Hassan, there are appropriate missions and sensors to study AOD like Aqua, Aura, CALIPSO, MISR, MODIS, NPP, Terra, VIIRS to name a few. I agree with Rangarajan, Landsat was not designed for AOD studies. I would strongly recommend you to follow some basic training on application of remote sensing in air quality studies. I have attached some links which you will find helpful. 

https://arset.gsfc.nasa.gov/airquality/webinars/introduction-satellite-remote-sensing-air-quality-applications

https://arset.gsfc.nasa.gov/airquality/webinars/advanced-AOD-PM

https://arset.gsfc.nasa.gov/airquality/webinars/observations-tools-southeast-asia

https://arset.gsfc.nasa.gov/airquality/webinars/Indian-subcontinent14

I don't think AOD can be retrieved from LANDSAT data. MODIS provides AOD data and using a MCTK toolkit in ENVI, you can also generate layers of other aerosol optical properties like single scattering albedo, etc. You may then calculate aerosol radiative forcing which may require calculation of NDVI and NDWI for which you can use LANDSAT data. 

Hassan, there are appropriate missions and sensors to study AOD like Aqua, Aura, CALIPSO, MISR, MODIS, NPP, Terra, VIIRS to name a few. I agree with Rangarajan, Landsat was not designed for AOD studies. I would strongly recommend you to follow some basic training on application of remote sensing in air quality studies. I have attached some links which you will find helpful. 

https://arset.gsfc.nasa.gov/airquality/webinars/introduction-satellite-remote-sensing-air-quality-applications

https://arset.gsfc.nasa.gov/airquality/webinars/advanced-AOD-PM

https://arset.gsfc.nasa.gov/airquality/webinars/observations-tools-southeast-asia

https://arset.gsfc.nasa.gov/airquality/webinars/Indian-subcontinent14

I would recommend the answer of James sir, there are many satellites and sensors which provides aerosol data .

Thanks all for your valuable suggestions, which are substantial for my studies.   

 Dear Hassan, 

If you are interested in retrieving AOD at higher spatial resolution from Landsat, then you can try Simplified Aerosol Retrieval Algorithm (SARA). I have tested the SARA algorithm on Landsat, HJ-satellite (Chinese), VIIRS and MODIS. 

https://www.researchgate.net/publication/236972717_A_Simplified_high_resolution_MODIS_Aerosol_Retrieval_Algorithm_SARA_for_use_over_mixed_surfaces

Good luck!

Article A Simplified high resolution MODIS Aerosol Retrieval Algorit...

 Dear Muhammad Bilal, thanks for sharing this paper. But your paper looks very complex to me. Can you provide any a step wise formula or activities that can help derive AOD from Landsat?

Dear Hassan I recommend to you using another satellite than using Landsat. It does not have enough information relate to finding AOD