Research on the granulation of montmorillonite and its adsorption for ammonium in wastewater

Process condition of the montmorillonite granule adsorbent Preparation and influencing factors and adsorption characteristic of NH4+ in wasterwater were studied. The results indicated that the montmorillonite, granule adsorbent had a good mechanical intensity and adsorptive capability by using polyvinylalcohol (PVA) crosslinked with boric acid when it was made with the following conditions: the concentration of PVA was 10%, the concentration of sodium alginate was 0.2%, the entrapping rate was 1:1, and the immobilized time was 24 hours. The adsorptive effect gradually increased with the reducing of the original concentration of ammonium in the wastewater. When the oriiginal concentration of ammonium was lower than 10mg/L, the remove rates of NH4+ was 99.8%. Adsorbent had a better ammonium adsorption effect in pH=4 similar to 10, the ammonium remove rates reduced with the increasing of the concentration of electrolyte NaCl. Equilibrium adsorption of the montmorillonite granule adsorbent for ammonium was conformed to langmiur isotherm, showing as single molecule tier adsorption and the max adsorption capacity is 3.21mg/g.