A novel hybrid material zirconium polyacrylamide (ZrPACM-43) was synthesized by mixing aqueous solution of zirconium oxychloride and mixture of acrylamide following an environmental friendly sol–gel method. The material was characterized by FTIR, XRD, TGA-DTA, and SEM-EDS. The extent of arsenic removal capacity was tested by the material by varying the solution parameters like adsorbent dose, adsorbate concentration, pH of the solution, contact time and temperature. The maximum removal efficiency of arsenic(III) was 98.22% under optimum conditions with adsorption equilibrium time of 120min. The adsorption process followed second order kinetics and adsorption data were best fitted to linearly transformed Freundlich isotherm with correlation coefficient of R2>0.999. Adsorption capacity (qo) calculated from Langmuir isotherm was found to be 41.48mgg−1. The thermodynamic parameter ΔH indicates an endothermic adsorption process. The regeneration study shows that the material is regenerated by 1M alkali solution

Neutralization of red mud using CO ₂ and activated by calcined at 500 °C.

The object of this study was to evaluate the efficiency of safranin-O dye removal from aqueous solutions with application of red mud waste as an adsorbent. For this propose, the surface of the red mud was modified by the addition of sodium dodecyl sulphate as an anionic surfactant. Different instrumental techniques were used to understand the physiochemical properties and the surface properties of the modified red mud for the adsorption of safranin-O dye. Batch adsorption experiments were carried out to understand the optimum conditions with respect to solution pH, contact time and initial dye concentration. Kinetics data were best fitted with a pseudo-second-order model. The adsorption isotherms data were a good fit to the Langmuir model with a maximum monolayer adsorption capacity of 89.4 mg g⁻¹ at 308 K. Desorption experiments were carried out by testing several solvents such as water, sulphuric acid, hydrochloric acid and acetic acid and the maximum (93.2%) desorption was found using hydrochloric acid.