| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4419597 | Ecotoxicology and Environmental Safety | 2015 | 9 Pages |
•Adsorption uptake decreased with increase in temperature.•Optimal contact time was found to be 4 h.•Kinetics followed pseudo-second order model.•Equilibrium data agreed well with Langmuir model.•Adsorption process was thermodynamically spontaneous, feasible and exothermic.
The agricultural wastes like Citrus Limettioides peel and seed to be suitable precursor for the preparation of carbon [Citrus Limettioides peel carbon (CLPC) and seed carbon (CLSC)] has been explored in the present work, utilizing sulfuric acid as the activating agent. Adsorption studies were performed by varying contact time, solution pH, adsorbent dose and temperature. The equilibrium time for Ni(II) ions was determined as 4 h and optimal pH was 4–7. Surface morphology and functionality of the CLPC and CLSC were characterized by SEM, EDX and FT-IR. The experimental data were analysed using the Freundlich, Langmuir, Temkin, Redlich–Peterson, Sips and Dubinin–Radushkevich adsorption isotherm equations using nonlinear regression analysis. Equilibrium data were found to fit well in the Langmuir isotherm, which confirmed the monolayer coverage of Ni(II) ions. The Langmuir monolayer adsorption capacity of CLPC and CLSC was found to be 38.46 and 35.54 mg/g. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic in nature. The kinetic data followed pseudo-second order model with film diffusion process. The adsorbents were tested with Ni(II) plating wastewater in connection with the reuse and selectivity of the adsorbents.
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