Study of the removal of aqueous contaminants with calcined bone and sand from Monte Hermoso

Abstract

Water contamination by arsenic (As), fluorides (F^-), nitrates (NO₃^-), and ammonium (NH₄⁺) is a global public health problem. This study proposes the use of calcined cow bone powder and sand as low-cost adsorbents to implement an accessible water purification solution in rural and vulnerable areas. In removal tests, calcined bone was significantly more efficient than sand, achieving up to 79.92% removal of F^- and 62.50% of As in samples without ionic competition. This efficiency maintained outstanding performance (68.50% for F^- and 55.72% for As) even in the presence of more than one contaminant simultaneously. As a limitation, however, both materials, bone and sand, contributed nitrates (NO₃^-) to the environment. It is concluded that calcined bone is an effective and accessible alternative for the removal of As and F^-, requiring the implementation of a complementary reducing treatment for the elimination of residual nitrate and the performance of additional studies to optimize the removal of NH₄⁺.