Microbiological methods for removing heavy metals from saline water-based drilling mud: challenges and practical strategies

This study highlights the potential of Aquibacillus halophilus and microbial treatments to address water quality issues in drilling operations, offering promising avenues for mitigating heavy metal contamination and reducing total water hardness to achieve sustainable development goal (SDG) 6 (Clean Water and Sanitation) and SDG 14 (Life Below Water). Aquibacillus halophilus exhibited rapid growth and remarkable water quality enhancement capabilities. Its robust growth at pH 7 suggests minimal interference from in situ bacteria, thereby preserving the optimal pH level for drilling operations and promoting sustainable water resource management. Keeping the total hardness below 800 ppm is essential to utilize water in well-logging effectively. Aquibacillus halophilus offers an alternative approach to hardness reduction that reduces reliance on chemical additives such as caustic soda. By incorporating Aquibacillus halophilus, a conventional treatment requiring 100% caustic soda to treat 19,100 ppm hardness, it can be reduced to 19.37%, obtaining a remarkable 80% reduction in material consumption. This reduction facilitates wastewater reuse significantly, promotes resource efficiency, and is consistent with SDG 6. In addition to reducing well-logging costs, the microbial technique safeguards the environment by addressing heavy metal contamination, which aligns with SDG 14’s objective of protecting aquatic life.