Rapid growth of water conservancy/hydropower projects has spurred rising demand for sand-gravel aggregates. Under strict water use and zero-waste policies, treating wet-process aggregate washing wastewater is challenging. Flocculants—key chemicals in this process—directly influence treatment efficiency and operational costs via their type, dosage, and efficacy. Further development of the intelligent control system for flocculant dosing can reduce flocculant consumption by 50% to 67%. However, existing studies have an insufficient understanding of the identification of emerging contaminants in aggregate washing wastewater and the migration of flocculants in multi-medium environments, as well as a lack of research on the synergistic effects of multiple flocculants. Another key core challenge lies in the accurate identification of the impact of flocculant residues on concrete performance, along with the problems of high cost and poor adaptability of intelligent systems. Future research directions will focus on precise flocculation, residue control and resource utilization to drive the development of efficient and environmentally friendly treatment technologies.