METHOD FOR EFFICIENTLY CONTROLLING TOTAL NITROGEN CONTENT IN WASTEWATER PRODUCED IN PRODUCTION PROCESS OF COPPER PHTHALOCYANINE

摘要

PURPOSE: A wastewater treatment method is provided which is capable of controlling total nitrogen content in wastewater containing nitrogen content produced in production process of copper phthalocyanine more efficiently compared with a wastewater treatment method according to the prior art. CONSTITUTION: The method comprises a step (a) of agitating and filtering the mixture after putting dried copper phthalocyanine; a step (b) of washing wet cake filtered in the step (a) using water, agitating and filtering the mixture after putting an acid solution into the water washed wet cake, and evaporating and concentrating first filtered liquid produced in the step (a); and a step (c) of preparing copper phthalocyanine by drying wet cake filtered in the step (b), neutralizing the second filtered liquid by acid treating and alkali treating second filtered liquid produced in the step (b), removing sludge from the neutralized second filtered liquid by organic coagulant treatment and pressing flotation, removing monovalent copper ions from the sludge removed filtered liquid by inorganic coagulant treatment and sedimentation, removing nitrogen from the monovalent copper ion removed filtered liquid by chlorine gas treatment, and discharging a neutralized filtered liquid after neutralizing the nitrogen removed filtered liquid.