Aluminum water treatment residuals as permeable reactive barrier sorbents to reduce phosphorus losses

作者：Miller Matthew L; Bhadha Jehangir H; O'Connor George A^*; Jawitz James W; Mitchell Jennifer

来源：Chemosphere, 2011, 83(7): 978-983.

DOI：10.1016/j.chemosphere.2011.02.014

• Permeable reactive barrier
• Water treatment residual
• Adsorption/desorption kinetics
• Phosphorus

Two aluminum water treatment residuals (Al-WTRs) from water treatment plants in Manatee County, FL and Punta Gorda, FL were evaluated as potential permeable reactive barrier (PRB) media to reduce groundwater phosphorus (P) losses. Short-term (<24 h) P sorption kinetics and long-term P sorption capacity were determined using batch equilibration studies. Phosphorus desorption was characterized following P loadings of 10, 20, 30,40 and >70 g kg(-1). Sorption and desorption studies were conducted on the <2.0 mm material and three size fractions within the <2.0 mm material. The effect of dissolved organic carbon (DOC) on P retention was determined by reacting Al-WTRs with P-spiked groundwater samples of varying initial DOC concentrations. Phosphorus sorption kinetics were rapid for all size fractions of both Al-WTRs (>98% P sorption effectiveness at shaking times >= 2 h). The effect of DOC was minimal at <150 mg DOC L(-1), but modest reductions (<22%) in P sorption effectiveness occurred at 587 mg DOC L(-1). The P sorption capacities of the Manatee and Punta Gorda Al-WTRs (<2.0 mm) are similar to 44 g kg(-1) and >75 g kg(-1), respectively, and the lifespan of an Al-WTR PRB is likely many decades. Desorption was minimal (<2% of the P sorbed) for cumulative P loadings <40 g kg(-1), but increased (<9% of the P sorbed) at cumulative P loads >70 g kg(-1). The <2.0 mm Manatee and Punta Gorda Al-WTRs are regarded as ideal PRB media for P remediation.

• 出版日期2011-5