Assessing the efficacy of poly-ferric sulfate and polyaluminum hydroxychloride in remediating partially stabilized landfill effluent

Abstract

In this study, we implemented agglomeration-flocculation as a straightforward method combining physicochemical processes. The usage of polymeric metal precipitants, which are increasingly employed in the treatment of water, lacks comprehensive documentation in the context of wastewater management. To address this gap, our research focused on the evaluation of poly-ferric sulfate (PFS) and polyaluminum hydroxychloride (PAHC) for the treatment of partially fixed wastewater. We conducted a series of coagulation-flocculation experiments to improve the precipitating dosage, pH levels, and operational parameters such as mixing speed and duration. The optimal dose of PFS was determined to be 2.1 g/L with a pH value of 7.3, while for PAHC, it was 12.6 g/L with a pH value of 6.9. The simultaneous optimization of mixing speed and duration led to a significant improvement in chemical oxygen demand (COD) removal, with PAHC achieving 86.13 % removal and PFS achieving 60.53 % removal. The application of PFS resulted in almost complete removal of physical parameters in the wastewater, including turbidity (98.22 %), color (96.75 %), and TSS (99.05 %). In comparison, PAHC exhibited lower removal efficiencies with turbidity at 93.44 %, color at 91.69 %, and TSS at 94.84 %. However, the results indicated that PFS was less effective than PAHC in terms of COD elimination, as the required dose of PAHC (12.6 g/L) was approximately six times that of PFS (2.1 g/L).