Water pollution, industrial exhaust gases, and hazardous solid waste pose significant challenges for Vietnam and other developing countries, while conventional treatment technologies often address only a single group of pollutants, with low efficiency and high operating costs. This study introduces the Vacuum–suction technology as an integrated solution capable of simultaneously treating wastewater, exhaust gases, and solid waste within a single closed system. The operating principle combines vacuum suction and compression pressure to maximize gas–liquid mixing and contact within the enclosed Octola reactor, thereby enhancing neutralization, precipitation, and absorption efficiency. Results show that, for industrial wastewater, the system achieved removal efficiencies of 87.1% for COD, 88.6% for TSS, 90.0% for NH3–N, >85% for heavy metals, and 99.4% for total coliforms, meeting both Vietnamese QCVN and WHO standards for water reuse. For exhaust gases, the system removed 91.8% SO2, 85.7% NOx, >95% HCl and HF, >90% VOCs and CO, and 92% total particulates, while reducing chemical consumption by 30–50% compared with conventional wet scrubbers. In solid waste treatment, leachable heavy metals from sludge and bottom ash decreased by more than 98%, with a 90% reduction in landfill volume and recovery of valuable metals. Compared with current technologies, this system reduces installation footprint by up to 40%, shortens hydraulic retention time to 2–4 hours, and enables resource recovery after treatment. With its high treatment efficiency, multi-functional integration, and broad application potential, Vacuum–suction technology offers a viable solution for waste management and environmental protection towards a circular economy.
Luong et al. (Sun,) studied this question.