1. Treatment of silk textile wastewater by
chemical coagulation,
fenton oxidation and
their combination.
Khanittha Charoenlarp,Tipanan
Phangthong, Sunanta Punteaum, and Mayuree
Aomsomboon
Department of Textile Chemistry
Engineering, Rajamangala University of
6. Silk product community in Surin
Silk worms Silk cocoons Boiling the silk cocoons
Reeling Bleaching and dyeing Weaving
7. Environmental concerns
• The wastewater from bleaching and dyeing
process was not properly treated and
discharged into the environment.
8. The main problem of dyeing
wastewater treatment
• How to remove the contamination
of dyes in wastewater which is
mainly complex structure
compound and toxic.
10. Coagulation flocculation
• Chemical coagulants cause formation of
a sludge phase that can be separated by
density difference.
• Major coagulants:
– Al2(SO4)3.14H2O (Alum)
– FeCl3.6H2O
– Fe2SO4
11. Fenton oxidation method
• Discovered by Henry John Horstman Fenton
in the1890.
• Applied for the decolorization of effluents
from the textile dyeing process.
(Kim,T.H.,et al.,2004)
13. Method
• Analysis of silk textile wastewater.
• Study the optimum condition and the
treatment efficiency of
– Chemical coagulation
– Fenton oxidation
– A combination between Chemical
coagulation and Fenton oxidation
method
14. Analysis of silk textile wastewater
• The silk textile wastewater from Surin
province, Thailand was used in this study.
• The properties of wastewater to be analyzed
were pH, COD, BOD, SS, and TS.
17. Results
Properties of silk dyeing wastewater
Parameter Mean SD Standard
measureement Value
value
pH (25oC) 4.16 0.2 5.5 - 9
COD (mg/L) 1669.24 76.50 <120
BOD (mg/L) 386.60 23.55 <20
SS (mg/L) 541.60 34.16 <50
TS (mg/L) 8289.60 261.87 <3000
18. Chemical coagulation experiment
• The influence parameters for the chemical
coagulation
– Type and amount of coagulants
– Type and amount of coagulant aids
– Initial pH
19. Chemical coagulation parameter
Condition Value
Coagulants 0.4, 0.6, 0.8, 1.2, 1.6, 2.0,
(Al2SO4 and Fe2SO4) and 2.4 g/L
coagulant aids 0.2, 0.4, 0.6, and 0.8 g/L
(Ca(OH)2 and cationic
polymer)
pH 5, 6, 7, 8, and 9
Rapid stirring rate (rpm) 100
Slow stirring rate (rpm) 20
20. The effect of pH value and types of
coagulants 90.6%
Color removal efficiency (%)
67.7%
1.2 g/L Al2SO4
1.2 g/L Fe2SO4
Initial pH
21. The effect of chemical coagulant
dosages
Color removal 97.1%
COD removal
Efficiency (%)
61.6%
-
Al2SO4 dosages (g/L)
22. The effect of chemical coagulant aids
types and dosages
97.1% 98.9% 98.8%
Efficiency (%)
Color removal
COD removal
70.8%
65.9%
61.6%
2.4 g/L Al2SO4 2.4 g/L Al2SO4 + 2.4 g/L Al2SO4 +
0.4 g/L Lime 0.4 g/L Polymer
24. Fenton oxidation parameter
Condition Value
H 2O 2 1.2, 2.4, 3.6, 4.8, and 6.0 g/L
FeSO4 0.2, 0.4, 0.6, 0.8, and 1.0 g/L
pH 2,3, 4 and 5
25. The effect of initial pH
Efficiency (%)
Color removal
COD removal
initial pH
26. The effect of the ferrous dosages
91.5%
Efficiency (%)
66.5%
Color removal
COD removal
Ferrous dosages (g/L)
27. The effect of the H2O2 dosages
90.8% 91.3%
Efficiency (%)
66.9% 67.5%
Color removal
COD removal
H2O2 dosages + 0.8 g/L Fe2SO4
28. The efficiency of silk dyeing wastewater
treatment by combination chemical
coagulation and Fenton oxidation
Chemical Fenton oxidation Coagulation +
coagulation Fenton
Color removal (%) COD removal (%)
29. Conclusions
• The chemical coagulation and Fenton
oxidation method was limited when
wastewater contains high
concentration of SS and COD.
• The combination of chemical
coagulation and Fenton oxidation were
more efficient than one.
30. Recommendations
• To compare the cost of each method.
• To compare the sludge of each method.
• To reduce pollution from the source.
33. Silk product community in Surin
Silk worms Silk cocoons Boiling the silk cocoons
Reeling Bleaching and dyeing Weaving
Notes de l'éditeur
.
The figures show the instruments used for measurements ; pH, conductivity and turbidity.
Thai silk is produced from the cocoons of Thai silkworms. The processes begins by raising silkworms on mulberry leaves. When they are mature, the silkworms spin silk cocoons. The cocoons is treated with boiling water. The silk is then unbound from the cocoon by softening the sericin and then carefully reeling the filaments. The yarns with the original cream colour are bleached in a mixture of hot water and chemical substances to become white. The yarns are dyed and then woven to create different types of Thai silk fabrics.