Evaluation of Cement Kiln Dust (CKD) as an Amendment for the Sandy Soils. 1- Preliminary Studies

THE REUSE of some industrial wastes or by-products such as the cement kiln dust (CKD) is beneficial to prevent or at least to reduce the environmental pollution. The CKD is beneficial as a raw material, construction material, absorbent, and improving the sandy soil properties. Preliminary studies were carried out to study the possibility of using the CKD as an amendment for the sandy soils. Two cement kiln dusts were investigated, one was collected from El-Minia white cement factory and the other was collected from Beni - Suef black cement factory. The two CKD had a high total soluble salts (T.S.S.), soluble cations (Ca+2, Mg+2, Na+ and K+) and soluble anions (CO3-2, HCO3-, Cl- and SO4-2) therefore, each CKD was modified by leaching with water using four leaching treatments (leaching with 0, 5, 10 and 20 times water). Thereafter, a pot experiment using a sandy soil cultivated with corn was set up to study the efficiency of using the modified white CKD (leached with 20 times water) as a soil amendment. The modified white CKD was applied to the sandy soil at six rates (0, 5, 10, 15, 20 and 25 Mg ha-1). The obtained results of the current study show that the T.S.S., Cl-, Na+ and K+ of the raw black CKD were higher than those of the raw white CKD, however, the CO3-2, Ca+2 and Mg+2 of the raw white CKD were higher than those of the raw black CKD. Leaching the two CKD with water decreased the T.S.S. and soluble ions. The best leaching treatment for modifying the CKD is the leaching with 20 times water. The leaching efficiency for the white CKD was better than that for the black one. Application of the modified white CKD at the rate of 25 Mg ha-1 to the sandy soil decreased the real density, porosity, percolation rate, and infiltration rate; while; it increased the plant height, fresh and dry weight of the corn shoots, and water use efficiency by the plants, but it decreased the water consumptive use by the plants. In general, application of the modified white CKD improves the sandy soil properties, decreases the lost water by leaching, rationalizes the irrigation water use, and enhances the corn growth. It could be recommended to use the modified white CKD at the rate of 25 Mg ha-1 as an amendment for the sandy soils under the conditions of EI-Minia Governorate.