Development of Mn3(PO4)2 nanoplates assisted treatment strategy for the removal of cadmium from synthetic domestic wastewater

Abstract

This study reports an adsorption treatment strategy for the removal of cadmium ions from wastewater using manganese (II) phosphate nanoplates (Mn-3(PO4)(2) NP) as adsorbent. The proposed method was combined with flame atomic absorption spectrometry to aid in quantification. Different concentrations of cadmium were spiked to synthetic domestic wastewater and applying the optimized treatment conditions yielded removal efficiency values in the range of 82-99%. An adsorption capacity (q(e)) of 16.4 mg/g was calculated for 25 mg/L Cd2+ under the optimum conditions of pH 9.0, 50 mg Mn-3(PO4)(2) NP and 60 s mixing by ultrasonication. Equilibrium values obtained using four types of Langmuir adsorption isotherm models were modeled mathematically, and the results showed that the Type 1 isotherm model fitted well with the experimental data. According to these results, the maximum adsorption capacity (q(m)) was calculated as 20.01 mg/g at optimum conditions. Removal efficiency and the established equilibrium between the adsorbent and the adsorbate validated Mn-3(PO4)(2) NPs as an effective adsorbent for the removal of Cd2+ from wastewater.