The low bio-production of Fe as a leaching agent is one of the main limitations to implementing industrial bio-processes at feasibility conditions. The main limitation of the bio-oxidation process of Fe is the low oxygen transfer to the aqueous phase because of the low oxygen solubility. This study assesses the effectiveness of the venturi jet as an innovative and intensive aeration device for overcoming the oxygen limitation in a continuous ferrous oxidation process in a fixed-bed reactor with immobilized , in contrast to the conventional diffuser aeration device. Firstly, the influence of the airflow and the influence of the medium concentration were determined for the following parameters for both aeration devices; Volumetric mass transfer coefficient (ka), Standard Oxygen Rate (SOTR), Standard Aeration Efficiency (SAE), and Standard Oxygen Transfer Efficiency (SOTE). Then, both aeration devices were compared in a continuous bio-oxidation process in an up-flow packed bio-reactor (UFPB). The system performance was assessed by monitoring temperature, pH, oxidation-reduction potential, and dissolved oxygen concentration for 69 days. Findings displayed that when aerating with the diffuser, the ferrous oxidation rate was restricted by the low dissolved oxygen availability, being about 1 ppm (1 mg L). Under these oxygen-limiting conditions, the maximum ferrous (Fe) oxidation rate was 9.09 g L h. However, when aerating with the venturi jet, the dissolved oxygen concentration increased up to 2.70 mg L, achieving a maximum of 29.11 g L h. So, this study has demonstrated that the change in the aeration device has resulted in an improvement in the process, achieving a 3.5-fold increase in the oxidation rate. Furthermore, the venturi jet offered additional advantages over the diffuser, such as requiring less power to deliver the same amount of air, being unaffected by jarosite precipitates, and not requiring a supply of compressed air.

中文翻译：

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使用文丘里射流作为强化曝气系统改善 Fe2+ 生物氧化过程中溶解氧的传输


作为浸出剂的铁的生物产量低是在可行性条件下实施工业生物过程的主要限制之一。 Fe 生物氧化过程的主要限制是由于氧溶解度低，向水相的氧转移量低。本研究评估了文丘里射流作为一种创新的强化曝气装置的有效性，与传统的扩散器曝气装置相比，它克服了固定床反应器中连续亚铁氧化过程中的氧气限制。首先，确定了两种曝气装置的下列参数的气流影响和介质浓度影响；体积传质系数 (ka)、标准氧传输率 (SOTR)、标准曝气效率 (SAE) 和标准氧传输效率 (SOTE)。然后，在上流式填充生物反应器（UFPB）中的连续生物氧化过程中对两种曝气装置进行了比较。通过连续 69 天监测温度、pH 值、氧化还原电位和溶解氧浓度来评估系统性能。研究结果表明，当使用扩散器曝气时，亚铁的氧化速率受到低溶解氧可用性的限制，约为 1 ppm (1 mg L)。在这些限氧条件下，最大亚铁 (Fe) 氧化率为 9.09 g·L·h。然而，当使用文丘里射流曝气时，溶解氧浓度增加至2.70 mg·L·h，最高达到29.11 g·L·h。因此，这项研究表明，曝气装置的改变导致了工艺的改进，氧化速率提高了 3.5 倍。 此外，与扩散器相比，文丘里喷射器还具有其他优势，例如输送相同量的空气所需的功率更少、不受黄钾铁矾沉淀物的影响，并且不需要供应压缩空气。