What is the ruling on placing a trash can in front of worshippers in the mosque, and does the ruling differ between placing it in front of them or behind them, and what is the ruling on placing it next to the Imam in the mihrab with dirty tissues in it?

Allah has commanded the glorification of mosques, their elevation, and their purification from all that is unfitting for them, whether in word or deed, such as idle talk and filth. This includes spitting and anything that the soul finds repugnant. Mosques must be kept free from anything that would harm worshippers. If there is a need to place a waste bin, it must be covered and away from the qibla (definition) of the worshippers, and its contents must be emptied regularly to avoid foul odors. Sheikh Ibn Uthaymeen prohibited placing waste bins in the qibla of the worshippers, but he permitted placing tissue boxes out of necessity, provided they are removed after use.