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Author: search.filters.author.Nair, N.

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    Soil toxicity and remediation techniques
    (Elsevier, 2022) Manikandan, S.K.; Shilli, A.; Noronha, F.R.; Nair, N.
    Soil is a major component required for the growth of plant, and its studies have been carried out intensively for enhanced agricultural production. The need to fulfill the food demands of the increasing human population and the requirement to safeguard food crops has resulted in the heavy usage of pesticides. However, the continuous usage of pesticides and their ability to persist in soil for a longer period has become a threat to society. The pesticide residue in the soil can cause severe environmental problems due to their high accumulative and persistent existence, that are biomagnified through the food chain of various life forms. Different disposal techniques classified as physicochemical technologies, biological technologies, and thermal technologies have been reported to be effective in pesticide removal from soil. Similarly, the application of green chemistry and nanotechnology have been stated to be effective for the removal of pesticides from the soil. This chapter provides detailed information on the various remediation involved in pesticide removal from soil. In addition, it also provides insights on the new technologies for treating contaminated soil and the economic aspect involved in the disposal of pesticides. © 2022 Elsevier Inc. All rights reserved.
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    Potential environmental applications of Helianthus annuus (sunflower) residue-based adsorbents for dye removal in (waste)waters
    (Elsevier, 2022) Anastopoulos, I.; Giannopoulos, G.; Islam, A.; Ighalo, J.O.; Iwuchukwu, F.U.; Pashalidis, I.; Kalderis, D.; Giannakoudakis, D.A.; Nair, N.; Lima, E.C.
    Under the framework of Circular Economy, agricultural residues that once were considered an unwanted byproduct, are currently gaining popularity as novel bio-based products for environmental applications. This chapter evaluates the potential of Helianthus annuus (sunflower) biomass residues for (waste)water dye removal considering the factors regulating its subsequent chemical processes and equilibria. The initial pH, which affects both the dye speciation in solution and the surface charge of the adsorbent, is one of the most critical parameters and determines the optimum conditions for efficient dye removal. The soluble dyes, that present a high affinity for water, are generally ionized (e.g., possess positive or negative charge), and therefore, the sorption capacities of an adsorbent are strongly affected by the initial pH of the dye solution. The equilibrium data regarding the removal of various dyes from aqueous solutions using sunflower-based adsorbents (in pristine or chemically modified form) are usually better described by the Langmuir equation; however, in some cases, the Freundlich adsorption model seems to better fit the experimental data. The majority of the kinetic data associated with the removal of dyes using sunflower-based adsorbents follows the pseudo-second-order model. In addition to the thermodynamic adsorption data, this chapter summarizes and discusses also data of desorption experiments performed using dye-loaded adsorbents. © 2022 Elsevier Inc. All rights reserved.
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    Black titania: Turning the surface chemistry toward visible-light absorption, (photo) remediation of hazardous organics and H2 production
    (Elsevier, 2022) Prekodravac, J.; Giannakoudakis, D.A.; Colmenares, J.C.; Nair, N.; Vasiljević, B.; Kepić, D.
    Environmental protection and energy conversion by state-of-the-art photocatalysts emerge as imperative in pursuit for ideal, sustainable, and green oriented solutions. However, major drawbacks in broader application of one of the most promising semiconductor photocatalyst, titanium dioxide (TiO2), lie in the need for enhancing visible-light absorption and elevating the photocatalytic reactivity. Toward these directions, narrowing the material band gap and functionalization of the surface chemistry are among the most prosperous materials design approaches. As reported in earlier work, the surface structure engineering proved to be an encouraging approach to endow optical and electrical properties of the TiO2-based material. For the first time, the black powder of TiO2 with a disordered lattice and hydrogen surface doping was obtained through hydrogenation under high pressure and temperature, consequently leading to narrowing the optical band gap to 1.54eV. The presented chapter aims to reveal in-depth all the literature available information related to the black titania synthesis in addition of sharing in details its prosperous physicochemical properties. Feature information related to the photocatalytic activity of black TiO2 as well as of the most crucial features will also be provided. Finally, the chapter will conclude with the derived significant benefits of such material properties in photocatalytic treatment of organic pollutants and hydrogen production. © 2023 Elsevier Inc. All rights reserved.