CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zequan Liu,Tao Ou,Minhua Su,Hairong Peng,Gang Song,Lingjun Kong,Diyun Chen
Uranium and uranium-containing pollutants are excessively released into the environment, leading to serious water and soil contamination. Minerals such as alumina are naturally abundant and frequently affect the fate and migration behavior of uranium ions. A thorough understanding of the migration and immobilization behavior of uranium on Al-rich minerals (e.g., α-alumina [α-Al 2 O 3 ] and γ-alumina [γ-Al 2 O 3 )]) is essential for unraveling numerous environmental issues. We performed a systematic comparative analysis of U(VI) retention by α-/γ-alumina. The effects of coexisting ions and natural organic matter were explored. Solution pH contributed critically to the retention of U(VI) by α-/γ-alumina. The adsorption rate of γ-Al 2 O 3 for U(VI) removal was faster than that of α-Al 2 O 3 , reaching equilibrium within 15 min with a high removal efficiency of 94.43%. PO 4 3− ions significantly promoted U(VI) adsorption, especially for the case of α-Al 2 O 3 . The addition of phosphate resulted in a 15-fold enhancement in adsorption capacity. Humic acid promoted U(VI) removal by γ-Al 2 O 3 under acidic conditions while strong inhibition on both α-Al 2 O 3 and γ-Al 2 O 3 in basic conditions. The removal mechanism of U(VI) by alumina is mainly ascribable to electrostatic interaction and surface complexation from various oxygenated functional groups. The present findings are pivotal to the understanding of uranium migration and immobilization in the environment.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Jin-zhi Luo,Yan-yan Cai,Jin Yu,Jun-feng Huang
While traditional biochar demonstrates promising performance in diverse settings, its efficacy may be constrained under specific conditions of high acidity and heavy metal concentrations. In this study, researchers developed a new polysilicon-aluminum alkali mineral-enhanced biochar composite material, GBMSs (green biochar-metakaolin-sodium silicate), by pyrolyzing fibers from dragon fruit peels and blending them with metakaolin and sodium silicate. Using a response surface methodology, this environmentally friendly composite material was optimized for removing copper and zinc contaminants across a range of initial pH levels from 2 to 6. Experimental findings indicated that the adsorption capacity of GBMSs for copper and zinc was significantly enhanced, ranging from 1.5 to 4 times greater compared to pure biochar or biochar mixed solely with a silicon-aluminum mineral. Various analytical techniques including scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were utilized to examine the influence of poly-silica-aluminum alkali minerals (GBMSs) on biochar composites. The findings revealed an upsurge in surface binding locations and oxygen-related functional groups because of integrating GBMSs. This augmentation of electronegative features on the biochar surface was credited to the development of stabilizing silica-aluminum connections, ultimately boosting its adsorption effectiveness in acidic surroundings. By applying Langmuir and Freundlich models, it was deduced that the adsorption of GBMSs adheres to a multilayer uniform adsorption mechanism, with surface ion interchange and complexation restricting the adsorption capability. This research highlights the potential of clay mineral-altered biochar in efficiently dealing with intricate environmental contamination.
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
Journal of Materials Research and Technology-JMR&T
·
2020
·
IF 5.289
Deqing Zhu,Yuxiao Xue,Jian Pan,Congcong Yang,Zhengqi Guo,Hongyu Tian,Dingzheng Wang,Yue Shi
The alumina content of iron ores for sintering is gradually increasing with the growing depletion of high-grade iron ores, which is harmful to the sintering process. Therefore, it is essential to reveal the action mechanism of alumina on sinter quality. In this paper, the aluminum occurrence of various iron ores was determined by applying X-ray diffraction (XRD), optical microscopy, scanning electron microscopy and energy dispersive spectrum analysis (SEM-EDS). Then, the effects of iron ore type, aluminum occurrence (free alumina, gibbsite, diaspore, alumogoethite and kaolinite) and alumina content on formation characteristics of SFCA bonding phases as well as sinter matrix strength were investigated based on laboratory compact sintering tests. The results show that the discrepancy of aluminum occurrence contributes to different SFCA formation characteristics and then sinter matrix strength, due to different reactivity of various aluminum-containing minerals with iron oxides and fluxes. Increasing alumina content generally results in an increase in the porosity of sinters and deterioration of sinter matrix strength for all aluminum occurrence. Aluminum in the form of kaolinite is more conducive to form dendritic or acicular SFCA with superior sinter matrix strength compared with other aluminum occurrences. In contrast, aluminum occurring in free alumina presents greatest adverse impacts on sinter matrix strength due to its poor reactivity and high porosity of resultant sinters.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Yue Wu,Ying Jiang,Jiaguo Jiao,Manqiang Liu,Feng Hu,Bryan S. Griffiths,Huixin Li
Laccases play an important role in the degradation of soil phenol or phenol-like substance and can be potentially used in soil remediation through immobilization. Iron and aluminum minerals can adsorb extracellular enzymes in soil environment. In the present study, we investigated the adsorptive interaction of laccase, from the white-rot fungus Trametes versicolor , with soil iron and aluminum minerals and characterized the properties of the enzyme after adsorption to minerals. Results showed that both soil iron and aluminum minerals adsorbed great amount of laccase, independent of the mineral specific surface areas. Adsorbed laccases retained 26–64% of the activity of the free enzyme. Compared to the free laccase, all adsorbed laccases showed higher K m values and lower V max values, indicating a reduced enzyme-substrate affinity and a lower rate of substrate conversion in reactions catalyzed by the adsorbed laccase. Adsorbed laccases exhibited increased catalytic activities compared to the free laccase at low pH, implying the suitable application of iron and aluminum mineral-adsorbed T. versicolor laccase in soil bioremediation, especially in acid soils. In terms of the thermal profiles, adsorbed laccases showed decreased thermal stability and higher temperature sensitivity relative to the free laccase. Moreover, adsorption improved the resistance of laccase to proteolysis and extended the lifespan of laccase. Our results implied that adsorbed T. versicolor laccase on soil iron and aluminum minerals had promising potential in soil remediation.
研究领域:
环境生物学
·
土壤科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）