SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Maonan Zhang,Qing Xia,Xiaodan Zhao,Jiaming Guo,Li Zeng,Zhen Zhou
Residual anion polyacrylamide (APAM) and fluctuating calcium ion (Ca 2+ ) in flue gas desulfurization wastewater after pretreatment could result in ion-exchange membrane fouling during electrodialysis process. Concentration effects of Ca 2+ on APAM fouling were systematically investigated and the mechanisms were illustrated. Results of desalination performance indicated that Ca 2+ alleviated APAM fouling and the mitigating effect increased firstly and then declined, obtaining the mildest fouling phenomenon in the presence of 1.0 mM Ca 2+ . Zeta potential and particle radius of APAM in the feed solutions increased as Ca 2+ changed the charge balance of APAM molecules and complexed with them. Morphology and chemical structure analysis concluded that APAM molecules were adsorbed on the membrane surface and the fouled layer changed with increasing Ca 2+ concentration, from dense layer to reticular structure and then to sophisticated multilayer structure. Calculation of interfacial free energy based on Extended Derjaguin-Landau-Verwey-Overbeek theory confirmed that electrostatic interaction dominated the membrane fouling process. Concentration effects of Ca 2+ were more remarkable on membrane-APAM attraction and APAM-APAM repulsion at 0.0–1.0 and 1.0–10.0 mM, respectively. The results contribute to establishing comprehensive understanding of the concentration effects of Ca 2+ on polymer fouling of membranes and provide new insights into cleaning process optimization.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2021
·Vol. 29
·期 12
·17964-17976
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IF 4.223
Chen Heng,Liu Fengjun,Cai Chenjian,Wu Hao,Yang Linjun
A novel adsorbent consisting of tannic acid (TA) immobilized on graphene oxide (GO) was proposed and used to remove Hg 2+ from desulfurization wastewater. The morphology and physicochemical properties of tannin-immobilized graphene oxide (TAIGO) were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The characterization results showed that TA was successfully immobilized on GO, and that new functional groups were introduced on TAIGO. The effects of contact time, adsorbent dose, pH, and ion components on removal efficiency were evaluated. The adsorption process was found to be complete within 15 min, and the removal efficiency increased with increasing adsorbent dosage. The pH value affected the protonation of TAIGO and the form of Hg 2+ in wastewater. High concentrations of Cl − and SO 3 2− hindered the adsorption performance, whereas SO 4 2− and cations had a negligible effect. In addition, the excellent economic benefits of TAIGO were analyzed in an economic evaluation, and the Hg 2+ removal efficiency remained at 88% after three recycles. A pseudo-second-order kinetic model ( R = 0.9995) was used to fit the adsorption process, and the oxygen-containing functional groups and chelation reaction played critical roles in adsorption. TAIGO is a low-cost adsorbent with high Hg 2+ removal efficiency and could be further used in practical desulfurization wastewater. Graphical abstract
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
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2025
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IF 5.7
Jian Zhou,Qiaojun Liu,Hangfei Zhang,Yan Kong,Yanhong Li,Kui Huang
Anion exchange membranes polypyrrole-modified(PPy-M), polypyrrole-graphene oxide-modified(PPy-GO-M), and polypyrrole-polyethyleneimine-graphene oxide-modified(PPy-PEI-GO-M) were synthesized using in situ polymerization for advanced desulfurization wastewater treatment and cathodic scaling inhibition in membrane electrolysis(ME). Characterization by SEM-EDX(scanning electron microscope-energy-dispersive X-ray spectroscopy), AFM(Atomic force microscopy), FT-IR(Fourier-transform micro-infrared spectrometer), XPS(X-ray photoelectron spectroscopy), and Raman spectroscopy revealed the membranes morphology and chemical properties, and their basic performances, including ion exchange capacity, water uptake, contact angle, zeta potential,perm-selectivity, and the membrane resistance, were rough analyzed. PPy-PEI-GO-M showed the best performance, with an ion exchange capacity of 2.57 mmol g -1 , contact angle of 85°, zeta potential of +15.59mV, membrane resistance of 6.97 Ω cm 2 , and perm-selectivity of 98%. Under optimal electrolysis conditions (ME time 180 min, temperature 30°C, current density 40 mA cm -2 , electrode spacing 4 cm), it achieved a Cl - removal rate of 96.83% without cathodic scaling, with treated effluent successfully reused in a flue gas desulfurization system. This modified membrane shows strong potential for water treatment applications.
研究领域:
环境工程
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膜科学与技术
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水处理
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电化学工程
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材料化学
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工业废水治理
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功能高分子材料
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2025
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IF 4.3
Shaonan Shan,Mai Wei,Liwei Ma,Youqian Wang,Guoqiang Li,Guojie Zhang
Formaldehyde, as a common pollutant in industrial exhaust gases, poses a serious threat to human health due to its highly toxic nature. Therefore, the development of efficient catalysts for formaldehyde removal is of great environmental significance. The accumulation of by-salts in the desulfurization waste stream of coking industry has become a major challenge in environmental protection. This paper used the by-salt ammonium thiocyanate as a precursor to prepare Cu-based g-C 3 N 4 (CN) by impregnation pyrolysis method, and applied it to the efficient catalytic oxidation of formaldehyde. The results showed that CN/Cu-10 %-a exhibited the best catalytic performance, with its specific surface area increasing 2.07 times compared to pure CN. The formaldehyde removal rate reached 98 %, which is 7.38 times higher than before modification, and it decreased by only 7.91 % after six cycles, demonstrating excellent cyclic stability. The improved photocatalytic performance is due to Cu doping, which increases the number of active sites, boosts visible light absorption, and facilitates the separation and transfer of photogenerated carriers. The secondary calcination further optimized the close contact between the metal Cu ions and the semiconductor interface, enhanced the specific surface area and the electron transfer efficiency to the metal Cu ions, and suppressed the charge carrier recombination. This study provides a new strategy and theoretical basis for the resourceful utilization of desulfurization waste liquid and the efficient degradation of formaldehyde.
研究领域:
环境科学
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催化
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材料科学
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化学工程
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光催化降解
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DOI
高影响因子
ENERGY & FUELS
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2018
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IF 3.024
Yang Peng,Xiangjiang Liu,Xun Gong,Xiaomin Li,Yifu Liu,Erwei Leng,Yang Zhang
In this study, three kinds of monocarboxylic acids, formic, acetic, and propionic acids, are first applied to modified microalgae residuals (M1-RD, M2-RD, and M3-RD, respectively) after lipid extraction, aiming to enhance the adsorption capacity and selective binding ability for Hg(II) ions in simulated wastewater. The effect of pH, temperature, and initial Hg(II) concentration was investigated to identify the optimum adsorption conditions. Batch adsorption tests showed that the maximum adsorption efficiency obtained was 96.7% for M1-RD, 91.1% for M2-RD, and 84.4% for M3-RD at pH 4.05 compared to 48.5 and 57.6% for raw and residual microalgae at pH 5.01, respectively. The adsorption capacity of raw, residual, and modified microalgae increased with the increase of the temperature. Langmuir and Freundlich isotherm model tests showed that the maximum equilibrium adsorption capacity among three modified adsorbents reached 63 ± 3 mg/g for M1-RD, in contrast to 17 ± 1 and 25 ± 2 mg/g for raw and residual microalgae, respectively. The characterization of the modified sample by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and scanning electron microscopy showed that the fibrous structure of the algae was decomposed by carboxyl groups in organic acids involved in microalgae, resulting in a larger surface area and more binding sites. In consideration of ion interference in the actual process, a kind of actual desulfurization wastewater from a 1000 MW coal-fired power plant (Guangdong, China) was introduced in the simulated adsorption system. Verification tests in desulfurization wastewater showed that up to 96% of Hg(II) ions were removed, probably as a result of co-precipitation of mercury and other co-existing ions.
研究领域:
环境科学
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化学工程
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废水处理
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）