Kinetics of Nitrite Adsorption onto a Styrene Divinylbenzene Macroporous Strong Base Polymer

Abstract

A suitable adsorbent for the treatment of nitrite in wastewater was investigated using a macroporous styrene divinylbenzene strong base polymer for 10⁻³ M to 6 x 10⁻³M NaNO₂ at room temperature using a batch protocol. The supernatant concentrations were determined rapidly and inexpensively by an electrochemical method. To investigate the sorption mechanism and the rate-determining step, four kinetic models were investigated. The pseudo-second order kinetic model best fit the nitrite adsorption onto the polymer. The highest correlation coefficient (0.9999) and chi square (7.59 x 10⁻⁴) values were obtained for 0.046 to 0.276 g L⁻¹ NO₂^- which is characteristic of chemosorption. The results demonstrate that the investigated polymer is suitable at room temperature for removing nitrites for water to the legally allowed values for 10⁻³ M to 1.5 x 10⁻³ M NaNO₂ but dilution is required for higher concentrations.

Keywords:

• Batch adsorption
• kinetics
• linear sweep voltammetry (LSV)
• macroporous styrene divinylbenzene polymer
• sodium nitrite

Acknowledgments

Special thanks to Eng. Septimiu Tripon for his support with SEM/EDS analyses.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS-UEFISCDI, Project number PN-III-P1-1.1-TE-2021-0358, within PNCDI III.