血液灌流吸附剂对百草枯吸附作用的实验研究

目的探讨血液灌流吸附剂对百草枯的吸附作用。方法采用0．5％百草枯溶液200ml、100ml、50ml及0．01％百草枯溶液200ml进行体外循环吸附2h，观察百草枯浓度的变化，以计算活性炭及大孔吸附树脂对百草枯的吸附率。结果百草枯的浓度为0．5％，循环容积为200ml，百草枯含量为1000mg时，活性炭和树脂的吸附率为46％、35％；百草枯的浓度为0．5％，循环容积为100ml，百草枯含量为500mg时，活性炭和树脂的吸附率为65％、47％；百草枯的浓度为0．5％，循环容积为50ml，百草枯含量为250mg时活性炭和树脂的吸附率为88％、57％；百草枯的浓度为0．01％，循环容积为200ml，百草枯含量为20mg时，活性炭和树脂的吸附率为95％、87％。结论在百草枯浓度较低0．01％、较低含量20mg时，活性炭及大孔吸咐树脂对百草枯的吸附率无明显差异；在百草枯浓度较高0．5％、较高含量时，活性炭清除百草枯的作用优于大孔吸附树脂；临床上清除百草枯可以根据患者情况选用炭肾或树脂吸附柱进行血液灌流治疗。     

3种吸附剂对百草枯吸附能力的对比观察

目的 比较白陶土、蒙脱石散、活性炭三者对百草枯吸附能力.方法 在体外,用白陶土、蒙脱石散、活性炭处理相同的百草枯溶液,比较处理过的百草枯溶液的百草枯含量;临床上,服药量相近的患者分别经白陶土、蒙脱石散、活性炭治疗后比较患者尿中百草枯的含量.结果 体外实验:经蒙脱石散处理过的溶液中的百草枯含量最低;临床观察:经蒙脱石散治...     

Mechanism of adsorption of humic acid by modified aged refuse

In the present study, aged refuse (AR) was modified to be applied as an adsorbent to remove humic acid from water. The efficiency of humic acid removal by modified aged refuse (MAR) under different preparation conditions (calcination temperature, dose of aged refuse for calcination and holding time) was systematically investigated. Results showed that the optimum preparation conditions are calcination temperature = 700 °C, AR dose for calcination = 25 g, and holding time = 2.0 h. The characteristics of the modified aged refuse obtained under different calcination conditions were determined by Fourier transform infrared, X-ray diffraction and X-ray photoelectron spectroscopy analysis. In addition, the effects of modified aged refuse dose and initial solution pH on adsorption performance were studied. The removal of humic acid increased with higher doses of modified aged refuse, and weak alkaline (initial pH = 8.0) conditions were favorable for humic acid removal. A pseudo-second order model fitted the experimental data well. Moreover, the adsorption isotherms were well described by the Langmuir isotherm model, in which the monolayer surface loading was calculated to be approximately 37 mg g⁻¹. During the adsorption process, the molecular weight, degree of condensation and aromaticity of humic acid were considerably decreased, according to 3D-EEM analysis. MAR as a new type of adsorbent thus provides a potential adsorption method for humic acid.

In the present study, aged refuse (AR) was modified to be applied as an adsorbent to remove humic acid from water.     

Reversible adsorption and desorption of PFAS on inexpensive graphite adsorbents via alternating electric field

Per- and polyfluoroalkyl substances (PFAS) have been extensively utilized in practical applications that include surfactants, lubricants, and firefighting foams due to their thermal stability and chemical inertness. Recent studies have revealed that PFAS were detected in groundwater and even drinking water systems which can cause severe environmental and health issues. While adsorbents with a large specific surface area have demonstrated effective removal of PFAS from water, their capability in desorbing the retained PFAS has been often neglected despite its critical role in regeneration for reuse. Further, they have demonstrated a relatively lower adsorption capacity for PFAS with a short fluoroalkyl chain length. To overcome these limitations, electric field-aided adsorption has been explored. In this work, reversible adsorption and desorption of PFAS dissolved in water upon alternating voltage is reported. An inexpensive graphite adsorbent is fabricated by using a simple press resulting in a mesoporous structure with a BET surface area of 132.9 ± 10.0 m² g⁻¹. Electric field-aided adsorption and desorption experiments are conducted by using a custom-made cell consisting of two graphite electrodes placed in parallel in a polydimethylsiloxane container. Unlike the conventional sorption process, a graphite electrode exhibits a higher adsorption capacity for PFAS with a short fluoroalkyl chain (perfluoropentanoic acid, PFPA) in comparison to that with a long fluoroalkyl chain (perfluorooctanoic acid, PFOA). Upon alternating the voltage to a negative value, the retained PFPA or PFOA is released into the surrounding water. Finally, we engineered a device module mounted on a gravity-assisted apparatus to demonstrate electrosorption of PFAS and collection of high purity water.

In this study, a reversible adsorption and desorption upon alternating electric field for per- and polyfluoroalkyl substances (PFAS) using inexpensive graphite is reported.     

Retraction: Tuning the chemistry of graphene oxides by a sonochemical approach: application of adsorption properties

Retraction of ‘Tuning the chemistry of graphene oxides by a sonochemical approach: application of adsorption properties’ by Yubing Sun et al., RSC Adv., 2015, 5, 24886–24892, DOI: 10.1039/C5RA02021B.

The Royal Society of Chemistry, with the agreement of the named authors, hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article.The TEM image in Fig. 1B duplicates data published in another publication by Pan et al., but presented as different materials.¹The AFM images in Fig. 1C and D illustrate duplication of data, given that these experiments were reported under different reaction conditions.The EXAFS spectra in Fig. 4 duplicate data in another publication, but reported as different materials.²Given the number and significance of the concerns about the validity of the data, the findings presented in this paper are no longer reliable.Signed: Yubing Sun, Shubin Yang, Congcong Ding and Wencai ChengDate: 27^th March 2020Zhongxiu Jin was contacted but did not respond.Retraction endorsed by Laura Fisher, Executive Editor, RSC Advances     

Insight into the significant roles of microstructures and functional groups on carbonaceous surfaces for acetone adsorption

To understand the roles of pore structures and functional groups on acetone adsorption, activated carbons (ACs) with different properties were obtained by surface modification. XRD, SEM, TEM and nitrogen adsorption were used to identify the structural characteristics of the ACs, while TG-DTA, FTIR, XPS and Boehm titration were applied to analyse the surface chemistries. The microporous surface areas showed a positive linear correlation to the acetone adsorption amounts, and increasing the carboxylic groups could improve the uptake of strongly adsorbed acetone. HNO₃ modified AC (AC-N) was found to exhibit an excellent adsorption capacity of 5.49 mmol g⁻¹, which might be attributed to the developed microporous structures and abundant carboxylic groups. The desorption activation energies (E_d) of strongly adsorbed acetone on AC-N and AC were both determined to be 81.6 kJ mol⁻¹, indicating the same adsorption sites on different activated carbons, suspected to be carboxylic groups. The possible adsorption mechanism of acetone on carbonaceous surfaces was also proposed.

To understand the roles of pore structures and functional groups on acetone adsorption, activated carbons (ACs) with different properties were obtained by surface modification.     

The impact of humic acid on metaldehyde adsorption onto powdered activated carbon in aqueous solution

Metaldehyde has been detected in surface water and drinking water in the UK, exceeding the EU and UK standard of 0.1 μg L⁻¹. The presence of natural organic matter (NOM) is considered to affect the removal efficiency of metaldehyde using traditional treatment methods such as adsorption by granular activated carbon. This paper selected humic acid (HA) to represent NOM and investigated the single and binary adsorption systems of metaldehyde and HA by powdered activated carbon (PAC). Metaldehyde was effectively removed by PAC in both systems. Since the percentage removal of metaldehyde was only 3% lower in the binary adsorption system, HA was therefore not considered as a significant compound competing with metaldehyde for adsorption sites on PAC. An adsorption equilibrium study and kinetic study for metaldehyde in a single system suggested that the Langmuir isotherm and the pseudo-second order kinetic model were more suitable in this case than the Freundlich isotherm and the pseudo-first order kinetic model. The two models revealed that the maximum adsorption capacity (q_m) of metaldehyde by PAC was 28.3 mg g⁻¹ and the adsorption rate (k₂) was 0.16 g mg⁻¹ min⁻¹. The effect of pH of metaldehyde solution was also investigated in a single system. Higher percentage removal of metaldehyde was found under alkaline conditions. In contrast to metaldehyde, HA was not effectively and efficiently removed by PAC in both systems, even with higher PAC dosages and longer contact times. Hence, the microporous and mesoporous PAC was suitable for removing metaldehyde even in the binary system.

Powdered activated carbon with abundant micropores and mesopores can effectively remove metaldehyde from aqueous solution in the presence of humic acid.     

Efficient O-demethylation of lignin-derived aromatic compounds under moderate conditions

Lignin is a potential feedstock to produce renewable aromatic chemicals. However, lignin-derived aromatics are heavily methoxylated, which affects their reactivity in some downstream valorization attempts. Herein, we report an efficient method for the demethylation of the aromatics derived from lignin depolymerization using acidic concentrated lithium bromide (ACLB) under moderate conditions (e.g., 1.5 M HCl, 110 °C, and 2 h). Aromatics with one or two methoxy groups (G-type and S-type), alkyl hydroxyl and carbonyl groups, and electron-donating and electron-withdrawing substituents were used to investigate the demethylation mechanisms. S-type aromatics were demethylated faster than their G-type analogs. Alkyl hydroxyl groups were brominated under the conditions. Carbonyl groups (aldehydes and ketones) promoted unwelcome condensation. Electron-donating substituents promoted demethylation, whereas electron-withdrawing substituents retarded the demethylation. An ortho-carboxylic group enhanced the demethylation because of the formation of a stable intermediate.

Lignin-derived aromatics can be efficiently demethylated with a high yield in an acidic lithium bromide solution under moderate conditions.     

Graphene and zeolite as adsorbents in bar-micro-solid phase extraction of pharmaceutical compounds of diverse polarities

A bar micro-solid phase (bar μ-SPE) extraction method using either graphene or zeolite or their mixtures as an adsorbent, coupled with high-performance liquid chromatography (using a C1 column) was developed for the simultaneous determination of pharmaceutical compounds (metformin (MET), buformin (BUF), phenformin (PHEN) and propranolol (PROP)) of diverse polarity (log P from −1.82 to 3.10). Parameters influencing the extraction, such as conditioning solvents, pH of the sample, sample volume, amount of adsorbent, stirring rate, time of extraction, type and volume of desorption solvent and time of desorption were investigated. Under the optimized conditions, the extraction method using graphene (extraction efficiency, % EE, ∼6–15%) resulted in the least amount of extracted drugs. However, the use of zeolite and zeolite/graphene mixtures improves the % EE significantly, i.e. 30% for PHEN and 42% for PROP using zeolite; 22% for MET and 18% for BUF using the adsorbent mixture. Under similar conditions, enrichment factors for these drugs range from 11–15. The validated method was performed for the determination of the drugs that were spiked to urine samples. Good recoveries ranging from 72.8 to 116% were achieved.

A bar micro-solid phase (bar μ-SPE) extraction method using either graphene or zeolite or their mixtures as an adsorbent, coupled with high-performance liquid chromatography was developed for the determination of pharmaceutical compounds of diverse polarity.     

Anti-HSV-1 activity of synthetic humic acid-like polymers derived from p-diphenolic starting compounds

A panel of ten humic-acid-like polymers was synthesized by oxidation of p-diphenolic compounds and characterized by relative molecular weights, FT-IR spectra and functional group analysis. Using the XTT-based tetrazolium reduction assay EZ4U, both the low-molecular starting compounds and the synthesized polymers were examined for antiviral and cytotoxic activities in HSV-1-infected Vero cells. With the exception of hydroquinone, 2,5-dihydroxytoluene and 2,5-dihydroxybenzoquinone, the starting compounds failed to inhibit herpesvirus replication. The polymeric oxidation products, however, developed anti-HSV-1 activity with EC50 values in the range of 0.65 (2,5-DHPOP) and 322 microg/ml (2,5-DHBQOP). The CC50 values of the polymers varied among 32.0 (TMHYDROP) and >512 microg/ml (2,5-DHBQOP, HYDSULFOP). The most effective polymers were found to be 2,5-DHPOP 2,5-DHTOP and GENOP (EC50: 0.65, 1.6 and 2.2 microg/ml, respectively, and SI: > or = 400, > or = 80 and > or = 58, respectively). Functional group analysis revealed that increasing numbers of carboxyl groups together with a high content of hydroxyl groups tend to enhance the antiviral activity of polymers derived from p-diphenolic compounds.     

Hydroxyl porous aromatic frameworks for efficient adsorption of organic micropollutants in water

Environmental pollution is an important issue in sustainable human development. People give great importance to environmental protection, especially with regards to increasingly scarce water resources. Water pollution is becoming more and more serious due to the existence of organic micropollutants. As a platform with good stability, porous aromatic frameworks (PAFs) have been widely studied. Because of their high surface area and thermal stability, they are considered to be a good sewage treatment agent. However, the aromatic nature of PAFs makes their skeletons mostly hydrophobic. This characteristic of PAFs seriously affects their diffusion rate in water as an adsorbent, resulting in a low adsorption rate. In this work, we synthesized a series of hydroxyl functionalized porous aromatic frameworks (PAF-80, PAF-81, and PAF-82) via the Sonogashira–Hagihara cross-coupling reaction, which created polar motifs on the hydrophobic surfaces, and carried out adsorption tests on typical organic micropollutants in water such as bisphenol A (BPA), 2-naphthol (2-NO) and p-chloroxylenol (PCMX). Among the three PAFs, PAF-82 exhibited the highest BET surface area, polar active sites, and a high degree of conjugation, which led to the best adsorption performance compared to that of PAF-80 and PAF-81. The Langmuir adsorption capacity of PAF-82 for BPA, 2-NO, and PCMX is 689 mg g⁻¹, 431 mg g⁻¹, and 480 mg g⁻¹, respectively, which surpasses most previously reported adsorbents. In addition, after 5 cycles of regeneration, it still maintained a high removal rate for pollutants. The obtained results reveal that micropollutant adsorption in water is not controlled by a single factor, but is the result of a synergy of multiple factors, including specific surface area, polar functional groups, pore size distribution, and skeleton conjugation. Our study has revealed the great potential of hydroxyl PAFs for efficient adsorption of organic micropollutants in water.

A series of hydroxyl functionalized PAF materials (PAF-80, PAF-81, and PAF-82) were synthesized, which create polar channels to the hydrophobic surfaces and explored as efficient adsorption of organic micropollutants in water.     

Effective removal of aromatic pollutants via adsorption and photocatalysis of porous organic frameworks

PAF-45 with a wholly aromatic framework, intrinsic microporosity and π–π conjugation system shows excellent performance in aromatic pollutant removal. It exhibits a high adsorption capacity for the benzene series and moderate photocatalytic performance. As an adsorbent, PAF-45 can adsorb 35 wt% benzene and 68 wt% chlorobenzene in static adsorption experiments at room temperature and pressure. In benzene simulation wastewater, PAF-45 also shows excellent adsorption capacity, without significant reduction after 10 cycles of the adsorption–desorption process. Moreover, PAF-45 exhibits an impressive photocatalytic degradability of aromatic compounds, like aniline and phenol, under visible light illumination.

PAF-45 with a wholly aromatic framework, intrinsic microporosity and π–π conjugation system shows excellent performance in aromatic pollutant removal.     

Water-soluble gold nanoparticles: recyclable catalysts for the reduction of aromatic nitro compounds in water

A structure/catalytic activity study of water-soluble gold nanoparticles, stabilized by zwitterionic ligands derived from imidazolium salts, in the reduction of aromatic nitro compounds in pure water at different temperature, as well as their recyclability, was performed. Our studies indicate that the nanoparticles synthesized by an easy, fast and reproducible process, need a short characteristic induction time to restructure the surfaces and make them active. The differences observed in the catalytic activity of the nanoparticles, determined by using the typical Langmuir–Hinshelwood model, are strongly based on the degree of coverage and spatial arrangement of the imidazolium salts on them. Finally, we demonstrate that gold nanoparticles stabilized by non-traditional ligands can be an excellent choice for nitro compound degradation.

A structure/catalytic activity study of water-soluble gold nanoparticles, stabilized by zwitterionic ligands derived from imidazolium salts, in the reduction of aromatic nitro compounds in pure water, as well as their recyclability, was performed.     

Preparation of boron-doped mesoporous carbon with aromatic compounds as expanding agents

Boron-doped ordered mesoporous carbon (B-OMC) was synthesized using the aromatic compounds benzene, 1,3,5-trimethylbenzene, 1,3,5-triethylbenzene and 1,3,5-triisopropylbenzene as expanding agents. The expanding mechanism as well as the effect of the expanding agent molecule on the properties of B-OMCs were studied. Compared with the unmodified one, the order of B-OMCs treated with aromatic compounds is improved significantly. In addition, along with the increase in hydrophobicity and steric hindrance of the expanding agents, the pore size and pore volume of B-OMCs increase, while their surface area and specific capacitance increase first, and then drop off slightly. The obtained B-OMC-TEB has a high boron content (1.54 wt%), the largest surface area (693 m² g⁻¹), a much better electrochemical performance and the highest specific capacitance (290 F g⁻¹), 30% higher than that of ordinary B-OMC. Furthermore, the specific capacitance can be maintained at 155 F g⁻¹ even at a high current density of 20 A g⁻¹, indicating that it has a high capacitance retention rate.

TMB, TEB and TiPB exhibit both penetration and swelling effects, and the pore size of B-OMCs increases with their increasing hydrophobicity.     

Enhancing adsorption capacity and structural stability of Li1.6Mn1.6O4 adsorbents by anion/cation co-doping

Modifying the structure of Li_1.6Mn_1.6O₄ (LMO) to enhance its structural stability and adsorption capacity is an effective method to generate materials to recover Li⁺ ions from mixed solution. Herein, the co-doping of trace non-metal ion (S) and metal ion (Al) into Li_1.6Mn_1.6O₄ (LMO-SAl) is established and shows excellent Li⁺ adsorption capacity and Mn anti-dissolution properties. The adsorption capacity (when [Li⁺] is 6 mmol L⁻¹) is increased from 26.1 mg g⁻¹ to 33.7 mg g⁻¹. This is attributed to improved charge density via substitution of S at O sites, which facilitates the adsorption/desorption process. The Mn dissolution is also reduced from 5.4% to 3.0% for LMO-SAl, which may result from the stronger Al–O bonds compared to Li–O bonds that enhance the structural stability of the LMO. The ion-sieving ability of the co-doped material goes by the order of K_d (Li⁺ > Ca²⁺ > Mg²⁺ > Na⁺ > K⁺), indicating that Li⁺ can be efficiently separated from Lagoco Salt Lake brine. These results predict that lithium ions are effectively adsorbed from brine by the co-doped LMO material, which manifests the feasibility of lithium recovery and provides basic data for further industrial applications of adsorption.

Modifying the structure of Li_1.6Mn_1.6O₄ (LMO) to enhance its structural stability and adsorption capacity is an effective method to generate materials to recover Li⁺ ions from mixed solution.     

不同吸附剂对肝衰竭患者血浆总胆红素、血氨及胆汁酸的吸附作用对比研究

目的比较几种吸附剂对肝衰竭患者血浆总胆红素、胆汁酸及血氨的吸附作用。方法收集4名肝衰竭患者血浆，将每位患者血浆分为6份，分别用以下6种吸附材料进行血浆灌注：丽珠HA330吸附树脂（HA330组）；用人血白蛋白包被的活性炭（活性炭＋HSA组）；AB-8大孔吸附树脂（AB8组）；用人血白蛋白包被经化学处理的AB-8大孔吸附树脂（化学处理的AB-8＋HSA组）；人血白蛋白包被乙基纤维素（EC＋HSA组）；用人血白蛋白包被经化学处理的乙基纤维素（化学处理的EC＋HSA组）。观察各组吸附剂对总胆红血素、胆汁酸和血氨的吸附效果并进行比较。结果除EC＋HSA组外其余各组对总胆红素、胆汁酸的吸附均有效（P〈0．05），其中化学处理的EC＋HSA组对总胆红素的吸附率最高（10．82±1．24）％，活性炭＋HSA组对胆汁酸吸附率最高（9．85±1．50）％；各组对血氨的吸附均有效（P〈0．05），化学处理的EC＋HGA组的吸附率最高（33．83±2．51）％。结论化学处理的EC＋HSA组对总胆红素、血氨、胆汁酸有较好的吸附效果。     

Magnetite-based adsorbents for sequestration of radionuclides: a review

As a result of extensive research efforts by several research groups, magnetite-based materials have gained enormous attention in diverse fields including biomedicine, catalysis, energy and data storage devices, magnetic resonance imaging, and environmental remediation. Owing to their low production cost, ease of modification, biocompatibility, and superparamagnetism, the use of these materials for the abatement of environmental toxicants has been increasing continuously. Here we focus on the recent advances in the use of magnetite-based adsorbents for removal of radionuclides (such as ¹³⁷Cs(i), ¹⁵⁵Eu(iii), ⁹⁰Sr(ii), ²³⁸U(vi), etc.) from diverse aqueous phases. This review summarizes the preparation and surface modification of magnetite-based adsorbents, their physicochemical properties, adsorption behavior and mechanism, and diverse conventional and recent environmental technological options for the treatment of water contaminated with radionuclides. In addition, case studies for the removal of radionuclides from actual contaminated sites are discussed, and finally the optimization of magnetite-based remedial solutions is presented for practical application.

As a result of extensive research efforts by several research groups, magnetite-based materials have gained enormous attention in diverse fields.     

Retraction: Enhanced electrocatalytic activity and durability of highly monodisperse Pt@PPy–PANI nanocomposites as a novel catalyst for the electro-oxidation of methanol

Retraction of ‘Enhanced electrocatalytic activity and durability of highly monodisperse Pt@PPy–PANI nanocomposites as a novel catalyst for the electro-oxidation of methanol’ by Özlem Karatepe et al., RSC Adv., 2016, 6, 50851–50857. DOI: 10.1039/C6RA06210E.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article.The two high resolution transmission electron micrograph insets in Fig. 2 that represent Pt@PPy–PANI NPs polymer composites are identical. In addition, these insets are duplicated and scaled versions of the high-resolution transmission electron micrograph insets in Fig. 1 in an International Journal of Hydrogen Energy article,¹ and in Fig. 2 in a Journal of Cluster Science article,² by the same author group representing different nanoparticles or synthetic methods. Fig. 1 in the International Journal of Hydrogen Energy article¹ represents Pt(0)/DPA@GO NPs and Fig. 2 in the Journal of Cluster Science article² represents Pt(0) NPs. The authors claim that this was a mistake and provided replacement data for consideration. However, an expert reviewed the author’s response and concluded that it did not satisfactorily address the concerns, and that the replacement figure did not fully support the conclusions. Given the significance of the concerns about the validity of the data, the findings presented in this paper are no longer reliable.Sinan Eriş and Fatih Sen oppose this retraction. Handan Pamuk, Yunus Yıldız, Özlem Karatepe and Zeynep Dasdelen were contacted but did not respond.Signed: Laura Fisher, Executive Editor, RSC AdvancesDate: 23^rd September 2021