Abstract

Fluorine is a natural component of many sources of drinking water. An excess of fluorine in drinking water leads to metabolic disturbances in bone tissues. In this context, the International Drinking Water Quality Standards recommend adhering to a fluoride content of drinking water of no more than 1.5 mg/dm³. If this value is exceeded, water requires defluoridation. In this work, defluoridation by galvanocoagulation in a drum-type galvanocoagulator was studied. The half-cells of the galvanic couple were aluminum and shungite mined at the Polezhaevskii deposit, Karelia, Russia. The occurring electrochemical processes result in anodic dissolution of aluminum to form the corresponding hydroxides. The fluoride ion forms aluminofluoride complexes with them, which are adsorbed on freshly formed hydroxide flakes. The ratio between the half-cells of the galvanic couple as a significant factor of controlling the process efficiency was studied. It was shown that the fluoride ions were removed most completely at an aluminum : schungite ratio of 1 : 1.5. Experiments on model aqueous solutions of sodium fluoride detected a significant dependence of the process on the initial pH value. The experimental results enabled one to choose a mode of defluoridation of water with various fluoride contents. By the example of treatment of artesian water with a fluoride content of 9.1 mg/dm³ from Mashevka, Poltava oblast, Ukraine, a high efficiency of the studied process was demonstrated: the fluoride ion content of the water treated for 5 min decreased to 0.9 mg/dm³. In addition, when using shungite as a half-cell of the galvanic couple, its disinfecting effect was observed: whereas the initial content of coliform bacteria was 700 in 100 cm³, they were absent in the treated water. The redox potential was also reduced from 340 to 255 mV, which is noteworthy because this parameter has recently received considerable attention as being one of the most important parameters of water in its interaction with the human body.

中文翻译：

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锌矿在电凝法水中除氟中的应用

摘要

氟是许多饮用水的天然成分。饮用水中过量的氟会导致骨骼组织的代谢紊乱。在这种情况下，《国际饮用水质量标准》建议坚持饮用水中的氟化物含量不超过1.5 mg / dm ^3。。如果超过该值，则水需要脱氟。在这项工作中，研究了在鼓型电凝器中通过电凝除氟。电偶的半电池是在俄罗斯卡累利阿Polezhaevskii矿床中开采的铝和钨矿。发生的电化学过程导致铝阳极溶解，形成相应的氢氧化物。氟离子与它们形成氟化铝络合物，并被吸附在新形成的氢氧化物薄片上。研究了电偶半电池之间的比例作为控制工艺效率的重要因素。结果表明，氟离子在铝与次氯酸钠的比例为1：1.5时能最彻底地去除。在氟化钠模型水溶液上进行的实验检测到该过程对初始pH值的依赖性很大。实验结果使人们能够选择一种具有多种氟化物含量的水的脱氟模式。以氟化物含量为9.1 mg / dm的自流水处理为例³来自乌克兰波尔塔瓦州Mashevka，证明了所研究过程的高效率：处理5分钟的水中的氟离子含量降至0.9 mg / dm ³。另外，当使用锌矿作为电偶的半电池时，观察到了其消毒效果：尽管大肠菌的初始含量为100 cm ^3中为700 ，但在处理过的水中却没有。氧化还原电势也从340 mV降低到255 mV，这是值得注意的，因为该参数最近作为水在与人体相互作用中最重要的参数之一而受到广泛关注。