Pilot-Scale Field Demonstration of Environmental Nanotechnology for Groundwater Defluoridation
Pilot-Scale Field Demonstration of Environmental Nanotechnology for Groundwater Defluoridation
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DOI：
10.1021/acsestengg.2c00284
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Zi-Ping Deng;Sikai Cheng;Nian Xu;Xiaolin Zhang;B. Pan
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作者：
Zi-Ping Deng;Sikai Cheng;Nian Xu;Xiaolin Zhang;B. Pan
地下水氟污染是一个全球性问题。纳米级的Zr（IV）、Al（III）和Ti（IV）氧化物可以通过配体交换与氟化物形成内球络合物，为高效净化地下水提供了新的机会。然而，纳米技术在地下水降氟中的中试规模现场示范非常罕见。在此，我们进行了150天的现场除氟研究，使用纳米复合材料HZO@D201，这是通过封装纳米水合氧化锆（HZO）内的强碱性阴离子交换剂D201制备。将HZO@D201珠填充在五级串联柱中（每个柱40 L），并将地下水依次泵送通过柱。单柱有效处理量（[F-] < 1.0 mg/L）超过3000床体积（BV）。用NaOH-NaCl溶液原位处理耗尽的HZO@D201，使其完全更新，可重复使用，脱氟反应性无明显损失。由于与HZO的特异性相互作用，在150 d的现场示范中，氟浓度可稳定降至1.0 mg/L以下，而地下水中常见的阴离子（K+、Na+、Ca 2+、Mg 2+、SO 42-、Cl-等）几乎保持不变。深度除氟的运行费用为0.574元/吨，远低于目前广泛研究的反渗透法。TEM、XPS和傅里叶变换红外（FTIR）分析表明，HZO@D201的结构和化学组成在长期的现场试验后发生了微不足道的变化。本研究为纳米水处理技术的中试和工程示范提供了有益的启示。
Fluoride contamination in groundwater is a global issue. Nanoscale oxides of Zr(IV), Al(III), and Ti(IV) can form the inner-sphere complex with fluoride through ligand exchange, offering a new chance for efficient groundwater purification. However, pilot-scale field demonstration of nanotechnology in groundwater defluoridation is very rare. Herein, we conducted a 150-day field defluoridation study using the nanocomposite HZO@D201, which was prepared by encapsulating nano-hydrated zirconium oxide (HZO) inside the strongly basic anion exchanger D201. The HZO@D201 beads were packed in five-stage series columns (40 L for each column), and the groundwater was pumped through the columns sequentially. The effective treatment amount for the single column ([F–] < 1.0 mg/L) exceeded ∼3000 bed volume (BV). The exhausted HZO@D201 was fully refreshed throughex situtreatment with NaOH–NaCl solution for repeated use without significant loss in defluoridation reactivity. Owing to the specific interaction with HZO, the fluoride concentration could be steadily reduced below 1.0 mg/L throughout the 150-day field demonstration, while the common anions coexisting in groundwater (K+, Na+, Ca2+, Mg2+, SO42–, Cl–,etc.) remained almost unchanged. The operational cost for deep defluoridation was estimated as 0.574 RMB per ton of groundwater, much less than that of the widely studied reverse osmosis. TEM, XPS, and Fourier transform infrared (FTIR) analysis indicated that negligible change occurred in the structure and chemical composition of HZO@D201 after the long-term field assay. This study may inspire more attempts at the pilot scale and engineering demonstration of nano-enabled water treatment techniques.