The low-cost hybrid sorbents for immobilization of dyes: sorbents features characterization

4-8 May 2020

Agnieszka Solińska

Tomasz Bajda

Faculty of Geology, Geophysics and Environmental

Protection

Department of Mineralogy, Petrography and

Geochemistry

Introduction

The sorption experiments were conducted using the hybrid sorbents:

halloysite-fly ash (HPL) and palygorskite-lignite (PLG). Moreover, the

halloysite (H) and lignite (LG) were also investigated to compare sorption

properties raw sorbents and hybrid sorbents.

Two dyes were tested in experiments:

» remazol brilliant blue r (RBBR)

» rhodamine b (RB)

HPL-RBBR H-RBBR PLG-RB LG-RB

mg/kg

4577.81 4130.07 3962.03 3723.09

the experimental conditions: initial pH-8, 100 mg/L RBBR or RB, dosage 20 g/L

RB

RBBR

Sorption results:

Thermal analysis: halloysite-fly ash (HPL) and

halloysite (H) with absorbed RBBR

exo exo

endo endo

Ion c

urr

en

t (a

.u.)

HPL

HPL-RBBR

CO2

H2O

100 200 300 400 500 600 700 800 900 1000

Temperature (°C)

TG

DTA75

80

85

90

95

100

Mass

loss

(%) 538oC

660oC

Ion c

urr

en

t (a

.u.)

H

H-RBBR

CO2

H2O

100 200 300 400 500 600 700 800 900 1000

80

85

90

95

100

Mass

loss

(%

)

Temperature (°C)

TG

DTA

400oC

700oC

The arrows show the decomposition of RBBR on the hybrid and raw material

IR spectra: halloysite-fly ash (HPL) and

halloysite (H) with absorbed RBBR

peaks changing caused by adsorbed RBBR (?)

• 3700-3600 cm-1 - O-H streching vibrations

• 3447 and 1632 cm-1 bands- adsorber water molecules

• 400- 1200 cm-1- vibrations within aluminosilicate framework

Ion

Cu

rren

t (a

.u.)

PLG

PLG-RB

CO2

H2O

100 200 300 400 500 600 700 800 900 1000

Temperature (°C)

50

60

70

80

90

100

Mass lo

ss (

%)

TG

DTAIo

n C

urr

en

t (a

.u.)

LG

LG-RB

CO2

H2O

100 200 300 400 500 600 700 800 900 1000

Temperature (°C)

10

20

30

40

50

60

70

80

90

100

Mass lo

ss (

%) TG

DTA

Thermal analysis: palygorskite-lignite (PLG)

and lignite (LG) with absorbed RB

exo exo

endo endo

480oC

355oC

452oC

527oC

327oC

The arrows show the decomposition of RB on the hybrid and raw materials

IR spectra: palygorskite-lignite (PLG) and

lignite (LG) with absorbed RB

peaks changing caused by adsorbed RB (?)

Lignite:

• 2800- 2920 and 1450-1370 cm-1- aliphatic

C-H vibrations

• 1700-1600 cm-1 bands- aromatic groups

• ~1500 cm-1 C=O vibrations

• 1270- 1100 cm-1 range - C-O vibrations

• 900-750 cm-1 bands- C-H groups attributed to

aromatic ring

SEM images of halloysite and fly ash

2 μm

5 μm

200 μm

1 mm

elements weight %

N 0.36

C 31.15

S 0.82

H 0.52

CHNS analysis

unburned carbon

tubular shape of halloysite

SEM images of

lignite

100 μm

300 μm

EDS spectrum

Conclusions

» the hybrid sorbents are capable for removing of

dyes

» the IR and especially thermal analysis results

show that dyes molecule are uptaken onto

sorbents

» the sorbent features have important influence on

their sorption properties

Conclusions

» lignite and fly ash possess attractive sorption

features: presence organic functional groups,

porosity

» halloysite and palygorskite sorption properties are

caused by presence inorganic functional groups,

negative surface charges, porosity

» mixing of inorganic with organic materials leads to

production of hybrid sorbents with varied sorption

properties

Thank you for your attention!