Strategies for reusing canal sediments in the Scottish ...Rolling mill STW “After-Life” roll-out...

Strategies for reusing canal

sediments in the Scottish Circular

Economy Dr Richard Lord

University of Strathclyde

10th International SedNet Conference “Sediments on the move” Genoa, 14-17th June 2017

Alasdair

Hamilton Senior Project

Manager

@ScottishCanals

Bringing North Glasgow to Life

Regeneration

Ellen MacArthur Foundation (after Braungart & McDonough)

Scottish Circular

Economy Strategy

2016

• Scotland first country to join EMF CE100 programme in 2013

• A more circular economy could reduce C emissions by 11 MT pa by 2050

• £620M additional turnover and 5,700 new jobs by 2020

• Focus: food, bio-economy, energy infrastructure, construction sectors (last is 50% of total waste)

• Reduce food waste by 33% by 2025

Challenges (opportunities)

for Circular Economy

applied to sediments

18

• What are the “restorative & regenerative” options for dredged sediments? – Use in bank repairs?

– Replacing eroded soils?

– Contaminant removal?

• Renewable energy recovery?

• Soil/nutrients for bio-based economy?

• Preserve/enhance natural capital (eco-system services)

Knowledge Transfer Partnership 2012-15

Scottish Canals Knowledge

Transfer Partnership

“To embed an environmentally sustainable approach to sediment management, reducing operational costs, generating opportunities for revenue growth and addressing emerging waste legislation requirements”

The challenges

• Dredged sediments considered as “waste”

• EU Landfill Directive, Regulations and Landfill Tax makes landfilling “waste” costly

• Scotland’s Zero Waste Plan (2010): 70% recycling, 5% landfill by 2025

• Distributed, potentially contaminated, liquifaction on transport

• Uncontaminated treated as inert waste (but more likely non-haz)

Waste hierarchy approach

• Reduction: preventing siltation & targeting dredging

• Reuse: of materials

• Recycling: processing of materials for recyclates

• Renewable energy recovery

Reduction: (1) Plough dredging

in lochs on Caledonian Canal

23

24

(2) Targeted

spot dredging

25

(3) In-house dredging capability (≠ landfill)

Reuse: (1) Bankside restoration

under exemption Mar ‘14

26

27

Jun ‘14

28

Sept ‘14

29

Jan ‘15

30

May ‘16

31

Jun ’17

(2) Nicospan* trial

(with Scheduled

Ancient Monument

consent)

32 *www.greenfix.co.uk

Recycling (1) Pinkston Basin

contaminated sediment in

concrete?

33

34

35

Pinkston Basin – cube tests

36

0

2

4

6

8

10

12

14

16

18

20

Control 10% 20% 30% 50% 70% 100%Replacement of sand by dredgings

14 DAY TEST (MPa) 28 DAY TEST (MPa)

Cement (19), stone (45), sand (37)

Recycling: (2) Co-composting &

soil manufacture

37

38

39

40

41

42

43

44

Re-using brownfield sites for renewable energy crops

BioReGen Life Project 2005-10

Biomass Remediation (Re)Generation

Can brownfield (previously developed) sites be reused for (renewable energy) crops ?

BioReGen sites:-

Demonstrations 2007 Sewage works

Landfill

Colliery & coke works

Slag heap

Pilots 2004-6

Rural control

Urban control

Landfarm Coal ash landfill

Shipyard Steel works

Rolling mill

STW

“After-Life” roll-out 2010

Scotland 2013-14

Tees Barrage 2007-2012

Placed dredgings, Tees Barrage (2007)

50

Renewable Energy: (1) Bankside

vegetation – Phalaris arundinacea

(2) Weed cutting (the Berky)

52

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Distiler's spent grain

Dredged weed & rush

Green waste

Green RCG

Brown RCG

H20 % Ash % VS

60 NL. kg-1 VS

249 NL. kg-1 VS

Methane yields (m3 per wet tonne)

43.5 m3.t-1

49.3 m3.t-1

110 NL.kg-1 VS

20.8 m3.t-1

236 NL.kg-1 VS

13.8 m3.t-1

422 NL.kg-1 VS

85.9 m3.t-1

(3) Reuse dredgings to restore

canalside brownfield land or landfills?

Then use to grow renewable fuels?

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Derelict Land

Vacant Land

Glasgow_2

0 0.5 1 1.5 2Kilometers

Sources:© Crown copyright and database right (2017). All rights reserved.

Ordnance Survey Licence number 100024655The Scottish Government April 2017

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Scottish Vacant & Derelict Land Survey 2016 (2017)

North Glasgow

1 km

(4) Future: Advanced phyto-conditioning?

Yorkshire Water using ryegrass (Lollium multiflorum) to de-water sewage sludge (or sediments), blended with chipped recovered wood & sand for reuse as soils.

Regeneration