Abstract:
Forty-six samples of clay from different locations in Pakistan were collected and chemically analysed to find out their mineral constituents. The clays containing high percentage of Kaolin and high insecticidal properties, were selected for activation, and a method was standardized for activation of the clays.
The optimum Level for mixing activated clay, with wheat grains, to obtain Maximum insecticidal effects, was determined, The effectiveness of the clays in checking insect activity depended on percentage of the activated clays used and the storage conditions of wheat. The clays with high Alumina contents (more than 35%), when activated showed high insecticidal properties. Large scale insecticidal activity trials of the clays were conducted by Pakistan Agricultural Storage and Service corporation Limited and the clays were found to possess high insecticidal activity.
Rat feed trials were conducted to assess possible toxic effects of these clays when mixed with wheat and milled into flour for human consumption. It was observed that the rats thrived on the test or the control diet equally well.
Aluminium Sulphate (if H2SO4 is used for activation) or Aluminium chloride (if HCl is used for activation) are bye-products of activation process These chemicals are being consumed by textile, paper and other industries. Production of activated clays will help in reducing dependence on import of these chemicals.
