Cellulose mill liquid alkaline waste and gypsum as a substitute for lime in soils

Abstract

Alkaline liquid effluent from cellulose factories was used in an experimental study to appraise the feasibility of utilizing this material with industrial gypsum (residual material from superphosphate production) for the correction of soil acidity. A soil + gypsum column was prepared and leached with the sodium rich industrial waste. Soil pH was raised but the amont of material needed bring it to 6.5 was found to vary with soil chemical composition and soil acidity buffering capacity. The soil leachate was richer in Na when gypsum was presented. Results obtained show that industrial gypsum combined with alkaline waste neutralizes soil acidity, increases soil calcium content and prevents sodium accumulation in the soil.