Filter Media Additives for Phosphorus Removal

From LID SWM Planning and Design Guide
Revision as of 19:30, 21 November 2017 by Alanav (talk | contribs)
Jump to navigation Jump to search

A number of granular amendments have been demonstrated to improve nutrient removal from discharge water in BMPs such as bioretention systems, absorbent landscapes, sand filters or green roofs. There are two primary processes involved, chemical precipitation and adsorption. Both mechanisms are ultimately finite, but have been shown in come cases to make significant improvements on the discharged water quality over several years.

Soil Additives
Material Benefits Potential concerns
Biochar Renewable
Enhances soil aggregation, water holding capacity and organic carbon content
Currently expensive
Energy intensive to produce
Some sources say ineffective for phosphorus removal
Bold & GoldTM Documented total phosphorus removal of up to 71%[1] Proprietary
Iron filings (ZVI) Proven phosphorus retention
Retained phosphorus is stable
May harm plants[2]
Removal efficiency declines with increased concentration of incoming phosphorus
Red sand Proven phosphorus removal
Also removes TSS
Poor orthophosphate removal in hypoxic or anoxic conditions
Smart SpongeTM Removes phosphorus, as well as TSS, fecal coliform bacteria and heavy metals
1-3 year lifespan, after which the product is removed as solid waste
Sorbtive mediaTM High phosphorus removal efficiency Proprietary
Water treatment residuals Waste product reuse Quality control (capabilities depend on source, treatment methods, storage time, etc of WTR)
  1. Hood A, Chopra M, Wanielista M. Assessment of Biosorption Activated Media Under Roadside Swales for the Removal of Phosphorus from Stormwater. Water. 2013;5(1):53-66. doi:10.3390/w5010053.
  2. Logsdon SD, Sauer PA. Iron Filings Cement Engineered Soil Mix. Agron J. 2016;108(4):1753. doi:10.2134/agronj2015.0427.