A method for disinfecting and deodorizing a toilet system by employing an air cleaning apparatus for disinfecting and deodorizing a toilet system, the apparatus comprising: a housing having an air inlet and an air outlet, the housing encloses a droplet removal chamber for removing droplets, a deodorization and disinfection chamber for removing gaseous contaminants delivered from droplet removal chamber and an air delivery unit for airflow generation, wherein along the airflow direction, the droplet removal chamber is in front of the deodorization and disinfection chamber which is in front of the air delivery unit; wherein the droplet removal chamber encloses a reactive oxidizing species generator for release of reactive oxidizing species and a droplet filter for removal of droplets, wherein along the airflow direction the reactive oxidizing species generator is in front of the droplet filter; wherein the droplet removal chamber has a water exhaust outlet; wherein the deodorization and disinfection chamber encloses a reactive oxidizing species generator for release of reactive oxidizing species, a dust filter for trapping dust, bacteria and virus, and an adsorbent filter for adsorption of gaseous contaminants, wherein along the airflow direction, the reactive oxidizing species generator is in front of the dust filter which is in front of the adsorbent filter; said method comprising the steps: a) The air delivering unit is switched on to generate airflow; b) Droplets and air from urinal or toilet bowl are extracted into the air cleaning apparatus through the air inlet; c) In the droplet removal chamber, reactive oxidizing species released by the reactive oxidizing species generator are actively transferred by the airflow towards the droplet filter for deodorization and disinfection of the contaminated droplets trapped on the droplet filter, and droplets from the airflow are removed by the droplet filter; and d) In the deodorization and disinfection chamber, reactive oxidizing species released by the reactive oxidizing species generator are actively transferred by the airflow towards the adsorbent filter for decomposition of air contaminants and disinfection; wherein the treated airflow is either discharged through the air outlet or redirected to the toilet system for further circulation. a housing having an air inlet and an air outlet, the housing encloses a droplet removal chamber for removing droplets, a deodorization and disinfection chamber for removing gaseous contaminants delivered from droplet removal chamber and an air delivery unit for airflow generation, wherein along the airflow direction, the droplet removal chamber is in front of the deodorization and disinfection chamber which is in front of the air delivery unit; wherein the droplet removal chamber encloses a reactive oxidizing species generator for release of reactive oxidizing species and a droplet filter for removal of droplets, wherein along the airflow direction the reactive oxidizing species generator is in front of the droplet filter; wherein the droplet removal chamber has a water exhaust outlet; wherein the deodorization and disinfection chamber encloses a reactive oxidizing species generator for release of reactive oxidizing species, a dust filter for trapping dust, bacteria and virus, and an adsorbent filter for adsorption of gaseous contaminants, wherein along the airflow direction, the reactive oxidizing species generator is in front of the dust filter which is in front of the adsorbent filter; said method comprising the steps: a) The air delivering unit is switched on to generate airflow; b) Droplets and air from urinal or toilet bowl are extracted into the air cleaning apparatus through the air inlet; c) In the droplet removal chamber, reactive oxidizing species released by the reactive oxidizing species generator are actively transferred by the airflow towards the droplet filter for deodorization and disinfection of the contaminated droplets trapped on the droplet filter, and droplets from the airflow are removed by the droplet filter; and d) In the deodorization and disinfection chamber, reactive oxidizing species released by the reactive oxidizing species generator are actively transferred by the airflow towards the adsorbent filter for decomposition of air contaminants and disinfection; a) The air delivering unit is switched on to generate airflow; b) Droplets and air from urinal or toilet bowl are extracted into the air cleaning apparatus through the air inlet; c) In the droplet removal chamber, reactive oxidizing species released by the reactive oxidizing species generator are actively transferred by the airflow towards the droplet filter for deodorization and disinfection of the contaminated droplets trapped on the droplet filter, and droplets from the airflow are removed by the droplet filter; and d) In the deodorization and disinfection chamber, reactive oxidizing species released by the reactive oxidizing species generator are actively transferred by the airflow towards the adsorbent filter for decomposition of air contaminants and disinfection; wherein the treated airflow is either discharged through the air outlet or redirected to the toilet system for further circulation.