When a packed water decarbonator underperforms despite normal hydraulics, check whether CO₂-rich exhaust is recirculating into the blower intake. Intake location, stack discharge, wind, building wakes, air CO₂ concentration, and gas-flow direction can control stripping performance more strongly than additional packing.

When a high-pH ammonia stripper treating landfill leachate develops scale, evaluate calcium, magnesium, alkalinity, carbonate chemistry, CO₂ stripping, pH setpoint, packing openness, distributor fouling, and pretreatment. Better NH₃ speciation can create a new precipitation problem inside the tower.

When a permanganate odor scrubber develops manganese-containing deposits, evaluate reaction chemistry, pH, oxidant concentration, solids generation, distributor opening size, packing openness, sump solids removal, and cleaning. The tower may be fouling because successful oxidation creates insoluble reaction products.

When TEG dehydration performance declines and the regenerator shows deposits or unstable operation, investigate salts, hydrocarbons, corrosion products, glycol degradation, filtration, reboiler conditions, and regenerator packing before changing the gas-contactor internals.

When amine-system performance declines because heat-stable salts accumulate, more regenerator packing or higher reboiler duty may not solve the problem. Analyze solvent composition, degradation, corrosion, fouling, reclaiming needs, and actual regenerator hydraulics separately before changing tower internals.