Enrichment of lead and cadmium from water using P−ZrO2CeO2ZnO nanoparticles/alginate beads: Optimization and determination of significant factors and interaction using response surface methodologies

The optimization, determination of significant factors and interactions between factors of the solid phase extraction method for the enrichment of lead and cadmium in water using P−ZrO2CeO2ZnO nanoparticles/alginate beads was evaluated using Half factorial and Taguchi designs as response surface methodologies in this study. Methods. The beads were characterized using Fourier Transform Infra-Red spectroscopy, Brunauer-Emmet-Teller analysis, Scanning Electron Microscopy and Powder X-ray Diffraction. The amount of adsorbent (50, 100, 150 mg), sample volume (10, 50, 100 mL), eluent volume (10 mL), sample pH (3, 6, 9), eluent concentration (0.5, 1.0 and 2.0 M) and sample flow rate 2 rpm and eluent flow 3 rpm were used during the optimization experiments. The Half factorial design was used to screen for the most significant variables and the Taguchi design was then used to optimize the screened significant variables. Findings The sample volume was the most significant variable for cadmium recovery at p  = 0.05. Interactions were noted between sample volume and sorbent dosage, sample volume and pH as well as sorbent dosage and pH. The method was validated by spiking cadmium and lead into borehole and well water samples. The recoveries for metal ions ranged from 57.0 -147.70% for cadmium and 33.12–116.5% for lead, limits of detection were 0.0297 ng/L for cadmium and 0.1022 ng/L for lead. This method exhibits potential for the enrichment of lead and cadmium from water samples.