Low-cost Activated Carbon from Agricultural Wastes by Phosphoric Acid Activation

Activated carbon is a versatile adsorbent because of its good adsorption properties. Activated carbons can be prepared via a physical or chemical activation process from different carbon sources like coal. wood and agricultural wastes. The use of activated carbon derived from agricultural wastes as low-cost adsorbent to remove organic or inorganic contaminants would be most ideal since these materials are available in abundance in many countries. The objective of this work was to demonstrate the potential use of different agricultural wastes to produce carbon adsorbent. Low cost adsorbents are prepared from different agricultural wastes (apricot stones, almond, hazelnut, pistachio and walnut hard shells) by chemical activation. The activation was performed by phosphoric acid solution under different operating conditions. The experimental results indicated that the nature and particle size of precursors, activation conditions (final temperature. heating rate, time) and impregnation rate of phosphoric acid were important in the process yield and quality of activated carbon. The properties of the prepared adsorbents were compared to those of commercial ones. These carbon adsorbents could be suitable for separation of metal ions from wastewaters.