Hello Rani,higs :(
Thanks for enquiring about thesis subjects in my group. Unfortunately, both projects that are most related to environmental engineering will end soon, which makes it impossible to offer you a subject in these projects. We can offer you a subject in one of the projects on production of biological control agents for control of malaria mosquitoes; we design different bioreactors for growing fungal spores in solid-state fermentation and these spores will be used to kill mosquitoes. Please let me know whether you're interested.