| respiration | Respiration: The Unsung Hero of Environ… | Wastewater Treatm… |
| respirator | Breathing Easy: Respirators in Environm… | Environmental Hea… |
| respirometer | Respirometers: Unlocking the Secrets of… | Wastewater Treatm… |
| restoration | Restoring the Balance: Environmental & … | Environmental Hea… |
| Retec | Retec: A Revolutionary Approach to Heav… | Wastewater Treatm… |
| retentate | Understanding Retentate: The Unwanted G… | Water Purification |
| retention pond | Retention Ponds: A Vital Tool in Enviro… | Sustainable Water… |
| retention time | Understanding Retention Time in Environ… | Water Purification |
| Re-Therm | Re-Therm: A Revolutionary Approach to V… | Air Quality Manag… |
| Retox | Retox: Redefining Air Pollution Control… | Air Quality Manag… |
| retrofit | Retrofitting for a Cleaner Future: Enha… | Environmental Hea… |
| Retroliner | Retroliner: A Revolutionary Approach to… | Water Purification |
| return activated sludge (RAS) | Return Activated Sludge (RAS): The Engi… | Wastewater Treatm… |
| return sludge | Return Sludge: The Backbone of Wastewat… | Wastewater Treatm… |
| reuse | Reusing Our Waste: A Crucial Step in E… | Environmental Hea… |
| reverse deionization | Reverse Deionization: A Powerful Tool f… | Water Purification |
| reverse osmosis (RO) | Reverse Osmosis: A Powerful Tool for Wa… | Sustainable Water… |
| reversible effect | Reversible Effects in Environmental & W… | Sustainable Water… |
| Revolver | Revolver: A New Spin on VOC Abatement a… | Air Quality Manag… |
| Rex | REX: A Familiar Name in Water & Wastewa… | Wastewater Treatm… |
