Strategic Optimization of PFC Coagulation for Saline Water Pre-treatment: Enhancing RO Filtration Efficiency in the Mekong Delta

Abstract

This study critically evaluates the application of Poly Ferric Chloride (PFC) as a pre-treatment coagulant in desalination, particularly for enhancing Reverse Osmosis (RO) filtration in the saline-affected Mekong Delta region. The research focuses on the optimization of PFC dosages and pH levels to maximize coagulation efficiency in varying salinity conditions. Through an extensive series of experiments, an optimal coagulation efficiency of 93.7% for Total Suspended Solids (TSS) removal was achieved with a PFC dosage of 0.7 ml at a pH of 11 in a 5 ppt saline solution. However, increasing salinity levels were found to complicate this relationship, revealing a nuanced interplay between PFC dosage, pH, and salinity. A particularly critical observation was the decreasing effectiveness of PFC as salinity levels rose, indicating a need for escalating PFC dosages in higher saline waters to sustain coagulation effectiveness. The study significantly contributes to the understanding of PFC pre-treatment in water desalination processes, highlighting the compound's role in improving the input quality for RO systems and extending membrane longevity. These findings are pivotal for designing adaptive water treatment strategies, ensuring the sustainability and effectiveness of water purification in salinity-vulnerable contexts.