Abstract: A process for coating zeolite crystals with paraffin, a wax other than paraffin, a fat or oil, or a mixture of at least one QAC and a wax, fat, or oil. Preferably, the crystals are dehydrated until they have about 5% moisture content, and are then mixed with paraffin to produce paraffin-coated zeolite crystals having a desired content of paraffin. When the coated zeolite crystals are used for removing benzene from contaminated water, their paraffin content is preferably about 8% (by weight). Other embodiments are methods for using zeolite coated with paraffin, another wax, a fat, an oil, or a mixture of at least one QAC and a wax, fat, or oil to filter a contaminant from contaminated liquid or gas. The zeolite crystals are optionally impregnated with a chemical such as permanganate before they are coated with the desired wax, fat, oil or mixture. A zeolite crystal having pores coated with wax, fat, oil, or a mixture of at least one QAC and wax, fat, or oil is within the scope of the invention.