Hydroxyapatite and ionic liquid coupled with hybrid membranes for toxic pollutant removal and remediation

Access to clean water is the mandatory requirement for every living being to sustain life. So, membrane-based integrated approach of adsorption and separation technology has recently been preferred by scientists over other conventional techniques, for wastewater treatment. Current research focused on the synthesis of novel imidazolium (A1) based IL, which was further functionalized with hydroxyapatite (HAp; extracted from Labeo rohita scales), to create possible solutions towards environmental remediation. Cellulose acetate (CA) was used for the fabrication of three different ionic liquid membranes. All the synthesized products were characterized by FTIR, XRD and TGA. Two dyes of different nature, i.e., congo red (anionic) and crystal violet (cationic) were selected because of their highly toxic and carcinogenic effects, for batch adsorption experiments. Antibacterial activity of the synthesized membranes was also evaluated against S. aureus. Results of the study revealed that CA-HA1 1:2 acted as the best adsorbent towards the removal of crystal violet, exhibiting removal efficiency of 98% with the contact time of 24 h while in case of congo red adsorption, CA-HA1 (1:2) proved as prime adsorbent with the removal efficiency of 96% for the same preceding contact time. Considering the antibacterial character of the synthesized membranes, CA-A1 (1:1) emerged as very efficient antibacterial agent with the inhibition zone of 50 mm after 48 h. The overall behavior of monolayer and multilayer adsorption was witnessed for both dyes while kinetic studies favored the pseudo-second order reaction for all adsorbents.