Dr. Debajyoti Bhattacharjee was awarded with Ph.D. degree in Chemical Sciences by Tezpur University, Assam for his work on application of Computational Chemistry in various environmental related issues. He was a CSIR-JRF and his scientific works are already published in more than fifteen peer reviewed international research journals and book chapters. His area of research is mainly focused on the study of removal of toxic gases from our environment as well as the study on atmospheric chemistry of various volatile organic compounds. His experience in the topics of atmospheric chemistry has resulted in writing a chapter in this book.