Activated Alumina is the latest type of polymer bead is infused with iron oxide in an attempt to develop a one-step coagulation process for arsenic removal in drinking water (American Chemical Society, 2006). This technology is still under development and will be available in the future, as a potential answer to the arsenic problem at the Deloro Mine.
The primary technologies being used in arsenic removal rely on coagulation and particulate removal, by either sedimentation or filtration. Recent lowering the U.S. EPA standards for Arsenic in drinking water has sparked a surge in technology development (Siegel et al., 2006). Many of these new technologies are simply improvements on older processes. At a recent conference on arsenic technology, AdEdge technologies scored as the most efficient in removal of arsenic from drinking water (Siegel et al., 2006). Many of these new technologies are still in the pilot stage.
The bottom line is the provision of safe drinking water to the people. Older technology focused on total source reduction. This is a monstrous task at the Deloro site. New technology that focuses of point of entry into the home may prove the most promising solution in the future. Cost and other factors may effect this decision and the new units would have to prove effective. This prospect will have to be analyzed further before a decision can be made. These new technologies may hold the solution to arsenic removal at the Deloro Mine Site.
There are several new technologies that hold promise for increasing the amount of arsenic removed prior to reentry into the Moira River. However, these new technologies are as of yet untested, let alone field tested. Although new technologies such as nanoparticles and new filtration techniques hold promise, they are still in the research and development stage. It will be many years before they are ready to meet the needs at the Deloro Mine Site. New technology is not likely to be a reliable source to meet the current needs of the community surrounding the Moira River.
Sampling technique plays a significant role in the results obtained and in the reliability of the sample results. The Deloro Mine Site has a continual internal monitoring process. The purpose of this sampling procedure is to verify, or demonstrate whether the results of self-reported sampling are reliable for the purposes of public safety. These results will be compared to posted results at various stages of the water treatment process.
One of the key considerations in taking water samples for the analysis of arsenic is the preservation of highly reactive constituents within the sample. Many factors can influence the preservation of arsenic and arseno-compounds in water samples. For instance, light, pH, temperature, available oxygen, organisms and other factors can alter arsenic levels in the sample from the time of collection to the time of analysis. Samples were collected using groundwater sampling procedures contained in "Ground Water Sampling Guidance-GD12"; Appendix B. This procedure is considered standards acceptable procedure for the preservation arsenic in groundwater.
Samples were taken of the pre-treatment sludge, leachate, influent and effluent. Samples were taken at Well #4 and at other locations as indicated on the sampling documentation. The effluent results reflect water that is considered processed and ready to be released into the Moira River. These samples were submitted to AGAT Laboratories and analyzed for total arsenic using graphite furnace atomic absorption. This assay did not reflect arsenic speciation and included organic, inorganic, arseno-pyrite, and any other arsenic containing compound at the site. The results of the laboratory results are found in the Appendices of this research study.
Current technology at the Deloro Mine Site is reported to remove approximately 99.8% of the total arsenic, resulting in an effluent of 0.21 mg/L (Ministry of the Environment, 2007). Although, to the lay-person this would appear to be a considerable reduction in arsenic levels, one must place these numbers in context. To arrive at 0.21 mg/L after a 99.8% reduction, the amount of arsenic in the pre-treatment sample would have to be approximately 0.19 mg/L. This result in consistent with sludge samples taken in this research study. Sludge samples were well-over 2000 mg/L.
Total arsenic in sludge samples over 2000 mg/L. Leachate after initial treatment reduced the arsenic contamination to approximately 5-16 mg/l. These results demonstrate a considerable