Simple and combined acidic extraction of phosphorus from sewage sludge ash

Abstract

A comparative behavior of inorganic and organic acids as extraction agents for phosphorous extraction from sewage sludge ash provided by a municipal wastewater plant from Timis County, Romania, was studiedinthiswork.Thephysical-chemicalandmorphologicalpropertiesweredeterminedbyX-raydiffraction, FTIRspectroscopyandscanningelectronmicroscopy.Batchsimpleextractionexperimentswithhydrochloric acid,sulfuricacidandcitricacidwereconductedonthesewagesludgeashforphosphorousextraction.The operating conditions for acidic extraction with each acid and combination of sulfuric acid and citric acid were optimized in relation to the acid type, concentration and liquid:solid (LS) ratio. The combination of sulfuricacidandcitricacidinvolumetricratioof0.5waschosenasoptimumextractionagentforphosphorus recovery.