Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Liwei Ma,Shihua Zheng,Guoqiang Li,Xuejun Wang,Kangdi Chen,Guojie Zhang
Fe(II)EDTA can remove NO efficiently, but it has not been industrially applied. This is because the oxygen present in the flue gas will oxidize Fe(II)EDTA and Fe(II)EDTA-NO to Fe(III)EDTA and deactivate them. In order to solve this problem, this paper innovatively proposes to use NaHS to reduce Fe(III) EDTA, because NaHS has high reducing ability and low price. Therefore, a series of experimental conditions were explored in order to obtain the best reaction setup. The results indicate that increasing the concentrations of NaHS, temperature, and pH enhances the rate of NaHS reduction. The mechanism of the increase in reduction rate was studied in depth using potentiometric titration. It was found that an increase in OH - concentration will generate S 8 precipitate, which is beneficial to the forward progress of the reaction and promotes the large-scale production of the active component Fe 2+ . Oxygen is an inevitable factor in actual flue gas, so this study innovatively proposed a kinetic model under aerobic conditions and used this model to predict the trend of Fe(III)EDTA reduction by NaHS. On this basis, NO removal experiments were conducted under high oxygen conditions. After 15 cycles, the reduction performance of NaHS was still very high, and the NO removal rate was higher than 70%. The reason for this phenomenon is that the stabilizer exists in a form that is conducive to the removal of NO by the active component Fe 2+ . Therefore, this study provides theoretical guidance for promoting the industrial application of Fe(II) EDTA technology for NO removal.
研究领域:
环境科学
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化学工程
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Amina,Xiongyuan Si,Kang Wu,Youbin Si,Balal Yousaf
In this study, a modified Fenton system using calcium peroxide (CaO 2 ) powder, as an effective source of hydrogen peroxide (H 2 O 2 ), for the degradation of sulfamethoxazole (SMX) in aqueous solution was investigated. Our results indicated that degradation of SMX in Fe(II)-EDTA catalyzed CaO 2 system was readily more efficient than in Fe(II) catalyzed CaO 2 system. The SMX degradation efficiency was found maximum at pH 6.0 and SMX degradation was suppressed as the initial solution pH was increased. Nevertheless overall removal efficiency in this system was favorable near to neutral pH. In addition, it was observed that the higher bicarbonates (HCO 3 − ) contents had a considerable scavenging ability to SMX degradation while low concentration exhibited auspicious role. The presence of chlorides (Cl − ), nitrates (NO 3 − ), sulfates (SO 4 2− ), and humic acid (HA) could improve SMX removal in this Fenton-like system. Furthermore, chemical probe and radical scavenging activity confirmed the formation of hydroxyl (HO ) and superoxide (O 2 − ) radicals, and also described that the SMX degradation was predominantly due to the HO -induced oxidative destruction. Electron paramagnetic resonance (EPR) studies for different systems, different pH values and different reaction times were carried out to determine the HO radical intensities. EPR results showed that HO intensities were higher in Fe(II)-EDTA catalyzed CaO 2 system, at pH 6.0 and at 90 s reaction time, respectively. Intermediate products of SMX were identified and possible mechanism of SMX degradation was suggested. In conclusion, this work provided comprehensive knowledge for the use of Fe(II)-EDTA catalyzed CaO 2 system for remediation of SMX contaminated sites.
研究领域:
环境科学
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水处理
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化学工程
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污染控制
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DOI
高影响因子
ACS Omega
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2022
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IF 4.132
Liwei Ma,Guoqiang Li,Youqian Wang,Siqi Chai,Guojie Zhang
Fe2+ complexation wet denitrification technology has become a research hotspot. It is very important to achieve efficient regeneration of the absorbent and increase NO absorption in the Fe2+ complexation system. They are the key to the industrial application of the Fe2+ complexation absorption process. In this paper, 2-phosphonate-butane-1,2,4-tricarboxylic acid and ethylenediamine tetraacetic acid were used as ligands to prepare a composite system for the first time. The characteristics of NO removal were investigated under different temperatures, pHs, Fe2+ concentrations, O2 contents, NO concentrations, CO2 contents, and SO2 concentrations. Compared with the single ligand, the results show that the denitrification performance of the solution with a complex ligand is significantly improved. In this system, pH 9, 40 °C temperature, and 20 mmol/L Fe2+ concentration are the economic ideal conditions for NO removal. The system can realize simultaneous removal of NO and SO2, but SO2 in flue gas has a dual effect on the NO removal reaction.
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2026
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IF 9.1
Liwei Ma,Heting Li,Shaonan Shan,Yanqing Qin,Xu Yang,Guoqiang Li,Guojie Zhang
Wet Fe(II)EDTA complexation is a promising technology for NO removal, but its practical application is severely hindered by O 2 -induced oxidation of Fe(II)EDTA and inefficient regeneration of Fe(II)EDTA–NO. Herein, an oxygen-vacancy-rich BiOCl/g-C 3 N 4 S-scheme heterojunction with interfacial Bi–O–C covalent bonds was constructed for oxygen-resistant photocatalytic–complexation denitrification. Structural characterizations and density functional theory calculations confirmed that Bi–O–C bonds served as atomic-level charge-transfer channels, strengthening interfacial coupling and promoting directional S-scheme charge separation. This configuration preserved strongly reductive electrons on g-C 3 N 4 for the reduction of Fe( III )EDTA and Fe(II)EDTA–NO, while retaining oxidative holes on BiOCl. Meanwhile, oxygen vacancies on BiOCl acted as preferential O 2 adsorption and activation sites, converting O 2 into ·O 2 − and thereby transforming O 2 from a competitive oxidant into an electron-buffering species that suppresses BiOCl photocorrosion and regulates interfacial redox cycling. The optimized 20BCN–Fe( II )EDTA system achieved an average NO removal efficiency of 88.92% under 14% O 2 and maintained above 80.02% efficiency after 30 cycles. Product analysis revealed a reduction-dominated NO conversion pathway, with NH 4 + and N 2 as the major reduced nitrogen products, a total reduced-product selectivity of 91.9%, and a nitrogen recovery of 94.4%. Kinetic analysis confirmed that NO absorption proceeded in a fast reaction regime enhanced by interfacial redox reactions. This work provides an atomic-level strategy for designing oxygen-resistant photocatalytic systems for wet denitrification under realistic flue-gas conditions.
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高影响因子
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