2.2.4.2. Removal of MTBE by column filter of polymer–zeolite composite mixed with activated carbon. The experiment was performed at MTBE concentrations of 0.4 mg/L, in glass columns of 25 cm length and 5 cm diameter. The column was filled with a mixture of 39 g of zeolite composite and 180 g of granular activated carbon. For com- parison, a column filled with 220 g of granular activated carbon was also prepared. A MTBE solution (150 L) was passed through the zeo- lite composite + GAC and GAC columns at a flow rate of 50 mL/min. In the experiments above the MTBE solution was kept in polypro- pylene sample bags to avoid MTBE volatilization. However, volatil- ization occurs when employing large volumes. In the current experiment MTBE volatilization was monitored and the calculations of MTBE removal at each pore volume took into account this volatilization.