The invention belongs to the field of soil repairing materials and relates to a preparation method of a
hydrotalcite composite material for repairing soil of farmland with
copper ions exceeding the standard. According to the preparation method, modified
hydrotalcite is composited into holes of ammoniated
bagasse, and the preparation method comprises specific processes such as cleaning of
bagasse, ammoniation of the
bagasse, modification of
hydrotalcite, preparation of the
composite material and the like. The bagasse and hydrotalcite
composite material prepared with the method has the advantages as follows: (1) the hydrotalcite is fixed in the bagasse by the aid of
ethyl cyanoacrylate, the characteristics of
low density and large specific surface area of the bagasse can be realized, and the
advantage that the modified hydrotalcite has high adsorption capacity for the heavy
metal copper ions can also be utilized; (2) compared with hydrotalcite
powder, the composite material solves problems of agglomeration of the hydrotalcite
powder and reduction of adsorption capacity for the
copper ions and can also solve the problem of secondary soil
pollution due to the fact that the hydrotalcite adsorbing the copper ions is difficult to recover; (3) compared with the bagasse, the composite material has the
advantage that the copper
ion saturated adsorption amount of the soil repairing material is substantially increased.