... rate(via burning oil & asphalt approach),%≥95Activity(NaAc approach)≥180Free acid (H2SO4),%≤0.15Water content before leaving factory,%≤12.0Granularity(over ... remove the harmful pigment,aflatoxin,phosphatide,saponin,colloid,and cotton acid from the oil to make it high-grade edible oil ... performance will be affected by moisture due to its high water absorption ability. acid activated clay for corn oil