Design and operation of centralized wastewater treatment facilities in printing and dyeing industry agglomeration improvement zone

Abstract

The construction scale of a wastewater centralized treatment facility in a printing and dyeing cluster improvement park in Zhejiang Province was 30 000 m3/d. According to the characteristics of wastewater in the park, the main process of “regulation tank+cooling system+reaction initial sedimentation tank+anaerobic hydrolysis tank+A/O biochemical tank+secondary sedimentation tank+high-efficiency sedimentation tank” was adopted. The results showed that the process was stable and efficient. When the average COD, BOD5, and total antimony in the influent were 1 370, 360 and 1.17 mg/L, the COD, BOD5, and total antimony in effluent were respectively reduced to 88, 7.4, and 0.049 mg/L, with the corresponding removal rates of 94%, 98% and 96%. The effluent met the indirect discharge requirements in Table 2 of “Discharge Standards of Water Pollutants for Dyeing and Finishing of Textile Industry”(GB 4287-2012). The project adopted a coagulation agent enhanced initial sedimentation process to achieve effective carbon capture of wastewater and indirectly export energy, which was conducive to the reduction of carbon emissions. The main treatment unit adopted intensive combination and deep pool design to save land, which could be used as a reference for land limited wastewater plants.

Keywords

• printing and dyeing agglomeration improvement zone
• printing and dyeing wastewater
• centralized treatment
• total antimony
• carbon capture