Spectroscopy is the study of matter interacting with electromagnetic radiation (e.g., light). The electromagnetic spectrum in Figure 1 illustrates the many different types of electromagnetic radiation, including gamma rays (γ-rays), X-rays, ultraviolet (UV) radiation, visible light, infrared (IR) radiation, microwaves, and radio waves. The frequency (ν) and wavelength (λ) ranges associated with each form of radiant energy are also indicated in Figure 1.

Introduction to Spectroscopy

Environmental application of biochar: Current status and perspectives

Assessment of heavy metal pollution from anthropogenic activities and remediation strategies: A review.

Comparison of sorption and desorption studies of heavy metal ions from biochar and commercial active carbon

Present paper involved the review of fixed-bed column studies for removal of various contaminants from synthetic wastewater. Basic concept of adsorption, its types (i.e., chemisorption and physisorption) and its mechanism, adsorbents and adsorbates were included. Comparison of batch and column adsorption study is mentioned. Complete study of breakthrough curve for designing adsorptive column is interpreted. This paper explicates the detailed explanation of various process parameters and isotherm models for column study. Fixed-bed adsorption studies using various adsorbates, i.e., metal, ion, dye and other hazardous materials, are reviewed, in which adsorption of chromium metal is most exploitable. Conclusion and some challenges for utilization in real world are also exposed.

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Fixed-bed column adsorption study: a comprehensive review

Biosorption of Co(II) ions from aqueous solution using Chrysanthemum indicum: Kinetics, equilibrium and thermodynamics

Continuous column adsorption studies were performed in this work using native and biochar form of Tectona grandis leaves to remove Ni (II) and Co (II) ions from aqueous solution. Column performance was evaluated by varying the bed height, flow rate and inlet metal ion concentration. Further, column adsorption models including Adam-Bohart, Thomas, and Yoon-Nelson were applied to evaluate different column parameters. Thomas model was found to be in good agreement with higher R2 and closer experimental and theoretical uptake capacity values. Interpretation of the breakthrough curves indicated that the exhaustion time of column extended with increasing bed height and decreasing flow rate and metal ion concentration. Column desorption studies using hydrochloric acid signified the potential of the adsorbents to effectively desorb the adsorbed metal ions. Thus, evaluation of the adsorption potential of Tectona grandis in this study revealed its adequate inherent potential with high adsorption capacities to remove nickel and cobalt ions from aqueous solution evidencing its practical applicability as adsorbent. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

Column adsorption studies on nickel and cobalt removal from aqueous solution using native and biochar form of Tectona grandis

In this research, the potential of a relatively new adsorbent prepared from Tectona grandis leaves by pyrolysis for heavy metal removal from aqueous solution was studied. Adsorption behavior of the pyrolytic biochar was investigated with respect to Ni2+ and Co2+ removal with its affinity examined through batch studies and the mechanism elucidated using different empirical isotherm and kinetic models. A significantly higher efficiency of 92.46% and 91.21% was achieved at a weakly acidic pH of 6 and 5, dose of 3 g L−1 and 2 g L−1 for Ni2+ and Co2+ removal, respectively. Pseudo-second-order kinetics and Langmuir isotherm model best represented the adsorption process for both Ni2+ and Co2+. Thermodynamic analysis proved the endothermic and spontaneous nature of the process. Desorption studies revealed hydrochloric acid to have a high potential toward eluting the adsorbed metal ions. The well-organized microporous structure, the significant surface area value along with the presence of relative functio...

Ni2+ and Co2+ adsorption using Tectona grandis biochar: kinetics, equilibrium and desorption studies.

In the present study, batch experiments were carried out to elucidate the potential of teak leaves powder (TLP) to remove Ni(II) and Co(II) ions from aqueous solution. The TLP was characterized by Bruanauer, Emmett and Teller surface area, Fourier transform infrared spectroscopy and scanning electron microscopy. Effects of various process parameters such as initial pH (2–8), adsorbent dose (1–10 g L–1), initial metal ion concentration (25–200 mg L–1), contact time (5–120 min) and temperature (303–323 K) were investigated in their respective range and their optimum conditions were ascertained. Maximum percentage removal of 75.64 and 76.04% was achieved for Ni(II) and Co(II) ions, respectively, at an initial concentration of 50 mg L–1, at their respective optimum pH of 6 and 5, adsorbent dose of 8 and 6 g L–1 in an equilibrium time of 30 and 60 min at 303 K. Adsorption kinetics was analyzed by pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion kinetic models. It was found t...

Removal of Ni(II) and Co(II) ions from aqueous solution using teak (Tectona grandis) leaves powder: adsorption kinetics, equilibrium and thermodynamics study

The present study investigates the adsorption capability of raw and biochar forms of Chrysanthemum indicum flowers biomass to remove cobalt ions from aqueous solution in a fixed-bed column. Column adsorption experiments were conducted by varying the bed height (1.0, 2.0, 3.0 cm), flow rate (1.0, 2.5, 5.0 mL min−1) and initial cobalt ion concentration (25, 50, 75 mg L−1) to obtain the experimental breakthrough curves. The adsorption capacity of the raw and biochar forms of C. indicum flowers were found to be 14.84 and 28.34 mg g−1, respectively, for an initial ion concentration of 50 mg L−1 at 1.0 cm bed height and 1.0 mL min−1 flow rate for Co (II) ion adsorption. Adam–Bohart, Thomas and Yoon–Nelson models were applied to the experimental column data to analyze the column performance. The Thomas model was found to best represent the column data with the predicted and experimental uptake capacity values correlating well and with higher R
 2 values for all the varying process parameters. Desorption studies revealed the suitability of the adsorbents for repeated use up to four adsorption–desorption cycles without significant loss in its efficiency. It can thus be inferred from the fixed-bed column studies that C. indicum flowers can suitably be used as an effective adsorbent for Co (II) ion removal from aqueous solution on a higher scale.

Sowmya Vilvanathan

Papers

Biosorption of Co(II) ions from aqueous solution using Chrysanthemum indicum: Kinetics, equilibrium and thermodynamics

Column adsorption studies on nickel and cobalt removal from aqueous solution using native and biochar form of Tectona grandis

Ni2+ and Co2+ adsorption using Tectona grandis biochar: kinetics, equilibrium and desorption studies.

Removal of Ni(II) and Co(II) ions from aqueous solution using teak (Tectona grandis) leaves powder: adsorption kinetics, equilibrium and thermodynamics study

Modeling of fixed-bed column studies for removal of cobalt ions from aqueous solution using Chrysanthemum indicum