Industrial emissions cause significant ecological damage, making wastewater treatment essential for resource efficiency and environmental protection. Phytases, microbial enzymes that hydrolyze phytate, demonstrate considerable biotechnological promise by degrading phytic acid, an antinutritional compound in plant foods. Our findings demonstrate that these enzymes are effective across a broad temperature range (20-50ºC), with peak activity at 30ºC (0.83 unit/ml) and maintain stability (20-60ºC) for one hour, retaining over 50% of their activity. They are active across a wide pH range (4-8), with optimal activity at pH 6 (0.81 unit/ml) and pH 5 (0.79 unit/ml), and are stable at pH 5 and 6 for one hour at 37ºC. Among metal ions, only MgSO4 enhanced phytase activity (117.36% residual activity), while CuSO4 and ZnCl2 were the most inhibitory. Bacillus subtilis (B. subtilis), producing phytase, was isolated, characterized, and used for wastewater remediation from the Samarra Drugs Factory and Baiji Refinery, resulting in significant reductions in Biochemical Oxygen Demand (BOD5) and (64.9% and 56.4%) and Chemical Oxygen Demand COD (59.6% and 53%), as well as decreased nitrate and metal levels. Phytase administration to rats in varying doses (0, 0.1, 0.2, 0.3 units) every three days for 15 days caused a dose-dependent decrease in white blood cell counts, thereby improving water quality and enhancing immune function.