Remediation Process Research Articles

Calcium carbonate enhanced As uptake in Pteris vittata by increasing pH and As bioavailability and mediating rhizosphere As-transformation bacterial community

Pteris vittata is the first reported arsenic (As) hyperaccumulator, which is also a calcium (Ca) indicator and adapts to calcareous environment. Therefore, it is hypothesized that Ca plays a role in As accumulation but detail effects and mechanisms are unclear. Typical Ca-compounds (CaCO3, Ca3(PO4)2 and CaSO4) were added to hydroponics. CaCO3 and Ca3(PO4)2 increased pH by 0.75 and 0.31, while CaSO4 decreased it by 0.26. Besides, CaCO3 increased As concentration in P. vittata frond by 25.8 % from 65.4 to 82.3 mg kg–1, while Ca3(PO4)2 and CaSO4 decreased it by 15.1–38.2 % to 40.4–55.5 mg kg–1. So the effect of CaCO3 on soil pH, As bioavailability and As-transformation bacterial community was further examined. In pots, CaCO3 increased soil pH by 0.57 and increased bioavailable As concentration by 6.2 μg kg–1, thereby induced 27.3–28.5 % promotion in As plant accumulation. Rhizosphere bacterial community variance can be explained by soil pH and bioavailable As changes at 49–66 %. P. vittata frond As concentration was negatively correlated with rhizosphere As-transformation bacterial diversity (arrA and arsM) (R=-0.57 and -0.66), and positively correlated with the relative abundance of Geobacter (R=0.66) and Pseudomanas (R=0.48), which mediating As mobilization and transformation. This indicated that CaCO3 can enhance As uptake by P. vittata via increasing soil pH, As bioavailability and mediating As-transformation bacterial community in the rhizosphere. The information helps to better understand how calcareous environment-adaptation benefits P. vittata to uptake and accumulate As. This helps to strategize more efficient processes for As-contaminated soils remediation using the hyperaccumulating plants.

Photocatalytic activation of peroxymonosulfate by Ti-oxo clusters grafted carbon nitride: Enhanced charge transfer and bisphenol A degradation efficiency

Photocatalytic peroxymonosulfate (PMS) activation process is promising for the organic wastewater treatment. A simple amide bonding strategy has been developed to synthesized Ti-oxo clusters (TiOCs)-g-C3N4 (TiOCs-CN) catalyst. The prepared TiOCs-CN was used to remove bisphenol A (BPA) under simulated sunlight-driven PMS. The experimental and computational results demonstrate that the incorporation of TiOCs can efficiently regulate the electronic structure of CN. Thus, an excellent performance with a BPA removal rate of 100 % and a totalorganic carbon(TOC) removal rate of 87.2 % within 40 min was achieved in the AM 1.5/PMS-TiOCs-CN system.Among, the reaction rate constant of AM 1.5/PMS-TiOCs-CN (97.24 × 10−3 min−1) is higher than that of AM 1.5/PMS-CN (25.10 × 10−3 min−1) by nearly 4 times. The synergistic effect of photocatalytic PMS activation greatly facilitated the generation of reactive radicals and obviously increased the removal rate of BPA. This work can offer inspiration for rational design of high efficiency photocatalysts in the PMS oxidation process for organic wastewater remediation.

Efficient removal of Cr(VI) from contaminated kaolin and anolyte by electrokinetic remediation with foamed iron anode electrode and acetic acid electrolyte.

Combined electrokinetic remediation employing reducing agents represents an extensively utilized approach for the remediation of hexavalent chromium (Cr(VI))-contaminated soil. In this investigation, electrokinetic remediation of artificially contaminated kaolin was conducted utilizing a separate circulation system for the anolyte, with a 0.5M solution of acetic acid (HAc) as the electrolyte and foamed iron serving as the anode. The experimental outcomes demonstrated that employing HAc as the electrolyte enhances the electromigration of Cr(VI) and establishes an acidic milieu conducive to the reduction of Cr(VI) by foamed iron, thereby facilitating the rapid reduction of Cr(VI) accumulated in the anolyte through electrokinetic remediation. In the self-prepared contaminated kaolin, the initial concentration of Cr(VI) was 820.26mg/L. Following the remediation process under optimal experimental conditions, the concentration was significantly reduced to 11.6mg/L, achieving a removal efficiency of Cr(VI) in the soil of 98.59%. In the optimal experimental setup, the Cr(VI) concentration in the anolyte was reduced to 0.05mg/L, which is below the EPA's Safe Drinking Water Act standard for Cr(VI) content of 0.1mg/L. The removal mechanism of Cr(VI) from the electrolyte primarily involves reduction, precipitation, and co-precipitation, with the foamed iron playing a predominant role. HAc and foamed iron exhibit a synergistic effect. The findings of this study substantiate that the integration of foamed iron with HAc is efficacious for the electrokinetic remediation of soil contaminated with Cr(VI).

Rational design double S-scheme heterosystem based Photo-Electrocatalytic membrane device for continuous phytotoxin remediation

Today, the escalating contamination of water sources with phytotoxins poses a significant danger to both ecosystems and human health. Consequently, the implementation of advanced and sustainable remediation technologies becomes imperative for the effective removal of toxins. This study introduces a pioneering method for continuous phytotoxin remediation by integrating a photoelectrocatalytic membrane reactor, which utilizes a ZnCdFeSe heterojunction photocatalyst with a double S-scheme, is derived from the ZnCd prussian blue analog. This design capitalizes on the unique electronic structure and synergistic effects of the catalyst enabling efficient photo-electrocatalysis in the device. The proposed system attains an impressive phytotoxin rejection efficiency of 98.39%, accompanied by enhanced membrane permeation and anti-fouling performance. The obtained results are noteworthy for an emerging process that combines the simultaneous degradation and separation of toxic species, enabling prolonged and uninterrupted remediation processes. Experimental and density function theory (DFT) results demonstrate that, under optimal conditions, the well-stabilized double S-scheme ZnCdFeSe heterojunction achieves a mineralization rate of 85.67%. Even after six cycles of the photocatalytic membrane, the removal rate of ricin remains high at 78.96%, indicating the membrane’s commendable reusability and stability. This research not only contributes to the advancement of innovative environmental remediation strategies but also provides valuable insights for designing and optimizing photoelectrocatalytic systems for the persistent removal of toxins in water treatment applications.

Remediation of cadmium contaminated soil using electrokinetic-phytoremediation system with rotary switching electrodes.

Considering both electrokinetic remediation and phytoremediation have limitations, an electrokinetic phytoremediation (EP) system was constructed to obtain efficient and environmentally friendly remediation results. This study indicates that the electric field can promote the absorption of Cd by ryegrass with little impact on soil physicochemical properties under the condition of rotary switching electrodes, and the accumulation of Cd in the aboveground and underground parts of ryegrass increased by 145.2% and 93.7%, respectively. The DC electric field combined with ryegrass under rotary switching electrode mode proved to be the optimal condition for the remediation of Cd contaminated soil with a remediation efficiency of 66.7%. Moreover, the rotary switching of the electrodes alleviated the suppression of the growth of ryegrass by the DC electric field. During the EP remediation process, the electric field promoted the transformation of the residue state of Cd to the other forms, which accelerated the desorption rate of Cd from the soil and facilitated the migration of Cd into plants. In conclusion, EP is a green and efficient remediation technology for heavy metal contaminated soil with good application prospects.

Impact of carbonization reactor compartment size on groundnut (Arachis hypogaea) shell biochar properties

Abstract This study investigates the impact of low-temperature top-lit updraft reactor chamber size on GNSBC yield and properties. For this study, the volumes of carbonization chamber (2,364, 2,013, 1,468, and 970 cm3) in a biomass-fueled TLUD biomass gasifier were varied, and the resulting biochar was analyzed using SEM, EDX, and FTIR. The novelty of this work lies in its investigation of the unexplored impact of carbonization reactor compartment size on groundnut shell biochar properties and yield, driven by the need to optimize biochar production efficiency and support sustainable waste management practices. The results showed that carbonization chamber size variation significantly affected GNSBC yield, with an initial increase followed by diminishing returns. An increase in the carbonization compartment size led to decreased carbonization duration, increased carbonization temperature, increased porosity, and decreased oxygen content. SEM analysis revealed consistent amorphous and multi-layered morphological features across BC samples, while EDX analysis confirmed high carbon content in the samples. FTIR spectroscopy confirmed the presence of oxygenated functional groups suitable for pollutant adsorption, supporting GNSBC’s role in environmental remediation and industrial processes. This research contributes to optimizing biochar production efficiency, advancing circular economy goals, and sustainable waste management practices.

The MOF-on-MOF hybrids of MIL-101(Fe)@CoZn-ZIFs as efficient catalyst for the removal of deys from wastewater

In this study, MOF-on-MOF hybrids were successfully synthesized by interfacial growth method using CoZn-ZIF as guest MOF and MIL-101(Fe) as host MOF, and then employed as heterogeneous catalysts to activate peroxymonosulfate (PMS) in the degradation of dyes. The hybrids exhibited different morphologies depending on the Co/Zn ratios (10/0, 10/2, 10/10, and 2/10), all of which displayed exceptional catalytic performance. Notably, the hybrid with a Co/Zn ratio of 10/2 showed the highest degradation rate of MB, reaching 100 % removal within 3 min with a kobs value of 452.75 Lg−1 min−1 based on the pseudo-second-order kinetic model. Through EPR characterization and scavenging experiments, it was determined that the degradation of dyes occurred through a combination of radical (SO4•-, •OH)and non-radical (1O2) pathways, with 1O2 and SO4•- playing prominent roles. Various factors such as Co/Zn ratio, catalyst dosage, PMS concentration, initial pH, temperature, and MB solution concentration were systematically investigated to understand their influence on the catalytic performance. Furthermore, the influence of inorganic ions, humic acid (HA), and the reusability and stability of the catalyst was evaluated, demonstrating its potential for practical applications. Overall, this research provides valuable insights into the design and application of MOF-based catalysts for environmental remediation processes.

Remediation effect and mechanism of immobilized laccase on actual trichloromethane-contaminated soil samples

Trichloromethane (TCM) in soil causes adverse effects on the soil ecosystem and human health. Therefore, it is urgent to develop an efficient and low-cost soil TCM removal technology. In this study, we prepared sodium alginate-biochar-laccase immobilized pellets (SA-BC-LC) using composite immobilization technology, exploring the fitting impact of artificial neural network model (ANN) and general linear model (GLM) models on laccase loading and the correlation properties of SA-BC-LC. The SA-BC-LC exhibited a porous multi-layer network structure internally. Compared to free laccase, the relative activity of SA-BC-LC remained above 50 % after 5 reuses and still maintained at 48 % after 50 days of storage. Moreover, SA-BC-LC demonstrated significant capacity for adsorption and degradation of TCM in soil with ratios approximately at 31.3 % and 68.7 %, respectively. During the remediation process of TCM-contaminated soil from Taizhou Chemical plant, there was a rapid decrease in TCM concentration within the first hour. Under IM (Immobilization) treatment (added with 5 % SA-BC-LC), the removal rate of TCM reached up to 88.9 % in the first hour. The adsorption of TCM by SA-BC-LC was mainly chemical adsorption, which induced the improvement of the relative abundance of the co-metabolic dechlorinated microbial Pseudomonas. Our research presents a promising material for effectively remediating soils contaminated with chlorinated hydrocarbons (CHs), with excellent removal efficiency.

Biogenic Synthesis Based on Cuprous Oxide Nanoparticles Using Eucalyptus globulus Extracts and Its Effectiveness for Removal of Recalcitrant Compounds

Recalcitrant compounds resulting from anthropogenic activity are a significant environmental challenge, necessitating the development of advanced oxidation processes (AOPs) for effective remediation. This study explores the synthesis of cuprous oxide nanoparticles on cellulose-based paper (Cu2O@CBP) using Eucalyptus globulus leaf extracts, leveraging green synthesis techniques. The scanning electron microscopy (SEM) analysis found the average particle size 64.90 ± 16.76 nm, X-ray diffraction (XRD) and Raman spectroscopy confirm the Cu2O structure in nanoparticles; Fourier-transform infrared spectroscopy (FTIR) suggests the reducing role of phenolic compounds; and ultraviolet–visible diffuse reflectance spectroscopy (UV-Vis DRS) allowed us to determine the band gap (2.73 eV), the energies of the valence band (2.19 eV), and the conduction band (−0.54 eV) of Cu2O@CBP. The synthesized Cu2O catalysts demonstrated efficient degradation of methylene blue (MB) used as a model as recalcitrant compounds under LED-driven visible light photocatalysis and heterogeneous Fenton-like reactions with hydrogen peroxide (H2O2) using the degradation percentage and the first-order apparent degradation rate constant (kapp). The degradation efficiency of MB was pH-dependent, with neutral pH favoring photocatalysis (kapp = 0.00718 min−1) due to enhanced hydroxyl (·OH) and superoxide radical (O2·−) production, while acidic pH conditions improved Fenton-like reaction efficiency (kapp = 0.00812 min−1) via ·OH. The reusability of the photocatalysts was also evaluated, showing a decline in performance for Fenton-like reactions at acidic pH about 22.76% after five cycles, while for photocatalysis at neutral pH decline about 11.44% after five cycles. This research provides valuable insights into the catalytic mechanisms and supports the potential of eco-friendly Cu2O nanoparticles for sustainable wastewater treatment applications.

A novel combination of wetland plants (Eichhornia crassipes) and biochar derived from palm kernel shells modified with melamine for the removal of paraquat from aqueous medium: a green and sustainable approach

Herbicide contamination in aquatic systems has become a global concern due to their long- term persistence, accumulation and health risks to humans. Paraquat, a widely used and cost-effective nonselective herbicide, is frequently applied in agricultural fields for pest control. Consequently, the removal of paraquat from contaminated water is crucial. This research presents a sustainable and environmentally benign method for paraquat removal from aqueous system by integrating wetland plants (Eichhornia crassipes) with biochar derived from melamine-modified palm kernel shells. The prepared biochar was characterized by using various analytical techniques. The effectiveness of biochar in enhancing phytoremediation was evaluated through a series of experiments, showing significant paraquat removal efficiencies of 99.7, 98.3, and 82.8% at different paraquat concentrations 50, 100, and 150 mg L−1, respectively. Additionally, present study examined the impact of biochar on the growth of E. crassipes, highlighting its potential to reduce the toxic effects of paraquat even present at higher concentrations. The paraquat removal mechanism was elucidated, focusing on the synergistic role of biochar adsorption and phytoremediation capability of E. crassipes. This innovative approach is an effective, feasible, sustainable and eco-friendly technique that can contribute to the development of advanced and affordable water remediation processes for widespread application.

"When You're in It, It Feels Like It's Everything": Medical Students' Experience of Failure and Remediation in the United States and the Netherlands.

Medical training institutions worldwide must be prepared to remediate struggling learners, but there is little empirical evidence around learners' perspectives on remediation efforts. Research shows that emotion has a significant effect on learning, but it has not been well studied in remediation in medical education. Given the high stakes of remediation, understanding more about learners' emotional experience could lead to improvements in remediation programs. This study aimed to explore medical students' emotional experience of failure and remediation to offer opportunities to improve remediation. This study is a thematic analysis of data collected from July to September 2022 from one-to-one interviews with students from 4 institutions (2 in the United States and 2 in the Netherlands) who had not met expectations on 1 or more medical school assessment(s). Interview questions explored students' experiences with learning of and responding to a performance that was below expected standards, with probes around any mentions of emotions. Fourteen students participated: 9 from schools in the United States and 5 from schools in the Netherlands. The students perceived the failure and remediation event to be highly significant, reflecting negatively on their suitability for a career as a physician. We identified 5 themes: (1) shame was pervasive and only retrospectively perceived as unwarranted; (2) self-doubt was common and weighty; (3) resentment, blame, and other external-facing emotions were present but softened over time; (4) worry and stress related to perceived career effect differed across countries; and (5) students had mixed emotional reactions to the remediation process. Medical students have strong emotional responses to failure and remediation. Expecting and considering emotions such as shame, self-doubt, and anger could help educators design better remediation programs. Differences across countries may be at least partially explained by different degrees of time variability and flexibility within the curricula.

Arsenate adsorption, desorption, and re-adsorption on Fe–Mn binary oxides: Impact of co-existing ions

Fe–Mn binary oxides have demonstrated impressive arsenate removal efficiencies as adsorbents. However, their interaction with co-existing ions can lead to arsenate desorption, complicating the remediation process. The dynamics of both desorption and subsequent readsorption of arsenate on these oxides under the influence of various ions remain largely unexplored. This study illuminates these processes through a detailed six-month batch experiment, examining the behavior of arsenate in the presence of both single and multiple competing ions. Our findings demonstrate varied desorption impacts by different ions. Notably, the desorption effects induced by bicarbonate (HCO3−) and phosphate (PO43−) were the most significant, with maximum desorption rates reaching 21.8 % and 20.8 %, respectively. Following desorption, As(V) exhibited varying re-adsorption rates; notably, As(V) desorbed by HCO3− and PO43− achieved nearly complete re-adsorption at rates of 100 % and 97.8 % respectively after 150 days. The dynamics altered substantially in the presence of multiple ions. Specifically, the co-presence of Ca2+ and Mg2+ significantly reduced the desorption of As(V) by HCO3−, with maximum desorption rates decreasing to 0 % and 2.9 %, respectively. Moreover, the inclusion of silicate (SiO32−) in the system markedly enhanced the re-adsorption of As(V), surpassing rates observed in the presence of HCO3− alone. In contrast, when PO43−and HCO3− were present together, almost no re-adsorption of As(V) occurred, leading to a higher final desorption rate of 27.4 %. These results highlight the complex and significant role that specific ions and their combinations play in the desorption and re-adsorption of As(V) on Fe–Mn binary oxide surfaces. The study emphasizes the importance of considering the types and interactions of co-existing ions in environmental settings when utilizing Fe–Mn binary oxides for efficient arsenic removal.

Electrochemical Synthesis of Urea from Carbon Dioxide and Nitrite at Cobalt Phthalocyanine-Ion Liquid Electrodes

Electrochemical coreduction of carbon dioxide and nitrogen oxyanion/oxide pollutants are attractive processes for simultaneous environmental remediation and sustainable production of urea. The development of suitable technology requires catalysts and electrodes that provide higher efficiencies by decreasing the overpotential required and increasing the faradaic efficiency. Electrode design is a key element in this process through which the environment of the catalyst can be manipulated to optimize activity and selectivity. Here, ionic liquids have been used to control the coreduction of carbon dioxide and nitrite at a cobalt phthalocyanine catalyst. Increasing the hydrophobicity of the catalyst layer with a mixture of 1-butylpyridinium hexafluorophosphate and trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide was found to increase the faradaic efficiency for urea formation to 27% at the lowest overpotential (−0.064 V vs RHE), from 3% for a Nafion binder. Modulation of the electronic structure, arrangement (aggregation vs adsorption on the carbon support) and/or mobility (via solubilization) of the CoPc catalyst appear to play a role in determining the rate and faradaic efficiency of urea production. Combining the CoPc catalyst with a carbon supported Cu cocatalyst increased the rate of urea production by 195% at –0.064 V.

Characterization of solar-derivate ultraviolet radiation for water solar treatment applications

Water resources are under increasing pressure from ever-increasing demand from industry and society. However, water is a limited resource that must be sustainable and protected. This problem is highlighted in desert areas, where water quality and abundance are scarce. Solar-powered water treatment systems are an inexpensive solution to ensure water quality for human consumption. This research analyzes solar ultraviolet radiation (UVR) in three populated Chilean cities to study the potential feasibility of the solar-powered photo-Fenton process for wastewater remediation. To generate long-term UVR values, satellite and reanalysis data and the Radiative Transfer Model were used. Results show high daily levels of solar ultraviolet irradiation, 1299.95kJm−2 for Antofagasta. The shortest treatment time for summer operation was observed in Santiago (21 min), followed by Antofagasta (34 min), and Concepción (35 min). Santiago presented the lowest volume of photoreactors during the summer (297 L) and Antofagasta during the winter (1589 L). This is the first preliminary analysis showing the possibilities of exploiting the potential of UVR in Chilean cities to provide tools for integrating water treatment technologies. This research motivates further studies on spectral radiation and emerging advanced oxidation technologies and the development of prospects for water and wastewater treatment.

Production and Application of a New Biosurfactant for Solubilisation and Mobilisation of Residual Oil from Sand and Seawater

Significant research has been conducted to minimise environmental impacts and promote the sustainable use of resources and raw materials. Microbial surfactants are an example of advanced materials obtained from sustainable production processes. In the present study, a biosurfactant was produced by the yeast Starmerella bombicola ATCC 22214 grown in a previously selected low-cost mineral medium containing 10% sucrose, 1.2% canola oil, and 0.5% corn steep liquor. The biosurfactant reduced surface tension from 72 ± 0.1 to 32.76 ± 0.3 mN/m. The yield was 23 g/L, and the critical micelle concentration was 0.6 g/L. The biosurfactant emulsified 96.25 ± 0.08% of used motor oil, was characterised as a sophorolipid, and exhibited stability under extreme conditions with no significant loss of its properties. Toxicity was assessed by exposing the microcrustacean Artemia salina and the zebrafish (Danio rerio) to the biosurfactant. The biosurfactant proved efficient for use in remediation processes, removing 97.8% and 69.2% of the petroleum derivative from sand in kinetic and static tests, respectively, and removed 91.5% of the contaminant from seawater. The results indicate the potential of this new biosurfactant for the mobilisation and solubilisation of hydrocarbons in the marine environment. This green biomolecule is a promising technology for the replacement of chemical dispersants in the remediation of aquatic and soil systems.

Hydrothermal synthesis of CeVO4/g-C3N4 Z-scheme photocatalyst for removal of dyes under photocatalysis

Wastewater treatment emerged as the major concern as the water scarcity increases. Photocatalysis is the efficient way to reduce the pollutants from wastewater without causing destruction to environment. Herein, simplistic preparation of pristine and g-C3N4-CeVO4 nanocomposites for photocatalysis was explored. The structural, optical and vibrational study was confirmed by standard analysis. The samples possess good crystalline nature and g-C3N4 was corroborateed by XRD. The Raman modes were confirmed Ce-O and V-O bending and stretching bonds. The photocatalysts bandgap were narrow down on assisting g-C3N4 and the bandgap engineering was altered by g-C3N4 heterojunction. The morphology of CeVO4 and its composites showed the formation of ball-like structure and the sheets of g-C3N4 was also confirmed. Janus Green B (JG) dye was model pollutant and metal halide lamp was employed as light source. The prepared pure CeVO4 photocatalysts showed better efficiency. Nevertheless, g-C3N4 assisted sample shows good efficiency and greater rate constant. This was characteristic feature of proper heterojunction development amid g-C3N4 and CeVO4. CeVO4, 0.1 g g-C3N4-CeVO4 and 0.2 g g-C3N4- CeVO4 rate constant were 9.2 × 10-4, 1.1 × 10-2, 1.54 × 10-2 and 2 × 10-2 min−1. The photogenerated electrons and holes were enthusiastically break up and reactive species were generated which paved the path for enhanced photocatalytic removal of pollutants. Among various photocatalysts, 0.2 g g-C3N4-CeVO4 is prospective material for wastewater remediation process.

Potential and characteristics of heavy metals electrokinetic removal from the copper-zinc mine tailings: Study on the simulated and actual tailings

Tailing ponds, as the storage of solid waste from metal mining processes, contain large amounts of residual heavy metals, potentially posing risks to the ecological environment. Despite extensive research on electrokinetic remediation of metals from tailings, comprehensive studies analyzing the migration dynamics of tailing metals under electric fields from multiple perspectives are limited. In this study, we comprehensively evaluated the removal of heavy metals from both simulated and actual tailings during the electrokinetic remediation processes. Zn, Cu, and Mn in simulated tailings showed accelerated migration rates under a 30 V two-dimensional electric field compared to the actual, achieving maximum removal efficiencies of 42.8 %, 20.1 %, and 52.1 %, respectively. This outcome was attributed to the lower effective concentration of heavy metals observed in actual tailings. Two monocotyledonous Poaceae plants, vetiver grass and sorghum, exhibited a robust growth in the remediated tailings with germination rates of 85 %. Moreover, microbial richness in these remediated tailings was clearly increased, indicating alleviation of heavy metal inhibition. The experimental results demonstrated the effective removal of residual heavy metals from tailings through electrokinetic remediation, alleviating the adverse impacts of heavy metals on both plant growth and microbial diversity, which holds significant implications for future reclamation and ecological restoration of tailing ponds. In conclusion, a comparative analysis between simulated and actual tailings, employing plant growth assessment and assessing the applicability of electrokinetic remediation for addressing metal pollution in tailing ponds from a microscopic perspective, presents a promising research direction.

Efficient removal of plasticiser dibutyl phthalate on CoP cluster anchored MXene via boosting peroxymonosulfate activation: Catalytic performance and decomposition mechanism

A novel Ti3C2 synthesis method via strong alkaline etching (MXeneba) was developed to degrade dibutyl phthalate (DBP) using a CoP/MXeneba + peroxymonosulfate (PMS) system. The MXeneba's modified surface properties enabled stable Co2+ adsorption and homogeneous loading of ultrasmall CoP clusters post-phosphatisation. Complete DBP degradation was achieved within 30 min, facilitated by reactive oxygen species (ROS: SO4·-, ·OH, O2·-, and 1O2) and the highly reduced titanium atoms promoting Co3+ to Co2+ conversion. Density functional theory (DFT) calculations elucidated PMS adsorption sites and active species for DBP degradation. This study clarifies the activation mechanism, linking catalyst structure to performance, and provides insights for future advanced oxidation processes in environmental remediation. The findings emphasize the practical application and significance of the CoP/MXeneba catalyst in treating harmful plasticisers in water, contributing to efficient and sustainable water purification methods. The research also highlights this novel catalyst system's robustness and versatility in tackling diverse pollutants.

Continuous Remediation of Congo Red Dye Using Polyurethane-Polyaniline Nano-Composite Foam: Experiment and Optimization Study

This study employed an innovative approach, utilizing prepared dried polyurethane-polyaniline nano-composite, through in-situ polymerization, for continuous remediation of Congo red dye. Response Surface Methodology (RSM) based on the Box-Behnken design (BBD) model was utilized to optimize the processing parameters, including initial dye concentration, flow rate, and pH. The two-factor interaction (2FI) model emerged as the most significant, highlighting the influence of individual and interaction effects of the factors. Optimization of the dye remediation process yielded the optimal conditions of a flow rate of 10 mL/min, acidic pH of 5.00, and dye concentration of 20 mg/L, resulting in an impressive, predicted removal efficiency of 99.09% agreeing with the experimental value. Moreover, the maximum adsorption capacity was determined to be 329.68 mg/g. Characterization of the adsorbent material involved techniques such as Scanning electron microscopy (SEM), Fourier transforms infrared spectra (FTIR), X-ray spectroscopy (XRD), and Zeta potential analysis. This material offers a sustainable alternative in industries to treat Congo red dye before being disposed of into the environment.

Analysis of Interview Results on The Remediation Process of The Dynamic Equilibrium Concept With The Representation-Metacognitive Reinforcement Conceptual Change Model (R-MR CCM)

Objective: This research aims to determine conceptions and changes in conceptions and analyze the results of interviews regarding the remediation process of the dynamic equilibrium concept. Theoretical Framework: Theories associated with student misconceptions, methods for identifying student misconceptions, and methods for resolving student misconceptions. Method: The method used in this study is a mixed method which is a combination of qualitative and quantitative methods, namely the Concurrent Embedded Strategy, which is a combination of qualitative methods and quantitative methods carried out at the same time. This method is very useful for students to find out the conceptions and misconceptions that occur in students. Results and Discussion: After conducting interviews and tests on respondents, the results of the analysis were obtained in the form of misconceptions among respondents that could be identified in the test and interview results at the stage of creating cognitive conflict and respondents could realize the misconceptions experienced after going through the stage of providing assistance for equilibration and using metacognition on an example of a concept so that respondents could dispelling misconceptions altogether. Research Implications: To reduce students' misconceptions about chemical equilibrium material, it is necessary to carry out research on this. With this gradual test instrument, students can get instant feedback and correct any misconceptions they have. Originality/Value: To provide insight into students' perceptions of the misconceptions they experience and how to reduce existing misconceptions. Apart from that, it is to provide insight to teachers regarding how to identify and reduce misconceptions that occur in students.