Hansen solubility parameters and green nanocarrier based removal of trimethoprim from contaminated aqueous solution

Abstract

The study aimed to address efficient and safe green nanoemulsions (NE) to remove Trimethoprim (TMT) contaminated water using water/cremophor EL/propylene glycol/isopropyl myristate (IPM). HSPiP software predicted excipients and experimental solubility data were used to screen oil, surfactant and co-surfactants. Pseudo-ternary phase diagram dictated the selection of Smix (cremophor-EL to propylene glycol) ratio. Various NE (PNE1-PNE5) were prepared and studied for globular size, PDI (polydispersity index), viscosity (η), refractive index, and surface charge (zeta potential as ZP). Moreover, PNE1-PNE5 were studied for thermodynamic stability test under stress conditions. All of them were subjected to investigate % removal efficiency (%RE) followed by the effect of size, compositions (water and IPM), η and exposure time (min). Eventually, the treated-water was tested to negate its presence using SEM-EDX (scanning electron microscopy-EDX mode) and ICP-OES (inductively coupled plasma-optical emission spectrometry). Findings executed that PNE5 possessed the lowest size (53 nm), size distribution (0.21), η (∼67.1 cP), and optimal ZP (−25.1 mV). Globular size, η and composition had significant impact on %RE values whereas exposure time and refractive index were of least impact. The highest %RE was achieved with the high content of water and low concentration of IPM in PNE5. ICP-OES and SEM-EDX results confirmed the absence of TMT and trace content of several alkali, alkali earth metals and transition metals. Considering findings, PNE5 can be the most robust and optimized one as promising strategy to treat water being simple, rapid, economic, scalable and high efficiency as compared to conventional methods.