Decontaminating Materials Used in Groundwater Sampling Devices

摘要

In these studies, the efficiency of various decontamination protocols was testedby using small pieces of materials commonly used in groundwater sampling devices. Three types of materials that ranged in their ability to sorb organic solutes were tested: stainless steel, polyvinyl chloride (PVC), and polytetrafluoroethylene (PTFE). These test pieces were exposed to two aqueous test solutions: one solution contained three volatile organic compounds and one nitroaromatic compound, and the other solution contained four pesticides of varying hydrophobicity. Also, three types of polymeric tubing were exposed to pesticide solutions. Generally, contact times for sorption and desorption were 10 minutes and 24 hours. The test results indicate that, generally, organic contaminants are removed from these materials simply by washing with a hot detergent solution and rinsing with hot water. The exceptions were low-density polyethylene tubing that was exposed to a pesticide test solution for 24 hours and allowed to desorb for 24 hours, and PTFE that was exposed to volatile organics for 24 hours. For these, a hot detergent water wash and rinse followed by oven drying at -105 deg C was the most effective treatment. With this treatment, VOCs were not detected desorbing from the PTFE, and pesticide contamination desorbing from LDPE was substantially reduced. Solvent rinsing did not improve removal of VOCs and only marginally improved removal of pesticides from LDPE.