Luukkonen Tero, Věžníková Kateřina, Tolonen Emma-Tuulia, Runtti Hanna, Yliniemi Juho, Hu Tao, Kemppainen Kimmo, Lassi Ulla
a Kajaani University of Applied Sciences , Kajaani , Finland.
b Faculty of Chemistry , Brno University of Technology , Purkyňova Brno , Czech Republic.
Environ Technol. 2018 Feb;39(4):414-423. doi: 10.1080/09593330.2017.1301572. Epub 2017 Mar 16.
Ammonium [Formula: see text] removal from municipal wastewater poses challenges with the commonly used biological processes. Especially at low wastewater temperatures, the process is frequently ineffective and difficult to control. One alternative is to use ion-exchange. In the present study, a novel [Formula: see text] ion-exchanger, metakaolin geopolymer (MK-GP), was prepared, characterised, and tested. Batch experiments with powdered MK-GP indicated that the maximum exchange capacities were 31.79, 28.77, and 17.75 mg/g in synthetic, screened, and pre-sedimented municipal wastewater, respectively, according to the Sips isotherm (R ≥ 0.91). Kinetics followed the pseudo-second-order rate equation in all cases (k = 0.04-0.24 g mg min, R ≥ 0.97) and the equilibrium was reached within 30-90 min. Granulated MK-GP proved to be suitable for a continuous column mode use. Granules were high-strength, porous at the surface and could be regenerated multiple times with NaCl/NaOH. A bench-scale pilot test further confirmed the feasibility of granulated MK-GP in practical conditions at a municipal wastewater treatment plant: consistently <4 mg/L [Formula: see text] could be reached even though wastewater had low temperature (approx. 10°C). The results indicate that powdered or granulated MK-GP might have practical potential for removal and possible recovery of [Formula: see text] from municipal wastewaters. The simple and low-energy preparation method for MK-GP further increases the significance of the results.
从城市废水中去除铵[化学式：见原文]对常用的生物处理工艺构成挑战。特别是在废水温度较低时，该工艺常常效率低下且难以控制。一种替代方法是使用离子交换。在本研究中，制备、表征并测试了一种新型的[化学式：见原文]离子交换剂偏高岭土地质聚合物（MK-GP）。使用粉末状MK-GP进行的批量实验表明，根据Sips等温线（R≥0.91），在合成的、经过筛选的和预沉淀的城市废水中，最大交换容量分别为31.79、28.77和17.75 mg/g。在所有情况下，动力学均遵循准二级速率方程（k = 0.04 - 0.24 g mg⁻¹ min⁻¹，R≥0.97），且在30 - 90分钟内达到平衡。粒状MK-GP被证明适用于连续柱模式使用。颗粒强度高，表面多孔，并且可以用NaCl/NaOH多次再生。中试规模的试验进一步证实了粒状MK-GP在城市污水处理厂实际条件下的可行性：即使废水温度较低（约10°C），也能持续达到<4 mg/L的[化学式：见原文]。结果表明，粉末状或粒状MK-GP在从城市废水中去除并可能回收[化学式：见原文]方面可能具有实际潜力。MK-GP简单且低能耗的制备方法进一步提高了结果的重要性。
