EVALUATION OF A CATIONIC POLYSACCHARIDE COAGULANT FOR OPTIMIZING THE TREATMENT OF OILY EFFLUENTS FROM THE MANAUS REFINERY (REAM) – QQS COA S

Abstract

This technical-scientific report details the results of a treatability study conducted with effluents from the Manaus Refinery (REAM), focusing on the evaluation of a high-performance organic coagulant, QQS COA S, a starch-based polysaccharide modified with cationic groups. The main objective was to compare its efficiency with the conventional treatment of the refinery, which employs a tannin-based coagulant with a daily consumption of approximately 200 kg, aided by about 2 kg of a flocculant polymer. The assays, carried out in Jar Test equipment, simulated the coagulation and flocculation conditions, revealing that the QQS COA S, in dosages in the range of 10 to 30 ppm, promotes a clarification and phase separation (water/oil/solids) visually superior to that obtained with approximately 33,333 ppm of the tannin coagulant. This dose reduction, greater than 99% (or 1,000 times), is justified by the macromolecular structure of cationic starch and its mechanisms of action, which include charge neutralization and formation of interparticle bridges, efficient in breaking the oil-in-water emulsion. The study concludes that the replacement of tannin by cationic starch represents a strategic opportunity for REAM, with the potential for a drastic reduction of operating costs, logistics optimization, and a significant advance in environmental sustainability, aligning the practice with the fundamental theory of colloid and polymer chemistry and encouraging the local production of high value-added inputs.