Journal of Cleaner Production
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2021
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IF 9.297
Kai-Qiang He,Chun-Gang Yuan,Yang-Hong Jiang,Yan Li,Xue-Lei Duan,Qi Guo
Some sorbents have been developed for arsenic (As) compounds capture from flue gas . However, most of the conventional sorbents have cost constraints and can cause secondary pollution due to the leaching of arsenic after use. To solve this problem, a new and highly efficient adsorbent for gaseous arsenic was successfully developed in this paper with excellent immobilization performance and low-cost. A series of Mn-supported attapulgite (ATP) composites were fabricated, characterized, and investigated for arsenic capture. The modification of ATP with Mn not only considerably enhanced the adsorption efficiency but also stabilized the adsorbed As in the spent sorbents. SO 2 in flue gas promoted the adsorption performance through As-sulfate binding, whereas NO was beneficial for the oxidation of As(III) to As(V) on the surface of Mn-modified ATP. The incorporation of Mn with ATP generated abundant hydroxylate (OH − ) from hydration and accelerated the formation of As-sulfate compounds, which was beneficial for physical encapsulation. The results of the toxicity characteristic leaching procedure and sequential extraction test revealed that adsorbed As could be considerably immobilized by the sorbent with low leaching ability. Mn modification changed more As into inert fractions and consequently inhibited release from spent sorbents, which considerably reduced the risks of secondary pollution. The developed composite can be potentially used as a new efficient sorbent for gaseous arsenic capture in flue gas.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Yipeng Wang,Kun Wang,Xuchan Wang,Qingliang Zhao,Junqiu Jiang,Ruiyuan Xue,Luzi Yuan
Heavy metals (HMs) in wastewater, including Cd, Pb and Ni, were toxic and needed urgent treatment. Using biochar as an adsorbent to purify HM-containing wastewater is effective. However, there are few studies on screening of high-efficiency modifier and comparing their adsorption capacity. Herein, three different modification methods, including heteroatomic doping (urea), alkali hydroxide (NaOH) and chemical oxidation (KMnO 4 ), were used to improve removal ability of HMs by biochar. The difference in impregnation solution resulted in completely differences in microscopic morphology, physicochemical properties and adsorption efficiency of modified biochar. Biochar modified by KMnO 4 (Mn-BC) had significantly better adsorption capacity for Cd, Pb and Ni, reaching 46.40 mg/g, 80.20 mg/g and 18.65 mg/g, respectively, compared with raw biochar and other modification biochar, which might be due to the highest surface area and pore volume, lower zeta potential and loaded MnO x onto Mn-BC surface. Chemical and monolayer adsorption was dominant during adsorption of HMs. After adsorption, HMs were detected on the Mn-BC surface in the form of carbonate, hydroxide or oxide. Mineral precipitation and cation exchange were the dominant mechanisms during adsorption, accounting for 17.4%-41.8% and 43.0%-77.2%, respectively. Moreover, according to the correlation analysis, the increase in biochar pH, pore volume and degrees of carbonization were beneficial for HM adsorption. Mn-BC could adapt to a wider pH range (pH=4–6), and its adsorption capacity would not be interfered by coexisting ions (50 mg/L). This research proved advantages of biochar with KMnO 4 modification and highlighted its application in treatment of wastewater contaminated with multiple HMs.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
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2019
·Vol. 30
·期 9
·1789-1800
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IF 1.335
Zhang Guojie,Hou Peng,Sun Yinghui,Xu Ying,Cheng Haizhu,Zhang Yongfa
Different activated carbons and manganese-modified activated carbons were prepared as deoxidizers for the low-concentration coalbed methane deoxidation. The results show that the deoxidation performance of the different activated carbons is affected by raw materials for preparation of deoxidizers. One type of activated carbon exhibited the best performance of oxygen removal, due to the relatively low ash content and better adsorption performance. Experimental results show that the manganese-modified deoxidizers exhibit an excellent deoxidation efficiency at low temperature. At 200 ºC, one kind of manganese-modified activated carbons decreased the oxygen content to less than 1 vol%, which could maintain about 600 min. This indicated that the addition of manganese greatly improved the reactivity of oxygen with activated carbon. Characterization results demonstrated that the physical structure and species types of oxygen of activated carbons, and manganese have important effects on the activity of deoxidizers in different temperature ranges.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Shengfeng Yang,Qingchao Xiao,Bin Li,Tao Zhou,Qihong Cen,Zewei Liu,Yue Zhou
Heavy metal contamination, particularly by lead and cadmium, poses a significant environmental challenge. Indiscriminate disposal of crop residues exacerbates environmental concerns. In this study, broad bean straw was utilized to produce biochar (BC), and further modifications were made using FeCl 3 -6 H 2 O and KMnO 4 to obtain Iron-Manganese Modified Biochar (FMBC) for remediating cadmium and lead-contaminated soil. Results show that both BC and FMBC increased soil pH, available phosphorus, and potassium compared to the control groups. Adding 5 % BC led to a notable reduction of 60.98 % in available cadmium and 51.63 % in available lead. Simultaneously, FMBC decreased active cadmium and lead by 57.51–73.73 % and 52.25–69.87 %, respectively. Furthermore, FMBC decreased the content of cadmium and lead in the unstable state while increasing content in the residual state, demonstrating its ability to reduce accumulation in plant tissues. FMBC adsorption mechanisms primarily involve surface complexation and co-precipitation, where oxygen-containing functional groups form stable complexes with free cadmium and lead ions. In conclusion, FMBC proved to be an effective, environmentally friendly soil remediation agent with strong adsorption capabilities and a prolonged shelf-life. This provides a promising solution to alleviate the pollution of heavy metals such as cadmium and lead in soil.
研究领域:
环境科学
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土壤学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Zulqarnain Haider Khan,Zhongyang Li,Minling Gao,Md. Shafiqul Islam,Ling Xiao,Weiwen Qiu,Zhengguo Song
As(III) and Cd(II) co-existence results in co-contamination in soil and water. It is still a great challenge for As(III) and Cd(II) simultaneous removal in the aqueous medium due to their contrasting chemical behaviour. Herein, we prepared a novel magnesium-manganese modified biochar composite (Mg/Mn@BC) for simultaneous Cd(II) and As(III) elimination from contaminated water . The synergistic effect of Mg/Mn@BC composite on synchronous Cd( II ) and As(I II ) removal was confirmed. In the mixed sorption system, the Langmuir sorption capacity of Mg/Mn@BC for As(III) and Cd( II ) was 164 and 316 mg g −1 , respectively, which was more than that in the single adsorption system (75 and 295 mg g −1 ). In the single sorption system, the Mg/Mn@BC sorption efficiency was > 61% and 100% for As( III ) and Cd( II ), respectively, while > 87% and 100% in the mixed adsorption system. The characterization results revealed that synergistic adsorption was mainly attributed to anion-bridging (Mn/MgO–As–Cd) and cation-bridging (Mn/MgO–Cd–As). The ion exchange, precipitation, Cd–π binding and inner-sphere surface complexation with functional groups were predominant in the sorption process, while hydrogen bonding force and ternary complexation were the primary pathways in mixed adsorption system to eliminate Cd(II) and As(III). The results suggested that Mg/Mn@BC composite can be a potential material for wastewater treatment .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMOSPHERE
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2023
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IF 8.8
Huang-gen Yang,Mang Lu,Xue-jiao Wu,Rui-ting Dong,Tao-peng Luo,Hui-hua Zhong
Persulfate non-radical oxidation have excellent catalytic capability for degrading specific contaminants in complicated water environments. Nevertheless, the preparation of high-performance activators and their application in actual water treatment in continuous flow mode are still scarce and unsatisfactory. In this work, copper-, manganese-, and copper/manganese-doped ceramsites (Cu–C, Mn–C and Cu/Mn–C), successfully fabricated through a facile impregnation-calcination approach, were characterized and evaluated for their performance to activate potassium peroxydisulfate (PDS) and degrade oxytetracycline (OTC) under different pH, ceramsite dosages, and PDS dosages. Compared with Cu–C and Mn–C, Cu/Mn–C showed the highest OTC degradation rate (0.0264 min −1 ) via activating PDS with an OTC removal efficiency of 98.2% in 240 min at an initial OTC concentration of 40 mg/L. The removal efficiency of OTC by Cu/Mn–C only decreased to 92.8% after 5 cycles; the activating ability of the used Cu/Mn–C was almost completely recovered through 2 h of calcination at 500 °C. The results of electron paramagnetic resonance and radical quenching suggest that singlet oxygen ( 1 O 2 ) was unveiled to be the dominant reactive oxygen species (ROS) for contaminant degradation, originating from the regrouping of superoxide ions or reduction of active Cu/Mn sites. Synergies between Cu and Mn species to enhance ROS yield were the primary activating mechanisms. Six possible routes of OTC decomposition were inferred. Additionally, Cu/Mn–C behaved excellently in treating an actual wastewater using a continuous flow fixed-bed reactor. It is believed that this novel Cu/Mn–C/PDS system may create a fresh path to design effective and cheap metal-ceramsite hybrid activators for degrading recalcitrant contaminants in the actual application process.
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
Advanced Sustainable Systems
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2025
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IF 6.1
Yu Ren,Youhao Zhang,Zizheng Zhou,Yi Fang,Yuzhuo Wang,Yingjie Li
Ca(OH) 2 can be used in CO 2 uptake from the flue gas in fossil-fired power plants. Compared with indirect method where Ca(OH) 2 is first converted into CaO and then uptakes CO 2 , direct CO 2 uptake by Ca(OH) 2 occurs at lower temperature, leading to slighter sintering. However, the direct CO 2 uptake capacity of Ca(OH) 2 should be further enhanced. In this study, Ca(OH) 2 is doped with Mn to improve its direct CO 2 uptake capacity in carbonation-calcination-hydration cycles. The cyclic tests are conducted in a triple fixed-bed reactor. The mechanism of CO 2 adsorbed on Mn-modified Ca(OH) 2 is determined by density functional theory calculations. In the first cycle, Mn-modified sorbents acquire highest carbonation conversion at 400 °C, which is 40 °C lower than Ca(OH) 2 . The modified Ca(OH) 2 with Ca/Mn molar ratio of 100:0.75 exhibits the best performance, and its carbonation conversions reach 0.76 and 0.59 in the 1st and 20th cycles, respectively, which are 28% and 18% higher than those of Ca(OH) 2 . Furthermore, carbonation conversion of this Mn-modified Ca(OH) 2 decreases by within 1.00% from cycle 5 to 20. Mn addition boots oxygen vacancy, increases the surface area and pore volume, and reduces the energy barrier for carbonation of Ca(OH) 2 . Mn-modified Ca(OH) 2 as CO 2 sorbent appears promising.
研究领域:
化学工程
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环境科学
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高影响因子
ACS ES&T Engineering
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2024
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IF 7.4
Kai He,Yuanfang Lai,Shuchen Wang,Li Gong,Feng He
Metal doping for improving the reactivity of zerovalent iron (ZVI) has been well studied, while Mn(II)-modified microscale ZVI (Mn-mZVI) has not yet been explored. Herein, ball-milled Mn-mZVI was fabricated and used for Cr(VI) removal. Characterization analysis showed that the structure, composition, and charge of mZVI changed after the Mn(II) modification. The comparative test showed that Mn-mZVI could remove 100% of Cr(VI) within 10 min, whereas mZVI removed negligible Cr(VI) within 60 min. The zeta-potential and electrochemical evidence verified that the enhanced electrostatic attraction and electron-transfer ability contributed to the superior Cr(VI) removal performance of Mn-mZVI. Moreover, the solution pH increase caused the decline of Cr(VI) removal, and the presence of NO3– inhibited Cr(VI) removal, whereas other coexisting ions showed little influence on the Cr(VI) removal performance of Mn-mZVI. Chemical and material characterization analyses revealed that Cr(VI) reduction by Mn-mZVI was the combined action of Fe(0) and generated Fe(II). In addition, the reusability of Mn-mZVI was not ideal due to the surface passivation and loss of Mn(II), but the reactivity could be reactivated by ball-milling the reacted Mn-mZVI again with Mn(II). Overall, this work provides a new mentality for mZVI modification and is important to develop promising mZVI-based materials for Cr(VI) pollution control.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Runlong Hao,Zhen Qian,Xiaojie Yang,Mengchao Luo,Xiaohe Feng,Wanting Qiao,Yi Zhao,Bo Yuan
Developing efficient catalysis-adsorption method for elemental mercury (Hg 0 ) removal with wide temperature window and good sulfur/water resistance is a hot topic. In this study, a novel method of microwave (MW) catalysis of MnO 2 modified molecular sieve (Mn@MOS) composite for Hg 0 removal was developed. Results indicated that Hg 0 removal efficiency of MOS was poor, only 18% at 150 °C, while the efficiency was significantly increased to 97.8% when MW/Mn@MOS was used. Compared with thermo-catalysis way, MW irradiation method achieved better Hg 0 removal efficiency (97.8% vs 86.4%) under a wider temperature window (150–450 °C), and sulfur/water resistance were greatly strengthened under MW irradiation. The dynamical adsorption capacity of Hg 0 was calculated as 1.52 mg/g when the efficiency was below 80%. Kinetic analysis indicated that MW field significantly increased the rate constant and reduced the activation energy. The fate of Hg 0 was unfolded: almost 96% of Hg 0 was chemisorbed as HgO, less than 4% was converted to gaseous Hg 2+ . The mechanism was speculated as followed: (i) excited active site of *MnO 2 was first generated under MW irradiation; (ii) then the oxidizing species including Mn(IV)/Mn(III), O ads , O latt and O* dominated the Hg 0 removal process; (iii) the reactive oxygen species of O ads , O latt and O* were replenished by the interaction between oxygen vacancies and free O 2 . This study first demonstrates the superiority of MW catalysis towards Hg 0 removal, and provides a new thought on the development of the novel Hg 0 removal technologies .
研究领域:
环境科学
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催化
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污染控制
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DOI
高影响因子
危险品化学品经营许可证（带存储）