High performance polymeric aluminum silicate sulfate (PASS) flocculant from abandoned molecular sieve

PASS is an innovative inorganic polymer flocculant (IPF), which possesses the advantages of a polysilicate/aluminum sulfate-based flocculant. Recently, solid wastes rich in Si and Al, such as kaolinite, rice husks, and abandoned molecular sieves (AMS) have been recognized as promising raw materials for the synthesis of flocculants. The present study involved the synthesis of PASS flocculant derived from AMS. The efficacy of the as-prepared PASS was evaluated through the flocculation of wastewater containing ultramarine blue (UB) pigment. The optimal flocculation performance of PASS was observed at a Si/Al molar ratio of 1.62 and a polymerization time of 9 h. Furthermore, we investigated the impact of PASS dosage, stirring/settling time, and pH on the flocculation process while also exploring potential mechanisms. The PASS flocculant prepared in this study exhibited superior performance compared to the commercially available polyaluminum sulfate (PAS). The results demonstrated the viability of preparing PASS flocculants from waste resources.