This study presents a novel approach for water decontamination using magnetically controlled polymeric microrobot swarms with "hands" that can capture bacteria and microplastics. The microrobots, composed of superparamagnetic beads functionalized with a cationic polymer, self-assemble into rotating planes under external magnetic fields, enabling coordinated propulsion and collective motion. These swarms can actively capture free-swimming bacteria and dispersed microplastics in water, offering a sustainable solution for environmental remediation. The captured contaminants can be released and disinfected using ultrasound and UV light, allowing for repeated use of the microrobots. The cationic polymer enhances the interaction with bacteria through electrostatic forces, improving capture efficiency. The study also demonstrates the reusability of the microrobots through a recycling process involving sonication and magnetic collection. The integration of materials science, magnetism, and microscale engineering highlights the potential of microrobots in addressing complex pollution issues in aquatic environments. The results show that the microrobots can effectively remove both bacteria and microplastics, providing a promising approach for environmental protection and water quality management.This study presents a novel approach for water decontamination using magnetically controlled polymeric microrobot swarms with "hands" that can capture bacteria and microplastics. The microrobots, composed of superparamagnetic beads functionalized with a cationic polymer, self-assemble into rotating planes under external magnetic fields, enabling coordinated propulsion and collective motion. These swarms can actively capture free-swimming bacteria and dispersed microplastics in water, offering a sustainable solution for environmental remediation. The captured contaminants can be released and disinfected using ultrasound and UV light, allowing for repeated use of the microrobots. The cationic polymer enhances the interaction with bacteria through electrostatic forces, improving capture efficiency. The study also demonstrates the reusability of the microrobots through a recycling process involving sonication and magnetic collection. The integration of materials science, magnetism, and microscale engineering highlights the potential of microrobots in addressing complex pollution issues in aquatic environments. The results show that the microrobots can effectively remove both bacteria and microplastics, providing a promising approach for environmental protection and water quality management.