Removal of sulfamethazine and sulfathiazole from water using modified bamboo biochar

Md. Boshir Ahmed (PhD, 2nd Year)Principle Supervisor: Professor John L. Zhou

Co-supervisor: Professor Huu Hao NgoUniversity of Technology Sydney (UTS),

Sydney, Australia.

School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney.

USBI: 2016 ConferenceOregon State University, Corvallis, OR, USA

22nd -25th of August, 2016

Contents

About Antibiotic Properties and DifferentsSorbents

Biochar and Modified Biochar Preparation

Properties, Isotherms, Kinetics and Details ofDifferent Sorption Mechanism’s Based on FTIRand Raman Spectroscopy, Resonance Effects andpH Shift Test.

Summery

Antibiotics and Their EffectsAntibiotics as emerging contaminants are of global concern due to the development of antibiotic resistant genes potentially causing superbugs. They are unique among medicines in that they act selectively on bacteria, among them the pathogens, while leaving cells and tissues unaffected (Ahmed et al., 2015).

Impacts of antibiotics: Significance impacts on aquatic organisms on their survival,

growth and body weight at μg L-1 – mg L-1 concentration level. Can alter the microbial communities leading to the antibiotic

resistance of some bacteria. May be absorbed eventually by humans through food chain and

drinking water. Geno-toxic effects

0.1

1

10

100

1000

10000

100000

1000000

BC AC Resin MWCNTs SWCNTs

Pric

e of

adso

rben

t ($/

kg)

Adsorbent

Lower price Higher price

Fig. The price of different adsorbents (BC = Biochar, AC = Activated Carbon, MWCNTs= Multi Wall Carbon Nanotubes, SWCNTs = Single Wall Carbon Nanotubes (Ahmed etal., 2015).

Ahmed, M. B., Zhou, J. L., Ngo, H. H., & Guo, W. (2015). Adsorptive removal of antibiotics from waterand wastewater: progress and challenges. Sci. Total Environ. 532, 112-126.

Price of Different Adsorbents

Biochar is a carbon dominant product which is obtained whenbiomass feedstock’s are heated at elevated temperature in a closedreactor with little or oxygen hungry conditions even (Ahmed et al., 2016a).Modified biochar is obtained when biochar is further activated or modified either chemically or physically in order to improve their sorptive properties of contaminants (Ahmed et al., 2016b).

Applications of Biochar: Sorptive removal of heavy metals, anionic contaminants, and

organic including emerging contaminants Reduction of trace-gas emissions from soil and atmosphere Bolster soil fertility agricultural and crop production Carbon sequestration

Biochar, Modified Biochar and Their Applications

Ahmed, M. B., Zhou, J. L., Ngo, H. H., & Guo, W. (2016a). Insight into biochar properties and its cost analysis. Biomass Bioenerg. 84, 76-86.Ahmed, M. B., Zhou, J. L., Ngo, H. H., Guo, W., & Chen, M. (2016b). Progress in the preparation and application of modified biochar for improved contaminant removal from water and wastewater. Bioresour. Technol. 214, 836-851.

Class Compound Acronym CAS Number

logkow pKa Molecular mass

Molecular formula

Sulphonamides (SAs) Sulfamethazine Sulfathiazole

SMTSMZ

57-68-174-14-0

0.140.05

2.65/7.652.2/7.24

278.34255.32

C12H14N4O2S, C10H11N3NaO3S+ [1]

Kow: Octanol-water partition coefficient & pKa : Acid dissociation constant

Moderately soluble in water and the logKow indicates that they are moderately hydrophilic

Physicochemical Properties of Sulfonamide Antibiotics

S

O

O

NH

NH2

N

N

CH3

CH3

S

O

O

NHS

N

NH2

R1

R2

SMT

SMZ

SMT0/ SMZ0

SMT+/-/ SMZ+/-

SMT+/ SMZ+ SMT-/ SMZ-

pKa1

pKa1

pKa2

pKa2 NH2

S

O

O

NH R1/R2

Sulfonamide structures

General formula of sulfonamides

Sulfonamide species

At pH range: 0-3.0, SMZ+ species dominant At pH range: 3.00-6.0, SMZo species dominant (negligible)At pH range: 6.00-10, SMZ- species dominant (Fukahori et al., 2011)

At pH range: 0-3.00, SMT+ species dominant At pH range: 3.00-7.50, SMTo species dominant At pH range: 7.50-11, SMT- species dominant (Teixido et al., 2011)

Biochar and Modified Biochar Preparation

BiomassCut into

small sizes

Wash & drying at

105 °C

Pyrolysis at 380 °C for 2 h

at 2 psi

Increased N2pressure 10 psi at

380 °C for 15 minutes

Cooling in room temp.

Crushed into desired size, wash with DI &

drying

Biochar

(BBC380)

Biochar (BBC380)

Soaking in 50%

phosphoric acid

solution

Leave at 50 °C for 3

h

Heated at 600 °C for 2 h at

2.0 psi

Cooling in room temp.

Wash with DI & adjust pH to 7.0 and dry

Modified

Biochar

(1MbBBC

600)

Experimental Design: Pyrolyser

3

4

Vent

Gasses OutletN2 Inlet

Pyrolyser Head

Furnace

N2 Cylinder

Valve

Pyrolysis Cham

ber

Screws

Results

1

Sample Composition data

Yielddry basis (%) Moisture content (%) Ash (%) Volatile mater (%) Fixed carbon (%)

Biomass 5.61 12.93 63.83 26.67

Biochar 43.50

Modified Biochar

Initial pH 1.62 3.00 4.35 6.13 10.00

Final pH 1.15 2.74 3.39 4.09 8.28

Zeta potential (mV) 5.34±0.32 -3.25±0.24 -12.76±1.23 -19.6±1.15 -45.9±4.67

Sample EDS analysis BET surface area BJH Adsorption pore

diameter

C % O % P % Molar O/C

Biochar 81.18 18.83 - 0.219 0.50 m2 g-1 113.5 Å

Modified Biochar 51.96 39.52 8.16 0.71 1.12 m2 g-1 83.8 Å

Physicochemical Properties of Biochar and Modified Biochar

Scanning Electron Microscopic (SEM) Picture of Biochar and Modified Biochar

Effect of pH on Distribution Coefficient (Kd) for (a)Sulfathiazole (SMZ) and (b) Sulfamethazine (SMT) Sorption

HPLC Analysis Method: Mobile Phase A (Acetonitrile : Formic Acid = 99.99% : 0.1% , v/v) andMobile Phase B ( Milli Q Water : Formic Acid = 99.99% : 0.1% , v/v), Measured at 285 nm.Initial Flow Rate 0.400 mL min-1 at 40% A and 60%B and At 0.10 min Flow Rate Change to 0.30 mL min-1

over 8 minutes.

20000

25000

30000

35000

40000

45000

50000

55000

60000

65000

70000

1 3 5 7 9 11

K dva

lues

(L K

g-1)

Initial pH

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

1 2 3 4 5 6 7 8 9 10 11

K dva

lues

(L K

g-1)

Initial pH

(a) (b)

Distribution Coefficient (Kd) values for Sulfamethazine (SMT) and Sulfathiazole (SMZ) Sorption

Pseudo first order (PFO) and Pseudo second order (PSO) kinetic model for SMT and SMZ sorption on modified biochar

0 200 400 600 800 1000 1200 1400

0

10

20

30

40

50

60

70 SMZ sorption on 1MbBBC600 SMT sorption on 1MbBBC600 PFO kinetic model fit for SMZ PFO kinetic model fit for SMT PSO kinetic model fit for SMZ PFO kinetic model fit for SMT

Qt (

mg

g-1)

t (min)

Sorption Isotherm Models of Sulfamethazine (SMT) and Sulfathiazole (SMZ)

0 10 20 30 40 500

10

20

30

40

50

60

70

SMT sorption data Langmuir Model Fit Freundlich Model Fit

qe

(mg

g-1

)

Ce (mg L-1)

SMZ sorption data Langmuir Model Fit Frundlich Model Fit

0 10 20 30 40 500

20

40

60

80

100

120

qe(

mg

g-1

)

Ce(mg L-1)

Sorption Isotherm Data Using Modified Biochar

Kinetic Parameters

PFO at 21 ± 0.5 °C PSO at 21 ± 0.5 °C Intra-particle Diffusion Model

Name Qe cal (mg g-

1)

K1 (min-

1)

R2 Qe cal (mg g-1) K2 (g mg-1

min-1)

R2 C (mg g-1) Ki (mg g-1

min-0.5)

R2

SMZ 56.71±1.70 0.00783 0.960 66.08±1.17 0.0001412 0.992 12.01±3.2 1.66±0.18 0.857

SMT 37.46±1.84 0.00627 0.907 43.30±1.18 0.0001840 0.963 7.25±1.49 1.08±0.08 0.921

Freundlich Isotherm Parameter’s Langmuir Isotherm Parameters

Antibiotics At 21 ± 0.5 °C Temperature At 21 ± 0.5 °C Temperature

KF n R2 Qmax KL R2

SMZ 27.03±0.946 2.6±0.072 0.998 127.7±18.87 0.058±.0105 0.995

SMT 24.81±2.77 5.94±1.253 0.915 65.74±6.25 0.208±0.087 0.897

FTIR Spectra Based Sorption Mechanisms

4000 3500 3000 2500 2000 1500 1000-0.01

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08 -OH bending 990-1020

1520

C=O stretching of -COOH

1690C=O stretching Including ketone, -COOH, ester & anhydries

2340C=O i.e. carbonyl Bond Group

2920

-CH stretching vibration of asymmetric aliphatic -CH, -CH2 & -CH3

Abs.

Wave length (cm-1)

Raw Bamboo BBC380 1MbBBC600 SMT-1MbBBC600 SMZ-1MbBBC600

-OH group3800-3900 3320

-OH Group

Sorption Mechanisms Inferred from Raman Spectra

500 1000 1500 2000 2500 3000-1500

0

1500

3000

4500

6000

7500

9000

10500

12000

13500

15000

(ID/IG =1.0056722= 1MbBBC600-SMT)

(ID/IG =0.849705= BBC380)

(ID/IG =0.991932 =1MbBBC600.SMZ)(ID/IG =1.056722 = 1MbBBC600)

Inte

nsity

(cou

nts)

Raman shift (cm-1)

BBC380 1MbBBC600 1MbBBC600-SMT 1MbBBC600-SMZ

1589-15991332-1345

D and G bands refer to carbon SP3 and SP2 hybridization, respectively. Intensity ratio (ID/IG) indicate the degree of graphitization

Schematic Sorption Mechanism

O O

O

O

OO

OO

O

O

H

H

H

H

H

H

OH

O

O HO H

NH2S

O

O

N-

R

NH2 S

O

O

N-

R

NH2 S

O

O

NH R

NH2

SO O

NH

R

NH2 S

O

O

N R

H

δ -

δ+

δ -

δ+

δ -

δ -

δ -

δ +

δ -

δ +

π

π π

π π

H

NH2S

O

O

NR

δ +

δ -

CAHB

CAHB

Lewis acid base interaction

SMT (R1)

SMZ (R2)

..

..

π π π

π

π π π

π

..

Diffusion

Higher electron density

..:

δ -

δ -

δ - δ+

δ+ δ+

electron acceptorπ

δ + δ + - EAA π π

δ -

δ - δ -

..

π - EDA

Where, R=R1/R2

π ..

..

π + at low pH

at high pH

For neutral molecules

at higher pH where negative species exist (mostly favored)

at higher pH where negative species

exist (less favorable)

t= t t= o

Sorption affinites and Kd values trend: SMZ>SMT

Summery

Phosphoric acid modified biochar (1MbBBC600) can be used asan alternate adsorbent to effectively remove emergingcontaminants such as antibiotics.

Adsorption distribution coefficient (Kd) values followed thetrend of SMZ > SMT.

Freundlich isotherm sorption parameters slightly better fits thanLangmuir isotherm sorption parameters

Mechanism of the sorption largely pH dependent and mostlygoverned by strong H-bond formation, π+-π electron-donor-acceptor (EDA), and by Lewis acid-base interaction at neutralregion. Sorption at very low pH followed π-π EDA interaction.At high pH, sorption was favored through –OH exchange withwater molecule leading to formation of π-π EAA interaction.

Acknowledgements

Professor John L. Zhou Professor Huu Hao NgoDr Wenshan Guo IRS, FEIT Scholarships and Blue Sky FundingFEIT, Centre for Technology in Water and

Wastewater (CTWW), and my colleges’ support in University of Technology Sydney (UTS), Sydney, Australia.

Thanks !! Questions ???

Mohammad Boshir AhmedPhD Student (2nd Year)Civil and Environmental EngineeringUniversity of Technology Sydney (UTS)Sydney, NSW, Australia.Email: Mohammad.B.Ahmed@student.uts.edu.au

Contact for Collaboration or Exchange: Professor John ZhouHead of SchoolSchool of Civil & Environ. Eng.University of Technology Sydney (UTS)Tel: +61295142023Email: junliang.zhou@utd.edu.au