The water leach test was conducted at room temperature
according to ASTM International method D 3897
(ASTM International, 2004), except that a 2 g sample of waste molding sand was mixed with 40 mL of deionized (DI) water as described above. The aqueous extracts were centrifuged for 10 min. at 3000g and then filtered through a 0.45 mm
membrane filter.