Research Projects

In recent work, eco-friendly bio-inspired methods have been developed for preparing novel variations of metal-doped photocatalysts and other nano materials for the degradation of pharmaceutically active compounds (PhACs)/organic pollutants and killing of undesired microorganisms such as E. coli and E. subtilis (Environ Prog Sustain Energy 2017 (36) 192, Colloid Surf A Physicochem Eng Asp 2016 (506) 557). These methods make use of earth-abundant materials and plant based analytes, and are straightforward to prepare, both the mechanisms of photocatalytic degradation, and Ag, Pt, Au, Cu and Ni ions activities will be combined in this project to enable broader-spectrum photocatalytic activity (Objective 1). Recovery of photocatalysts is always a challenge for field applications. For their practical use, it was proposed to integrate this technology with the membrane based-separation for the recovery and recycle of used catalysts (Objective 2). The IIT Guwahati team has already achieved success in this direction (Water, Air & Soil Poll 2018 (229) 2, Inter J Coal Sci Tech 2016 (3) 226). Investigators will begin the study with locally abundant plants and plant organs for the room-temperature application of bio-based analytes for the functionalization of a diverse range of semiconductor supports (TiO?, ZnO, etc.) and dopants (Ag, Pt, Au, Cu and Ni ions activities). It is anticipated that the use of this unprecedented photocatalytic materials could revolutionize the harvesting of solar light for the decontamination of toxic pollutants such as PhACs. Investigators will evaluate the enhancement in the spectrum of PhACS decomposition and microbial killing. Photocatalytic materials (~0.1 g/L catalyst load) will be tested under solar and visible light irradiation (12-24 K lux) both in batch and circulating modes of operations with a proposed operating capacity of 1 to 10 L. Microbes have immense potential for the degradation of wide range of toxic organic micro-pollutants including PhACs and organic solvents (I&ECR 2014(53)11571). The PI of the collaborating institute, NIT Rourkela, has characterized arsenite-oxidizing bacteria isolated from arsenic-contaminated groundwater (Arch Microbiol 2017(199)191). She has also isolated antibiotic resistant and degrading bacteria from medical wastes, Rourkela. The proposed process consists of two components run in series: a broad-spectrum photocatalytic system that integrates the technologies of the IIT Guwahati team and a biological process from the NIT Rourkela team. The photocatalytic materials will be tested separately and in tandem with the biological process. Investigators will also balance these two processes so that the quantum yield of PhACs degradation is maximized with an efficient BOD reduction in the biological process running in series which will be designed, fabricated, installed and demonstrated at IIT Guwahati (Objectives 1-3, Figure A enclosed).