Ecofriendly Decolorization of Textile Wastewater using Natural Coagulants.

5thRajamangala University of Technology International Conference: Technology and Innovation towards ASEAN

23-25 July 2014, Phra Nakhon Si Ayutthaya, Thailand

Assoc. Prof. Khanittha Charoenlarp and Assist. Prof. Dr. Pathumthip Prabphane

Rajamangala University of Technology Krungthep,

E-mail: khanittha.C@rmutk.ac.th

Overview

• Objective• Wastewater treatment from textile mill• Coagulation experiments• Conclusion

Objective

• To study the ability of moringa, corn, green bean and tamarind to remove reactive and disperse dye from aqueous solutions.

• To study the optimal conditions pH, coagulant dose and contact time.

• To compare the efficiency between natural and chemical coagulants.

80 -100 •m3 of textile wastewater are generated per ton fabric

(Savin et al, 2008)

10-15% –of the unfixed dye will be discharged in textile effluent…..

•High concentration of non-biodegradable organics, suspended solids, conductivity, turbidity and intense color

•Cause serious and very harmful to the environment•Necessary to remove dyes before discharge.

•The dye’s structures are high MW and complex structures.•Conventional biological system fails to treat textile wastewater

Why is coagulation necessary?

Particles with high specific gravity

Settle under influence of gravity

Particles with low specific gravity

Do not settle under influence of gravity

Coagulation Helps in flock formation

Increase specific gravityand help them to settle

• Inorganic coagulant: such as

Aluminium sulphate (alum)

poly-aluminum chloride

Ferric Chloride.• Synthetic organic polymers:

poly-electrolytes • Natural coagulants / flocculants.

Coagulants use in water treatment

Why use Bio-coagulants?

• Potential health and environmental problems in the use of chemical coagulants.–Alzheimer’s disease–Large sludge volumes–pH alkalinity adjustment

Why use Bio-coagulants?

• Non toxic• Biodegradable• Less sludge volume• No pH alkalinity adjustment

Natural coagulantsMoringa Tamarind seed

Common bean

Mucuna seed

Nirmali seed

Materials

Seed type Dry powder Seed type Dry powder

Moringa oleifera Corn

Green bean Tamarind

Preparation of natural coagulants seed powder

Dry seedsGrinding

Dry seed powder

Sieving

Extraction of active component from seed

10 g of dry seed powder1L of 0.5 M NaCl

Fitered using Whatman no. 42

Stirred for 10 mins

Reactive dye 1 %

(blue, red, yellow)

absorbance

turbidity

pH

COD

2N NaCl 3.2 g Na2CO3

3.2 g NaOHH2O 20 L50oC 1 hr

Preparation of dyeing synthetic wastewater

30 RPM100 RPM

1 min

Upper clarified liquid

Sedimentation60 mins

Absorbance

Turbidity

pH

optimum coagulant doseoptimum pH

30 mins

Coagulation experiments

Analytical methods• All analytical methods followed the Standard

Methods (APHA 1995).

pHTurbidimeter

UV-VIS spectrophotometer Jar test

% Color removal

• % removal = [(Co-Ce)/Co] x 100• where Co and Ce (mg L−1) are the

concentrations of dye before and after adsorption

Corn

Green bean

Moringa

Tammarind

The effect of treating reactive wastewater with four difference seeds extract.

The effect of difference seeds extract and aluminum sulphate by using 30 mgL-1 concentration

Moringa Corn Green bean

Tamarind alum68

70

72

74

76

78

80

82

colo

r re

mov

al e

ffic

ien

cy (

%)

Effect of coagulant dose on dye removal

10 20 30 40 5064666870727476788082

Moringa Corn Green bean Tamarind

seed extracts concantration (mg/L)

colo

r re

mov

al e

ffic

ien

cy (

%)

Moringa

Corn

Green bean

Tammarind

Mechanism of polymer coagulation

Mohamed Bizi. 2012. Stability and flocculation of nanosilica by conventional organic polymer. Natural Science. Vol.4, No.6, 372-385http://dx.doi.org/10.4236/ns.2012.46052

Protein extracts from natural seeds have coagulant properties because of their polyelectrolytes.

It can reduces the amount of SS in the water.

Moringa Corn

Green bean Tammarind

Effect of pH on dye removal

Treated 100 mgL-1 of 250 ml of dye solution with 30 mgL-1 of seeds extract by vary pH 5-9

Effect of pH on dye removal

pH 5 pH 7 pH 965

70

75

80

85

90

Moringa Corn Green bean Tamarind

Col

or r

emov

al e

ffic

ien

cy (

%)

Effect of dye types

reactive dye disperse dye0

20

40

60

80

100

120

blue red yellow

Col

or r

emov

al e

ffic

ien

cy

(%)

The statistics with t test showed that the types of dyes affects color removal efficiency significantly.

Reactive dyeMoringa alum

Disperse dye

20 mgL-120 mgL-1 60 mgL-1 60 mgL-1

20 mgL-1 60 mgL-1

Effect of coagulation time on dye removal

30 60 90 120 150

Moringa (30mg/L) 81.58 86.45 87.55 88 87.62

Corn (30mg/L) 77.25 80.27 81.17 79.7 78.94

Green bean (20mg/L) 76.34 77.47 83.28 82 81.36

Tammarind (20mg/L) 79.21 81.28 85.62 86.64 85.96

Alum (210mg/L) 82.83 83.4 86.79 86.23 86.23

71737577798183858789

Col

or r

emov

al e

ffic

ien

cy (

%)

The performance of wastewater treatment between

each seed extracts and alum

Moringa (30mg/L)

Corn (30mg/L)

Green bean

(20mg/L)

Tamarind (20mg/L)

Alum (210 mg/L)

Moringa (30mg/L)

Corn (30mg/L)

Green bean

(20mg/L)

Tamarind (20mg/L)

Alum (210 mg/L)

color removal (%)

86.45 80.26 77.47 81.13 83.43

turbidity removal (%)

72.54 65.5 74.06 69.05 84.26

COD removal (%)

20.03 39.52 18.95 19.19 55.84

sludge content (mg/L)

34.56 34.56 14.4 12.8 655.36

5

15

25

35

45

55

65

75

85

95

50

150

250

350

450

550

650

Efficien

cy

(%

)

Slu

dg

e co

nten

t (m

L/L

)

Conclusion

• It is important to develop a bio-degradable and eco-friendly organic coagulant without secondary pollution for wastewater treatment.

• Seeds of molinga, corn, green bean and tammarind contain materials that are effective as coagulant.

Conclusion

• pH and Coagulant dose are important factors influencing the mechanism of coagulation.

• The type and chemical structure of the dyes plays an important role in the coagulation process.

Acknowledgement

• This research is supported by Rajamangala University of Technology Krugthep.

ThankYou