Treatment of copper phthalocyanine production wastewater by two-stage A/O + iron salt coupled sedimentation combined process

Abstract

Copper phthalocyanine production wastewater after copper removal pretreatment contains large amounts of nitrogen-containing organic compounds such as phthalocyanine，which are difficult to biodegrade. The traditional combined process of “biological treatment and advanced treatment” was used to treat this wastewater，but the effect was unstable and the total nitrogen（TN） in the effluent was difficult to reach the standard. The combined process of “two-stage A/O and iron salt coupled sedimentation” was used to treat the wastewater. The treatment effect was investigated，and the removal mechanism of pollutants in the wastewater by fluorescence spectrum，ultraviolet spectrum and humus substances（HS） content determination were exeplored. The results showed the combined process of “two-stage A/O and coupled sedimentation” treated copper phthalocyanine production wastewater，the removal rates of chemical oxygen demand（COD），ammonia nitrogen and TN were 96.5%，99.8% and 93.2%，respectively. Two-stage A/O treatment could effectively remove most of the pollutants，and increased the content of HS in the two-stage A/O effluent. Then，the two-stage A/O effluent was treated by iron salt coupled sedimentation，which had good removal effect on HS and organic nitrogen. The final effluent COD，ammonia nitrogen and TN concentrations were 29，0.5 and 23.8 mg/L，respectively，meeting the effluent discharge standard.

Keywords

• copper phthalocyanine production wastewater
• two-stage a/o
• iron salt coupled sedimentation
• humic substances