Desalination and Water Treatment
·
2024
·
IF 1
Binglu Deng,Xingqiu Zhou,Xingjian Yang,Zhi Dang,Guining Lu
ABSTRACT This study reports on the adsorption of polychlorinated biphenyls (PCBs) by powder activated carbon (PAC) in soil washing eluents containing tween-80 surfactant micelles. Factors influencing of adsorption were studied (i.e., time, adsorbents doses, molecular structure of different PCBs congeners, dynamic and thermodynamic models). The adsorption of PCBs on nano bamboo charcoal (NBC) was compared with those on PAC. Finally, the prospect for recycling soil eluents was explored. We found that the PAC and NBC were both effective in removal of 12 mg/L PCBs in soil washing eluents. The results of the adsorption kinetics showed that both materials have different adsorption rate controlling step, the particles diffusion became adsorption rate controlling step of NBC while particle diffusion and adsorption reaction like chemical bonding reactions co-control the adsorption rate of PAC. The adsorption of PCBs on PAC was probably chemisorption through interaction between aromatic rings and oxygen-containing functional groups while the adsorption on NBC was mainly physisorption by micropore filling. After the PAC treatment, the residual tween-80 in the eluents was 27.78% (total mass ratio). The addition of acetone to break micelles before adsorption could increase the recovery of tween-80 to 73.30% while PCBs removal rate could still reach 78.06%. Therefore, the surfactant solutions can be reused after adsorption. The studies provide valuable information on the adsorption of PCBs by PAC in soil washing eluents, which may improve the utilization and selection of PAC in the recovery of soil washing eluents.
研究领域:
环境科学
·
污染治理
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DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Gao Yuchen,Jiang Jianguo,Tian Sicong,Li Kaimin,Yan Feng,Liu Nuo,Yang Meng,Chen Xuejing
Soil washing is an effective remediation method to remove heavy metals from contaminated soil. However, it produces wastewater that contains large amounts of heavy metals, which lead to serious pollution. This study investigated the removal of vanadium (V) from synthetic soil washing effluent using BOF steel slag. The effects of particle size, slag dosage, initial pH, and initial vanadium concentration on removal behavior were studied. Adsorption kinetics and isotherms were also analyzed. The results showed that the vanadium removal efficiency increased as the steel slag particle size decreased and as the amount of slag increased. The initial pH and vanadium concentration did not play key roles. At the optimum particle size (<0.15 mm) and dosage (50 g/L), the removal rate reached 97.1% when treating 100 mg/L of vanadium. The influence of the washing reagent residue was studied to simulate real conditions. Citric acid, tartaric acid, and Na 2 EDTA all decreased the removal rate. While oxalic acid did not have negative effects on vanadium removal at concentrations of 0.05–0.2 mol/L, which was proved by experiments using real washing effluents. Considering both soil washing effect and effluent treatment, oxalic acid of 0.2 mol/L is recommended as soil washing reagent.
研究领域:
环境科学
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土壤修复
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 28
·19795-19805
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IF 3.9
Longyan Song,Minxia Liu,Min Nian,Gang Yang
Manganese-based lithium-ion sieves have become some of the promising adsorbents for extracting Li+ from brines. However, manganese dissolution loss (MDL) severely impairs the stability and cyclicity of ion sieves. A novel ozone eluent was first developed to extract Li+ from lithium manganese oxides, which decreased MDL decreased from 5.89% to 0.11%, and after ten regeneration cycles, the adsorption capacity retained 85.39% of the initial value, which was better than 55.15% when only hydrochloric acid (HCl) was used as the eluent. Based on these phenomena, the mechanism for the O3 lowering of MDL was investigated. First, the catalytic decomposition reaction of O3 competed with the disproportionation reaction, and the involvement of O3 inhibited the occurrence of the disproportionation reaction. Additionally, the presence of O3 and reactive oxygen species provided a preferential electron acceptor compared to Mn3+ during the migration of electrons from the bulk phase to the surface. In this study, MDL was greatly reduced with a very simple strategy, and the cycling stability of the adsorbent was improved.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Shuang Sun,Yuefeng Deng,Ji Chen,Rui Qin,Zhongte Du,Qianshun Wen,Yang Meng
With the amid surging demand for lithium, solvent extraction has gradually developed into a key method for lithium recovery in industry. Due to the problems of large dissolution loss and high extraction equilibrium pH of β -diketone system, di-(2-ethylhexyl) phosphinic acid (P227) was selected to recover Li + from the desorption solution of salt lakes (SL-DS). Compared with di-2-ethylhexyl phosphoric acid (P204), 2-ethylhexyl phosphoric acid mono 2-ethylhexyl ester (P507), and bis (2,4,4-trimethylpentyl) phosphinic acid (Cyanex272), P227 showed better separation ability for Li + and Na + . The extraction conditions, including saponification degree, initial pH, extractant concentration and phase ratio were studied. It could be found that the extraction efficiency of Li + was maintained at a high level in the initial pH range of 2.25–12.61. A cascade process consisting of eight-stage extraction and five-stage scrubbing was performed to verify the feasibility of this technology. 99.9 % of Li + from the SL-DS was extracted at the equilibrium pH of 7.60, and P227 exhibited superior selectivity for Li + over Na + . Moreover, under the optimal condition of 3.8 mol/L HCl and O/A of 20:1, the stripping ratio of Li + reached 99.76 % via a four-stage stripping experiment. The Li + concentration of stripping liquor attained 23.11 g/L and a high-purity (99.5 %) Li 2 CO 3 product was obtained by precipitation. After five cycles, P227 demonstrated excellent regeneration stability. Eventually, the composition of extraction complex was revealed as LiR•NaR by slope analysis, and the cation exchange mechanism was further confirmed using FT-IR and 31 P NMR.
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产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 52
·32769-32776
·
IF 3.108
Feng-Lian Wang,Yong-Gang Zhao,Nadeem Muhammad,Shu-Chao Wu,Yan Zhu
A rapid and simple approach involving two-dimensional ultrahigh-performance liquid chromatography (UHPLC) combined with ion chromatography (IC) through valve-switching was developed to determine parabens and inorganic anions in cosmetics simultaneously. Compared with a conventional IC column-switching technique, the proposed method required UHPLC coupled with IC via valve-switching without refreshing the pretreatment column. In this chromatographic system, a mobile phase with 60% methanol and 40% deionized water was used to simultaneously separate parabens, namely, methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP), and to eliminate the matrix, and KOH eluent (20 mmol L−1) was utilized to separate inorganic anions, such as nitrite, sulfite, sulfate, and nitrate. Organic compound analysis, and inorganic anion pretreatment and analysis were simultaneously performed with a single injection. Under optimized conditions, matrix–calibration curves were examined by preparing and analyzing different concentrations of mixture standard solutions containing parabens and inorganic anions. Linearity was between 0.9994 and 0.9999. The limits of detection ranged from 8.0 to 80 μg L−1. Satisfactory recoveries of cosmetic samples were obtained between 93.9% and 106.2% by adding three representative standard solutions. The proposed method can be applied to routine analysis, as indicated by the validated linearity, accuracy, and precision and potential application on the analysis of MP, EP, PP, BP, nitrite, sulfite, sulfate and nitrate in eight commercial samples.
研究领域:
分析化学
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色谱学
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化妆品科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）