Amount Of Removal Research Articles

The feasibility of endoscopic stapes surgery: A three‐dimensional planning method

AbstractObjectiveThe primary aim of this study was to investigate the accuracy of a semi‐automatic algorithm in assessing the feasibility and complexity of endoscopic stapes surgery preoperatively.MethodsA semi‐automatic algorithm was developed to simulate endoscopic stapes surgery in 3D. To test the accuracy of the algorithm, five fresh‐frozen cadaveric heads (ten ears) were used. Each head was CT‐scanned, followed by segmentation and 3D reconstruction of the bones including the ear canal, middle ear, and ossicular chain. Two interventions were tested on each ear. Initially, the algorithm was digitally employed to simulate the endoscopic ear surgery. Subsequently, the actual endoscopic ear surgery was performed. Primary outcomes for each intervention included the amount of scutum removal (postoperative 3D model subtracted from preoperative 3D model), visibility of important landmarks, feasibility score, and a complexity questionnaire. Finally, the outcomes of the pre‐operative planning and the actual procedure were directly compared to evaluate the algorithm's accuracy and usability.ResultsThe preoperative planning method achieved an accuracy rate of 70% in predicting the need for scutum removal. The mean volume of the removed scutum was 0.5 mm3. Endoscopic surgery was feasible in all ten ears, with all relevant anatomical landmarks adequately visualized as estimated by the preoperative planning algorithm.ConclusionPreoperative planning models can assist ENT surgeons in evaluating the feasibility and complexity of endoscopic stapes surgery. With adequate training and testing on clinical cases, these models can significantly improve their predictive accuracy and thereby improve patient outcomes.

Electrocatalytic Oxidation of Toxic Wastewater using Electrodes based on Transition d-metal Oxides

The process of electrooxidation of the active substances Paracetamol (PCT), benzoquinone (BQ) and hydroquinone (HQ) was studied using a set of different dimensionally stable anode (DSA) and Boron doped diamond (BDD) electrodes. Comparison of the efficiency of electrocatalytic anodes was assessed using percent total organic carbon (%TOC) removal and PCT amount removal values. The removal of %TOC in synthetically prepared waters for the BDD anode reached 96%, for DSA electrodes Ti/PbO2-IrO2-RuO2 57%, Ti/IrO2-RuO2-TiO2 35%, Ti/IrO2-RuO2-SnO2 31%, Ti/RuO2-SnO2 30% and Pt 24%. BDD effectively degrades PCT and almost completely mineralizes BQ and HQ. A DSA-Ti/PbO2-IrO2-RuO2 electrode and a BDD electrode were used in the electrooxidation process of real industrial wastewater containing PCT. The BDD electrode had a TOC removal efficiency of 58%, while the DSA-Ti/PbO2-IrO2-RuO2 electrode achieved 52%. Despite similar values ​​of PCT removal by both electrodes, the Ti/PbO2-IrO2-RuO2 anode showed low mineralization of organic matter. The originality of this paper lies in the study of the electrooxidation of real PCT wastewater and the use of a Ti/PbO2-IrO2-RuO2 electrode.Graphical

Diclofenac Degradation by Immobilized Chlamydomonas reinhardtii and Scenedesmus obliquus.

Diclofenac (DCF), a commonly used anti-inflammatory medication, presents environmental concerns due to its presence in water bodies, resistance to conventional wastewater treatment methods, and detection at increasing concentrations (ng/L to µg/L) that highlight DCF as a global emerging pollutant. While microalgae have been effective in degrading DCF in wastewater, immobilization into a matrix offers a promising approach to enhance treatment retention and efficiency. This study aimed to evaluate the efficacy of DCF removal using immobilized freshwater microalgae. Two algal species, Chlamydomonas reinhardtii (Chlamydomonas) and Scenedesmus obliquus (Scenedesmus), were tested for 6 days in both free and immobilized forms to determine if immobilized algae could degrade DCF comparably to free cells. The findings indicate that by Day 3, immobilized Chlamydomonas and Scenedesmus removed 78.0% and 80.1% of DCF, outperforming free-cell cultures. Mixed cultures demonstrated synergistic effects, with removal amounts of 91.4% for free and 92.3% for immobilized systems. By Day 6, all conditions achieved complete DCF removal (100%). Mechanistic analysis showed 80.0% biodegradation and 20.0% bioaccumulation in free Chlamydomonas and 56.8% biodegradation with 43.2% bioaccumulation in Scenedesmus. Immobilization shifted pathways slightly: in Chlamydomonas, 61.6% of DCF removal occurred via biodegradation, 18.3% via bioaccumulation, and 20.1% via abiotic degradation. For Scenedesmus, immobilization achieved 45.6% biodegradation, 36.6% bioaccumulation, and 17.8% abiotic degradation, enhancing abiotic degradation while maintaining biodegradation efficiency. This research serves as a proof of concept for utilizing immobilized algae in DCF removal and suggests an avenue for improved wastewater treatment of emerging contaminants.

Understanding Climate Change by Modeling the Earth's Atmosphere as a Well‐Stirred Tank

AbstractComing to terms with climate change by understanding climate processes and their policy implications is essential not only for climate scientists and policymakers, but also for the general public, for industrial practitioners, and for engineers, including process system engineers. We have developed a simplified linear climate model (SLCM) to enable non‐specialists to explore the essential physical and chemical processes caused by greenhouse gas emissions. Trading‐off simplicity and accuracy, achieved by calibrating model parameters using established simple climate models, the SLCM allows (i) determining the climate impact of given past and future emissions, (ii) determining the amounts of CO2 removal needed to compensate for any unavoidable emissions of CH4 and N2O from agriculture, and (iii) back‐calculating emission pathways to meet specified global warming targets.

Agroforestry for Carbon Neutrality: An Effective Pathway to Net Zero

Agroforestry is a promising strategy to achieve carbon neutrality and net zero emission, aiming towards the balance between greenhouse gas emissions and equal amount of carbon removal through sequestration Among several methods of carbon sequestration, agroforestry stands out for its unique ability to simultaneously sequester carbon while reducing greenhouse gas emissions, particularly nitrous oxide (N2O) emissions associated with chemical fertilizer use in conventional agriculture. These systems store carbon through multiple pathways like, in above-ground biomass, below-ground root systems, and enhanced soil organic carbon accumulation while maintaining the agricultural productivity. Acknowledged under the afforestation and reforestation programs of the Kyoto Protocol, agroforestry has attracted interest for its several advantages from both industrialized and developing countries for its multifaceted benefits, including its potential to combat desertification and reduce anthropogenic emissions. Beyond carbon sequestration, it enhances soil fertility, supports biodiversity conservation, and provides economic diversification for farmers through multiple income streams. The role of REDD+ (Reducing Emissions from Deforestation and Forest Degradation) negotiations in extending the Kyoto Protocol's second commitment period has further strengthened agroforestry's position in global climate action, particularly through the development of REDD offset credits in compliance carbon markets. The World Agroforestry Centre defines agroforestry as a dynamic, ecologically based natural resources management system that integrates trees on farms and in the agricultural landscape, diversifying and sustaining production for increased social, economic, and environmental benefits. The Association for Temperate Agroforestry (AFTA) defines it as an intensive land management system that optimizes the benefits from biological interactions created when trees and/or shrubs are deliberately combined with crops and/or other natural resources. This review article critically examines agroforestry's crucial role as an effective pathway toward achieving carbon neutrality and net zero goals, synthesizing current knowledge and future prospects.

Experience of using robot-assisted (da Vinci) operations in the treatment of common endometriosis

Background. Currently, genital endometriosis is considered as one of the most severe conditions in women of reproductive age, which has detrimental consequences for social, professional and psychological functioning. It ranks third in the structure of gynecological diseases after inflammatory diseases of the female reproductive system and uterine fibroids. Because of this, it acquires a more pronounced social significance and ceases to be only a medical problem. Aim. To study the results of surgical treatment of patients with severe forms of genital endometriosis using the da Vinci surgical robotic complex.Materials and methods. A retrospective analysis of the treatment results of 51 patients operated on at the N.I. Pirogov National Medical and Surgical Center for the period from January 2015 to July 2024, who underwent robot-assisted (da Vinci) operations for deep endometriosis involving neighboring organs. The duration of surgery and hospital stay, the amount of blood loss, the frequency of intra- and postoperative complications, the clinical course of the disease in the long-term postoperative period, the frequency of detection of residual infiltration in the postoperative period, and the implementation of reproductive plans were analyzed.Results. The duration of the surgical intervention was 220.8 ± 21.87 minutes. The postoperative bed-day was 6.9 ± 1.5 bed days. The average blood loss was 160.2 ± 67.58 ml. There were no intraoperative complications. Postoperative complications accounted for 7.8 %. Residual infiltration occurred in 11.7 % of cases. 94.1 % of the patients had no clinical symptoms of endometriosis in the long-term postoperative period. The pregnancy rate was 31.9 %.Conclusion. Surgical treatment of deep endometriosis using da Vinci surgical robotic complex in the amount of radical removal of endometrioid infiltrate has a positive effect on both the clinical course of the disease and the reproductive potential of a woman. Real-time fluorescence navigation has demonstrated additional imaging capabilities in robotic surgery for deep endometriosis, potentially increasing the radicalism of surgical treatment of infiltrating endometriosis and may lead to a reduction in recurrence rates.

Spiral feed polishing uniform removal and compensation strategy of sapphire components.

A single crystal sapphire component has been widely used in various high-tech fields because of its significant advantages such as high hardness, high stability, and excellent optical and mechanical properties, and has put forward high requirements for surface accuracy and quality. The existing sapphire polishing technology has problems such as low polishing efficiency, difficult control of polishing accuracy, and difficulty in removing surface defects and subsurface damage introduced by the front grinding process. Therefore, for the polishing and damage removal stage of sapphire optical components, the surface shape accuracy should be strictly controlled, especially for the surface shape accuracy after ultra-precision grinding. It is of great significance to study the uniform removal technology of grinding damage based on not destroying the surface shape. This study focuses on the mechanical polishing of sapphire. Firstly, the characteristics of the sapphire removal function of the elastic polishing tool are analyzed and the stability of the polishing tool is verified. Secondly, by establishing the relationship between the amount of workpiece material removal and the radius of rotation, the feed rate is planned to achieve the effect of uniform spiral removal. By optimizing the center feed speed of the tilting axis small-size polishing tool, the center feature of the polishing surface is controlled to be sharp. Finally, based on the sub-aperture polishing figuring theory, the influence of the center feature on the surface profile is reduced by using the spiral grating processing method. This study provides an efficient and stable strategy for the uniform removal and polishing of rotationally symmetric optical elements (such as aspheric surfaces) of high-hardness material sapphire and is expected to play a role in scenes that are particularly difficult to process, difficult to detect full aperture, difficult to calculate removal function and dwell time, such as higher steep aspheric surfaces and Gaussian aspheric surfaces.

A comparative experimental study on abrasive flow machining vs flow peening GOV processes on Inconel 718

Inconel 718, a nickel-based super alloy, has a broad applications area from aerospace, medical and defence to traditional industries because of its high durability, corrosion resistance and elevated temperature performance. Unconventional surface treatment methods of abrasive flow machining (AFM) and shot peening (SP) are applied to improve the mechanical performance of Inconel 718. In this work, a new surface treatment process known as flow peening (GOV) already developed by combining the advantages of abrasive flow machining (AFM) and shot peening methods such as surface finishing and residual compressive stress generation respectively was applied experimentally for Inconel 718. The effects of process parameters for GOV and AFM processes on the surface quality of the specimens were experimentally investigated. White layer decrease, surface roughness decrease and material removal amount were discussed for both processes. The best surface quality with 0.56 μm Ra surface roughness value and material removal amount of 7.2 mg were obtained by GOV process while similar level of surface roughness value of 0.52 μm was obtained by removing 6648.03 mg material for AFM. When the AFM process was continued, the best values of 0.24 μm Ra was obtained removing excess material of 17,385.60 mg compared to the GOV process. Also, all these results were supported by SEM images.

Fe and Mn Removal from Acid Mine Drainage by Utilizing Chlorella sorokiniana and Monoraphidium neglectum as Biosorbent

The mining industry generates acid mine drainage (AMD) characterized with a low pH value and high dissolved metal concentration that leads to the negative impacts on the environment and human health. The objectives of this research were to investigate the growth response of mixed culture of microalgae Chlorella sorokiniana and Monoraphidium neglectum in a liquid media contaminated with AMD; generate the optimum environmental conditions (pH value and contact time) to determine the efficiency biosorption of iron and manganese contained in the solution of AMD into the consortium of microalgae; and quantify the maximum removal amount of iron and manganese contained in the solution of AMD by utilizing microalgae consortium of Chlorella sorokiniana and Monoraphidium neglectum as biosorbent. AMD used in this research was characterized with a pH value of 1.65 with iron and manganese concentrations of 8.28 mg/L and 4.57 mg/L. The research of biosorption was conducted in 150 rpm with pH level variations of 4, 5, and 6, and contact time variations of 60, 120, and 180 min. The maximum value of iron and manganese removals occurred when pH level reached 5 at 180 min of contact time with removal efficiency of 89.73% for iron and 94.53% for manganese. The results proved that the mixed culture of microalgae namely Chlorella sorokiniana and Monoraphidium neglectum can be utilized to remove iron and manganese contained in acid mine drainage.

Long lasting degradation of all alkanes in soil by Pseudomonas activated after Fenton pre-oxidation

This study investigated the function and mechanism of Fenton pre-oxidation on the long lasting degradation of all alkanes in soil contaminated by petroleum. The findings demonstrated that the biological removal amount of all alkanes in the respiratory regulation group reached 4083.46 mg/kg, which was twice that of the non-regulation group, and the removal amount gradually increased in the four stages of bioremediation. In addition, the removal amount of all alkanes in the non-regulated group did not change much and showed a downward trend, indicating that long lasting degradation of all alkanes could be achieved by the respiratory regulation group, and the biodegradation cycle was saved by 251 days compared with the non-regulated group. Furthermore, the total number of bacteria in the respiratory regulation group (6.73 log CFU/g) was significantly higher than that in the non-regulation group (2.25 log CFU/g). Pseudomonas became the dominant genus in the respiratory regulation group with an average relative abundance of 32.17 %. In the respiratory regulation group, a large amount of ammonia nitrogen (1703.62 mg/kg) was consumed during the degradation process, which stimulated the tricarboxylic acid cycle respiratory metabolism process of Pseudomonas and accelerated the hydrocarbon conversion. This may be the reason why the long lasting degradation of all alkanes in soil could be achieved by the respiratory regulation group.

Potential of Salvinia biloba Raddi for the remediation of water polluted with ciprofloxacin: Removal, physiological response, and root microbial community

This paper investigated the removal amount of Ciprofloxacin (CIP) by Salvinia biloba Raddi (S. biloba) under various conditions, the physiological response under different CIP concentrations, the influence of CIP on the root microbial community structure of S. biloba, the possible metabolic pathways and removal mechanism. The results showed that under 4 mg/L CIP, the removal rate of CIP was 98 %. Under different CIP concentration conditions, low CIP concentration promoted the growth of S. biloba, while high CIP inhibited the growth of S. biloba and S. biloba was exposed to different degrees of oxidative stress. CIP affected root microbial community diversity and changed microbial community structure. Five possible degradation pathways were proposed through the determination of intermediate metabolites. According to mass balance calculations, biodegradation was the most critical degradation pathway. This study demonstrated the potential use of S. biloba for treating CIP-contaminated water and provided insights into the mechanisms of plant-based antibiotic degradation.

Effect of the membrane processing on tannin removal from soluble fraction of Persian gum

SummaryTannins, which are known as anti‐nutrient compounds with capability of limiting proteins and minerals bioavailability, are present in Persian gum. Ultrafiltration (UF, polysulfone membrane, 30 and 90 kDa, 1, 2 and 5 bar) and nanofiltration (NF, polysulfone, 400 Da, 2.5 and 5 bar) were used to remove tannin from the soluble fraction of Persian gum. The results revealed that the highest amount of tannin removal was achieved in UF (5 bar) and NF (5 bar). However, the use of the membrane process significantly decreased the apparent viscosity of the permeate, which might have an undesirable effect on the functionality of the gum. The effects of membrane molecular weight cut‐off, feed temperature, ultrasound pre‐treatment, feed concentration and pH, on the amount of tannic acid reduction, and changes in permeate flux, volume concentration factor difference, tannin reduction efficiency, and permeate apparent viscosity were evaluated. The results showed that total tannin removal efficiency was increased by ultrasound pre‐treatment, reduction of feed pH, and higher membrane molecular weight cut‐off. Increasing the feed temperature and concentration enhanced the apparent viscosity of permeate, although its value was lower than the control sample.

Preparation, characterization, and application of chitosan-silver nanoparticles for Cu(II) and Zn(II) removal from oil refinery wastewater

Copper and zinc stand as one of the most alarming contaminants, presenting a formidable challenge in the realm of drinking water across numerous countries. To deal with this challenge, the sequestration of copper and zinc by adsorption has been extensively investigated in the solid media. Here, an adsorbent system based on a natural polymer - chitosan with physical cross-linking using silver nanoparticles is investigated for high binding, to get a new modified adsorbents (CS/AgNPs) that used these metal ions from simulated oil refinery wastewater. The adsorption mechanism is extensively studied via FTIR, zeta potential, dynamic light scattering (DLS), EDS, SEM, and BET. The prepared adsorbents (CS/AgNPs) have a bigger surface area than pristine chitosan that expanded from 4.74 to 36.34 m2/g, respectively. The prepared CS/AgNPs showed stronger adsorption ability than pristine chitosan attributable to its permeable structure and expanded surface area. In batch experiments, the Langmuir adsorption isotherms revealed that the highest uptake removal amount for Copper (II) and zinc (II) onto CS/AgNPs are 110.67 and 92.13 mg/g, correspondingly. These findings indicate that CS/AgNPs show a great potential as a proficient and selective materials for eliminating copper and zinc ions from aqueous solutions.

An investigation of phase boundary effect on the cutting force fluctuation in orthogonal micro-cutting of Ti6Al4V alloy

In micro-cutting, microstructure induced anisotropic properties highly affect the machinability of materials because the removal amount is almost on same level as the size of microstructures such as grains and phases. In this paper, cutting force fluctuation induced by different phases is theoretically and experimentally investigated in the micro-cutting of dual-phase Ti6Al4V alloy. Particularly, a significant change of cutting force was observed as the tool traverses phase boundaries. Furthermore, the mechanism of the variation of cutting forces is discussed from perspectives of crystallographic orientation, critical resolved shear stresses and slip systems. Constitutive model and geometrical relationship between the tool and workpiece are also proposed to analyzed the resolved shear stresses of phases with different crystallographic orientations. The results agree well with experimental data, indicating that activation of various slip systems is directly determined by the values of corresponding resolved shear stresses. Additionally, cutting force fluctuation is primarily attributed to the change of slip systems at phase boundaries in the micro-cutting. The main findings of this study present the significant role of crystallographic orientations and slip systems in governing cutting force fluctuations at phases and phase boundaries, which provide valuable insights for optimization of cutting parameters in machining of titanium alloys.

Performance of loach to reduce clogging matter in vertical-flow constructed wetlands: Hydraulic evaluation and metabolic processes

Extracellular polymeric substances (EPS) secreted by microorganisms cause constructed wetlands (CWs) clogging, which is a major challenge for the long-term stable operation of CWs. This study provided a comprehensive and in-depth study of the hydraulic evaluation and metabolic processes of loach (Misgurnus anguillicaudatus) in mitigating clogging. The results showed that the loach reduced the clogging content in the substrate layer and improved the hydraulic performance of the system. The loach system increased the initial porosity in the sand layer by 11.52 %, 25.11 %, and 28.15 %, and the initial porosity in the gravel layer by 15.49 %, 15.85 %, and 13.83 %, respectively. Loach also increased the actual and theoretical hydraulic retention time (HRT), improved the connectivity between different layers, and reduced the “dead zone” area of the system. The analysis of EPS components revealed that the daily EPS removal amount of each loach was 36.64 mg L-1, in which S-EPS, LB-EPS, and TB-EPS were 21.80, 8.02, and 6.82 mg L-1d-1, respectively. Direct feeding and the indirect coordination with microorganisms effectively reduced the contents of polysaccharides and proteins in EPS, and increased the proportion of humic acid and nucleic acid. The clogging characteristics analysis also confirmed that loach decreased tyrosine and tryptophan fluorophores groups and reduced the proportion of protein or peptide substances in the macromolecules in EPS. In addition, loach increased the activities of dehydrogenase, fluorescein diacetate, and the relative abundance of Chlorobiaceae in the sand layer, which was conducive to the hydrolysis of clogging matters with the metabolic activity of microorganisms. Loach increased the relative abundance of denitrifying microorganisms such as Aeromonadaceae, Rhodocyclaceae, and Hydrogenophilaceae in the gravel layer, which enhanced the denitrification process of the system and was conducive to pollutant transformation and clogging matter degradation. In conclusion, this study proposes a novel, eco-friendly strategy for preventing CW clogging in wetland animals.

Metallurgical influence of separated endodontic instruments on the retrieval capability of katana-sword-like ultrasonic tip under different lubricants: In vitro study

Abstract Introduction: Ultrasonic retrieval is a time-consuming procedure sacrificing considerable amounts of dentin. This study aimed to assess the retrieval capability of katana tip on different alloys under different lubricants regarding dentin thickness and retrieval time. Materials and Methods: Extracted premolars were used to reach 40 samples. The apical 4 mm of X2 ProTaper Next and A1 Neoniti instruments were fractured, and katana tip was utilized for retrieval, using ethylenediaminetetraacetic acid or olive oil as intracanal lubricants. Dentin thickness was assessed using cone-beam computed tomography, and the time of retrieval was recorded. Results: There was no significant difference in the retrieval capability among the groups. Different alloys and lubricants had no significant effect on dentin thickness. However, olive oil significantly reduced the retrieval time. Conclusion: Katana tip proved to be efficient enough to retrieve apically separated instruments in curved canals, with instrument’s metallurgical makeup presenting minimal effect on its capability. Katana tip and high-viscosity lubricants reduced the retrieval time, which might reduce the dentin removal amount.

Biocompatible and capacitive PDA-Ov-Co3O4@CC anode augmented exoelectrogens enrichment and extracellular electron transfer in microbial fuel cells

Metal oxides rich in oxygen vacancies (Ov) possess excellent intrinsic conductivity, variable valence metal center and high capacitance, which were potential candidates as microbial fuel cells anode. However, their high bacterial toxicity greatly hindered the activity of biofilm. To solve this issue, in this work, polydopamine (PDA) covered capacitive Ov doped Co3O4 nanosheets were designed and successfully grown on carbon cloth (CC). The introduction of Ov significantly promoted the charge storage, the net charge and the accumulated charge were 217.1 and 2680.3 C/m2, respectively, surpassed Co3O4 anode without Ov. In addition, Ov also decreased the charge-transfer resistance (Rct), effectively accelerating EET. The Rct of PDA/Ov-Co3O4@CC was 29.51 Ω, lower than CC (382.10 Ω). The cover of PDA prevented the direct contact between metal ions and microorganisms, greatly enhanced the bacterial viability. The power density of MFCs with PDA/Ov-Co3O4@CC anode was 2.77 W/m2, 1.45 times higher than that of bare CC (1.90 W/m2). In addition, PDA/Ov-Co3O4@CC anode displayed excellent coulombic efficiency and daily COD removal amount (23.5 % and 147.6 mg/L/d), higher than the control groups. The community analysis showed the abundance of Geobacter on PDA/Ov-Co3O4@CC anode was 91 %, higher than other anodes. Present study developed a facile and effective PDA coating strategy to simultaneously enhance the biocompatibility and capacitance of Ov-rich metal oxides, which will be a promising method for the preparation of high performance MFCs anode.

Effective strategy for Cr(VI) removal from water in evolution process of ferroan brucite by redox and intercalation

Cr(VI)-contaminated wastewater treatment is of great significance to ecological environment and human health. In this work, ferroan brucite with different Fe2+ doping amounts (Mg1-XFeX(OH)2, x = 0.1–0.8) were synthesized for the removal of Cr(VI) from wastewater. The effect of Fe content, initial concentration of Cr(VI), reaction time, co-existing ions and pH for Cr(VI) removal performance were examined. As Fe2+ content increased, the removal efficiency initially increased and then decreased, Mg0.4Fe0.6(OH)2 exhibited the maximum removal amount of 494.63 mg/g. Kinetic studies showed Cr(VI) removal well fitted pseudo-second-order model and achieved equilibrium at approximately 40 min. Isotherm data was well described by Langmuir model. The coexisting ions except CO32− had negligible effect, while pH had a significant influence on Cr(VI) removal since different dominated form of Cr(VI) existed at different pH. The removal mechanism towards Cr(VI) under different pH values was explored. At acidic environment, most Cr(VI) in Cr2O72− was reduced to Cr(III) by Fe2+ resulting in the precipitation of (Fe,Mg)(Cr,Fe)2O4, the remaining part was immobilized by interlayer of reaction product LDHs, and the intercalation amounts of Cr2O72− were 114.05 mg/g and 106.78 mg/g at pH of 3 and 6. While under alkaline conditions, most CrO42− entered the interlayer of LDHs with amounts of 262.3 mg/g at pH = 11, and the rest was absorbed on the surface. Furthermore, the reaction product could be recovered as chromite with recovery rate of 83.94 %. The excellent removal performance suggested a promising strategy in sewage water remediation.

Synergistic catalytic enhancement of chemical oxygen demand removal using Mn-Bi doped submicron fly ash carrier: Mechanistic insights and environmental adaptability

This study presents a novel approach to enhancing the removal efficiency of Chemical Oxygen Demand (COD) from water using a submicron fly ash carrier (MFA) doped with manganese (Mn) and bismuth (Bi). The synthesis process involved mechanical ball milling and alkali activation of original fly ash (FA) to obtain MFA, followed by impregnation calcination to prepare the Mn-Bi@MFA composite. The synergistic effect of Mn and Bi facilitated the formation of abundant oxygen vacancies on the catalyst surface, significantly reducing the band gap width. The Mn-Bi@MFA composite exhibited remarkable properties with a specific surface area and pore structure reaching 15.17 m2/g and 0.062 cm3/g, respectively, surpassing FA by 7.16 and 20.67 times, respectively. Utilizing the Mn-Bi@MFA/O3 system, the COD removal amount reached 562.73 mg/g under specific conditions (reaction time = 60 min, pH=7.0, catalyst dosage = 1.0 g/L, ozone dosage = 2.0 g/h), exceeding that of the ozone-alone system by 51.62 %. Moreover, Mn-Bi@MFA demonstrated excellent environmental adaptability and repeatability. An investigation into the contribution order of different free radicals revealed •OH>O2•- >1O2 in COD removal, elucidating the mechanisms of ozone oxidation, catalytic ozonation, and photocatalysis. This research provides valuable insights into the development of efficient and sustainable water treatment strategies employing advanced nano-material-based catalysts.

A Green and Energy‐Supply‒Free Artificial Plant for Efficient and Non‐Selective Enrichment of Heavy Metal Ions Out of Soil

AbstractRemoving heavy metal (loid) s (HMs) from contaminated soil in a nonselective, highly efficient, and energy‐free manner is a major global challenge. Herein, this work synthesizes and assembles a biomimetic materials system (BMS) consisting of an artificial plant, a hemispherical glass cover, and a reflective plate, capable of non‐selective and highly efficient remediation of soil contaminated by various HM ions under sunlight. Specifically, a water cycle is driven to establish between the soil, artificial plant, and atmosphere by solar energy in the BMS, which induced water‐soluble HM ions to enrich and precipitate at the top edge of the artificial plant. The formed HM precipitate is easily removed, contributing to the extremely strong recyclability of BMS. This system has significant advantages in terms of soil properties, contamination characteristics, energy consumption, processing time, and removal amount over other representative remediation methods, demonstrating its great potential for practical application in the remediation of various HM‐contaminated soils.