Development of nanohybrid adsorbent for defluoridation from aqueous systems

- The ZAC nanohybrid composite were developed by a simple steps and FESEM image showing highly nanoporus morphology.
- The nanohybrid composite exhibited high fluoride removal in pH range from 3 to 8.
- The adsorbent-desorption study with showed high adsorption capacity after fourth reuse cycles.
- The presence of competitive ions with moderate concentrations had almost no significant effect on the F− adsorption.
- The adsorption kinetics and isotherms was well described by different kinetic and isotherm models.

The objective of present study is advancement of an efficient nanomaterial which was investigated to substantiate its efficiency, using kinetic studies to ensnare fluoride in order to make water potable. A new crystalline ZrAlCa nanohybrid adsorbent for fluoride removal was successfully synthesized by a co-precipitation method in this study. The prepared adsorbents were characterized by XRD, FT-IR, TGA, BET and FESEM and EDX. The adsorption properties of the developed adsorbent were studied using batch adsorption method which shown the noticeable fluoride removal efficiency up to 99% at near neutral pH as well as in acidic pH range. The reaction kinetics for adsorption of fluoride was established using reaction based kinetic models which fitted well with Avarami kinetic model as compared to pseudo-first-order, pseudo second-order and power function rate expression. The equilibrium isotherm modelling described adsorption process and Langmuir, Jovanovic, Temkin and Freundlich isotherms provides best fit to experimental data. The fluoride loaded adsorbent was efficiently regenerated by using an alkali solution and has no significant counter ion effect on fluoride adsorption efficiency. Interestingly, the developed nanomaterial has fluoride removal efficacy over varied concentration ranges. It has capability of reanimate and reuse the nanohybrid adsorbent makes it an attractive sustainable material.

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