The rate of release is between 50 and 70% lower

than the European Union Waste Water Treatment

Directive 97/271/EEC requirements

• Ammonia-nitrate removal rates are similar to ortho-

phosphate-phosphorus rates

• Increase of nitrate-nitrogen within the systems, but

still lower concentrations if compared to EU WWTD –

(approximately 40%)

• Carbon dioxide values clearly show increased

microbial activity during warm seasons

Conclusions


January 2008

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• Microbial pathogenic organisms may be found

because of higher temperatures throughout the year.

• Outside rigs have much better removal rate

performances than the controlled ones

Conclusions


January 2008

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• Introduction of the second year switching pattern

• Statistical analysis and modelling

• Denaturing Gradient Gel Electrophoresis (DGGE)

and Polymerase Chain Reaction (PCR) sediment

analysis for more accurate representation of

micro-organisms within the systems

• Determination of Escherichia coli

• Temperature distribution modelling within

PPS with GSHP installation (potentially another PhD

project)

Future Research


January 2008

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• Brian Garrat, Peter Jones and Steven Spikes

(Hanson Formpave)

• The University of Edinburgh

• Coventry University

• Various Final Year Project students and occasional

visitors

Acknowledgements


January 2008

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Thank You!

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