There is a method of capturing, removing or collecting the particulate matter from a fluid containing a toxic liquid reaction and particulate matter produced from the reaction. The method includes partly or completely disposing a screen into the toxic fluid. Mixing the toxic fluid allowing the particulate matter to contact the screen. Moving the screen to capture the particulate matter on the screen. Removing the particulate matter from the screen by washing or scraping. There is also a cleaning apparatus to capture, remove or collect particulate matter from a toxic fluid. A cleaning apparatus contains at least a screen and a structure securing the screen. The cleaning apparatus can optionally include a scraping or washing means, a drive means, a flow inducer and a housing structure.