Abstract: A wastewater treatment system including carbon dioxide gas injection means for injecting a carbon dioxide gas into wastewater which takes place during silicon processing to obtain raw wastewater to be treated; a wastewater tank; a filter membrane through which the raw wastewater is filtered; a liquid forwarding pump which forwards the raw wastewater to the filter membrane; and circulation/forwarding control means which can forward concentrated water and/or filtered water to the wastewater tank and which can regulate the pH of the raw wastewater to 4.0 to 6.5 to forward this wastewater to the filter membrane, when the amount of the raw wastewater present in the wastewater tank is below a reference amount.

Abstract: A wastewater treatment system 20 including carbon dioxide gas injection means 3 for injecting a carbon dioxide gas into wastewater which takes place during silicon processing to obtain raw wastewater to be treated; a wastewater tank 2; a filter membrane 11 through which the raw wastewater is filtered; a liquid forwarding pump 9 which forwards the raw wastewater to the filter membrane 11; and circulation/forwarding control means 30 which can forward concentrated water and/or filtered water to the wastewater tank 2 and which can regulate the pH of the raw wastewater to 4.0 to 6.5 to forward this wastewater to the filter membrane 11, when the amount of the raw wastewater present in the wastewater tank 2 is below a reference amount.