Bag filters to treat industrial fumes can simply de-dust fumes or pollutants with dry injection of sodium bicarbonate, in the flue gas to be purified. The injected basic reagent neutralizes acids - hydrochloric acid, sulfur dioxide, hydrofluoric acid, etc. with extreme effectiveness.
The combined injection of sodium bicarbonate with active carbon or lignite coke, purifies heavy metals and dioxins allowing to comply with the strictest regulations on atmospheric emissions.
The products of the acid-base reaction are sodium salts - sodium chloride, sodium sulfate, sodium fluoride, sodium carbonate, etc. They are called residual salts (P.S.R.). Such salts are separated from the flue gases through suitable filter systems. As this process takes place completely dry, no liquid effluent is generated having in turn subdued to treatment.