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Leaching of Heavy Metals from Infills on Artificial Turf by Using Acid Solution [Received May 23, 2008 ; Accepted December 5, 2008] The present study is aimed at determining the concentration of zinc leached from various types of rubber infills on artificial turfs by using acid solutions as a representative of acid rain. Acid solutions with pH values of 3.0, 3.5, 4.0, and 4.5 were prepared from 0.1 mol/L sulfuric acid and distilled water. Leaching was carried out according to the standard method prescribed by the Ministry of Environment in Japan. The concentrations of heavy metals such as zinc leached in the acid solutions were determined by inductively coupled plasma spectrometry (ICP-MS). The concentrations of heavy metals in the infills were analyzed using an ICP analyzer after the infills were burnt to ashes and dissolved with aqua regia. Zinc (Zn), Iron (Fe), Barium (Ba), and Manganese (Mn) in styrene-butadiene rubber (SBR) infills were leached in acid solutions. Their concentrations increased with increasing acidity of the acid solutions. In the case of the SBR infill, the concentrations of Zn exceeded the effluent standard (2 mg/L) in Japan, but decreased with aging time, and were less than the effluent standard for aging time greater than 1.25 years. The concentrations of Zn leached from SBR coated with polyurethane (PU-SBR), ethylene-propylene rubber (EPDM), Eco-fill, and the bark of a cedar tree were less than the effluent standard of Zn in Japan, and were approximately proportional to the Zn contents (%) in all these infills except for the cedar bark. Keywords: artificial turf, infills, leaching of heavy metals, acid solution |