Enhanced phosphate removal during the simultaneous adsorption of phosphate and Ni2+ from electroless nickel wastewater by calcium silicate hydrate (CSH)

- Calcium silicate hydrate (CSH) was synthesized from natural resources as white carbon black and calcium carbonate.
- Phosphate removal by CSH could be enhanced during the simultaneous adsorption than that of the independent process.
- Independent/simultaneous adsorption of the phosphate and Ni(II) was characterized using SEM, EDS and XRD.
- Adsorption potential for phosphate and Ni(II) by CSH for actual electroless nickel wastewater reached 98.67% and 98.75%, respectively.

Enhanced phosphate removal during the simultaneous adsorption of phosphate and Ni2+ using calcium silicate hydrate (CSH) were investigated. Firstly, it was found that the maximum adsorption capacity of CSH for phosphate reached 179.4 and 209.6 mg/g during the independent and the simultaneous adsorption process, respectively. Meanwhile, higher and steady sorption capacity for phosphate could be obtained at the pH ranged from 3 to 7 and the accompanying Ni2+ concentration ranged from 0 to 300 mg/L. In addition, the independent/simultaneous adsorption of the phosphate and Ni2+ was characterized using SEM-EDS and XRD. Moreover, it was discovered that the kinetic constant for phosphate decay during the independent phosphate removal process reached 0.6052, while which was increased to 0.7571 during the simultaneous adsorption process. Finally, it was found that the adsorption efficiency for phosphate and Ni2+ by CSH from actual electroless nickel wastewater reached 98.67% and 98.75%, respectively.