Abstract

Sludge water with high total phosphorus (TP) and suspended solids (SS) easily causes the effluent quality to be substandard in wastewater treatment plants. Although the conventional coagulation process can achieve TP removal, higher sludge production occurred due to loose flocs generation. The prolonged stirring pelleting coagulation (PSPC) process, based on one-by-one agglomeration and mechanical syneresis theories, was proposed to achieve compact flocs and reduced sludge production. Compared with the conventional coagulation process, the removal efficiency of TP was improved by >20 %, settling volume was reduced by about 30 %, and the dosages of polyaluminum chloride (PAC) and polyacrylamide (PAM) were saved by 50 % and 30 %, respectively in the PSPC process. The PSPC process produced pellet-like flocs with the d50 of 6.27 mm, settling velocity of 21.07 mm/s, effective density of 0.1411 g/cm3, and three-dimensional fractal dimension (D3) of 2.094 under the optimal conditions of 50 mg/L PAC and 10 mg/L PAM. With the d50 decreased from 38.38 μm to 21.81 μm, fragmentation of primary particles was realized by high-intensity stirring. Therefore, the mechanism of the PSPC process involves reducing voids in primary particles, achieving regular combination of microflocs under appropriate PAC, PAM, and hydraulic control. The PSPC process shows promising prospects for treating high SS wastewater and may have practical implications for enhancing coagulation.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.