When a packed sour water stripper removes H₂S and NH₃ unevenly, review feed pH, temperature, contaminant speciation, steam rate, feed composition, downstream overhead capacity, and fouling risk before increasing packed height. The two contaminants do not respond identically to the same water chemistry.

When a packed amine absorber meets its CO₂-removal target but amine aerosol remains in the outlet, investigate aerosol nuclei, solvent condition, upper wash performance, gas temperature, velocity, droplet size, and final mist-control technology. Main-bed packing efficiency and amine-aerosol control should be treated as separate engineering duties.

When a hot potassium carbonate CO₂ absorber begins crystallizing, investigate local cold spots, solution concentration, shutdown cooling, branch-line temperature, distributor openings, and startup solids transport before changing the packing. Open packing can improve tolerance, but temperature and solubility control remain the root solution.

When a hydrogen-peroxide-based scrubber consumes far more reagent than the target-gas mass balance predicts, investigate peroxide decomposition caused by temperature, catalytic contaminants, metal ions, pH, storage conditions, and circulation-loop materials. More packing cannot compensate for oxidant that decomposes before it reacts with the contaminant.

When scrubber inlet/outlet testing shows good removal but the final stack remains high, inspect bypass ducts, dampers, isolation seals, branch flow, and sampling locations. Untreated bypass leakage can dominate overall plant emissions, and adding packing or liquid circulation will not correct that parallel gas path.