This study introduces a compact, scalable strategy for removal of suspended particles (micron and sub-micron size range) from impaired groundwater sources and secondary treated municipal wastewater. The proposed treatment approach integrates multi-point in-line coagulant dosing, hydrodynamic mixing, and hydrocyclone-based separation. The in-line dosing and mixing strategy with adjustable convective residence time for optimal coagulation to form flocs of size that can be effectively removed in a subsequent hydrocyclonic separation. Unlike conventional coagulation-flocculation systems that require large retention basins, high chemical doses, and mechanical mixing, the above approach exploits in-line tubular coagulation coils to drive rapid floc formation under turbulent flow. The approach enables reduction of the overall system footprint and provides for control over mixing time and dosing conditions. The study presents a systematic evaluation of the effects of coagulant dose, convective residence time, and flow conditions on the efficacy of removal of suspended solids in a continuous treatment system, as well as quantifying the turbidity of the hydrocyclone overflow stream. Based on the study with different water sources, a model was developed to describe the impact of key process dynamics, integrating parameters such as inlet concentration of suspended solid, flow conditions, and coagulation kinetics. Study results demonstrated significant particle removal at low coagulant doses with sequential co-dosing of FeCl₃ and PAM. By leveraging a first-principles approach to system design and performance evaluation, this work establishes a foundation for advanced modelling and control strategies to enhance pretreatment efficiency for removal of suspended solids to a level that meets the criteria for subsequent membrane-based treatment to generate safe potable water from via upgrading of impaired water supplies.
