Removal of phenolic compounds from aqueous solutions by adsorption onto manganese nodule leached residue.

Manganese nodule leached residue is a good adsorbent. Adsorption of phenol (PhOH) on water washed manganese nodule leached residue (WMNLR), waste materials from manganese nodules processing plant, has been investigated. The adsorbent (WMNLR) used for the removal of phenolic compounds were characterized by EDX, FTIR, SEM and BET surface area measurement before and after the adsorption process. Adsorption experiments were carried out to study the effect of various parameters like adsorbent dose, pH, adsorbate concentration, reaction time, temperature and calcination temperature. WMNLR calcined at 400 degrees C showed highest adsorption capacity. The equilibrium adsorption data for phenol was analyzed by using Langmuir isotherm model. The maximum adsorption of phenol was obtained at pH 3 (about 95% for adsorbent dose 1g/L and 30 mg/L adsorbate concentration). The increase in percentage of adsorption with increase in temperature indicates that adsorption is endothermic in nature. The pseudo-second-order kinetics was followed in the adsorption process.