NUCLEAR TECHNOLOGY
·
2023
·
IF 1.5
Guanghui Wang,Hui He,Yaorui Li,Meng Zhang,Yang Gao,Caishan Jiao
The contaminated solvent from the Purex process is washed with alkaline detergents such as sodium carbonate, which generates a large amount of secondary wastes. Therefore, hydrazine carbonate as a salt-free reagent deserves to be studied in depth. In this study, the Ce(IV), U(VI), and Zr(IV) metal ions in organic phases containing dibutyl phosphate (HDBP) of 30% tributyl phosphate (TBP)–dodecane were washed with hydrazine carbonate. The effects of the oscillation time (1 to 15 min); temperature (25°C to 85°C); cumulative number of washes (one to four times); mass fraction of hydrazine carbonate (0.1% to 20%); volume ratio of the aqueous phase to the organic phase (0.2 to 5); HDBP concentration (0 to 0.4 M); HNO3 concentration (0.05 to 8 M); and concentration of Ce(IV), U(VI), and Zr(IV) metal ions on the removal percentages of Ce(IV), U(VI), and Zr(IV) metal ions in polluted solvents were studied. The results showed that when the organic phase containing 0.02 M HDBP was washed three times with 5% hydrazine carbonate at 25°C, the removal percentages of the Ce(IV), U(VI), and Zr(IV) ions were 96%, 98%, and 94%, respectively. Meanwhile, the retention concentrations of the three in the organic phase were 35, 28, and 78 mg/L, respectively. The increase of the mass fraction of hydrazine carbonate enhances the removal of the metal ions from the organic phase into the aqueous phase. High acid is not conducive to alkaline washing of metal ions. The increase of HDBP concentration not only promotes extraction but also increases the retention capacity of the organic phase and has the most significant effect on Zr(IV). U(VI) promotes the preferential washing of Zr(IV) while Ce(IV) increases the metal retention concentration of Zr(IV) in the organic phase.
研究领域:
化学工程
·
核化学与化工
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Zhanmeng Liu,Xian Li,Lichun Xu,Rongrong Liu
ABSTRACT A novel composite coagulant of MFPAC was prepared from Fe 3 O 4 nanoparticles and polyaluminum chloride (PAC). Landfill leachate was pretreated by MFPAC coagulation combined with mineralized refuse adsorption. Higher COD and color removals were achieved by using the MFPAC magnetic coagulant than by adding the coagulant PAC alone. Under the working conditions of 1:3 Fe 3 O 4 /PAC mass ratios, 1.5 g/L MFPAC dosage, and pH 7.5, the removal rates of COD and color reached 63% and 67%, respectively. Infrared spectra showed that MFPAC is a type of hydroxyl-containing ligand with a nano-Fe 3 O 4 multi-core and a hydroxyl polymer of aluminum and iron that is similar complex valence and crystal structure as that of PAC. The effluent of MFPAC coagulation was further treated using mineralized refuse adsorption. Under the working conditions of <2 mm particle size of mineralized refuse, 700°C roasting temperature, 40 mg/L adsorbent dosage, and pH 9.0, the removal rates of COD and ammonia nitrogen reached up to 57% and 68%, respectively, after 12 h of treatment. Infrared spectra analysis revealed that OH, C=O, and C–O played key roles in the adsorption process. After the landfill leachate was treated with the combined process, the removal rates of COD, color, and ammonia nitrogen were enhanced to 84%, 80%, and 74%, respectively. The encouraging results demonstrated that the combined process could provide a viable alternative to the pretreatment of landfill leachate.
研究领域:
环境工程
·
废水处理
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Lei Chen,Zhi-Cong Wang,Dabo Chen,Lin-Xin Yin,Pei-Gao Duan
We report a new process to realize the deep removal of N, O, and S from the bio-oil when using a batch reactor to do the hydro-upgrading experiments. That is, within a fixed reaction time, hydro-upgrading of the bio-oil was carried out in several stages. After each stage reaction was finished, the reactor was cooled, and the gas in the reactor was replaced with fresh hydrogen, and then the reaction continued until the total reaction time was complete. A bio-oil produced from hydrothermal liquefaction of microalgae mixed with tetralin at a mass ratio of 1:1 was used as the feedstock . The experiments were performed at different temperatures (300–480 °C) and time (1–8 h) with fixed addition of 10 wt% Pt/C and 8 MPa H 2 . Higher treated bio-oil yield was always achieved if the reaction was performed in several stages. The N-, O-, and S- containing compounds in the gaseous products mainly consisted of C 2 H 4 N, C 3 H 7 N, C 6 H 7 N, NH 3 , (SCN) 2 , SO 2 , and H 2 O. The removal of these gas products avoided their secondary reactions with the bio-oil and slowed down the catalyst poisoning , and thus breaking through the equilibrium limitations of denitrogenation, desulfurization , and deoxygenation and prolonging the activity of the catalyst.
研究领域:
能源生物学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 28
·e202401039
·
IF 1.9
Xueqi Wang,Kai Li,Fei Wang,Lei Shi,Shuangyou Bao,Jiacheng Bao,Xin Sun
Graphical In this study, we prepared the thermally modified copper slag catalyst CS-CaO-900 and applied it to a pilot-scale Fenton-like denitrification system. In single-factor experiments, the effects of six factors, namely inlet NO concentration, H 2 O 2 concentration, catalyst dosage, reaction temperature, L/G ratio, and pH value, on desulfurization and denitrification were investigated. Through analysis of the experimental results, the three factors that had the greatest impact on the maximum denitrification efficiency, namely pH value, H 2 O 2 concentration, and reaction temperature, were selected. The response surface methodology was employed to investigate the significance of the three factors and optimize the parameters, and it was finally determined that the initial pH of the slurry had the greatest impact on the maximum denitrification efficiency, followed by the H 2 O 2 concentration. At the same time, the combination of initial slurry pH and reaction temperature, initial slurry pH and H 2 O 2 concentration also had a large impact on the maximum denitrification efficiency, and the combination of reaction temperature and H 2 O 2 concentration had a non-significant impact on the denitrification efficiency. And through the model optimization to get the best parameters, denitrification experiments under this parameter to achieve the maximum denitrification efficiency of 91.5 %, for further industrial application to provide reference and guidance. In this study, Response Surface Methodology (RSM) was employed to optimize the experimental factors influencing the simultaneous removal of NOx and SO 2 in a spray tower wet scrubbing experiment. Thermally modified copper slag (CS-CaO-900) was prepared by heat treating the original copper slag. The performance of CS-CaO-900 in the synchronized removal of NOx and SO 2 was then evaluated in an expanded experimental setup. Based on single-factor experimental results, the Box-Behnken design of RSM was used to optimize the reaction parameters in a two-stage sequential reactor (bubbling reactor + spray tower). NOx removal efficiency was modeled as a function of reaction temperature, pH, and H 2 O 2 concentration. Regression curves provided a visual representation of the interaction effects among these parameters on NOx removal efficiency in the thermally modified copper slag/H 2 O 2 composite slurry. This study elucidates the characteristics of each parameter under wet scrubbing conditions and provides essential data for industrial applications.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Haotian Li,Feng Liu,Shuhui Wang,Fengjia Wang,Xin Qian,Caiduan Zhang,Yongliang Ma,Lidong Wang
Based on advanced oxidation technology, a new method for the simultaneous removal of SO 2 and NO x from industrial flue gas using Na 2 S 2 O 8 /MgO was proposed. The method does not require the body structure of the wet desulfurization device is changed but adds Na 2 S 2 O 8 to the original equipment to realize simultaneous desulfurization and denitrification. After determining Cl − was additive, the effects of various reaction factors on the simultaneous removal of SO 2 and NO x were investigated, including the Cl − concentration, the initial concentration of the oxidant, the initial pH value of the solution, and the reaction temperature. According to the characterization of removal products and the types of free radicals involved in the reaction by XRD , XPS , and EPR , the reaction mechanism was elucidated. The experimental results indicated that the removal products were mainly sulfates and nitrates. The free radicals involved in the reaction were SO 4 ·− , ·OH, and Cl·, and the key free radical was Cl·.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Wei Wang,Yilong Hua,Shaolin Li,Weile Yan,Wei-xian Zhang
A common concern in the approval of nanotechnology for water treatment is whether there are advantages of these nanomaterials over conventional water treatment reagents. In this work, nanoscale zero-valent iron (nZVI) is compared with lime (Ca(OH) 2 ), the most widely used heavy metal precipitant, for Pb(II) and Zn(II) removal, in laboratory and field experiments. Water chemistry, treatment efficiencies and reaction products of the two reagents are compared and the study shows that the moderate solution pH of nZVI and its seed effect play vital roles in producing high-quality effluents. The results are then verified in a field continuous-flow experiment using tons of lime and kilos of nZVI. The results show that sub-ppm levels (∼0.1 mg/L) of Pb(II) and Zn(II) could not be achieved via lime precipitation alone, due to the solubility limits of metal hydroxides and their re-dissolution caused by the strong alkalinity of lime. In comparison, stable and lower levels of Pb(II) and Zn(II) were easily attained using nZVI, due to its multifunctional properties and good tolerance for influent fluctuation enabled by its inherent pH-stabilizing nature. SEM characterizations, particle size analyses and quiescent settling experiments show the ability of nZVI to generate large and consolidated solids that are amenable to gravitational separation. The study shows several key advantages of nZVI over lime technology in Pb(II) and Zn(II) removal. As lime is widely used for heavy metal removal, this work provides an effective advanced treatment process to supplement lime-based treatment methods.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 1
·48-57
·
IF 4.6
Boxuan Li,Shaoxin Wen,Jiacheng Li,Dedong He,Yongming Luo,Xiangqian Zheng,Dingkai Chen
Polysilicate-ferric-calcium-lanthanum (PSFCL) was synthesized through a co-polymerization method in order to treat the yellow phosphorus wastewater. Its morphology, composition and functional group were analyzed by X-ray Diffraction (XRD), Fourier Transform-Infrared Spectroscopy (FTIR), Scanning Electron Microscopic (SEM) and X-ray Photoelectron Spectroscopy (XPS), respectively. The optimization of the flocculant was also investigated, including La/Si molar ratio, pH, agitation time, dosage and sedimentation time. Results showed that PSFCL has reached an excellent removal efficiency of 95% and 97% towards phosphorus and fluoride, respectively. It could be inferred that charge neutralization, bridging effect and ligand exchange were the main coagulation mechanisms. As a whole, after the introduction of lanthanum, PSFCL was found to be a promising flocculant in yellow phosphorus wastewater treatment owing to its high removal efficiency and simple synthesis route.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Peng Lu,Xianhui Yan,Lyumeng Ye,Dingsheng Chen,Dongyao Chen,Jianhang Huang,Chaoping Cen
The co-removal of CO 2 while removing SO 2 and NO x from industrial flue gas has great potential of carbon emission reduction but related research is lacking. In this study, a wet scrubbing process with various urea solutions for desulfurization and denitrification was explored for the possibility of CO 2 absorption. The results showed that the urea-additive solutions were efficient for NO x and SO 2 abatement, but delivered < 10% CO 2 absorption efficiency. The addition of Ca(OH) 2 dramatically enhanced the CO 2 absorption, remained the desulfurization efficiency, unfortunately restricted the denitrification efficiency. Among various operating parameters, pH of solution played a determining role during the absorption. The contradictory pH demands of CO 2 absorption and denitrification were observed and discussed in detail. A higher pH of solution than 10 was favorable for CO 2 absorption, while the oxidizing of NO to NO 2 , NO 2 − or NO 3 − by NaClO 2 was inhibited in this condition. When 7 < pH < 10, it was favorable for the conversion and absorption of NO and NO x . However, the conversion of HCO 3 − to CO 3 2− was significantly inhibited, hence preventing the absorption of CO 2 . Large part of Ca(OH) 2 became CaCO 3 with a finer particle size, which covered the unreacted Ca(OH) 2 surface after the reaction. Kinetic analysis showed that the CO 2 absorption in urea-NaClO 2 -Ca(OH) 2 absorbent was controlled by chemical reaction in early stage, then by ash layer diffusion in later stage.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Junqi Cheng,Zhitao Han,Jiawei Li,Xinxiang Pan
Previous work proposed a one-stage wet scrubbing in situ combined with O3 oxidation for simultaneous removal of NO and SO2 from flue gas, and the results showed that wet scrubbing combined in situ with O3 injection could effectively improve O3 oxidant utilization efficiency. In this work, a follow-up research work was carried out to further explore the synergistic effect of dual oxidants of NaClO in the liquid phase and O3 in gas phase. The synergistic effects of O3/NO molar ratio and NaClO concentration in the circulating scrubbing solution on NOx removal performance was investigated systematically. The results showed that when molar ratio of O3/NO was 0.5 and NaClO concentration was 25 mM, NO could be oxidized completely and averaged NOx removal efficiency exceeded 70%. NOx concentrations in outlet gas and anion compositions in the scrubbed solution were analyzed, and the possible reaction paths of wet scrubbing NaClO solution in situ with O3 injection in denitration process were also discussed. When the solution pH was around 6, a relative balance between NOx oxidation and absorption might be achieved, resulting in a high NOx removal efficiency. The temperature of inlet flue gas imposed little impact on NOx removal efficiency due to the quick and efficient cooling effect by wet scrubbing. The increase of initial SO2 concentration led to a slight increase of NOx removal efficiency from 70 to 73.5%. A complete removal of SO2 could be achieved, but coexisting SO2 in flue gas would consume NaClO oxidant and shorten the reaction duration.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Huirong Zhang,Lin Luo,Zixiong Zhao,Yi Shen,Jinglei Cui,Xiaokai Shi,Xiaoliang Han
The production of high-performance activated carbon (AC) is recognized as an essential strategy for the effective utilization of lignin resources. In this work, the N-doped AC was successfully prepared by blending sodium lignosulfonate (SL) and different ratios of FeCl 3 through one-pot strategy. The AC structure evolution and performance were obtained by a series of characterization and tests. The results showed that, during the activation process, FeCl 3 first complexed with urea and catalyzed the depolymerization of SL, and the rapid pore development was mainly caused by the template, including formed FeCl 2 , Na 2 Fe 3 Cl 8 and Na 6 FeCl 8 . The ratio of FeCl 3 /SL adjusts the AC physicochemical texture. AC-3 processed a super total specific surface area and pore volume, respectively up to 2048 m 2 /g and 1.47 cm 3 /g. Meanwhile, AC-2 showed a higher nitrogen content of 11.4 %. The as-prepared AC shows super desulfurization, denitrification and Cr (Ⅵ) removal ability. AC-2 displayed maximum sulfur capacity and NO conversion, up to 199.1 mg/g and 42.4 %. This enhanced performance is primarily attributed to the pore structure induced by FeCl 3 activation, which provides a foundation for adsorption and catalytic processes, further augmented by the increased active sites due to nitrogen doping. AC-3 achieved an extremely high Cr (VI) adsorption capacity, up to 386.2 mg/g, which was primarily attributed to the redox effect of N-containing and O-containing groups on Cr (VI), in addition, the effect of physical adsorption including pore structure is not neglectable. This study highlights the significant potential of environmentally friendly lignin-based porous carbon materials for removing contaminants in both gas and liquid phases.
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
Environmental Chemistry Letters
·
2022
·Vol. 20
·期 4
·2243-2251
·
IF 13.615
Zhu Guocheng,Chen Junming,Zhang Shanshan,Zhao Zilong,Luo Huihao,Hursthouse Andrew S.,Wan Peng,Fan Gongduan
Black-odorous waters are an increasingly common phenomenon characterized by excessive levels of nutrients, the formation of metal sufide precipitates, volatile sulfurous compounds, low dissolved oxygen and high chemical oxygen demand. Black-odorous waters frequently occur in lake and river systems where inputs have restricted circulation. The key remediation issue is the removal of nitrogen and phosphorus. Here, we present a novel aeration-adsorption system using fiber balls and we study treatment parameters and removal mechanism. Kinetics and changes of the solid phase were followed using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Results show complete removal of ammonia N, initially at 31 mg/L, and 92.8% removal of total nitrogen, initially at 29 mg/L, after a 24 h reaction time at pH 9.67. At pH 5.67 and 9.67, total phosphorus and phosphate could be significantly reduced by 90–92% at 3.2–5.2 mg/L after 24 h. Treatment met China’s integrated wastewater discharge standards, demonstrating an effective and robust treatment capability. First-order and second-order kinetic models provided a good fit to the treatment data, indicating physical and chemical adsorption were involved in the treatment reactions. The reaction mechanism involved hydrogen substitution and binding to oxygen. These results present a cost effective and robust approach for the removal of N and P from black, odorous water, providing opportunity to abate environmental contamination.
研究领域:
环境工程
·
水污染治理
·
生态修复
·
环境化学
✓ 已验证
DOI
高影响因子
Chemistry-An Asian Journal
·
2023
·Vol. 18
·期 11
·e202300146
·
IF 4.1
Wen-ting Zhao,Huan Zhang,Ke Feng,Tian-yang Wang,Lei Han,Hai-feng Xing,Fei Huang,Wen-bo Wang
Graphical A feasible “one stone, three birds” strategy was developed to achieve simultaneously the harmless disposal and reutilization of waste acid-leaching liquid, the synthesis of new materials and the efficient decontamination of dye or Cd(II) pollutants, by converting Al, Mg-rich waste acid leachate into silicate adsorbent. The adsorbent showed excellent adsorption performance and reusability towards cationic dye and Cd(II) in real waters. An emerging “one stone, three birds” strategy was proposed to realize the value-added disposal of solid waste coal gangue (CG), the synthesis of superb adsorbent and the efficient decontamination of pollutants (i. e., dyes, heavy metals). In this process, the metal ions extrated from calcined coal gangue (CCG) was reconstituted by a one-step hydrothermal process to yield porous polymetallic silicate adsorbent (named HECCGA8h). The adsorbent has a high adsorption capacity of 270.27 and 185.53 mg/g for methylene blue (MB) and Cd(II), respectively. In the actual waters, the removal rate of MB by this adsorbent reaches 99.8% (in Yangtze River water) and 99.42% (in Seawater), and the removal rate of Cd(II) reaches 99.11% (in Yangtze River water) and 92.52% (in Seawater), respectively. Thermokinetic analysis showed that the adsorption of MB by HECCGA8h is spontaneous and endothermic with increased entropy, and the adsorption of Cd(II) is spontaneous and exothermic. The adsorption of MB is mainly driven by synergism of hydrogen bond, electrostatic attraction and ion exchange, and the adsorption of Cd(II) is mainly driven by the complexation and ion exchange between the surface group of the adsorbent and Cd(II). This research provides a new way for the realization of “treating waste with waste”.
研究领域:
环境科学
·
材料科学
✓ 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）