Ground Source Heat Pumps Installation Within Permeable Pavement Systems For Wastewater Quality Assessment

IIE Internal Seminar January 2008

Permeable Pavement Systems with integrated Ground Source Heating Pumps

Piotr Grabowiecki

IIE Internal Seminar January 2008

Contents 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 COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

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

Discussion Conclusions COVENTRY UNIVERSITY

Future Research Acknowledgements

IIE Internal Seminar January 2008

Introduction: Sustainable Drainage Systems Traditional systems capture storm runoff, and subsequently distribute it to nearby watercourses or sewer systems. Some of these expensive systems have become ineffective and inefficient.

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Introduction: Sustainable Drainage Systems

COVENTRY UNIVERSITY

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

IIE Internal Seminar January 2008

Introduction: Sustainable Drainage Systems 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.

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Introduction: Permeable Pavement Systems • 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 COVENTRY UNIVERSITY

• Low requirement for maintenance

IIE Internal Seminar January 2008

Introduction: Permeable Pavement Systems • Are effective in-situ bioreactors • Can be designed as tanked or infiltration systems • Hydrocarbon decomposition and low evaporation, if composite geotextiles are applied

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008 2007

COVENTRY UNIVERSITY

Introduction: Permeable Pavement Systems

IIE Internal Seminar January 2008 2007

Introduction: Ground Source Heating Pumps

COVENTRY UNIVERSITY

Source: http://www.waterfurnace.com

IIE Internal Seminar January 2008

COVENTRY UNIVERSITY

Introduction: Research Objectives •

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

IIE Internal Seminar January 2008

COVENTRY UNIVERSITY

Materials and Methods: Construction of Systems •

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: Experimental Setup

IIE Internal Seminar January 2008

Inside rig Feature

1

2

3

Inbitex composite

√

√

√

Inbitex geotextile

COVENTRY UNIVERSITY

√

4

Outside rig 5

√

√

√

√

Cooling or heating

√

Animal feaces

√

Air thermometers

√

√

Vessel thermometers

√

Carbon dioxide sampling

√

6

1

2

3

√

√

√

√ √

√

√ √

√

4

5

6

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

IIE Internal Seminar January 2008

COVENTRY UNIVERSITY

Materials and Methods: Inside Rig

IIE Internal Seminar January 2008

COVENTRY UNIVERSITY

Materials and Methods: Outside Rig

IIE Internal Seminar January 2008

Materials and Methods: Schematic Layout vessel

heater

pump Titan cooler

paving blocks

bin

bin sub-base mains 230 V

COVENTRY UNIVERSITY

bin water level

tubing coils

IIE Internal Seminar January 2008

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 COVENTRY UNIVERSITY

• All systems are tanked and the flow regime simulation is performed manually.

IIE Internal Seminar January 2008

Materials and Methods: Operational Conditions • Main pollutants used:  Gully pot liquor – simulates urban runoff  Animal faeces (i.e. dog droppings) – main pathogen source

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Materials and Methods: Analytical Methods • 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. COVENTRY UNIVERSITY

• Microbes are analysed for Salonellae, Enterococci and total heterotrophic bacteria using plate count techniques.

IIE Internal Seminar January 2008

Materials and Methods: Analytical Methods • 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.

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Results: Water Quality

2.5 2.0

-n m y ,s n e g itro

1.5 1.0

ia n o m A

0.5 0.0

1 2 3 4 5 6 IN IN+P

450 400 350 300 250 200 150 100 50 0

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

COVENTRY UNIVERSITY

(m /l ) g

3.0

500

-n s ,flw n e g itro

3.5

ia n o m A

(m /l ) g

Ammonia-nitrate for the inside and outside systems

IIE Internal Seminar January 2008

Results: Water Quality 40 1 2 3 4 5 6 IN IN+P

-p te a sp o h

1.0

m ,yte sru o h p

1.5

o rth O

2.0

30 25 20 15 10

0.5

5

0.0

0

-p te a sp o h

2.5

35

o rth O

3.0

(m /l ) g

3.5

flw ,in sru o h p

(m /l ) g

Ortophosphate-phosphorus for the inside and outside systems

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

1.8

400

1.6

350 1 2 3 4 5 6 IN IN+P

0.6

-h te a h sp o

0.2

250 200 150 100 50

0.0 Sep-06

0 Oct-06

Nov-06

Dec-06 Date

Jan-07

-p flw ,in ru sp o h (m /l ) g

0.8

300

Feb-07

-p te a sp o h

1.0

0.4

o rth O

COVENTRY UNIVERSITY

-p m ,yte ru sp o h (m /l ) g

1.2

o rth O

1.4

IIE Internal Seminar January 2008

Results: Water Quality Nitrate-nitrogen for the inside and outside systems 12 10 1 2 3 4 5 6 IN IN+P

8

-n /l) (m n e g itro

6

e itra N

4 2 0

May-06 Jul-06 Aug-06 Oct-06 Nov-06 Jan-07 Mar-07 Apr-07 Date 7 1

/l) g (m

6

2

5

3

4

4

3

5

2

6

e itra N

-n n e g itro

COVENTRY UNIVERSITY

IN

1

IN+P

0 Oct-06

Nov-06

Dec-06 Date

Jan-07

Feb-07

IIE Internal Seminar January 2008

Results: Carbon Dioxide Collection Points 0.5 cm clean stone

5 cm width

upper sub-base (0.5-2 cm aggregates)

10 cm width

upper part of lower sub-base (0.1-6.3 cm aggregates)

COVENTRY UNIVERSITY

lower part of lower sub-base (0.1-6.3 cm aggregates)

25 cm width

25 cm width

IIE Internal Seminar January 2008

Results: Carbon Dioxide Carbon dioxide for the inside and outside systems (p m ) p

2500 Point 1 Point 2 Point 3 Point 4 Point 5 Point 6 Point 7 Point 8 Air

2000 1500

e ix d n o rb a C

1000 500 0 Aug-06

Sep-06

Oct-06

Nov-06

Dec-06

Jan-07

Feb-07

Date 1800

(p m ) p

1600

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

1400 1200 1000 800

COVENTRY UNIVERSITY

e ix d n o rb a C

600 400 200 0 Oct-06

Nov-06

Dec-06

Jan-07 Date

Feb-07

Mar-07

IIE Internal Seminar January 2008

Results: Microbiology Microbiology: colony forming units (CFU) per 100ml of the samlpe Rig location Inside Outside Rig location Inside

COVENTRY UNIVERSITY

Outside

CFU per 100 ml Shigellae; Salmonellae Enterococci Total Heterotrophs Shigellae; Salmonellae Enterococci Total Heterotrophs CFU per 100 ml Shigellae; Salmonellae Enterococci Total Heterotrophs Shigellae; Salmonellae Enterococci Total Heterotrophs

Bin number 1 2 3 4 498 441 260 195 173 215 68 578 121000 56750 38500 74000 8931 368 598 371 704 251 370 198 51500 100833 180000 129800 Bin number Inflow 5 6 -P +P 198 68 636 920 59 185 883 3900 63500 78750 101250 7605000 708 485 160 78 95 98 178 598 77667 76833 171750 378250

IIE Internal Seminar January 2008

Results: Summary Statistics (Inside System) Variable BOD (mg/l) SS (mg/l) TDS (mg/l) DO (mg/l) pH (-)

COVENTRY UNIVERSITY

Cond (µS) AN (mg/l) NN (mg/l) OPP (mg/l)

Statistics Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD

1 0.7 0.30 166.7 179.98 202 19.0 5.0 1.52 7.4 0.26 403 38.4 0.15 0.219 3.2 3.69 0.89 0.460

Bin numbers 2 3 4 5 6 1.0 1.2 1.2 1.1 1.1 0.67 0.70 0.67 0.32 0.30 199.0 260.0 131.1 138.2 174.2 269.09 256.73 136.42 166.32 179.77 213 187 217 201 202 20.1 29.9 12.8 17.5 29.8 5.3 6.5 5.4 4.6 5.6 1.71 2.20 1.34 1.38 2.08 7.5 7.5 7.5 7.4 7.5 0.21 0.26 0.28 0.21 0.22 428 374 435 403 416 40.7 59.5 25.4 35.1 80.4 0.11 0.11 0.13 0.10 0.11 0.146 0.123 0.154 0.102 0.114 1.0 2.7 1.4 0.4 2.2 1.35 3.10 1.35 0.49 2.78 0.48 0.47 0.82 0.43 0.47 0.481 0.491 0.559 0.549 0.502

IIE Internal Seminar January 2008

Results: Summary Statistics (Outside System) Variable BOD (mg/l) SS (mg/l) TDS (mg/l) DO (mg/l) pH (-)

COVENTRY UNIVERSITY

Cond (µS) AN (mg/l) NN (mg/l) OPP (mg/l)

Statistics Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD

1 1.2 1.72 90.0 112.03 202 19.0 5.1 1.15 7.2 0.28 403 38.4 0.14 0.103 1.7 2.27 0.35 0.428

Bin numbers 2 3 4 0.1 0.3 0.1 0.30 0.65 0.30 77.3 130.0 71.3 146.70 275.56 97.02 213 187 217 20.1 29.9 12.8 6.1 6.8 5.5 0.90 1.17 0.87 7.4 7.5 7.4 0.14 0.15 0.16 428 374 435 40.7 59.5 25.4 0.03 0.03 0.04 0.027 0.022 0.036 0.3 2.6 1.0 0.25 1.26 1.56 0.22 0.22 0.60 0.336 0.253 0.298

5 0.3 0.65 96.0 208.44 201 17.5 6.4 0.81 7.5 0.12 403 35.1 0.03 0.020 0.7 0.72 0.14 0.120

6 0.4 0.67 42.0 78.00 202 29.8 7.3 1.41 7.5 0.15 416 80.4 0.03 0.027 1.8 0.99 0.23 0.236

IIE Internal Seminar January 2008

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 –

COVENTRY UNIVERSITY

sum of all acumulated elements and compounds Varied properties of gully pot mixture.

IIE Internal Seminar January 2008

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.

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Conclusions • 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 orthophosphate-phosphorus rates • Increase of nitrate-nitrogen within the systems, but still lower concentrations if compared to EU WWTD – COVENTRY UNIVERSITY

(approximately 40%) • Carbon dioxide values clearly show increased microbial activity during warm seasons

IIE Internal Seminar January 2008

Conclusions • 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

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Future Research • 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 COVENTRY UNIVERSITY

PPS with GSHP installation (potentially another PhD project)

IIE Internal Seminar January 2008

Acknowledgements • Brian Garrat, Peter Jones and Steven Spikes

(Hanson Formpave) • The University of Edinburgh • Coventry University • Various Final Year Project students and occasional visitors

COVENTRY UNIVERSITY

IIE Internal Seminar January 2008

Thank You!

COVENTRY UNIVERSITY