Mechanistic insights into ethidium bromide removal by palygorskite from contaminated water

Ethidium bromide (EtBr)-containing wastewater can be hazardous to biodiversity when released into the soil and water bodies without treatment. EtBr mutate living microbial cells pose toxicity even higher organisms. This work investigated removal of from aqueous solutions by a naturally occurring palygorskite (PFl-1) clay mineral via systematic batch adsorption experiments under different physicochemical conditions. existed in an undissociated form at pH ~7, was adsorbed on PFl-1 obeying Freundlich isotherm model. The maximum capacity 285 mmol/kg. best fitted kinetic model for pseudo-second order amounts exchangeable cations desorbed during linearly correlated adsorbed, with slope 0.97, implying that cation exchange-based mechanism dominating. Additionally, dimerization molecules release assisted increased high adsorbate concentrations. Detailed x-ray diffraction, Fourier transform infrared, scanning electron imaging energy dispersive analyses confirmed occurred dominantly surface which mineralogically constituted 80% bulk adsorbent. A small portion also through intercalation onto smectite impurity (10%) PFl-1. study suggested could excellent natural material removing pharmaceutical laboratory wastewater. • used ethidium (EtBr) water. as 275 mmol/kg corresponding 108 mg/g. Cation exchange main mechanism. facilitated concentration. Kinetic equilibrium reached 1 h; followed