Tertiary Treatment Process of Preserved Wastewater

Abstract

The effects of the composite coagulants on coagulation sedimentation for the preserved wastewater was investigated by changing the composite coagulant dosages, and the coagulant was composed of polymeric ferric sulfate (PFS), polyaluminium chloride (PAC), and polyaluminum ferric silicate (PAFSC), while the effect of the tertiary treatment process on the preserved wastewater was tested, which was exceeded the standard seriously. The results showed that 400 mg/L was the optimum composite coagulant dosage. The removal rates of salt and sugar were as high as 99.1% and 99.5% respectively, and the removal rates of CODCr and SS were 99.3% and 96.0%, respectively after the preserved wastewater was treated by the tertiary treatment technology, which both reached the primary standard of “The Integrated Wastewater Discharge Standard” (GB8978-1996).

Keywords

• tertiary treatment process
• preserved wastewater
• composite coagulant
• salt removal rate
• sugar removal rate
• CODCr removal rate
• SS removal rate