Removing arsenic, copper and iron from sewage sludge with reed (Phragmites Australis)

Abstract

Agriculture can use the sewage sludge resulting from wastewater treatment. In order to use sewage sludge, it is necessary to eliminate the content of toxic pollutants, including heavy metals through phytoremediation. The purpose of this research work was to assess the capacity of Phragmites australis to remove As, Cu and Fe in wastewater sludge of the municipal treatment plant in Cd. Victoria, Tamaulipas. We established four treatments: T1 = sewage sludge + soil + Phragmites australis; T2 = sewage sludge + soil; T3 = Sludge + Phragmites australis; T4 = Check test. Each treatment had six replicates. The phytoremediation process lasted eight months. We took monthly samples from the substrate and samples of P. australis every four months to determine the contents of As, Fe and Cu. The sludge + soil + P. australis treatment was able to remove higher percentages of Fe (96.63%) and Cu (47.67%); while sludge + P. australis was able to remove higher percentage of arsenic (81.18%), with a bio-concentration factor of 7.76. The amount of metals removed from the substrates from highest to lowest were: Fe > Cu > As. Furthermore, the final concentration of Fe, Cu and Arsenic in the sludge was below the allowable limit established by NOM-004- SEMARNAT-2002 Standard.