How to measure the performance of materials used as sorbents to treat diesel spills on roads

1. A study of measurement methods for
diesel sorbent performance, and the
components of road user delay associated
with diesel spills on the UK Strategic Road
Network (SRN)
Dr John C Bullas - Atkins, Southampton, UK ,
Jim Doxford & Paul Hupton, Project Sponsors,
Highways Agency, Manchester, UK .

2. 2
1 Introduction:
Diesel spills on the highway

3. 3
Diesel spill clear up is manually
intensive and often closes the road
(Photo: Cornish Guardian)
A sight and a sign no network
operator wants to see
(Photo: Express & Star)

4. 4
Diesel fuel on the road surface not only has the potential to reduce the
skidding resistance but can lead to the permanent damage of bituminous
materials if not removed promptly
Traffic queues -- A23 Angmering
(theargus.co.uk)
Consider the associated road user delays and
impact on the network!

5. 5
British, European and American standards already
provide appropriate tests for the assessment of the
various characteristics of granular diesel sorbents,
These were not immediately accessible to road network
stakeholders
•DD CEN/TS 15366:2009
•Winter and road service area maintenance equipment
•BS 7959-2:2000
•Technical Committee, CIV63, Chemical spill control

6. 6
“We prefer the use of mechanical recovery and/or
sorbents to remove oil from surface waters. These
methods for removing oil don’t add to the water
pollution and are designed to remove the oil from the
water.... alternatives often require the introduction of
further products to the water environment, some of
which are pollutants in their own right.”
“Oil clean-up products and their application in
England and Wales”. UK Environment Agency 2010

7. 7
“The Environment Agency are clear that oil spills on road
surfaces should be contained, sorbed and removed to
prevent pollution. The most appropriate sorbent should
be used for each application and laboratory test figures
can be used to guide that selection.
Remember that contaminated sorbent is hazardous
waste and can pose a pollution risk and it must be
removed and correctly disposed of.”
Jo Bradley,
Business Advisor,
National River Basin
Management Service, EA

8. 8
Thus the UK Highways Agency (HA) contracted Atkins to
undertake a combined research project :
•To produce a specification for the performance of diesel
sorbents for use on diesel spills
•To undertake timeline analysis for diesel spillage
incidents recorded in the HA’s Command and Control
(C&C)
....to better understand the broader
dynamics of the diesel removal process

9. 9
“This is one of our oldest employees. When nobody
else can get the job done, we break the glass”

10. 2 Why diesel sorbents are used
on the road following a diesel
spillage

11. 11
Otaraoa Rd Fairfax, New Zealand 100m-long oil slick
from leaking drilling equipment
(Photo: Cameron Burnell)

12. 12
There are three key elements to address following a
diesel spillage
•The diesel on the road surface may have greatly
reduced the skid resistance of the road surface
•A bituminous road surface may suffer structural
damage from diesel exposure
•Diesel on the road can readily be transferred into
local water courses and ground water

13. 13
•The diesel on the
road surface may have
greatly reduced the
skid resistance of the
road surface

14. 14
•A bituminous road surface may suffer structural
damage from diesel exposure
Approximately two hour to avoid permanent damage
Figure from Balwin, Carmody et al. (2005).

15. 15
•Diesel on the road can readily be transferred into local
water courses and ground water
Friday April 26th, 2013
State Highway 38 closed to all
traffic
2900 gallons of gasoline and
1700 gallons of diesel fuel onto
the roadway.
Fuel from the spill entered Cold
Creek and was detected in the
Santa Ana River
( Total Personnel 52)

16. 16
gazeta.ru
croydonadvertiser.co.uk

17. 17
3. Why there is a need to assess
the performance of sorbents
for the treatment of diesel
spillages

18. 18
•Sorbents that permanently retain any entrained
diesel within their structure are known as absorbent
•Sorbents that retain entrained diesel but then
release it when squeezed or otherwise exposed to
external forces are known as adsorbent
.........the term ‘absorbent’ appears freely used to
describe many sorbent products without any proven
absorbent capability

19. 19
“Quick and Dirty” [or “Clean and Steady”]
•“Quick and dirty” rapid
diesel recovery.
•Larger quantities of
adsorbent materials with a
higher rate of sorbency.
heavily reliant on procedures
to place, recover, remove and
dispose of the sorbent. High
risk of subsequent
contamination of vehicles and
the environment.
Sita.cz

20. 20
•“Clean and steady” method for
diesel recovery.
•Smaller quantities of
absorbent materials with a
higher capacity of sorbency.
Low risk of subsequent
contamination of vehicles and
the environment.
[“Quick and Dirty”] or “Clean and Steady”
adlerandallan.co.uk

21. 21
The key requirements for effective diesel sorbents:
Diesel spills pose both logistical and environmental
challenges, thus:
•A sorbent cannot make the road any more slippery
when applied, nor they damage it
•If sorbents cannot be recovered, they must not
release entrained diesel at a later stage.
•They cannot in themselves be a pollution risk!

22. 22
4. How to assess the
performance of granular diesel
sorbents

23. The AFNOR Procedure for Sorbent
Assessment (NF P98-190:2002)
23

24. 24
Prompted by a fatal crash
following the use of a clay
sorbent that made the road
MORE slippery!
hellopro.fr

25. 25
The AFNOR NF P98-190:2002-02 Protocol
Oui/ Non

26. 26
5. The Atkins Sorbent
Testing Programme
BSI, ASTM & AFNOR Tests

27. 27
higher sorbency rate vs. higher total sorbency
BS 7959 2004 Pt1 Sorbency @ 2,15 & 60 Minutes

28. 28
“Quick and Dirty” or “Clean and Steady”
Sorbency Rate over Time from BS 7959 2004 Pt1 data

29. 29
BAD vs. GOOD
ADsorbent vs. ABsorbent
ASTM F716-07 11.3 Residual Sorbency @ 2hrs

30. 30
BAD vs. GOOD
ADsorbent
vs.
ABsorbent
ASTM F726-06 10.4 5min 6k rpm centrifuge

31. 31
BAD vs. GOOD
Hydrophilic
vs.
Oleophilic
ASTM F726-06 9.2.2 Water Adsorbency

32. 32
Material
Initial
SRT (wet)
Final SRT
(after
treatment)
SRT (final)
SRT (initial)
SRT (final)
SRT(initial)
>0.9?
Sand 64 44 0.69 No
50% Polymer 1
/50% Sand 65 59 0.91 Yes
25% Polymer 1
/75% Sand 72 46 0.64 No
100% Polymer 2 60 52 0.87 No
Organic Material 1 65 45 0.69 No
Granular Material 1 72 56 0.78 No
AFNOR NF P98-190:2002 Annex A - Wet
Friction Tests undertaken by CEDRE
Pass or Fail Criteria

33. ...Saturate it, then get it off the road!
33
aberdareonline.co.uk

34. 34
The proposed Hybrid Standard 1/2
Sorbent Property Test Protocol Suggested Limit Performance Characteristic
Classification of
Sorbent as Absorbent
or Adsorbent
ASTM 726-06 Informative only A Measure of potential for
subsequent contamination
from the used sorbent
Diesel Sorbency ASTM F716-07
Class 2 sorbency >50% or
Class 1 sorbency >100%
(From Procedure in NF T 90-
361)
A measure of diesel sorbency
by weight, a 2 level
classification
ASTM 726-06
DDCEN/TS
15366:2009 or
Diesel Sorbency BS 7959: 2004 Pt 1 Informative: establish the
sorbency at 2, 15 & 60
minutes
A discriminator between short-
term rapid and longer-term
progressive sorption
characteristics
Release of Entrained
Diesel from Sorbent
to Other Materials
ASTM F716.07 Informative: Maximum
Effective Pickup and
Maximum Practical Pickup
A measure of the level of
sorbency achieved before
Transfer of diesel occurs
during storage on to adjacent
materials (method of
determination to suit intended
manner of storage)
Water Sorbency DD CEN/TS
15366:2009 or ASTM
F726-06:
<15% A measure of water sorption By
Weight, relative performance
(high water sorbency is
undesirable)

35. The proposed Hybrid Standard 2/2
35
Sorbent Property Test Protocol Suggested Limit Performance
Characteristic
Influence of
Sorbent on Wet
Friction
DD CEN/TS
15366:2009 Annex
D Part 1 (Wet
Friction of
Contaminated
Sorbent)
Class 2 wet friction ≥80
% SRT initial Coefficient
Class 1 rating if material
achieves ≥90 % SRT
initial Coefficient (as
required in NF P 98-190
Annex A)
The effect of the sorbent
on the wet friction of a
simulated road surface
during and after treatment,
a 2 level classification
Though from published
standards, the source of
these threshold values of
wet friction preservation
are yet to be determined
DD CEN/TS
15366:2009 Annex
D Part 2 (Wet
Friction of Surface
After Removal of
Contaminated
Sorbent)
≥85 % SRT initial
Coefficient both classes
Better performing sorbents
may be indicated by an
SRT initial Coefficient In
the Part 1 test of in excess
of 80%

36. “Horses for Courses”
36

37. Best Value?
37
•Resourcing and equipment
•Sorbency & road user delay
•Pollution risk on site
•Subsequent environmental impact
• Waste disposal
•Sustainable source of sorbent

38. 38
Don’t just blame the diesel!

39. Thank you for your time,
Any questions?
john.bullas@atkinsglobal.com
+44(0)1372 756 566
+44(0)7946 317 467