Predicting Cu and Zn sorption capacity of biochar from feedstock C/N ratio and pyrolysis temperature.
Environ Sci Pollut Res Int
; 25(8): 7730-7739, 2018 Mar.
Article
in En
| MEDLINE
| ID: mdl-29288302
ABSTRACT
Biochars have been proposed for remediation of metal-contaminated water due to their low cost, high surface area and high sorption capacity for metals. However, there is a lack of understanding over how feedstock material and pyrolysis conditions contribute to the metal sorption capacity of biochar. We produced biochars from 10 different organic materials by pyrolysing at 450 °C and a further 10 biochars from cedar wood by pyrolysing at 50 °C intervals (250-700 °C). Batch sorption experiments were conducted to derive the maximum Cu and Zn sorption capacity of each biochar. The results revealed an exponential relationship between Cu and Zn sorption capacity and the feedstock C/N ratio and a sigmoidal relationship between the pyrolysis temperature and the maximum Cu and Zn sorption capacity. FTIR analysis revealed that as temperature increased, the abundance of functional groups reduced. We conclude that the high sorption capacity of high temperature biochars is due to an electrostatic attraction between positively charged Cu and Zn ions and delocalised pi-electrons on the greater surface area of these biochars. These findings demonstrate a method for predicting the maximum sorption capacity of a biochar based on the feedstock C/N ratio and the pyrolysis temperature.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Water Pollutants, Chemical
/
Zinc
/
Charcoal
/
Water Purification
/
Metals, Heavy
/
Environmental Restoration and Remediation
/
Hot Temperature
Type of study:
Prognostic_studies
/
Risk_factors_studies
Language:
En
Journal:
Environ Sci Pollut Res Int
Journal subject:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Year:
2018
Document type:
Article
Affiliation country:
United kingdom