Published in:
CLEAN – Soil, Air, Water, 45 (2017) 11
Language:
English
DOI:
10.1002/clen.201600678
ISSN:
1863-0650;
1863-0669
Origination:
Footnote:
Description:
The application of biomass derived from the nuisance fresh‐water diatom speciesDidymosphenia geminatatoward the adsorption and removal of heavy‐metal ions from water is reported. The cell‐free polysaccharide‐based stalks of these diatoms are used as adsorbents to remove harmful metal ions: Pb(II), Ni(II), and Cd(II). Detailed analyses of the adsorption kinetics using both pseudo‐first‐order model and pseudo‐second‐order models are performed. The results show a strong correspondence to a pseudo‐second‐order kinetic model. The Langmuir and Freundlich models are used to describe the adsorption isotherms. The correlation coefficients (r2) of the Langmuir model are equal to 0.994 (Pb2+), 0.995 (Cd2+), and 0.995 (Ni2+), and ther2for the Freundlich model are equal to 0.991 (Pb2+), 0.991 (Cd2+), and 0.987 (Ni2+). The experimental data for all metal ions strongly support the Langmuir isotherm model. It is shown that stalks ofD. geminataexhibit exceptional sorption capacity (qm) for Pb(II) ions of 175.48 mg g−1. Additionally, a high sorption capacity for Cd(II) (145.86 mg g−1), and Ni(II) (130.27 mg g−1) is observed. The thermodynamic aspects of the adsorption process of selected metal ions are also discussed. Preliminary tests investigating applications ofD. geminatastalks for sewage purification from galvanic industry and battery and accumulator production were performed. These comprehensive studies show thatD. geminatacan be robustly applied for the removal of harmful metal ions from wastewater.