exhibit a generally rectangular aspect and dimensions enabling it to stably locate in the bottom of oil pan 33 alternatively such a macroporous multilayer zeolites structure 50 fig2 may be supported in oil pan 33 by oil pickup 43 not shown or by a bracket or other supporting structure not shown another approach could be to secure a more irregularly dimensioned macroporous multilayer zeolite structure to oil pick up tube 44 not shown yet another approach may be to position a more cylindrically shaped macroporous multilayer zeolite structure 50 u2032 in the hollow oil return cavity of engine oil filter 60 as shown in fig1 and in more detail in fig3 the engine oil filter 60 shown in fig3 is generally conventional a domed cover 62 is attached to a baseplate 65 to define an interior volume partially occupied by filter medium 68 often of pleated fibrous construction supported by a perforated cylindrical support 74 baseplate 65 is sealingly secured against a mating engine block by engagement of threads 72 with a threaded hollow boss not shown in the engine block which when tightened compresses compliant seal 66 against the engine block to eliminate oil leakage oil enters the filter as flow 45 and is directed around and through filter medium 68 and perforated support 74 before passing through macroporous multilayer zeolite structure 50 u2032 which at least partially occupies interior cavity 76 after its exposure to macroporous multilayer zeolite structure 50 u2032 the oil exits.