LL37 Microspheres Loaded on Activated Carbon-chitosan Hydrogel: Anti-bacterial and Anti-toxin Wound Dressing for Chronic Wound Infections

Antimicrobial peptide LL37 is a promising antibacterial candidate due to its potent antimicrobial activity with no known bacterial resistance. However, intrinsically LL37 is susceptible to degradation in wound fluids limits its effectiveness. Bacterial toxins which are released after cell lysis are found to hinder wound healing. To address these challenges, encapsulating LL37 in microspheres (MS) and loading the MS onto activated carbon (AC)-chitosan (CS) hydrogel. This advanced wound dressing not only protects LL37 from degradation but also targets bacterial toxins, aiding in the healing of chronic wound infections. First, LL37 MS and LL37-AC-CS hydrogel were prepared and characterised in terms of physicochemical properties, drug release, and peptide-polymer compatibility. Antibacterial and antibiofilm activity, bacterial toxin elimination, cell migration, and cell cytotoxicity activities were investigated. LL37-AC-CS hydrogel was effective against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. LL37-AC-CS hydrogel bound more endotoxin than AC with CS hydrogel alone. The hydrogel also induced cell migration after 72 h and showed no cytotoxicity towards NHDF after 72 h of treatment. In conclusion, the LL37-AC-CS hydrogel was shown to be a stable, non-toxic advanced wound dressing method with enhanced antimicrobial and antitoxin activity, and it can potentially be applied to chronic wound infections to accelerate wound healing.

Investigation of the removal kinetics, thermodynamics and adsorption mechanism of anionic textile dye, Remazol Red RB, with powder pumice, a sustainable adsorbent from waste water

Excessive growth and abnormal use of dyes and water in the textile industry cause serious environmental problems, especially with excessive pollution of water bodies. Adsorption is an attractive, feasible, low-cost, highly efficient and sustainable technique in terms of green chemistry for the removal of pollutants from water. This study aims to investigate the removal kinetics, thermodynamics and adsorption mechanism of Remazol Red RB, which was chosen as a representative anionic reactive dye, from synthetic wastewater using powdered pumice, taking into account various experimental parameters such as initial dye concentration, adsorption time, temperature and pH. Moreover, to support the proposed adsorption mechanism, before and after adsorption of the samples, the Fourier transform infrared spectrophotometer (FTIR) spectra, X-ray powder diffraction (XRD) diffractograms and High resolution transmission electron microscopy (HRTEM) images were also taken and used. The results show that powder pumice can be an efficient adsorbent for anionic dye removal with a relatively high adsorption capacity of 38.90 mg/g, and it is very effective in 30-60 min in mild conditions. The experimental data showed a high agreement with the pseudo-second-order kinetic model and the Freundlich adsorption isotherm equation. In addition, thermodynamically, the process exhibited exothermic nature and standard isosteric enthalpy and entropy changes of -4.93 kJ/mol and 16.11 J/mol. K were calculated. It was determined that the adsorption mechanism was predominantly based on T-shaped pi-pi interactions and had physical characteristics.

Prediction of methyl orange dye (MO) adsorption using activated carbon with an artificial neural network optimization modeling

In this study, methyl orange (MO) dye removal by adsorption utilizing activated carbon made from date seeds (DPAC) was modeled using an artificial neural network (ANN) technique. Instrumental investigations such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis were used to assess the physicochemical parameters of adsorbent. By changing operational parameters including adsorbent dosage (0.01-0.03 g), solution pH 3-8, initial dye concentration (5-20 mg/L), and contact time (2-60 min), the viability of date seeds for the adsorptive removal of methyl orange dye from aqueous solution was assessed in a batch procedure. The system followed the pseudo 2nd order kinetic model for DPAC adsorbent, according to the kinetic study (R2 = 0.9973). The mean square error (MSE), relative root mean square error (RRMSE), root mean square error (RMSE), mean absolute percentage error (MAPE), relative error (RE), and correlation coefficient (R2) were used to measure the ANN model performance. The maximum RE was 8.24% for the ANN model. Two isotherm models, Langmuir and Freundlich, were studied to fit the equilibrium data. Compared with the Freundlich isotherm model (R2 = 0.72), the Langmuir model functioned better as an adsorption isotherm with R2 of 0.9902. Thus, this study demonstrates that the dye removal process can be predicted using an ANN technique, and it also suggests that adsorption onto DPAC may be employed as a main treatment for dye removal from wastewater.

Synthesis of novel carbon-supported iron oxide sorbents for adsorption of dye from aqueous solutions: equilibrium and flow-through studies

Textile effluents contain dyes that negatively affect water bodies and inhibit photosynthesis by reducing sunlight penetration. This study investigated the adsorption capacity of an iron oxide sorbent immobilised on naturally derived carbon foam for the removal of organic methylene blue dye from water. In this study, the carbon precursor and iron oxide precursor were mixed and carbonised in a single vessel. Baking and carbonization of the natural grain combination produce a porous structure that can act as an effective support for the iron oxide particles. The carbon foam prepared had a self-assembled structure with flour as a basic element. Sorbents of 6 weight (wt)%, 15 wt% iron, and a 0 wt% iron control sample were prepared. Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) techniques were used to examine the synthesised carbon foam physical properties and surface morphology. The adsorption capabilities were investigated in batch tests by determining the effects of an increase in iron content, sorbent dosage, contact time, and dye concentration. Breakthrough curves were obtained by varying the height of the sorbent bed and varying the flowrate of the dye solution. A higher bed height corresponds to a greater amount of adsorbent. The breakthrough and equilibrium adsorption capacities were found to increase with increasing bed height. When the flow rate is high, the dye solution leaves the column before equilibrium, resulting in shorter breakthrough and saturation times. Higher bed heights and lower flow rates resulted in optimal dye removal in the flow through the system. Breakthrough time increases with increasing iron content. The 15 wt% iron sample displayed superior adsorption capabilities than the 6 wt% sample, while the 0 wt% iron control sample displayed minimal adsorptive capabilities. The pseudo-first order kinetic model was the best fit model for this study (R² > 0.96), and the adsorption equilibrium is best described by the Freundlich isotherm (R² > 0.99). The results showed that an iron oxide sorbent immobilised on carbon foam made from natural sources is a good adsorbent for removing methylene dye.

Characterization of Ziziphus lotus’ Activated Carbon and Evaluation of Its Adsorption Potential

This study aims to prepare activated carbon from an interesting biomaterial, corresponding to the cores of Ziziphus lotus, for the first time to the best of our knowledge, according to a manufacturing process based on its chemical and thermal activation. These cores were chemically activated by sulfuric acid for 24 h and then carbonized at 500°C for 2 hours. The obtained activated carbon was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller (BET) analysis. The adsorption of methylene blue (MB) on the activated carbon was evaluated, by Langmuir and Freundlich models examination, in order to explain the adsorption efficiency in a systematic and scientific way. Moreover, pseudo-first-order and pseudo-second-order kinetic models were used to identify the mechanisms of this adsorption process. The characterization results showed an important porosity (pore sizes ranging from 10 to 45 µm), a surface structure having acid groups and carboxylic functions, and a specific surface of 749.6 m²/g. Results of the MB adsorption showed that this process is very fast as more than 80% of MB is adsorbed during the first 20 minutes. In addition, increasing the contact time and temperature improves the MB removal process efficiency. Moreover, this adsorption's kinetic modeling follows the pseudo-second-order model. Furthermore, data on the adsorption isotherm showed a maximum adsorption capacity of 14.493 mg/g and fit better with the Langmuir model. The thermodynamic parameters (∆G₀, ∆S₀, and ∆H₀) indicate that the adsorption process is endothermic and spontaneous. Therefore, Ziziphus lotus can be used as a low-cost available material to prepare a high-quality activated carbon having a promising potential in the wastewater treatment.

Optimization of the Preparation of Activated Carbon from Prickly Pear Seed Cake for the Removal of Lead and Cadmium Ions from Aqueous Solution

In this study, we evaluated the use of prickly pear seed cake, a by-product of prickly pear seed oil extraction, as a new precursor for producing activated carbon by phosphoric acid activation, and the obtained carbon’s capacity for heavy metal removal from aqueous solution. Response surface methodology based on the full factorial design at two levels (24) was developed to reduce the number of experiments and reach optimal preparation conditions for the removal of cadmium and lead ions from aqueous solutions. Design Expert 11.1.2.0 Trial software was used for generating the statistical experimental design and analyzing the observed data. Factors influencing the activation process, such as carbonization temperature, activation temperature, activation time, and impregnation ratio, were studied. Responses were studied in depth with an analysis of variance to estimate their significance. Each response was outlined by a first-order regression equation demonstrating satisfactory correspondence between the predicted and experimental results as the adjusted coefficients of correlation. Based on the statistical data, the best conditions for the removal of heavy metals from aqueous solution by the obtained activated carbon were indicated. The maximum iodine number and methylene blue index were 2527.3 mg g−1 and 396.5 mg g−1, respectively, using activated carbon obtained at the following conditions: Tc = 500 °C, Ta = 500 °C, impregnation ratio = 2:1 (g H3PO4: g carbon), and activation time of two hours. The maximum adsorption reached 170.2 mg g−1 and 158.4 mg g−1 for Cd2+ and Pb2+, respectively, using activated carbon obtained at the following conditions: Tc = 600 °C, Ta = 400 °C, impregnation ratio = 2:1 (g H3PO4: g carbon), and activation time of one hour. The activated carbon obtained was characterized by Boehm titration, pH of point of zero charge (pHPZC), Brunauer–Emmett–Teller surface area (SBET), and scanning electron microscopy. Adsorption was performed according to different parameters: pH solution, adsorbent dosage, temperature, contact time, and initial concentration. Regeneration experiments proved that the obtained activated carbon still had a high removal capacity for Cd2+ and Pb2+ after five regeneration cycles.

An Intelligent Carbon-Based Prediction of Wastewater Treatment Plants Using Machine Learning Algorithms

Purification of polluted water and return back to the agriculture field is the wastewater treatment for plants. Contaminated water causes illness and health emergencies of public. Also, health risk due release of toxic contaminants brings problem to all living beings. At present, sensors are used in waste water treatment and transfer data via internet of things (IoT). Prediction of wastewater quality content which is presence of total nitrogen (T-N) and total phosphorous (T-P) elements, chemical oxygen demand (COD), biochemical demand (BOD), and total suspended solids (TSS) is associated with eutrophication that should be prevented. This may leads to algal bloom and spoils aquatic life which is consumed by human. The presence of nitrogen and phosphorous elements is in the content of wastewater, and these elements are associated with eutrophication which should be prevented. Adsorption of T-N and T-P activated carbon was predictable as one of the most promising methods for wastewater treatment. Many research works have been done. The issues are inefficiency in the prediction of wastewater treatment. To overcome this issue, this paper proposed fusion of B-KNN with the ELM algorithm that is used. The accuracy of the BKNN-ELM algorithm in classification of water quality status produced the highest accuracy of the highest accuracy which is $K=9$ and $k=10$ with rate of accuracy which is 93.56%, and the lowest accuracy is $K=1\text{of}65.34\%$ . Experiment evaluation shows that a total suspended solid predicted by proposed model is 91 with accuracy of 93%. The relative error rate of prediction is 12.03 which is lesser than existing models.

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review

Academic research regarding polymeric materials has been of great interest. Likewise, polymer industries are considered as the most familiar petrochemical industries. Despite the valuable and continuous advancements in various polymeric material technologies over the last century, many varieties and advances related to the field of polymer science and engineering still promise a great potential for exciting new applications. Research, development, and industrial support have been the key factors behind the great progress in the field of polymer applications. This work provides insight into the recent energy applications of polymers, including energy storage and production. The study of polymeric materials in the field of enhanced oil recovery and water treatment technologies will be presented and evaluated. In addition, in this review, we wish to emphasize the great importance of various functional polymers as effective adsorbents of organic pollutants from industrial wastewater. Furthermore, recent advances in biomedical applications are reviewed and discussed.

Efficiency of Sawdust as Low-Cost Adsorbent for Dyes Removal

In recent years, the removal of dyes from wastewater has attracted considerable attention due to their harmful effects to ecosystem and human health. Adsorption as a facile and effective technique has been widely used to eliminate a large variety of dyes from aqueous solutions. Activated carbon is the most preferred adsorbent to treat wastewater but its use is limited because of high cost. Therefore, several low-cost and natural materials and wastes have been used as precursors for the preparation of alternative adsorbents. Among them, sawdust as an abundant and low-cost by-product has been explored as adsorbent for the removal of dyes from wastewater. This review focuses on the various sawdust used as a precursor for the preparation of activated carbons. Extensive literature information about sawdust, its compositions, activation methods, its efficiency for dyes removal, and environmental conditions effects has been reviewed. The applicability of various adsorption kinetic models and adsorption isotherm models for dye removal by sawdust-derived activated carbons has been also reported. Finally, this paper highlights the use of sawdust as base material for various composites and mixture which can be used as granular activated carbon.

Activated Carbon for Dyes Removal: Modeling and Understanding the Adsorption Process

Batch adsorption experiments have been conducted to investigate the removal of methyl orange from aqueous solution by an activated carbon prepared from prickly pear seed cake by phosphoric acid activation. The adsorption process has been described by using kinetic and isotherm models. The kinetic of adsorption was examined by pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. Adsorption isotherm was modeled using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. The adsorption process of methyl orange was well explained by the pseudo-second-order model and Freundlich isotherm. Also, pseudo-n-order model has been applied to estimate the order of adsorption kinetic and it was found equal to 2 which confirm the good accuracy of the pseudo-second order. Moreover, Dubinin–Radushkevich isotherm reveals that the adsorption of methyl orange onto activated carbon was a physisorption process in nature. The adsorption capacity of activated carbon was found to be 336.12 mg/g at temperature 20°C andpH∼7. These results demonstrated that the prickly pear seed cake is a suitable precursor for the preparation of appropriate activated carbon for dyes removal from aqueous solution.

Adsorption Thermodynamic and Kinetic Studies of Methyl Orange onto Sugar Scum Powder as a Low-Cost Inorganic Adsorbent

In the present study, batch adsorption experiments were carried out to investigate the removal of methyl orange (MO) from aqueous solution using sugar scum powder as an effective inorganic adsorbent which is a cheap precursor and abundant. The characteristics of this material were determined using XRD, SEM/EDX, and FTIR. The adsorption performance of sugar scum powder was evaluated using MO as the model adsorbate. Effects of various parameters such as initial dye concentration, contact time, and adsorbent dose were studied. The adsorption process can be best described by the pseudo-second-order kinetic and Langmuir adsorption isotherm models. Maximum monolayer adsorption capacity for MO removal was found to be 15.24 mg/g at temperature 22°C and pH 7.2. Moreover, thermodynamic parameters suggested that the adsorption of MO onto sugar scum powder was a spontaneous and exothermic process. The results demonstrated that sugar scum is a suitable precursor for the preparation of efficient adsorbent for dye removal from wastewater.

Carbon Nanomaterials for the Treatment of Heavy Metal-Contaminated Water and Environmental Remediation

Nanotechnology is an advanced field of science having the ability to solve the variety of environmental challenges by controlling the size and shape of the materials at a nanoscale. Carbon nanomaterials are unique because of their nontoxic nature, high surface area, easier biodegradation, and particularly useful environmental remediation. Heavy metal contamination in water is a major problem and poses a great risk to human health. Carbon nanomaterials are getting more and more attention due to their superior physicochemical properties that can be exploited for advanced treatment of heavy metal-contaminated water. Carbon nanomaterials namely carbon nanotubes, fullerenes, graphene, graphene oxide, and activated carbon have great potential for removal of heavy metals from water because of their large surface area, nanoscale size, and availability of different functionalities and they are easier to be chemically modified and recycled. In this article, we have reviewed the recent advancements in the applications of these carbon nanomaterials in the treatment of heavy metal-contaminated water and have also highlighted their application in environmental remediation. Toxicological aspects of carbon-based nanomaterials have also been discussed.