Performance of zeolite powder and tubular membrane having different Si/Al ratio for removing As(III) in aqueous phase

Three different types of zeolite having pore sizes in the range 0.26-0.74 nm, (NaP, NaA, and NaY) powders and membranes are synthesized with different Si: Al ratio on low cost clay alumina tubular support. The results of the permeation and separation studies showed that the NaP zeolite powder and membrane removes maximum As(III) from the water solution (more than 80%) compared to other zeolites. The removal of As(III) to achieve drinking water standard, by zeolite membrane, in a single step process does not seem to have been reported before the present investigation. These are the novelty achieved

Altering Emulsion Stability with Heterogeneous Surface Wettability

Emulsions–liquid droplets dispersed in another immiscible liquid–are widely used in a broad spectrum of applications, including food, personal care, agrochemical, and pharmaceutical products. Emulsions are also commonly present in natural crude oil, hampering the production and quality of petroleum fuels. The stability of emulsions plays a crucial role in their applications, but controlling the stability without external driving forces has been proven to be difficult. Here we show how heterogeneous surface wettability can alter the stability and dynamics of oil-in-water emulsions, generated by a co-flow microfluidic device. We designed a useful methodology that can modify a micro-capillary of desired heterogeneous wettability (e.g., alternating hydrophilic and hydrophobic regions) without changing the hydraulic diameter. We subsequently investigated the effects of flow rates and heterogeneous wettability on the emulsion morphology and motion. The experimental data revealed a universal critical timescale of advective emulsions, above which the microfluidic emulsions remain stable and intact, whereas below they become adhesive or inverse. A simple theoretical model based on a force balance can be used to explain this critical transition of emulsion dynamics, depending on the droplet size and the Capillary number–the ratio of viscous to surface effects. These results give insight into how to control the stability and dynamics of emulsions in microfluidics with flow velocity and different wettability