School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, P. R. China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China.
Environ Sci Technol. 2020 Aug 18;54(16):10313-10322. doi: 10.1021/acs.est.0c01496. Epub 2020 Aug 7.
Selective removal and resource recovery of ammonium nitrogen (NH-N) from high-strength ammonium waste streams is of practical importance for biological wastewater treatment and environmental protection. In this study, we demonstrate the simultaneous removal and reclamation of ammonium from synthetic digested sludge centrate via a novel osmosis-distillation hybrid membrane (ODHM) process. Using NaHCO as the draw solute, ammonium diffuses from the synthetic centrate to the draw solution by utilizing the bidirectional cation transport nature of the thin film composite (TFC) membrane. Then, NH is converted to gaseous NH at 60 °C and recovered by a sweeping gas membrane distillation (SGMD) process. Herein, the bidirectional transport of monovalent cations in the osmotic process, selectivity of TFC membranes for different cations, and recovery of the draw solution following the extraction of ammonia through the SGMD process were systematically investigated. The removal of NH-N from the synthetic centrate achieved 21.34% during a 6-h continuous operation of the ODHM system, with ammonium fluxes through the TFC and SGMD membranes at 1.39 and 0.57 mol m h, respectively. A secondary interfacial polymerization was proposed to further enhance ammonium transport through the TFC membrane. Results reported here highlight the potential of the ODHM process for the selective removal and reclamation of ammonium from ammonium-rich waste streams.
从高强度氨氮废水中选择性去除和回收氨氮（NH-N）对于生物废水处理和环境保护具有实际意义。在这项研究中，我们通过一种新型的渗透蒸馏混合膜（ODHM）工艺展示了从合成消化污泥浓缩液中同时去除和回收氨氮的过程。使用 NaHCO3 作为汲取剂，利用薄膜复合（TFC）膜的双向阳离子传输特性，使氨氮从合成浓缩液扩散到汲取液中。然后，在 60°C 下将 NH 转化为气态 NH3，并通过扫气膜蒸馏（SGMD）过程回收。在此，渗透过程中单价阳离子的双向传输、TFC 膜对不同阳离子的选择性以及通过 SGMD 过程提取氨后汲取液的回收均得到了系统研究。在 ODHM 系统连续运行 6 小时的过程中，从合成浓缩液中去除 NH-N 达到 21.34%，TFC 和 SGMD 膜的氨氮通量分别为 1.39 和 0.57 mol m-2 h-1。提出了二次界面聚合反应以进一步增强 TFC 膜的氨氮传输。这里报道的结果突出了 ODHM 工艺从富含氨氮的废水中选择性去除和回收氨氮的潜力。
