What is the method that sewage uses to disinfect wastewater (as what comes from hospital material or reuse laundry water)?

There is no specific method to remove SARS-CoV-2. As SARS-CoV-2 are less robust in the sewage and water environment than other viruses, the same disinfiction method taken before should be still followed. To our knowledge, water at ambient temperatures will not rapidly inactivate the virus. The hotter the water, the faster the virus will be inactivated. If the water contains detergent or disinfectant, that greatly enhances virus inactivation. The soap will also dissociate the virus from other organic material, making it more exposed to the effect of detergents. In the study of Geller et al. (2012) we can also observe that alkaline pH’s could make coronaviruses less stable.