CoFe2O4 modified bentonite-based mixed matrix loose nanofiltration membranes for effective wastewater treatment.

Mixed-matrix membranes (MMMs) with an ideal polymer/hydrophilic flux enhancer interface considerably recuperates the separation and purification performance of membrane. In this direction, a novel CoFe2O4 functionalized natural clay-bentonite (CoFe2O4@BT) material as a compatible flux enhancer was synthesized for preparation of mixed matrix based in polyethersulfone (PES) matrix. Here, the influences of CoFe2O4@BT on the morphology and performance of the MMMs membranes were systematically investigated using various analytical techniques. Meanwhile, the water flux and sepration eficiency of the CoFe2O4@BT-PES membranes significantly enhanced due to the incorporation of CoFe2O4@BT that altered hydrophilicity, pore and surface characteristic features. The water flux as well as separation efficiency range up to 95%, 94.69%, 94.16% of Congo red (CR), Crystal violet (CV), and humic acid (HA) respectively. Meanwhile, the fouling parameters demonstrated that the CoFe2O4@BT-PES membranes exhibited better antifouling property in the long term experiment comparing with commercial polyamide membrane. CoFe2O4@BT material incorporated membranes showed less decline ratio and a better recovery ratio. The high rejection of dyes with a high permeation flux of the newly designed membranes indicated an amazing possibility for dye purification. In this study, a potential dye mechanism for composite membranes impacted by synthetic CoFe2O4@BT was also put forth. Within the context of application considerations for environmental protection, new materials stock in membranes show good potential for the separation of different organic contaminants.

Green route for synthesis of multifunctional fluorescent carbon dots from Tulsi leaves and its application as Cr(VI) sensors, bio-imaging and patterning agents.

We report a one pot green strategy for the synthesis of carbon dots using tulsi leaves and their potential application in sensing of Cr(VI) selectively. The detection mechanism is based on the phenomenon called inner filter effect (IFE) and a good linear static quenching was observed in the range of 1.6 µM to 50 µM with a detection limit of 4.5 ppb. The reversible switching in fluorescence has been tested and a good recovery in fluorescence was observed up to three consecutive cycles upon addition of ascorbic acid as reducing agent. Also the low toxicity, high fluorescence and photostabilty of the CDs make them excellent imaging and patterning agent. The acid and alkali resistant property of these CDs makes it suitable for real sample analysis. The fluorescent CDs were applied for successful detection of Cr(VI) in water with spike-recoveries ranging from 93 to 99%.