Kinetic Analysis of Lead Removal from Industrial Wastewater Using an Anionic Surfactant

Abstract

The release of untreated industrial wastewater, particularly when it contains heavy metals, significantly harms the aquatic environment. Among these metals, lead is recognized as one of the toxic heavy metals commonly found in industrial effluents. Elevated levels of lead in water can lead to various physiological and health issues in humans and other organisms. Research was conducted on the flotation kinetics of lead using sodium dodecyl sulfate, anionic collector. Study the prediction of lead separation kinetics from wastewater using ion flotation is critically important for several interconnected reasons; predictable, scalable, and economical engineering solution. The study explored chemical kinetics by examining key parameters such as wastewater pH and collector concentration. Time–recovery data for lead flotation were analyzed using a first–order equation for flotation kinetics , which allowed for the calculation of the flotation rate constant and the cumulative recovery at infinity ( ). The experimental results showed acceptable alignment with the first–order kinetic model. Results showed that the adsorption rate increased with initial SDS concentration from 25 to 100 mg/L, with the highest reaction rate observed at 100 mg/L (k = 0.0707 min^–1). Correlation coefficients (R²) confirmed acceptable linear relationships with consistent negative slopes across all data groups. For pH experiments conducted at constant initial SDS concentration (50 mg/L) across pH values of 3, 5, and 8, adsorption increased with rising pH up to an optimum at pH 5 (k = 0.0229 min⁻¹), after which it decreased at pH 8 (k = 0.0208 min^–1). The lowest reaction rate was observed at pH 3 (k = 0.0138 min^–1). Cumulative recovery values ranged from 56.10% to 89.52%, with the maximum recovery (89.52%) achieved at 50 mg/L SDS concentration and pH 8. These findings demonstrate that both initial lead concentration and pH significantly influence the adsorption mechanism of SDS onto lead surfaces.