1. USE OF ACTIVATED CARBON TO POLISH EFFLUENT
FROM METALWORKING TREATMENT PLANT:
COMPARISON OF DIFFERENT STREAMS
Nidal Hilala
*, Gerald Buscab
, Fernando Rozadac
and Nick Hankinsa
a-Centre for Clean Water Technologies, The University of Nottingham UK
b- Environmental Technology Centre, The University of Nottingham UK
c-Institute of Natural Resources, University of Leon Spain
INTRODUCTIONINTRODUCTION
Waste metalworking fluids are toxics and with a very high COD.Waste metalworking fluids are toxics and with a very high COD. In response to stringent legislation and increasing disposal cost designed a completeIn response to stringent legislation and increasing disposal cost designed a complete
process for metalworking fluid remediation was design, using membrane technology and bioremediation. The system produces 2 streams, a recoveredprocess for metalworking fluid remediation was design, using membrane technology and bioremediation. The system produces 2 streams, a recovered
oil with a calorific value ofoil with a calorific value of 42kJ/g42kJ/g and an aqueous phase that post bioreactor has a CODand an aqueous phase that post bioreactor has a COD 98% lower98% lower then the original waste. Nevertheless, loweringthen the original waste. Nevertheless, lowering
further the effluent COD appeared to be essential for process water recovery. Therefore, the team proposed to study the feasibility of using Activatedfurther the effluent COD appeared to be essential for process water recovery. Therefore, the team proposed to study the feasibility of using Activated
Carbon to polish the aqueous effluent. 3 streams were simultaneously studied and compared:Carbon to polish the aqueous effluent. 3 streams were simultaneously studied and compared:
(-e) Before the bioreactor, (-eB) After Bioreactor and (-eBF) After Bioreactor effluent micro-filtered(-e) Before the bioreactor, (-eB) After Bioreactor and (-eBF) After Bioreactor effluent micro-filtered
Acknowledgments:We thank the UK Engineering and Physical Sciences Research Council and CARDEV International Ltd for funding this work.
eB
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0 10000 20000 30000 40000 50000
V o l u me t r e a t e d ( m L )
eBF
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V o l u m e t r e a t e d ( m L )
e
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0 5000 10000 15000 20000 25000 30000 35000
V o l u m e t r e a t e d ( m L )
Co (mg/L)
Cs (mg/L)
feed average
1m
1m
0.7 l/day 500 l/day
Inlet flow rate x 715
Outlet flow rate x 715
Surface x 715
Number of columns
x 715
Flux kept constant
Lab scale Industrial scale
Height : 1m 1m
Diameter: 3cm 45cm
Mass of AC: 0.190 kg 151 kg
1m
1m
0.7 l/day 500 l/day
Inlet flow rate x 715
Outlet flow rate x 715
Surface x 715
Number of columns
x 715
Flux kept constant
Lab scale Industrial scale
Height : 1m 1m
Diameter: 3cm 45cm
Mass of AC: 0.190 kg 151 kg
Complete treatment system showing where Activated Carbon test were carried out
0
100
200
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0 200 400 600 800 1000
Ce (mg/L)
qe(mg/g)
eBF
eB
e
Adsorbate Qº (mg/g) K L (L/mg) R
2
n K F
e 345.0 0.007 0.994 2.1 23.11
eB 400.0 0.033 0.928 1.9 17.05
eBF 625.0 0.014 0.992 1.5 9.06
R
2
0.929
0.989
0.992
FreundlichLangmuir
Fittings to Langmuir’s and Freundlich’s models
Before activated carbon After activated carbon
Effluent -e -eB -eBF -e -eB -eBF
pH 9.2 8.2 8.2 7.7 7.9 8.2
Turbidity (NTU) 1.3 17.6 0.05 5.5 15 1.1
COD (mg/l) 7300 1150 1000 840 85 350
Effluents characteristics before and after AC treatment
Scale-up of the activated carbon column to fit the industrial system
ConclusionConclusion
The activated carbon has been proven to be effective in removing theThe activated carbon has been proven to be effective in removing the
COD and the colour of each effluent.COD and the colour of each effluent.
The absorption column used straight after the membrane system, by-The absorption column used straight after the membrane system, by-
passing the bioreactor, showed a good removal capacity but the columnpassing the bioreactor, showed a good removal capacity but the column
has been subject to major bacterial development leading to a completehas been subject to major bacterial development leading to a complete
blockage of the column.blockage of the column.
The results clearly show that using the activated carbon straight after theThe results clearly show that using the activated carbon straight after the
bioreactorbioreactor (-eB)(-eB) is theis the best solutionbest solution. Detached microorganisms from the. Detached microorganisms from the
bioreactor colonise the AC column enhance considerably the columnbioreactor colonise the AC column enhance considerably the column
performance without over developing and without blocking the column.performance without over developing and without blocking the column.
Break through curve for the three different types of effluent
1 Effluent
2 Ultrafiltration
3 Nanofiltration (-e)
4 Bioreactor (-eB)
5 Concentrate treatment
6 Buffering tank
7 0.45 μm filter (-eBF)
6
oil
7
3
-eB-e
4
Activated Carbon columns
Bioreactor recycling
loop
-eBF
5
1 2
1 Effluent
2 Ultrafiltration
3 Nanofiltration (-e)
4 Bioreactor (-eB)
5 Concentrate treatment
6 Buffering tank
7 0.45 μm filter (-eBF)
6
oil
7
3
-eB-e
4
Activated Carbon columns
Bioreactor recycling
loop
-eBF
5
1 2