Metal leaching from the bridge paint waste in the presence of steel grit

Field methods for rapidly characterizing paint waste during bridge rehabilitation

“…Detection limits included As = 0.7 lg L À1 , Ba = 0.4 lg L À1 , Cd = 0.5 lg L À1 , Cr = 0.7 lg L À1 , Pb = 0.5 lg L À1 , Se = 0.2 lg L À1 , Ag = 0.3 lg L À1 , Fe = 2.5 lg L À1 , Zn = 1.0 lg L À1 , and Hg = 2.0 Â 10 À3 lg L À1 . Data collected (Shu, 2014;Shu et al, 2015) from studying the leaching behavior were applied in mechanistic modeling, in the analysis of key variables, and then in the resulting statistically basedmodel.…”

“…Although magnetic separation is applied to remove the steel grit, a fraction remains in the paint waste. Iron oxide formed on the steel grit surface plays an important role in the system (Shu et al, 2015). In our companion paper (Shu et al, 2015) Protection Agency (U.S. EPA) toxicity characteristic leaching procedure (TCLP) (U.S. EPA, 1992) were less than the toxicity characteristic (TC) levels.…”

“…Iron oxide formed on the steel grit surface plays an important role in the system (Shu et al, 2015). In our companion paper (Shu et al, 2015) Protection Agency (U.S. EPA) toxicity characteristic leaching procedure (TCLP) (U.S. EPA, 1992) were less than the toxicity characteristic (TC) levels. Furthermore, the multiple extraction procedure (MEP) (U.S. EPA, 1986(U.S. EPA, , 2004) studies simulating long-term leaching behavior in a landfill environment demonstrated that 19 out of 24 samples resulted in concentrations less than the TC level.…”

“…This research builds on previous work (Shu, 2014;Shu et al, 2015). Through mechanistic modeling, the iron oxide coating formed on the steel grit surface was assessed for its role in metal mobility.…”

“…Furthermore, the multiple extraction procedure (MEP) (U.S. EPA, 1986(U.S. EPA, , 2004) studies simulating long-term leaching behavior in a landfill environment demonstrated that 19 out of 24 samples resulted in concentrations less than the TC level. To better understand the phases metals and metalloids were associated with, sequential extraction (Tessier et al, 1979) revealed the importance of the iron oxide surfaces in the leaching process (Shu et al, 2015).…”