Adsorption of Pb2+ onto freeze-dried microalgae and environmental risk assessment.
J Environ Manage
; 265: 110472, 2020 Jul 01.
Article
en En
| MEDLINE
| ID: mdl-32421550
ABSTRACT
Dry microalgae Spirulina platensis shows a high capacity for heavy metal uptake, but there is a concern about dissolved organic carbon (DOC) residue, which is the precursor of disinfection by-products (DBPs). Vsp, a kind of Spirulina platensis powder prepared by vacuum freeze-drying, and Osp, a kind of Spirulina platensis powder prepared by the conventional oven drying-pulverization method, were subjected to assessments of their adsorption potential for Pb2+ and DOC residue. The adsorption mechanism of Pb2+ by the two adsorbents was studied by SEM, FT-IR, EDX and N2-BET. The effects of pH, adsorbent dosage, initial Pb2+ concentration and contact time on the biosorption process were investigated. The results showed that Pb2+ biosorption by Vsp and Osp were fit well by a pseudo-second-order kinetic model and the Langmuir model. The maximum amount of Pb2+ biosorption by Vsp was 253 mg/g, which was 33 mg/g greater than that of Osp. In comparison with Osp, Vsp reached adsorption saturation 8 h earlier and had a remarkable effect on the control of DOC residue in water. When both adsorption capacity and environmental risks were considered, it was determined that the dosage of 0.5 g/L Vsp for 2 h of contact time was the best method, with 85.89 mg/g of Pb2+ removal and 3.45 mg/L of DOC residue. In summary, Vsp is a highly efficient and environmentally friendly biosorbent that can be used for heavy metal removal from water.
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Bases de datos:
MEDLINE
Asunto principal:
Contaminantes Químicos del Agua
/
Microalgas
Idioma:
En
Revista:
J Environ Manage
Año:
2020
Tipo del documento:
Article
País de afiliación:
China