SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Chengsi Hou,Shuai Peng,Zhengwei Zhou,Longqian Xu,Yue Wang,Jianfeng Zhu,Pan Zhang,Zuofeng Chen,Zhendong Lei,Deli Wu
Flow Electrode Capacitance Deionization (FCDI) has been frequently used for NH 4 + recovery from wastewater as a low-energy, high-efficiency electrochemical technique. However, issues such as high cost (mainly due to the use of ion-exchange membranes) and weak selectivity have limited the expansion of their applications. In this study, SDS-AC was prepared and applied in microfiltration membrane FCDI (MFFCDI) to recover ammonia (NH 4 + ). The material characterization results showed that the surfactant was stably loaded on the AC surface, and the adsorption capacity of modified AC for NH 4 + was greatly enhanced. During the recovery process, NH 4 + migrated to the electrode chamber and immobilized on the SDS-AC, while Na + migrated to the electrode chamber and then released to the desalination chamber due to co-ion repulsion. Based on this principle, selective recovery of NH 4 + was achieved (selectivity = 3.51). At the end of the recovery, more than 70 % of the NH 4 + was immobilized on the SDS-AC and the NH 4 + could be desorbed with NaOH. The results of the recycling experiments showed good stability of the SDS-AC-based MFFCDI system, and the recovery of food waste fermentation liquor demonstrated that the system could realize the selective recovery of NH 4 + from complex feed water. In summary, the SDS-AC-based MFFCDI technology has great potential for the application of NH 4 + recovery from wastewater. Although the scale of this study was limited to the laboratory stage, it still shows potential for application in engineering. In the future, larger scale applications in engineering will be carried out and the environmental and economic benefits of the technology will be assessed through a full life cycle analysis.
研究领域:
环境科学
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电化学工程
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产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2025
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IF 6.7
Yuansheng Tang,Wentian Zheng,Guangxing Yang,Wei Bi,Fengmi Zeng,Lu Xiao,Xianhui Li
Membrane contactors as an emerging separation technology exhibit great potential for ammonia recovery due to the thermal and chemical stability. However, membrane wetting remains a significant challenge, hindering its broader industrial application. This study explores the effects of membrane wetting on the ammonia absorption rates through membrane contactor under varying operation conditions. The wetting depth was in-situ monitored by the ultrasonic technique. Results reveal that reducing the feed flow rate and lowering the absorbent concentration can effectively mitigate the decline in ammonia absorption rates, while increasing the feed pH does not affect the membrane wetting process but enhances the ammonia recovery. Furthermore, the rare-earth wastewater proves suitable for treatment via membrane contactor as it requires no additional low-surface-tension surfactant and has a higher ammonia concentration. Moreover, a developed model is conducted to elucidate the transport mechanism of ammonia through membrane contactor during wetting process. With the increased wetting depth during membrane contactor process, the boundary layer thickness gradually increased, significantly strengthening the transfer resistance. This study provides an insight into further understanding the ammonia mass transfer through membrane contactor under wetting conditions.
研究领域:
环境工程
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化学工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Chi Zhang,Haotian Wu,Jiazhou He,Xiangtong Kong,Di He,Junjian Zheng,Jinxing Ma
The extraction of ammonia from waste sources, such as urine, presents significant potential for its utilization as fertilizers and chemical precursors. Conventional recovery techniques, such as air stripping and chemical precipitation, face limitations due to their high energy demands and substantial chemical usage. Although electrochemical alternatives offer improved selectivity for ammonia recovery, they remain constrained by slow ammonia mass transfer. In this work, we have designed an electrochemical system incorporating a parallel plate stack design with a membrane electrode assembly. This innovation leverages the benefits of electrochemical base production coupled with rapid ammonia separation and recovery from urine. The system achieved an ammonia removal rate of 19.4 g-N m −2 h −1 , with removal and recovery efficiencies recorded at 72.7 % and 93.5 %, respectively, while consuming 19.5 kWh per kg-N. The system’s performance and robustness were then evaluated using real urine. Over 96 h of continuous operation, at an ammonia removal rate of 14.5 g-N m −2 h −1 and an energy consumption of 33.1 kWh per kg-N, the removal and recovery efficiencies stabilized at 84.2 % and 78.4 %, respectively. The chemical scale that formed on the assembly was easily removed using a 0.1 M citric acid solution. Overall, the findings underscore the critical role of the nickel-based membrane cathode assembly in achieving chemical-free and efficient ammonia separation and recovery from urine, which may facilitate broader applications of membrane electrode assemblies in waste management and related fields.
研究领域:
环境科学
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化学工程
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废物管理
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Linjun Wu,Zhiqiang Shen,Yuexi Zhou,Jiane Zuo
This study rigorously assessed the efficacy of gas-permeable membrane (GPM) technologies in recovering ammonia from landfill leachate, focusing on polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE) membranes within in-situ (INS) and shell-tube (ST) configurations. The research spanned an array of determinants, including influencing factors, sustained operational efficiency, fouling dynamics, and recovery product purity. It was established that the INS-ePTFE configuration demonstrated formidable recovery capabilities and durable performance after fouling cleaning, with ammonia removal efficiency resurging to its initial state and stabilizing at 93 % post-maintenance. In contrast, the ST-PP configuration experienced an unrecoverable drop in removal efficiency to 83 %. Fouling analysis indicated that ePTFE membranes retained structural stability against organic and inorganic deposition, with humic substances and metal carbonates as predominant constituents. Conversely, PP membranes exhibited a decline in hydrophobic properties and structural integrity upon contamination. Furthermore, pH elevation significantly enhanced ammonia nitrogen mass transfer coefficients without increasing osmotic water transfer in INS systems. The INS system also showed promise for synergistic phosphorus recovery within the pH of 9 to 10. Then, NO 3 – , SO 4 2- and humic acid did not impede ammonia translocation, whereas a 1.5 % mass fraction of Ca 2+ incurred a roughly 30 % reduction in ammonia mass transfer coefficients across each system. The recovery of high purity (NH 4 ) 2 SO 4 attested to the exceptional retention capabilities of GPMs for organics and ions, with rejection rates surpassing 99.6 %. The comprehensive analysis underscored the operational superiority of the INS-ePTFE configuration in ammonia recovery.
研究领域:
环境工程
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Hyewon Jeon,Taehun Kim,Paula Jungwon Choi,Am Jang
With growing interest in hydrogen energy, liquid ammonia has emerged as a promising hydrogen carrier due to its low boiling point and high volumetric energy density. In addition to green and brown ammonia, white ammonia, produced through waste recycling, has gained attention. This study explored the use of a Janus membrane in a membrane contactor system for white ammonia recovery from high-strength wastewater, such as anaerobic digestion effluent, which is prone to membrane fouling owing to its complex organic and inorganic constituents. To address the challenge, a Janus membrane with asymmetric wettability, combining a hydrophilic surface and a superhydrophobic layer, was used to enhance interfacial stability and ammonia transport. The Janus membrane achieved a mass transfer coefficient (MTC) of 0.039 m/h, which was 8.3 % higher than that of the SHPO-only membrane and exhibited only a 5.13 % MTC reduction after extended fouling, compared to a 20.93 % reduction for the virgin membrane. Postoperative Fourier transform-infrared and X-ray photoelectron spectroscopy analyses confirmed the chemical integrity of both layers, and scanning electron microscopy imaging revealed limited surface deposition. In addition, the Janus configuration enabled directional vapor flow and reduced interfacial mass transfer resistance compared with symmetric membranes. The findings demonstrate that the Janus membrane provides a robust and scalable platform for stable ammonia separation in the presence of severe fouling and complex wastewater matrices.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2023
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IF 8.7
Ruichi Zhang,Yizhong Zhang,Ronn Goei,Wen-Da Oh,Zhao Zhang,Chao He
To realize sound disposal of hyperaccumulator harvested from phytoremediation , hydrothermal carbonization (HTC) has been employed to obtain superior hydrochar adsorbents for removal of phosphate and ammonium from water body. A series of hydrochars have been prepared under tuned HTC conditions to tailor hydrochar with desired properties. Generally, increased temperature and prolonged reaction time facilitated acidic oxygen functional groups on hydrochars, thereby improving adsorption capacity of hydrochar. In single solute system, a superior hydrochar, derived from HTC under 260 °C for 2 h, achieved a maximum phosphate and ammonium adsorption capacity of 52.46 mg/g and 27.56 mg/g at 45 °C, respectively. In binary system, synergistic adsorption was observed only in lower solute concentration , whereas competitive adsorption occurred under higher solute concentration. Characterization and adsorption kinetics suggested chemisorption may dominate the adsorption process , thus the adsorption capacity could be improved by tuning pH pzc of hydrochar. This study firstly demonstrates the sustainable utilization of hyperaccumulators into nutrients-enriched hydrochar as fertilizer for in-situ phytoremediation of contaminated sites with minimized environmental risks towards circular economy .
研究领域:
环境科学
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生物学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Taoqin Chen,Longqian Xu,Sheng Wei,Zhiqiang Fan,Ruibo Qian,Xueli Ren,Guo Zhou,Hongquan Yang,Jiayun Wu,Hongbin Chen
The conventional technologies for ammonia recovery from wastewaters usually requires high chemicals and energy input. And if the wastewater contains hardness, there is a risk of scaling with increasing in cost. Flow electrode capacitive deionization (FCDI) coupled with monovalent cation exchange membrane (MCEM) was employed to solve abovementioned problem. Our method was an effective strategy for the selective production of an ammonia-rich solution from coal gasification gray water by simply adjusting the charging and discharging processes. During the charging process, both NH 4 + and Na + were transported to the cathode due to electrosorption of the electrical double layers (EDLs) on charged carbon particles and electrodialysis of potential gradient, while Ca 2+ was retained by the MCEM. The Faradaic reactions induced the generation of OH - and led to the conversion of charged NH 4 + into uncharged NH 3 . When the electrode polarity was reversed, charged species such as Na + would be mostly pushed back into the spacer chamber, yet NH 3 was more likely to be trapped in the cathode due to sluggish pH variations, thereby producing an ammonia-rich solution. Under optimal operating conditions (i.e., a carbon content of 5 wt%, charge and discharge voltages of 4.5 and 0.2 V, respectively, charge 80 min and discharging 15 min, and six continuous cycles), a stable recovery efficiency (∼205 mg/L per cycle) and product purity of 70.4% were attained at a relatively low electrical energy consumption (11.1 kWh/kg N). Additionally, Ca scale was effectively avoided by MCEM. These results demonstrated that FCDI coupled with MCEM could be a promising technology for efficient NH 4 + removal, recovery as an ammonia-rich solution and TOC removal from industry wastewaters with alleviation of scaling.
研究领域:
环境工程
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化学工程
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DOI
高影响因子
WATER RESEARCH
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2024
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IF 11.4
Jiazhou He,Jieqin Zhou,Kui Yang,Liang Luo,Pan Wang,Zhiwei Wang,Jinxing Ma
Recovering ammonia from waste streams ( e.g. , urine) is highly desirable to reduce natural gas-based NH 3 production and nitrogen discharge into the water environment. Electrochemical membrane stripping is an attractive alternative because it can drive NH 4 + transformation to NH 3 via cathodic OH − production; however, the conventional configurations suffer from relatively low ammonia recovery (<80 %) and significant acid/material usage for ammonia adsorption. To this end, we develop a novel stack system that simply uses an oxygen evolution reaction to in-situ produce acid from water, enabling chemical-free ammonia recovery from synthetic urine. In batch mode, the percentage removal and recovery increased respectively from 74.5 % to 97.9 % and 81.8 % to 92.7 % when the electrode pairs increased from 2 to 4 in the stack system. To address the gas-sparging issue that deteriorated ammonia recovery in continuous operation, pulsed electric field (PEF) mode was applied, resulting in ∼100 % recovery under optimized conditions. At an ammonia removal rate of 35.1 g-N m −2 h −1 and electrical energy consumption of 28.9 kWh kg-N −1 , our chemical-free system in PEF mode has achieved significantly higher ammonia recovery (>90 %) from synthetic urine. The total cost to recover 1 kg of NH 3 –N from real human urine was $15.9 in the proposed system. Results of this study demonstrate that this novel approach holds great promise for high ammonia recovery from waste streams, opening a new pathway toward sustainable nitrogen management.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2025
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IF 6.7
Linjun Wu,Huan Li,Yuexi Zhou,Zhiqiang Shen,Jiane Zuo
This research evaluated the efficacy of self-sustaining alkalinity driven gas permeable membrane (SSAD-GPM) in ammonia recovery under low-rate aeration. This research initially confirmed the role of HCO 3 − and CO 3 2− in enhancing alkalinity release and ammonia conversion. It was determined that providing alkalinity through HCO 3 − necessitates the consumption of inorganic carbon (IC), and highlighting the criticality of maintaining a HCO 3 − /NH 4 + ratio exceeding 1.0 to optimize ammonia removal efficiency (>90.5 %). Alkalinity via CO 3 2− involves a two-stage hydrolysis process, consuming IC only in the second phase. Then, comparing SSAD-GPM with alkalinity addition driven GPM (AAD-GPM) for real anaerobic digestate treatment, SSAD-GPM demonstrated an initial ammonia removal efficiency of 99.1 %, which reduced to 82.8 % after 40 days of operation. In contrast, the efficiency of AAD-GPM decreased to 62.6 %. Superior anti-fouling performance of SSAD-GPM, due to aeration-induced turbulence, mitigated concentration polarization and fouling. Efficiency was restored to 98.1 % post-cleaning with tap water. Lastly, this research assessed the alkalinity consumption and cost of various ammonia removal/recovery strategies, demonstrating that SSAD-GPM can substantially lower operating costs, yielding a net profit of $0.081/kg N. These findings underscore the potential of SSAD-GPM as a cost-effective approach for treating high ammonia‑nitrogen wastewater with sufficient self-sustaining alkalinity (HCO 3 − /NH 4 + > 1.0).
研究领域:
环境科学
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污水处理
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产品关联
DOI
高影响因子
DESALINATION
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2022
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IF 11.211
Taoqin Chen,Longqian Xu,Sheng Wei,Xianchun Tang,Hongbin Chen
Carbon materials with abundant micropores and large specific capacitance (e.g., activated carbon, AC) are usually considered to be ideal candidates for flow-electrode capacitive deionization and are now widely employed to the ammonia recovery from wastewater. However, the microporous structure endows AC with a strong adsorption capacity toward ammonia nitrogen, which greatly reduces the recovery efficiency (the storage of ammonia nitrogen in the electrolyte). In this study, magnetic nickel-loaded carbon black (Ni 0 -CB) particles were simply synthesized by impregnating Ni onto the surface of the carbon black (CB) particles, endowing no <50 % of electrical energy savings and increasing ammonia recovery efficiency by ~20 % in comparison to AC. When charging, Na + and NH 4 + were migrated to the cathode, with the conversion of NH 4 + into NH 3 was accelerated due to the higher pH of Ni-CB systems. The excellent electrical conductivity of the CB body and compensation of the conductivity of Ni greatly decreased the electrical energy consumption. Followed by reverse discharge, Na + and less NH 4 + would be turned back into the spacer chamber; the adsorption toward NH 3 was effectively reduced due to the abundant mesopores of CB. Thus, NH 3 was more likely to be retained in the electrolyte. In addition, the superior magnetic features of Ni-CBs realized the rapid separation of the CB and ammonia-rich solution. The introduction of magnetic Ni-CB in flow-electrode electrochemical deionization technology realized the improved ammonia-rich solution production from wastewater and the recycling of carbon particles without additional solid–liquid separation (i.e., filtration, settlement).
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2016
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IF 5.267
Xinggang Wang,Shaoyu Lü,Chunmei Gao,Chen Feng,Xiubin Xu,Xiao Bai,Nannan Gao,Jinlong Yang,Mingzhu Liu,Lan Wu
To minimize the negative impact of nitrogen and phosphorus pollution from wastewater and improve fertilizer use efficiency, a novel multifunctional slow-release compound fertilizer was prepared by recovery of NH4+ and H2PO4– from aqueous solutions onto amphoteric straw cellulose (ASC) adsorbent. The effects of adsorbent dosage, solution pH, contact time and ionic strength on adsorption were investigated. The adsorption quickly reached equilibrium. The maximum NH4+ adsorption capacity of ASC was 68.4 mg g–1 at around pH 7.0, whereas it was 38.6 mg g–1 for H2PO4– adsorption at pH 5.0. Moreover, the feasibility of reusing the nutrients-laden carrier material as a multifunctional slow-release compound fertilizer was determined. The study demonstrated the product with excellent slow-release and water-retention properties. Thus, it could improve soil moisture content and reduce soil moisture evaporation rate and was economical and environmentally friendly for application in horticulture and agriculture.
研究领域:
环境科学
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农业科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Qin-Hua Xu,Yuxin Li,Junyue Bao,Zeting Li,Yaofeng Cai,Yanbin Xu
The widespread adoption of anaerobic digestion in manure management necessitates handling discharged ammonia–nitrogen (NH 4 + -N)-rich digestate, where electrochemical ammonia recovery is a viable solution but is limited by the cost of membrane fouling. Here, we present a membrane-free ion enrichment electrolyzer (MIEE) engineered with an electrode spatially decoupled structure, enabling NH 4 + and OH – ion enrichment in the anaerobic digestate for further ammonia recovery. Through in-situ measurements, we identify electrochemically induced relative concentration gradients of ions as the pivotal mechanism driving ion enrichment. MIEE maintains electroneutrality by migrating ions, and the effect is close to electrodialysis below ∼50 % migration of NH 4 + ions. Cathode effluent treated by MIEE achieves ∼80 % ratio of NH 4 + -N recovery in the stripping process, coupled with carbon mitigation. The cost of OH – ions supplied by MIEE is ∼50 % compared to directly dosing NaOH. The anode effluent neutralizes the stripping effluent pH from 9.3 to 8.6 and optimizes the organic carbon/nitrogen molar ratio from 1.5 to more than 3, enhancing compatibility with the bioprocess. This study presents a novel strategy for enriching ions without ion exchange membranes, which reduces the cost of membranes and stripping pretreatment in the ammonia recovery.
研究领域:
环境工程
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化学工程
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电化学
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废弃物管理
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可持续技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）