Study of tenorite (CuO) particles in removal of arsenic under natural water conditions

摘要

High levels of natural arsenic (As) found in groundwaters of many countries have raised health concerns. Thus, effective arsenic removal methods under natural water conditions will be useful. The objective of this study was to explore the potential of tenorite (CuO) mineral particles in removal of arsenic from groundwater samples across a wide range of water chemistries. Several groundwater water samples were collected from Colorado, Montana, Nevada, South Dakota, Utah, and Wyoming, USA for testing. Fifty mL of each groundwater sample was reacted with 0.5g of CuO particles without pH adjustments or preoxidation. Solutions were filtered through 0.45μm Millipore filters and clear filtrates were analyzed for arsenic with ICP-MS. Effect of pH and competing ions (e. g. phosphate, sulfate, silica) in removal of arsenic were evaluated. Results suggest that CuO particles successfully removed arsenic from samples with pH between 6 and 8.95. During the reaction CuO particles were very stable and released very small amounts of Cu into the water. Results further indicate that natural phosphate, silica, and sulfate concentrations as high as 5.89, 54.5, and 472mg/L, respectively showed no significant influence in removal of arsenic from samples. The effect of arsenic oxidation state and regeneration of used CuO particles is discussed.