Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study wa...Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study was to determine the impact of chemical amendments on WEP （water-extractable phosphorus） in applied treatments and DRP （dissolved reactive phosphorus） in runoff from biosolids-amended soils. Rainfall simulations were conducted in 2006 on field plots fertilized with biosolids that had been treated with alum [（A12804）3＂ 14H20], ferric chloride （FeC13） or an alum-based WTR （water treatment residual） at a rate of 20% （wt/wt） to reduce DRP in runoff. In 2007, rainfall simulations were conducted using WTR/biosolid blends of 15% and 30% （wt/wt） that were allowed to incubate for three weeks prior to application. Cumulative DRP runoff load observed for the 20% WTR treatment was not significantly different from other chemical treatments and resulted in a 45% reduction in DRP runoff as compared to the untreated biosolids application. Cumulative DRP runoff load in 2007 for the 15% and 30% WTR treatments resulted in significantly lower DRP loads compared to untreated biosolids and led to DRP runoff load reductions of 78% and 85% （compared to the untreated biosolids application）, respectively.展开更多
文摘Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study was to determine the impact of chemical amendments on WEP （water-extractable phosphorus） in applied treatments and DRP （dissolved reactive phosphorus） in runoff from biosolids-amended soils. Rainfall simulations were conducted in 2006 on field plots fertilized with biosolids that had been treated with alum [（A12804）3＂ 14H20], ferric chloride （FeC13） or an alum-based WTR （water treatment residual） at a rate of 20% （wt/wt） to reduce DRP in runoff. In 2007, rainfall simulations were conducted using WTR/biosolid blends of 15% and 30% （wt/wt） that were allowed to incubate for three weeks prior to application. Cumulative DRP runoff load observed for the 20% WTR treatment was not significantly different from other chemical treatments and resulted in a 45% reduction in DRP runoff as compared to the untreated biosolids application. Cumulative DRP runoff load in 2007 for the 15% and 30% WTR treatments resulted in significantly lower DRP loads compared to untreated biosolids and led to DRP runoff load reductions of 78% and 85% （compared to the untreated biosolids application）, respectively.
