SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Dachao Lin,Zhongsen Yan,Xiaobin Tang,Jinlong Wang,Heng Liang,Guibai Li
Nanofiltration is routinely applied as an advanced water treatment technology after conventional water treatment. However, the residual coagulant after coagulation process may affect the nanofiltration process and to our best of knowledge, few studies focused on this phenomenon. To address such issues, ferric and aluminum ions were adopted as the model coagulant, and the influences of coagulant concentrations, coagulant conditioning time and fouling strategies on gypsum scaling were systematically investigated. The results indicated that coagulant conditioned on the membrane surface could improve membrane flux, enhance scaling, and increase the conductivity of permeate. The contents of coagulant accumulated on the membrane surface gradually increased with its increasing concentration in feed solution and extending conditioning time, resulting in severer scaling and flux decline. Interestingly, the formation of heterogeneous scaling layer will contribute to membrane fouling alleviation and prevent the further flux decline regardless of the ongoing increase of coagulant concentrations in the feed water as well as on the membrane surface. As a result, a critical value of coagulant concentrations in the feed water was obtained in present conditions. Furthermore, it's found that successive fouling strategy could lead to less gypsum scaling but severer flux decline, compared to simultaneous fouling strategy. Both the scaling quantity and scaling morphologies conferred significant influence on the flux decline. It is suggested that the concentrations of coagulant should be strictly controlled prior to nanofiltration process, especially with practical relevance for the applications of it in treating the water rich in calcium ions and sulfate anions.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Di Xu,Zhigao Zhu,Guangming Tan,Xiangyang Xue,Jiansheng Li
Scaling in membrane distillation (MD) is inevitable in concentrating hypersaline wastewaters. Although adding antiscalants in hypersaline brines can effectively mitigate membrane scaling, the effectiveness and underlying mechanisms in preventing scaling on differently wettable membrane surfaces with different functional-group antiscalants have rarely been reported. Herein, the hydrophobic, superhydrophobic and Janus membranes with ultrathin scale inhibition layer were elaborately designed to elucidate the efficiencies of functional groups of antiscalants in preventing gypsum scaling on differently wettable membrane surfaces. The results show that the superhydrophobic and Janus membranes are the most effective in retardation of membrane scaling in the presence of a single antiscalant with carboxyl or amino functional groups, respectively. Besides, the performance of the superhydrophobic membrane can be further improved while the Janus membrane was continuously declined as amino and carboxyl-functional-group antiscalants were simultaneously added to the feed gypsum solution. A set of characterization analyses revealed that the significant improvement in membrane gypsum scaling resistance is ascribed to the obstruction of scale precursors to nucleation. Meanwhile, the physicochemical characteristics of antiscalants also contribute to reducing the salt deposited on the MD membrane surface in the supersaturated brine. This work provides new insight into the structure design of membrane and antiscalants tailored to MD for concentrating hypersaline brines with high water recovery and robust salts rejection efficiency.
研究领域:
环境工程
·
膜科学
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Chao Wang,Yangbo Qiu,Chengyi Wang,Long-Fei Ren,Jiahui Shao
Dense Janus membranes (JMs) have emerged as potential candidates to address the tough scaling issue in hypersaline wastewater treatments for membrane distillation (MD). However, behaviors and mechanisms of various scalants on dense JMs have not been systematically investigated. Herein, we designed three dense JMs to simultaneously compare their anti-scaling properties against gypsum and silica in MD and focus on the critical role of varied surface property in scaling control. Results showed that dense JMs with highly positive gypsum-membrane interfacial energy and with strong electrical repulsion against silica species were more effective in resisting gypsum and silica, respectively. Scaled membrane characterization, quartz crystal microbalance monitoring, interfacial energy analysis and AFM force measurement revealed the distinct anti-scaling mechanisms. Highly hydrophilic surfaces without specific interactions with scaling ions provided robust thermodynamic barriers and less kinetically affected local supersaturations, preventing gypsum nucleation and growth. In contrast, positively charged surfaces favorably attracted negatively charged silica species with high reactivity, promoting subsequent polymerization with silicic acid that kinetically dominated silica scaling. Moreover, coexisting oversaturated gypsum and silica influenced the scaling behavior of each other, and surface properties of the preferentially formed scaled layer might also matter in scaling process. This study shall provide useful insights into the anti-scaling mechanisms of dense JMs in MD and highlight the potential of dense surface design as an effective scaling control strategy to pave the way for potential MD applications.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Yue Shen,Jingyuan Zhou,Bin Wu,Mengni Ge,Naixin Wang,Yan Zhao,Quan-Fu An,Bart Van der Bruggen
Membrane scaling is one of the drawbacks of nanofiltration (NF) impeding its wide application in treatment of salt-containing water. Especially, the high concentration of Ca 2+ and SO 4 2− easily lead to a CaSO 4 scale layer on the membrane surface, limiting the separation process. Herein, a zwitterionic NF membrane with anti-scaling performance was fabricated through multi-carboxyl carboxylate (sodium citrate) incorporated by interfacial polymerization. Due to the synergistic effect of sodium citrate, the resulting NF membrane had a more negatively charged surface and a larger pore size than the pristine membrane. In desalination, this zwitterionic NF membrane exhibited a high selectivity (15.9) between SO 4 2− (73.1 ± 2.4% rejection) and Ca 2+ (4.6 ± 1.4% rejection) with a flux of 39.6 LMH, much higher than that of the commercial NF membrane (NF-270, a selectivity of 1.5). Based on the high SO 4 2− and Ca 2+ selectivity, it is difficult to form a CaSO 4 scale layer on the membrane surface, which yields an excellent anti-scaling performance of the resulting membrane. Furthermore, the zwitterionic monomer endowed the membrane with an anti-fouling effect due to zwitterions materials have strong hydration to resist nonspecific protein adsorption. This design strategy of ion selectivity zwitterionic membranes through the incorporation of carboxylate provides guidance for the design of highly ion selective anti-scaling NF membranes, which has potential applications in water treatment for salt-containing solutions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Yuhua Dong,Yutong Xie,Jiaqi Yu,Wenjiao Zhang,Xueyan Du,Qiong Zhou
Scaling and corrosion are common issues in the petroleum industry that compromise production safety. Currently, organic coatings are considered the most effective method for scaling inhibition. This paper presents the synthesis of hollow periodic mesoporous organosilica (HPMO) nanocontainers with a high specific surface area and a uniform, ordered mesoporous structure, using a hard template method. The morphology of HPMO was controlled by adjusting the water-to-ethanol ratio and precursor amount. Characterization of HPMO morphology and structure was conducted using scanning electron microscope, transmission electron microscope, X-ray diffraction, and nitrogen adsorption-desorption analysis. To enhance loading capacity, HPMO was modified with 3-aminopropyl triethoxysilane, increasing the encapsulation of the scale inhibitor ethylenediamine tetramethylphosphonic acid (EDTMP) from 3.6 % to 13.8 %. The modified HPMO, loaded with the scale inhibitor, significantly improved the protective and anti-scaling properties of epoxy resin coatings. Compared with pure epoxy coatings, the scale inhibition rate of the composite coating increased by 42 % under static conditions and 90 % under dynamic conditions. The crystalline morphology of calcium carbonate scale was also influenced by the scale inhibitor; EDTMP promoted the formation of acicular aragonite and inhibited cuboid calcite growth in static conditions. In dynamic conditions, aragonite was not observed, and the calcite crystals were smaller than those formed in static solutions.
研究领域:
材料科学
·
石油化工
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Jinjin Jia,Jinlong Wang,Dachao Lin,Jing Zhao,Hesong Wang,Longfeng Hu,Jiaxuan Yang,Han Zhang,Guibai Li,Heng Liang
Membrane scaling severely hinders practical application of nanofiltration (NF) for brackish water treatment. However, the contributions of residual aluminum ( Al ), especially various species with differing polymerization degrees and sizes, to gypsum scaling remain unclear. Herein, the complex interactions between three Al species (AlCl 3 , Al 13 and Al 30 ) and gypsum scaling were investigated, including surface and bulk crystallization processes. Results demonstrated that Al species adhering to the membrane surface promoted surface crystallization and altered crystal morphology. Notably, the Al 13 species induced the formation of dense, complete rosette crystals causing the most severe flux decline. For bulk crystallization, Al 30 was the primary species to promote nucleation. This promotion resulted from two factors: a lower nucleation energy barrier and the promoted aggregation of small crystals. Furthermore, molecular dynamics (MD) simulations revealed that the inhibition of nucleation due to the competition between Al species and calcium ions at nucleation sites was negligible compared to the strong promotion effect. These findings demonstrated that PACl exhibit higher scaling potential during NF than monomeric Al coagulants. Ultimately, the competition between surface and bulk crystallization determined the final membrane flux decline. This study offers valuable insights into the mechanisms of NF scaling caused by residual Al and guides mitigation strategies.
研究领域:
环境科学
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水处理
·
膜技术
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xinxia Tian,Jian Wang,Lei Tian,Yang Yang,Yangyang Wei,Guorong Xu,Jinbin Chen,Quan Kang,Jun Zhang,Yan Jin,Zhaokui Li
Long-term stable operation of nanofiltration membranes is critical to ensure safe and efficient water treatment processes, requiring membranes that exhibit both high permselectivity and robust scaling resistance. This study presents a novel surface functionalization strategy based on the dual-functional monomer betaine hydrazide hydrochloride for tailoring the surface charge of nanofiltration membranes. The functionalized membranes demonstrated a combination of high water flux, efficient monovalent/divalent salt separation, and good resistance to CaSO 4 scaling – a prevalent and persistent challenge in membrane processes. The optimal functionalized nanofiltration membranes displayed a water flux of 59.8 L·m −2 ·h −1 and a Na + /Mg 2+ separation factor of 48.6, corresponding to improvements of 32.3 % and 120.9 %, respectively, over the control membrane. In addition, the membrane achieved superior Li + /Mg 2+ separation, reducing the Mg 2+ /Li + ration from 80 in the feed to 1.328 in the permeate with a Li + /Mg 2+ separation factor of 60.6. This separation factor represents a 112.6 % improvement over that of the control membrane. Long-term scaling tests revealed improved anti-scaling performance, with the functionalized membrane retaining 91 % of its initial flux after 96 h of Ca 2+ and SO 4 2− exposure, compared to only 83 % for the control membrane. Real-time optical coherence tomography in situ monitoring further confirmed the enhanced scaling resistance of the functionalized membrane. These results highlight the great potential of functionalized nanofiltration membranes for high-performance desalination and ion separation applications.
研究领域:
膜科学与技术
·
水处理工程
·
材料表面改性
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分离科学
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环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Haiyun Li,Zhengshi Yu,Yibo Lin,Wentian Zhang,Cunxian Lai,Lichao Xia,Fangang Meng,Shanshan Zhao
Membrane distillation (MD) is a promising technology for hypersaline wastewater treatment. However, commercial hydrophobic MD membrane usually suffers from severe wetting/fouling/scaling challenges that seriously hinder its wide applications. It is urgent to develop a robust MD membrane with simultaneous wetting/fouling/scaling resistance in a facile way. In this study, a Janus membrane with a dense hydrophilic nanofiltration top layer was simply fabricated by co-deposition of pyrogallic and polyethylenimine on hydrophobic polyvinylidene difluoride membrane followed by glutaraldehyde cross-linking. The Janus membrane can maintain stable performance during long-term treatment of saline wastewater containing surfactants, oil, and/or mineral ions, suggesting its excellent simultaneous wetting/fouling/scaling resistance. The mechanisms analyses reveal that the excellent wetting/fouling resistance is owed to the combined effects of strong surface hydration barrier, size exclusion, and strong capillary force. Moreover, the positively charged amino groups on the membrane surface further enhance the scaling resistance. Remarkably, the Janus membrane demonstrated exceptional performance during long-term (>100 h) treatment of ethylene waste lye, a hypersaline organic wastewater containing a broad spectrum of contaminants. The membrane possessed stable vapor flux and exhibited near-perfect salt rejection (99 %) and organic rejection (98 %). Our study provides a simple method for designing a robust Janus membrane for treating hypersaline organic wastewater and demonstrates the significant industrial application potential of MD technology.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2022
·
IF 11.211
Songchen Xie,Ngie Hing Wong,Jaka Sunarso,Qiang Guo,Chunguang Hou,Zhiguang Pang,Yuelian Peng
Mineral scaling is one of the major challenges for membrane distillation in concentrating high-salinity brine. This work first investigated the characteristic of CaSO 4 scaling, then explored different cleaning reagents to evaluate their efficiencies and mechanisms. By analyzing the SEM and EDX mapping images, the CaSO 4 scaling process could be divided into surface and pore scaling stages. Three cleaning solutions, i.e., commercial detergent (20 %), EDTA-4Na (0.05 M), and MgCl 2 (0.8 M), were chosen for their high CaSO 4 solubility (0.7 g CaSO 4 per 100 g H 2 O). At the surface scaling stage, three cleaning solutions exhibited excellent removal of CaSO 4 scaling with approximately similar 96 % cleaning efficiencies. However, at the pore scaling stage, only the commercial detergent showed high efficiency (89 %). Such high cleaning efficiency was mainly attributed to the detergent's high total dissolved solids (salinity), low pH, and high diffusion rate (5.46 μm cm −1 min −1 ) across the membrane. Moreover, periodic cleaning at the surface scaling stage with the commercial detergent followed by drying throughout a 43.5 h continuous concentration test on an actual RO brine could restore the PTFE membrane performance completely, giving 90 % of the total water recovery . This work provides new insights into the cleaning mechanism for gypsum scaling in a hydrophobic porous membrane.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2023
·Vol. 11
·期 6
·1779
·
IF 3.5
Qiao Zhu,Zhe Li,Yafei Song,Yujun Tong,Tao Yang,Zhenmin Cheng
The reduced solubility of inorganic salts in supercritical water has a significant impact on the stable operation of desalination facilities as it may lead to surface fouling due to salt deposition. In this study, the solubility of Na2SO4was experimentally determined to be 0.04–15.34 mmol/kg water at 23–25 MPa and 390–420 °C. To investigate the precipitation behavior of Na2SO4in supercritical water, a reactor with a heating bar was designed and the deposition effect of salt on the superheated surface in an autoclave was tested at a temperature of 390 °C and a pressure of 23 MPa. Then, the deposition mechanism of salt in the autoclave was analyzed and the temperature field in the reactor was simulated using CFD commercial software. The experimental results showed that Na2SO4was present on both the heating rod and the bottom of the autoclave with a loose salt layer. The simulation results indicated that the temperature near the heating rod was significantly higher than the bulk fluid temperature and it provided the temperature condition where the inorganic salt preferentially nucleated and precipitated. Nickel foam was chosen as the porous media carrier to investigate the selective precipitation of salt on different superheated surfaces. The results showed that nickel foam could collect a large amount of salt on the heating rod and change the state of the compact salt layer on the kettle bottom wall, providing a technical choice for salt recovery under supercritical conditions.Keywords:supercritical water;desalination;temperature effect;surface fouling
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Yin-Shuang Hu,Shuo-Chun Ke,Yu-Xi Huang
Membrane fouling and scaling are two critical challenges in membrane distillation (MD). The traditional superhydrophobic anti-scaling strategy is contradictory to the hydrophilic anti-fouling coating, creating a crucial challenge to combine these two properties into one material. In this study, glutamic acid (GA) was grafted on a polyvinylidene fluoride (PVDF) membrane surface to achieve fouling and scaling resistance simultaneously. The hydrophilic GA modification endowed the membrane with a larger underwater oil contact angle without affecting the surface morphology. The direct contact MD (DCMD) tests demonstrated that the GA-modified membrane had excellent oil fouling resistance due to the formation of a hydration layer by the GA molecules. In addition, the surface carboxyl groups offered plenty of coordination sites for metal ions, such as calcium ions. The surface coordination of calcium resulted in a lower free calcium concentration on the membrane surface, thereby postponing the scale nucleation and preventing the scales from intruding into the membrane matrix. The scaling tests also showed that the gypsum scales grown on the modified membrane were smaller than those on the pristine PVDF membrane. Besides, membrane cross-section analyses revealed that no scale intrusion was observed in the GA-modified membrane. Long-term stability tests and practical application with ethylene plant spent caustic further confirmed the promising application potential of the membrane. These results demonstrated that anti-fouling and anti-scaling properties can be integrated using the GA modification. This study provides a new surface modification strategy for designing and fabricating a robust anti-fouling and anti-scaling MD membrane.
研究领域:
材料科学
·
化学工程
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 44
·e202404251
·
IF 1.9
Zichao Yin,Zhenhua Sun,Junyi Li,Haigang Zhou,Jingjing Qi,Weidong Wang
Graphical A multifunctional coating composed of PTFE, PDMS, and nano silica was successfully prepared via deposition coating and heating treatment in this study, which possessed excellent anti-corrosion, anti-scaling, anti-fouling, anti-icing, and self-cleaning properties. This superhydrophobic coating can be loaded onto various facilities and equipment as top finish, protecting the substrates from water containing contaminants. This coating may have broad applications in the field of metal substrate protection. PTFE-based superhydrophobic coatings have received increasing research and the fabricated coatings exhibited excellent anti-corrosion, anti-scaling, anti-fouling, and anti-icing properties. In order to further enhance the hydrophobicity of PTFE coating, a PTFE-based coating consisted of nano-silica and polydimethylsiloxane (PDMS) was fabricated by deposition coating and annealing treatment. The water contact angle and sliding angle of the coating achieved 160.65° and 3.02°, respectively, demonstrating it possessed superhydrophobic property. Due to its excellent surface feature, the coating exhibited resistance to milk, coffee, and mud water, and could be easily cleaned by water flow. Besides, the water droplet on the coating had a longer freezing time and the ice droplet could be easily removed from the coating. Ascribed to the abundant nonpolar groups and the air cushion formed under water, the prepared coating had outstanding anti-scaling and anti-corrosion properties. The electrochemical impedance of the steel plate with the coating (above 9000 Ω·cm 2 ) increased by two orders of magnitude compared with the non-coating one (78.2 Ω·cm 2 ), and the anti-scaling rates of the coating towards BaSO 4 and SrSO 4 were all above 80%. It is promising that the coating will be a competitive candidate in many application fields.
研究领域:
材料科学
·
表面工程
✓ 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）