This study introduces a novel approach to water purification using magnetically controlled microrobots with polymeric "hands" for capturing bacteria and microplastics. The microrobots, composed of superparamagnetic beads functionalized with a cationic polymer, self-assemble into rotating planes under external magnetic fields. These planes exhibit swarming behavior, allowing them to efficiently capture free-swimming bacteria (e.g., *Pseudomonas aeruginosa*) and microplastics in aquatic environments. The capture efficiency is enhanced by the electrostatic interactions between the cationic polymer and negatively charged bacterial cell walls. The captured contaminants can be released from the microrobots using ultrasound, and the residual water is treated with UV irradiation to eliminate any remaining bacteria. The study demonstrates the reusability of the microrobots, making them a sustainable solution for repeated use in decontamination processes. This multifunctional approach highlights the potential of microrobots in addressing complex environmental challenges, particularly in water purification and pollution remediation.This study introduces a novel approach to water purification using magnetically controlled microrobots with polymeric "hands" for capturing bacteria and microplastics. The microrobots, composed of superparamagnetic beads functionalized with a cationic polymer, self-assemble into rotating planes under external magnetic fields. These planes exhibit swarming behavior, allowing them to efficiently capture free-swimming bacteria (e.g., *Pseudomonas aeruginosa*) and microplastics in aquatic environments. The capture efficiency is enhanced by the electrostatic interactions between the cationic polymer and negatively charged bacterial cell walls. The captured contaminants can be released from the microrobots using ultrasound, and the residual water is treated with UV irradiation to eliminate any remaining bacteria. The study demonstrates the reusability of the microrobots, making them a sustainable solution for repeated use in decontamination processes. This multifunctional approach highlights the potential of microrobots in addressing complex environmental challenges, particularly in water purification and pollution remediation.