Flue-gas treatment that neutralizes acid gases (hydrogen chloride, hydrogen fluoride, sulfur oxides) formed during combustion of chlorinated, fluorinated, or sulfur-bearing waste. Implemented as wet scrubbers (alkaline solution spray), dry scrubbers (lime injection), or semi-dry scrubbers.
When chlorinated organics (PCBs, chlorinated solvents, AFFF) or fluorinated organics (PFAS) combust, the chlorine and fluorine appear in the flue gas as hydrogen chloride and hydrogen fluoride. Sulfur-bearing wastes produce SO2 and SO3. Each is a regulated acid gas and must be removed before the gas is released through the stack.
Wet scrubbers spray an alkaline solution (sodium hydroxide, lime slurry) through the gas stream, dissolving and neutralising the acids; dry scrubbers inject powdered lime or sodium bicarbonate that reacts with the acids and is then captured by the downstream baghouse. Hybrid semi-dry designs balance water consumption against removal efficiency. Acid-gas scrubbing is non-negotiable on any thermal remediation system that handles PCB, PFAS, or chlorinated solvent feeds.
Also known as: acid gas scrubbing, wet scrubber, dry scrubber, HCl scrubbing.
Dioxins and Furans (PCDD/PCDF): treatment approach
A family of 210 chlorinated tricyclic aromatic congeners — including 2,3,7,8-TCDD — formed as unintended byproducts of combustion, chlorine chemistry, and legacy herbicide manufacture; persistent, bioaccumulative, and destroyed only by high-temperature thermal treatment.
The regulatory metric for thermal destruction performance, expressed as the percentage of a target contaminant destroyed across the system. Common permit thresholds range from 99.99 percent for general hazardous organics to 99.9999 percent (six nines) for PCBs, dioxins, and PFAS.
The duration that gas, vapor, or solids remain inside the heated zone of a thermal treatment unit; together with temperature and turbulence, one of the three governing parameters of complete contaminant destruction.
Liquid that has percolated through contaminated soil, waste, or stockpiles, dissolving and carrying contaminants downward to groundwater or to a collection system. The principal migration pathway for PFAS, dissolved metals, salts, and hydrocarbons from impacted sites.
Laboratory method that oxidizes PFAS precursors in a sample into measurable perfluoroalkyl acids, then quantifies the difference against a pre-oxidation baseline. Reveals the hidden precursor mass that targeted PFAS analysis alone misses.