Team:IIT Delhi

Our Aim:

We aim to genetically engineer bacteria and design a prototype of a device that converts harmful components of exhaust gases (i.e NOx and SOx) coming out of chimneys of various industries and car exhausts into harmless byproducts. NOx and SOx are well known pollutants responsible for various respiratory disorders in humans such as asthma, bronchitis etc. They help in formation of Ozone in the lower troposphere where it acts as an irritant of the skin, eyes and lungs. On the other hand, oxides of Sulfur are the main culprits behind acid rain which corrodes buildings, destroys crops and acidifies water bodies, killing aquatic life.

We aim to genetically engineer E.coli and equip it with the genes to synthesize nitrite reductase enzyme NrfA and CysI (sulfite reductase) and Sqr (Sulfide Quinone reductase) enzymes. NrfA reduces NOx to ammonia (NH3) while Cys1 and Sqr reduce sulphur dioxide (SO2) to hydrogen sulfide (H2S) and H2S to sulfur(S) respectively. These would be immobilized on polymer beads that have a positive zeta potential and placed in a bioreactor. The bacteria will reduce the oxides present in the incoming gas stream and consequently the percentage of oxides of nitrogen and sulfur in the outgoing gas stream will be significantly lower.

Our proposed design promises easy and effective scalability. Depending on the site of installation (i.e.industrial chimney or in the exhaust of a vehicle), the volume of our inputs can be altered to obtain the desired output. Moreover, the fact that all the sub-components of our model work independently of each other means that they can be easily detached and replaced, making the system very handy. Around 56% of the population in India is still involved in agricultural activities. If the production of NOx and SOx continues unabated like today, the damaging effects of acid rain on the crops will jeopardize the livelihoods of a large section of India’s population in the future. This will have serious economic and social repercussions. And if the concentration of NOx and SOx in the atmosphere keeps building up, it will adversely affect the health of the people, particularly those who cannot pay for their treatment. Also, since our model makes use of bacteria instead of metallic catalysts to reduce the gases, the potential toxicity that can arise from metal by-products of catalyst degradation can be successfully eliminated. Hence, looking at all the positive aspects of our proposed model, we believe that it will help to create a greener and a healthier future.