Phosphorus treatment of secondary municipal effluent using oven-dried alum residual.

This study aims to investigate the effectiveness of alum residuals generated during drinking water treatment for adsorption of phosphorus from secondary municipal effluent. Bench-scale experiments (batch and fixed bed column tests) were conducted using oven-dried alum residuals. Experimental results observed maximum phosphorus removal of 91%-98% using alum residual concentrations of 4 g/L to 16 g/L. Oven-dried alum residual was a more effective adsorbent for orthophosphate phosphorus than total phosphorus. Effluent pH levels were suitable for surface water disposal with little or no lime addition. Aluminum leaching from oven-dried alum residual was not high enough to cause toxicity for aquatic species in surface water. Oven-dried alum residuals were also able to adsorb organic matter. The results indicated that oven-dried alum residuals have potential to provide a low cost technological solution for small- and medium-sized municipalities.