Using recycled coffee grounds for the synthesis of ZIF-8@BC to remove Congo red in water.
Ecotoxicol Environ Saf
; 236: 113450, 2022 May 01.
Article
in En
| MEDLINE
| ID: mdl-35364506
ABSTRACT
Around 6.6 million tons of spent coffee is produced per year, resulting in resources loss and potential environmental risks. Hence, a green technique is required to reuse the spent coffee grains. In this study, coffee grounds were burnt at 900 °C to generate the biochar (BC) for the synthesis of the porous adsorbent (ZIF-8 @BC) by growing ZIF-8 on the surface of BC. We applied the well-prepared ZIF-8 @BC to remove Congo red (CR) in water. The maximum adsorption capacity of ZIF-8 @BC on Congo red in water was up to 1080.4 mg/g, which was significantly higher than that of many different types of BCs reported in previous studies. The reasons for its highly efficient adsorption of CR probably was attributed to metal ions and coordinatively unsaturated sites in the material. Also, BC enabled the less aggregation of ZIF-8 to provide sufficient specific surface area for CR adsorption. From the analysis of the pseudo-second-order kinetic model and Langmuir model, the adsorption of ZIF-8 @BC on CR was a homogeneously chemical adsorption process regulated by electrostatic interaction, π-π stacking and metal coordination.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Water Pollutants, Chemical
/
Congo Red
Language:
En
Journal:
Ecotoxicol Environ Saf
Year:
2022
Type:
Article
Affiliation country:
China