Innovative materials for As(III) and As(V) removal in water treatment

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chimica

Teamwork:

Dr. G. Costamagna, Dr. L. Defereria, Dr. M. Ginepro,

a

Dr. S. Caro

b

a_{Department of Chemistry, University of Turin, Via Pietro Giuria 5, 10125, Torino, Italy}

b_{Department of Bioproducts and Biosystems – Clean Tecnologies, Aalto University, Vuorimiehentie 1, FI-00076, Aalto, Finland}

Dr. Giulia Costamagna

giulia.costamagna@unito.it Rimini, November 25th 2019

Innovative materials for As(III) and As(V) removal in

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Arsenic contamination

• Arsenic contamination -> naturally occurring high concentrations of Arsenic in deeper levels of groundwater. It is a high-profile problem due to the use of deep tubewells for water supply in the Ganges Delta, causing serious arsenic poisoning to large numbers of people. • A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water.

The problem became serious health concern after mass poisoning of water in Bangladesh. Arsenic contamination of ground water is found in many countries throughout the world, including the US.

Alternative and innovative arsenic removal solutions:

Biochar

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Nanosponges

Nanosponges (NS) are insoluble materials that comes from starch,

with distinctive nanometric porosity and superior absorption.

Maltodextrin NS

Initiator

Unit base

DABCO

1,4-diazabicyclo[2.2.2]octane

Choline

Maltodextrine

Functionalisation

with positive charge

BDE

1,4-Butanediol

diglycidyl

ether

Epoxide

Cross linker

GLUCIDEX®

Roquette®

Product

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Byopolimers synthetized

GLUBDE:

GLUCIDEX 2 + BDE (1,4-Butanediol diglycidyl ether)

GLUBDE:

GLUCIDEX 2 + BDE (1,4-Butanediol diglycidyl ether)

GLUCHOBDE:

GLUCIDEX 2 + Choline cloride + BDE (1,4-Butanediol diglycidyl ether)

GLUCHOBDE:

GLUCIDEX 2 + Choline cloride + BDE (1,4-Butanediol diglycidyl ether)

BDE

GLUTTE:

GLUCIDEX 2 + TTE (Trimethylolpropane triglycidyl ether)

GLUTTE:

GLUCIDEX 2 + TTE (Trimethylolpropane triglycidyl ether)

GLUCHOTTE:

GLUCIDEX 2 + Choline cloride+ TTE (Trimethylolpropane

triglycidyl ether)

GLUCHOTTE:

GLUCIDEX 2 + Choline cloride+ TTE (Trimethylolpropane triglycidyl ether)

TTE

GLUNGDE:

GLUCIDEX 2 + NGDE (Neopentyl glycol diglycidyl ether)

GLUNGDE:

GLUCIDEX 2 + NGDE (Neopentyl glycol diglycidyl ether)

GLUCHONGDE:

GLUCIDEX 2 + Choline cloride + NGDE (Neopentyl glycol diglycidyl ether)

GLUCHONGDE:

GLUCIDEX 2 + Choline cloride + NGDE (Neopentyl glycol diglycidyl ether)

NGDE

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Nanosponges Results

Limit of Detection of ICP-OES: 10 ppb

1 gr of material + 100 ml of contaminant solution

Stirring for 24h and analytical check (ICP-OES).

For the characterisation several batch tests were performed.

Abatement tests were carried out at different concentrations:

100 ppb – 10 ppm

GLUB DE GLUC HOBD E GLUT TE GLUC HOTT E GLUN GDE GLUC HONG DE 0 20 40 60 80 100

As (V) Abatement %

10 ppm 1 ppm 0,1 ppm GLUB DE GLUC HOBD E GLUT TE GLUC HOTT E GLUN GDE GLUC HONG DE 0 20 40 60 80 100

As (III) Abatement %

10 ppm 1 ppm 0,1 ppm

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Biochar

Biochar is a carbonaceous

material that comes from

thermal degradation of

woody matrices.

Water Treatment: As(III) and As(V)

pH

Biochar

Benefits:

Heavy Metals Retainer Organic Compounds Retainer

Biochar is currently

used as a soil

improver, acting on

Soil Density

Recent studies carried out by our research team, have found out an interesting property:

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Biochar samples preparation

Into the Falcon:

0,5 g biochar + 25 ml As (III) solution 1 mg/L

0,5 g biochar + 25 ml As (V) solution 1 mg/L

• Fig

• Elder

Woods

• Blade mill

(< 2 mm)

Milling

• Tubolar

furnce

• N

₂

Pyrolysis

Pyrolysis parameters

• Heating cycle in inert

enviroment

• Temperature 1100 °C

for 3h

ICP-OES Analysis

after 24h

• Fig wood

• Elder wood

• Walnut

wood

Woods

• Blade mill

(< 2 mm)

Milling

• Tubolar

furnce

• N

₂

Pyrolysis

Pyrolysis parameters

• Heating cycle in inert

enviroment

• Temperature 1100 °C

for 3h

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Biochar results

Abatement (24h)

pH

As (III)

As (V)

Medium (%)

St. Dev.%

Media %

St. Dev.%

Activated Carbon

_7,6±0,1

_61,3

_3,1

_81,8

_3,3

Commercial Biochar

_8,7±0,1

_80,3

_5,9

_63,7

_12,7

Fig wood Biochar

_10,6±0,1

_96,9

_2,8

_98,3

_2,3

Elder wood Biochar

_10,5±0,1

_89,3

_9,3

_73,7

_21,1

Walnut wood Biochar 10,3±0,1

90,1

5,4

93,8

5,7

As(III) and As(V) are in the HA

-

_{form that easily interact with biochar in that condition (pH~10)}

As release in water

As (III)

As (V)

µg/l

All Analyzed Samples

<25

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Conclusions

Law limits

Drinking Water

Superficial Waters Discharge

Law limits

Sewage discharge

Law limits

Nanosponges

10 µg/L

0,5 mg/L

GLUBDE

✓

GLUCHOBDE

✓

GLUTTE

✓

GLUCHOTTE

✓

GLUNGDE

✓

/ ✗

✓

GLUCHONGDE

✓

/ ✗

✓

Law limits

Drinking Water

Superficial Waters Discharge

Law limits

Sewage discharge

Law limits

Carbon & Biochar

10 µg/L

0,5 mg/L

Commercial Biochar

✗

✓

Activated Carbon

✗

✓

Fig wood Biochar

✗

✓

Elder wood Biochar

✗

✓

Walnut wood Biochar

✗

✓

Nanosponges and Biochar could be use to remove As(III) and As(V) in water treatment,

following the limits of Italian laws.

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chimica

Dr. Giulia Costamagna

giulia.costamagna@unito.it

Rimini, November 25

th

2019