Abstract Selenium (Se) is a rare metal refined from the by-product produced from copper anode slimes. Japan is the largest producer of Se in the world. Each year approximately 40 tons of Se is discarded in wastewater. As, in many regions, wastewater contains a low concentration of Se, which is masked by the high levels of other metal contaminants, it is challenging to recover pure Se using the currently available treatment technologies. Therefore, it is important to develop novel technologies to recover and recycle Se from wastewater, especially in Japan, as it is poor in metal resources. To recover Se from wastewater using bio-hydrometallurgy, we isolated Pseudomonas stutzeri NT-I, which reduces soluble seleno-oxyanions to insoluble elemental selenium (biomineralization) and produces volatile dimethyl diselenide (DMDSe) (biovolatilization) from elemental selenium. We investigated the effects of several factors significant for the reduction of seleno-oxyanions and the DMDSe synthesis rate, such as temperature, pH, agitation speed, and aeration rate, using a 5-L jar fermenter, and developed two methods for Se recovery from wastewater by controlling biovolatilization and biomineralization using P. stutzeri NT-I. The rates of selenium recovery from wastewater by biovolatilization and biomineralization were 35.9% at 120 h, and 78.8% at 24 h, respectively. Furthermore, elemental selenium was refined with a purity of 99%, or higher, either by an oxidation-reduction reaction, or by oxidizing roasting from each recovered compound. Thus, our study demonstrates that P. sutzeri NT-I can be used for the recovery of rare metals from wastewater.

中文翻译：

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使用硒酸盐还原菌 Pseudomonas stutzeri NT-I 从废水中回收硒

摘要 硒（Se）是一种稀有金属，由铜阳极泥产生的副产品精制而成。日本是世界上最大的硒生产国。每年大约有 40 吨硒被丢弃在废水中。由于在许多地区，废水含有低浓度的硒，而这被高浓度的其他金属污染物所掩盖，因此使用当前可用的处理技术回收纯硒具有挑战性。因此，开发新技术从废水中回收和回收硒非常重要，特别是在日本，因为它的金属资源贫乏。为了使用生物湿法冶金从废水中回收硒，我们分离了施氏假单胞菌 NT-I，它将可溶性硒氧阴离子还原为不溶性元素硒（生物矿化）并从元素硒中产生挥发性二甲基二硒（DMDSe）（生物挥发）。我们使用 5 L 罐式发酵罐研究了几个对减少硒氧阴离子和 DMDSe 合成速率具有重要意义的因素的影响，例如温度、pH、搅拌速度和通气速率，并开发了两种从通过使用 P. stutzeri NT-I 控制生物挥发和生物矿化处理废水。通过生物挥发和生物矿化从废水中回收硒的比率在 120 小时时为 35.9%，在 24 小时时为 78.8%。此外，元素硒通过氧化还原反应或通过氧化焙烧从每个回收的化合物中提纯到 99% 或更高的纯度。