Premium
Crushed Concrete as a Phosphate Binding Material: A Potential New Management Tool
Author(s) -
Egemose Sara,
Sønderup Melanie J.,
Beinthin Malde V.,
Reitzel Kasper,
Hoffmann Carl Christian,
Flindt Mogens R.
Publication year - 2012
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2011.0134
Subject(s) - surface runoff , eutrophication , sedimentation , environmental science , environmental chemistry , chemistry , water retention , particulates , phosphate , environmental engineering , nutrient , sediment , soil water , geology , soil science , ecology , paleontology , organic chemistry , biology
To avoid eutrophication of receiving waters, effective methods to remove P in urban and agricultural runoff are needed. Crushed concrete may be an effective filter material to remove dissolved and particulate P. Five types of crushed concrete were tested in the laboratory to evaluate the retention capacity of dissolved P. All types removed P very effectively (5.1–19.6 g P kg −1 concrete), while the possible release of bound P varied between 0.4 and 4.6%. The retention rate was positively related to a decreasing concrete grain size due to an increasing surface area for binding. The P retention was also related to a marked increase in pH (up to pH 12), and the highest retention was observed when pH was high. Under these circumstances, column experiments showed outlet P concentrations <0.0075 mg P L −1 . Furthermore, experiments revealed that release of heavy metals is of no importance for the treated water. We demonstrate that crushed concrete can be an effective tool to remove P in urban and agricultural runoff as filter material in sedimentation/infiltration ponds provided that pH in the treated water is neutralized or the water is diluted before outlet to avoid undesired effects caused by the high pH.