Abstract This study demonstrated the application of a new type of interlayer-free cobalt-doped silica membrane in treating ammonia solutions by pervaporation applied towards wastewater treatment. For enhanced hydrothermal stability, cobalt-doped silica (CoSi) membranes with increasing cobalt concentrations from 1 to 35 mol% were prepared and evaluated, namely CoSi-1, 5, 20 and 35. These membranes exhibited high water fluxes of 66 L m−2 h−1 for CoSi-1 and 15.5 L m−2 h−1 for CoSi-35 at 45 °C. The fluxes of the membranes decreased with increasing cobalt concentration; while the rejection to total nitrogen (TN, ammonia nitrogen) increased and hence allowed selective passage of water molecules. Enhanced thermostability was observed for the membranes, particularly CoSi-35 that exhibited TN rejection up to 99% at high temperature of 65 °C and highly alkaline environment (pH > 10). Also, the CoSi-35 membrane showed stable performance in treating ammonia present in industry wastewater by achieving stable TN and mineral rejections of 97% and 99%, respectively. Fouling was observed and confirmed by SEM morphological analysis and EDX elemental inspection. The results indicated the deposition of low solubility salts such as CaSO4.

中文翻译：

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用于氨溶液渗透蒸发的层间游离钴掺杂二氧化硅膜

摘要 本研究展示了一种新型无夹层钴掺杂二氧化硅膜在渗透蒸发处理氨溶液中的应用，适用于废水处理。为了增强水热稳定性，制备并评估了钴浓度从 1 mol% 增加到 35 mol% 的钴掺杂二氧化硅 (CoSi) 膜，即 CoSi-1、5、20 和 35。这些膜表现出 66 L m- 的高水通量在 45 °C 时，CoSi-1 为 2 h-1，CoSi-35 为 15.5 L m-2 h-1。膜的通量随着钴浓度的增加而降低；而对总氮（TN，氨氮）的排斥增加，因此允许水分子选择性通过。观察到膜具有增强的热稳定性，特别是 CoSi-35，在 65 °C 的高温和强碱性环境（pH > 10）下，TN 抑制率高达 99%。此外，CoSi-35 膜通过实现稳定的 TN 和矿物质截留率分别达到 97% 和 99%，在处理工业废水中存在的氨方面表现出稳定的性能。通过SEM形态分析和EDX元素检查观察并确认结垢。结果表明低溶解性盐如CaSO 4 的沉积。