Influence of Well Casing Composition on Trace Metals in Ground Water

摘要

These experiments determined the concentration dependence of trace inorganic priority pollutants (As, Cd and Pb) in ground water solutions exposed to polyvinylchloride (PVC), polytetrafluoroethylene (PTEE) and two types of stainless steel (SS304 and SS316). The test design used a factorial screening matrix with two concentrations of metals (As-Cr-Pb, 50 and 10 micrograms/L; C/d, 10 and 2 micrograms/L), pH (5.8 and 7.7), and total organic carbon (natural and natural plus 5 mg/L humic acid) as variables. Samples containing well casings and controls without pipe sections were run as duplicates. Aliquots were removed from all of the solutions after 0.5,4,8,24 and 72 hours. Aqueous metal concentrations were determined by graphite furnace atomic absorption spectroscopy. The results showed PTFE to have no significant influence on the metals monitored under any of the groundwater conditions. Metal concentrations in ground water exposed to SS316 and SS304 had large random variances believed to be caused by surface oxidation of the stainless steel. PVC had a more active surface than PTFE in terms of both sorption of Pb and of Cd. Keywords: Ground water monitoring; Ground water testing; Inorganic pollutants; Well casings; Water pollution; Chemical concentration. (edc)