SEPARATION SCIENCE AND TECHNOLOGY
·
2021
·
IF 2.475
Xuekai Zhang,Kanggen Zhou,Qingyuan Lei,Yan Xing,Changhong Peng,Wei Chen
A new approach was developed using NaH2PO4 as the stripping agent for Fe stripping from Fe-loaded Aliquat 336 during rare-earth elements recovery from red mud leachate. Owing to the strong coordination between Fe3+ and H2PO4‒, Fe mainly exists as FeH2PO42+ at [H2PO4‒] higher than 0.5 M, which can be readily stripped. The results showed a maximum Fe stripping efficiency of 95.5% under optimal condition. Moreover, the extraction capacity of the extractant after stripping was comparable to that of fresh extractant, and decreased only by 2% after 6 cycles, indicating the robustness of this approach for Fe stripping and extractant regeneration.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
AIP Advances
·
2021
·Vol. 11
·期 11
·
IF 1.548
Huang Lijie,Wei Zhehao,Wang Yanan,Han Xiaoxue,Chen Haobin,Huang Chongxing,Wei Yingnan
In this paper, the effect of D 0 temperature, Kappa factor and the final pH value on bleaching sulfate bleached pine wood pulp was studied. The results showed that the bleaching efficiency was better when the pH value was 4, and the amount of absorbable organic halogen (AOX) in the bleaching wastewater was decreased. The Kappa factor is linear with the whiteness in the range of 0–0.15. With the increase of the Kappa factor, the amount of AOX in bleaching wastewater of D 0 and Ep gradually increases. High temperature bleaching can reduce AOX production, but some fibers are hydrolyzed, leading to a decrease in pulp viscosity. The effects of chlorine dioxide solution adding sodium dihydrogen phosphate (NaH 2 PO 4 ) and dimethylsulfoxide (DMSO) on pulp bleaching were investigated. The results showed that both solutions could reduce the amount of AOX in bleaching wastewater. Among them, the addition of NaH 2 PO 4 in chlorine dioxide increased pulp whiteness, while the addition of DMSO was the opposite. Scanning electron microscope showed that a small amount of hollow cracks and more voids appeared on the surface of pulp fibers after the addition of NaH 2 PO 4 . Pulp fibers bleached by the chlorine dioxide adding DMSO have more folds and less voids on the surface. The surface wrinkles of pulp fibers increased with the addition of DMSO and the voids were less. FT-IR showed that the number of chromophore groups in the pulp bleached by chlorine dioxide adding NaH 2 PO 4 were decreased. However, the lignin characteristic absorption peak in the pulp bleached by chlorine dioxide adding DMSO increased at the intensity of 1062 and 1160 cm −1 , which indicated that there were more residual chromophore groups.
研究领域:
制浆造纸工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACTA MATERIALIA
·
2024
·
IF 8.3
Jinping Mu,Xiaohui Li,Rui He,Lijing Sun,Xue Bai,Lihui Zhang,Xi Zhang,Zhenfa Liu,Jing Gao,Aijia Wei
High-voltage (5-V) lithium–ion batteries (LIBs) have garnered substantial interest due to their superior energy density. Nevertheless, the unstable interphase of high-voltage LIBs can cause electrolyte decomposition, electrode collapse, transition metal dissolution, and lithium dendrite growth during cycling, which impedes their widespread commercial use. To mitigate these challenges, various alkali-metal phosphates were incorporated into a carbonate-based electrolyte as film-forming additives, aiming to improve the electrochemical performance of LiNi 0.5 Mn 1.5 O 4 (LNMO)-based LIBs. Following a detailed comparison of the electrochemical performances of various alkali-metal phosphates, KH 2 PO 4 and NaH 2 PO 4 were selected for an in-depth investigation in this research. The highly protective passivation film generated by KH 2 PO 4 and NaH 2 PO 4 on the electrode surface provided significant protection by effectively inhibiting continuous electrolyte decomposition. This finding was supported by density functional theory calculations and a variety of electrochemical and characterization tests. The H 2 PO 4 − primarily contributed to the formation of the cathode electrolyte interphase film on the cathode surface. KH 2 PO 4 (via the electrostatic shielding effect of K + ions) and NaH 2 PO 4 (through the co-precipitation of Na + and Li + ions) both effectively inhibited the growth of lithium dendrites on the lithium metal anode. Additionally, the KH 2 PO 4 and NaH 2 PO 4 additives regulated the amount of HF in the electrolyte through acid–base equilibrium reactions. The electrolytes containing additives significantly enhanced the electrochemical performances of Li||Li, LNMO/Li, LNMO/graphite, and LNMO/Li 4 Ti 5 O 12 cells. LNMO/Li half-cells with standard electrolyte (STD) supplemented with KH 2 PO 4 and NaH 2 PO 4 additives demonstrated capacity retentions of 92.9 % and 90.0 % after 500 cycles at 5 C, respectively, in contrast to only 79.4 % for the STD electrolyte alone. Furthermore, the LNMO/graphite full cell exhibited an increased capacity retention, reaching 81.1 % (STD+KH 2 PO 4 ) and 78.29 % (STD+NaH 2 PO 4 ), up from 70.8 % with the STD, after 100 cycles at 0.5 C. Given their ease of use, affordability, and widespread availability, KH 2 PO 4 and NaH 2 PO 4 additives show significant potential to enhance the electrochemical properties of high-voltage LIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2023
·
IF 8.7
Ruijie Ge,Tao E,Ying Cheng,Yuanfei Wang,Jia Yu,Yun Li,Shuyi Yang
Heavy metal stabilization is an effective method to treat chromium in tannery sludge . Here we show that mainly investigated NaH 2 PO 4 (MSP) and organic matter (OM) to stabilize chromium in tannery sludge. The experimental investigation revealed that the addition of montmorillonite (MMT) and MSP samples showed a significant increase in the percentage of reducible and oxidizable Cr in the former compared to the samples with the addition of MMT. This is attributed to the formation of Cr–O bond, which allows the MSP to undergo an inner-sphere complexation reaction with the metal oxide of Cr via ligand exchange . Significantly, the MSP moiety adsorbs on the surface of OM through monodentate, which increases the adsorption sites of OM for Cr 6+ and promotes the reduction of Cr 6+ to Cr 3+ . Moreover, PO 4 3− reacts with Cr 3+ to produce CrPO 4 precipitation, thus reducing the free Cr 3+ content. Finally, DFT calculations confirmed that a ternary system is formed between PO 4 3− , OM, and Cr, and the binding energy is negative, which indicated that PO 4 3− could co-stabilize Cr with OM.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2026
·Vol. 31
·期 12
·2137
·
IF 5.1
Zhiyong Zhang,Jingjing Xiao,Sheng Liu,Pan Xiao,Huijun Cao
Sphalerite–pyrite separation has always been one of the key issues of concern in the field of mineral flotation. To achieve selective flotation separation of sphalerite and pyrite, a novel flotation system, FeSO4+NaH2PO4-CuSO4-SIBX, was adopted. This study validated the novel separation system using mineral flotation experiments. The changes in the hydrophobicity and surface charge of the minerals were evaluated using experiments such as contact angle, zeta potential, and agglomeration. Finally, the mechanism of sphalerite–pyrite separation was revealed through XPS and solution chemistry analysis. The results showed that sphalerite and pyrite were effectively separated by flotation. In the novel flotation system, the synergistic effect of FeSO4and NaH2PO4shifted the surface potential of pyrite positively, and subsequent treatment with CuSO4and SIBX did not significantly alter its hydrophobicity. However, sphalerite, after treatment with FeSO4+NaH2PO4-CuSO4-SIBX, exhibited significantly enhanced hydrophobicity and marked mineral particle agglomeration. Further research revealed that within the pH range of 6.0–8.0, hydrophilic components formed by Fe2+and H2PO4−(e.g., Fe(H2PO4)+and Fe3(PO4)2·8H2O) selectively adsorbed onto the pyrite surface, enhancing its hydrophilicity. Meanwhile, sphalerite was activated by the substitution reaction of Cu2+with ZnS, forming a hydrophobic layer on its surface with SIBX in the slurry.
✓ 已验证
DOI
PubMed
高影响因子
Sustainable Chemistry and Pharmacy
·
2023
·
IF 6
Lihuan Chen,Jiahuan Xu,Qianli Wu,Jianbo Chu,Jing Shi,Qiyuan Shi
In the present study, a low-cost and environmentally-friendly method for the recovery of ellagic acid (EA) from waste pomegranate peel (WPP) was developed. Thermal hydrolysis assisted extraction (THAE) method was designed to efficiently prepare EA at low economic and environmental costs by the simultaneous extraction and hydrolysis of EA and its derivatives using NaH 2 PO 4 solution as extraction solvent, which could be reused at least 5 times after simple post-treatments. Ethyl acetate was chosen as liquid-liquid extraction (LLE) solvent to directly recover EA from THAE extract and regenerate NaH 2 PO 4 solution. After a series of optimization of operation parameters, the recovery rates of EA in the THAE and LLE processes reached ∼94% and 96%, respectively. As all of the solvents used above belong to cheap, eco-friendly, and edible solvents, this proposed method provides a good way to get safe and inexpensive EA-rich extract (with a purity of ∼89%), which could be used as natural ingredient in food, cosmetic, and medicinal industries, as well as starting materials for the preparation of pure EA.
研究领域:
化学工程
·
环境科学
·
食品科学
·
药学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Meiling Tang,Xiaoqi Yi,Haiming Huang,Yingli Feng,Gang Chen,Xiaojing Mu
Aqueous biphasic system (ABS) for extraction of active components attracted increasing attention due to advantages of high extraction efficiency and high product purity. However, solvent factors ruling extraction is still unclear. Four new ABSs with different organic solvent were designed for paeonol extraction, and the extraction conditions such as NaH 2 PO 4 concentration, organic solvent fraction, extraction period and temperature were examined with single factor method. The paeonol extraction yield, partition coefficient and paeonol purity with ABSs at optimized conditions were in the order as follows: ABS-THF-EA (33.6 ± 1.5 mg/g) ≈ABS-Ac-EA (33.0 ± 1.3 mg/g) > ABS-EtOH-EA (31.6 ± 1.6 mg/g)≈70 % ethanol (v/v) (31.2 ± 1.4 mg/g) > ABS-THF (28.8 ± 1.0 mg/g) > ABS-Ac (27.6 ± 1.2 mg/g) > ABS-EtOH (25.2 ± 1.2 mg/g), suggesting that replacing fraction of acetone/THF with ethyl acetate (EA) in ABSs could improve paeonol yield. Compositions and solvatochromic parameters for top phase of 12 ABSs were detected. Using LSER model, paeonol yield was strongly correlated to the dipolarity/dipolarizability (π*), hydrogen bond acidity (α) and hydrogen bond basicity (β) of top-phase medium in ABS ( r 2 = 0.982, n = 12); and partition coefficient was reasonably correlated to π*, α and β ( r 2 = 0.942, n = 12). Hydrogen-bond interaction and hydrophobicity interaction between paeonol and top-phase medium were crucial for efficient extraction. Solvatochromic parameters can offer guidance to solvent selection in extraction with ABS.
研究领域:
植物化学
·
药物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 19
·6465
·
IF 4.927
He Chang,Yang Lu,Yantao Sun
In this paper, a new aqueous two-phase extraction system(ATPES) consisting of UCON (poly(ethylene glycol-ran-propylene glycol) monobutyl ether)–NaH2PO4was established, and four trace polycyclic aromatic hydrocarbons (PAHs: fluorene, anthracene, pyrene and phenanthrene) in water and soil were analyzed by high-performance liquid chromatography (HPLC)–ultraviolet detection. In the multi-factor experiment, the central composite design (CCD) was used to determine the optimum technological conditions. The final optimal conditions were as follows: the concentration of UCON was 0.45 g·mL−1, the concentration of NaH2PO4was 3.5 mol·L−1, and the temperature was 30 °C. The recovery of the four targets was 98.91–99.84% with a relative standard deviation of 0.3–2.1%. Then UCON recycling and cyclic tests were designed in the experiment, and the results showed that the recovery of PAHs gradually increased in the three extractions because of the remaining PAHs in the salt phase of last extraction. The recovery of PAHs in the UCON recycling test was less than that in the extraction test due to the wastage of UCON. In addition, a two-phase aqueous extraction model was established based on the random forest (RF) model. The results obtained were compared with the experimental data, and the root mean square error (RMSE) was 0.0371–0.0514 and the correlation coefficient R2was 96.20–98.53%, proving that the model is robust and reliable.Keywords:aqueous two-phase separation;high-performance liquid chromatography;polycyclic aromatic hydrocarbons;determination
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）