Hollow Zinc Oxide Microflowers for Selective Preconcentration of Selenium Ions in Natural Water

Background: Selenium’s popularity in a wide variety of products and industries means that it has, unfortunately, become a common environmental pollutant, particularly from sources such as industrial wastewater discharge and agricultural runoff. Objective: Quantification of the selenium (IV) ion content of natural water sources via atomic fluorescence spectrophotometry (AFS) was performed using hollow ZnO microflowers as the enriched materials. The hollow ZnO microflowers were prepared via a hydrothermal method with polystyrene (PS) microspheres as the template. Methods: Since the pH of the selenium (IV) solution is known to influence the degree of adsorption onto the sorbent, both the acidity of adsorption and elution were studied at various pH values to obtain the adsorption isotherm and adsorption capacity of the sorbent. AFS was used to quantify the amount of selenium ion that was present in the samples. The structure of the hollow ZnO microflowers was characterized using XRD, SEM, and TEM characterization methodologies. Results: When the pH was between 6.0 and 7.0, the percentage of Se (IV) adsorption was as high as 93%. It was found that the amount of Se (IV) that was eluted from the sorbent exceeded 96% with 5.0 mL of a 0.01 mol L−1 NaOH solution over the course of 10 minutes. The maximum adsorption capacity was 31.5, 31.8, and 32.0 mg·g−1 at 273, 333, and 353 K, respectively. Conclusion: The LOD for Se (IV) detection via enrichment was achieved at 0.006 μg L−1 with a linear range between 0.1 and 200 μg L−1. Thus, this method is applicable to the analysis of natural water samples and GBW(E)080394.