ABSTRACT

Due to entrainment or dissolution, organic extractants can contaminate aqueous raffinate during the solvent extraction (SX) process. This study aims to evaluate the effect of conventional SX reagents on the bio-oxidation and metabolism of industrial bacteria. Evaluating the effect of LIX 984N, Chemorex CP 150, D2EHPA, and Acorga M5640 at three concentrations on mesophiles and moderate thermophiles revealed that all extractants reduced the bacterial efficiency at different extents. It was observed that organic phases at 0.02% v/v resulted in a decrement of ferrous iron bio-oxidation rate and a negligible decrease in the bacterial population. At high dosages like 2% v/v, bio-oxidation and bacterial reproduction were utterly disrupted. The oxime-based extractants had a more significant effect on bacteria due to their lower stability and production of toxic substances by hydrolysis. Organic phases more impacted moderate thermophiles at a higher temperature compared to mesophiles. The analysis of Kendall tau-b revealed a strong inter-correlation between the concentration of organic phase and bio-oxidation parameters such as pH, ORP, bacterial population, bio-oxidation rate, and iron precipitation.

摘要

由于夹带或溶解，有机萃取剂会在溶剂萃取 (SX) 过程中污染含水萃余液。本研究旨在评估常规 SX 试剂对工业细菌生物氧化和代谢的影响。评估 LIX 984N、Chemorex CP 150、D2EHPA 和 Acorga M5640 在三个浓度下对嗜温菌和中度嗜热菌的影响表明，所有萃取剂都不同程度地降低了细菌效率。据观察，0.02% v/v 的有机相导致亚铁生物氧化率的下降和细菌种群的可忽略不计的减少。在 2% v/v 等高剂量下，生物氧化和细菌繁殖被完全破坏。肟类萃取剂对细菌的影响更显着，因为它们的稳定性较低，并且会通过水解产生有毒物质。与嗜温菌相比，有机相在较高温度下对中度嗜热菌的影响更大。Kendall tau-b 的分析揭示了有机相浓度与生物氧化参数（如 pH、ORP、细菌种群、生物氧化速率和铁沉淀）之间的强相关性。