FOCUS AREAS

Most membrane separation processes, like microfiltration, ultrafiltration, nanofiltration and reverse osmosis, have inherent limitations. For example, these separation techniques fail to remove selective ions/ contaminants (having a size in picometer range). In addition, they operate at extremely high-pressure drops and rely on heavy energy duty. Hence, to address such issues, special composite membranes, known as mixed matrix membranes (MMM), can be prepared from a solvent, polymer and impregnated additive. These membranes operate at low pressure and exploit both filtration and adsorptive properties. They can sustain longer than most conventional membrane processes at a long stretch of filtration operations.

Conventional adsorbents lack suitability of high uptake capacity and inability to function in continuous/ dynamic water treatment. Also, these materials are costly and require complex chemical modifications, before they are used in operation. Functional materials made from low cost naturally amended soil particles can be used for adsorption columns to treat contaminated streams. For example, lava or sedimentary soils are a rich source of alpha and gamma phase iron and aluminium, which can be treated by physical/chemical methods to enhance their uptake capacity. These materials can further be used in fixed beds and effects of different input conditions can be studied for scaling up their operations. Other functional sorbents, like, metal-organic frameworks, nanoparticles and graphene sheets, can also be modified chemically to enhance their performance in water treatment.

Prediction of fixed bed process tenure in adsorption and membrane separation is quite tricky, based on its complex operation. Also, a rough idea beforehand is necessary for the manufacturer to develop a known quantity of material for prefixed operation. The breakthrough life of prepared membranes and adsorbents can be predicted by a PDE-based mathematical or continuous CFD-based model. Calculations can also be made to scale up the process to give an idea about the quantity of material required for higher throughput.

Today, sensors are a potential substitute for traditional analytical methods for regulating water quality, including natural water, process water and wastewater, before it is released into natural watercourses. The primary aim to have inline water quality sensors is to ensure that drinking or processed water is safe. However, most inline sensors are quite slow in response and require large calibration time. Therefore, high sensitivity, rapid response, specificity and a relatively low production cost are the fundamental and most significant properties of inline sensors. These fabricated sensors have the ability to monitor the amount of harmful compounds (such as pesticides, heavy metals, etc.) in both food and water. We work to enhance material science and fabrication technology for creating cutting-edge sensors. We first synthesize the sensing material and then calibrate the sensors at different operating conditions to accomplish these goals. Following the same, we characterize the sensor's performance, using an advanced potentiostat/galvanostat for determining the sweep current, voltage and limit of detection. Together with this, we employ machine learning, IoT, and big data to create intelligent sensing platforms.

Food preservation is one of the most challenging tasks, especially concerning crops. It is expected that major companies are expected to cut half per capita global food waste at the retail and consumer levels by 2030. Food losses occur due to production delays and sluggish supply chains, including post-harvest losses. Our lab is currently using biocompatible polymers and edible adhesives to synthesize electrospun nanofibers that can be used for food packaging.

The intensification of human activity raised the need for energy recently. An appealing approach to supply alternative energy sources is the treatment of contaminants found in wastewater combined with energy recovery. Hydrogen serves as a clean energy carrier for the shift to a decarbonized civilization. Hydrogen can be produced through photocatalytic/electrocataytic water splitting. It is fueled due to light energy received by the photocatalyst and results in the production of oxygen and hydrogen. This hydrogen can be produced from hydrogenated contaminants in water using photocatalysis, and the whole reaction is more favorable thermodynamically than water splitting for hydrogen. We are focusing on recent developments in research surrounding photocatalytic and photoelectrochemical hydrogen production from pollutants that may be found in wastewater.