Surface Modification of Graphene Oxide for Fast Removal of Per- and Polyfluoroalkyl Substances (PFAS) Mixtures from River Water.

Per- and polyfluoroalkyl substances (PFAS) make up a diverse group of industrially derived organic chemicals that are of significant concern due to their detrimental effects on human health and ecosystems. Although other technologies are available for removing PFAS, adsorption remains a viable and effective method. Accordingly, the current study reported a novel type of graphene oxide (GO)-based adsorbent and tested their removal performance toward removing PFAS from water. Among the eight adsorbents tested, GO modified by a cationic surfactant, cetyltrimethylammonium chloride (CTAC), GO-CTAC was found to be the best, showing an almost 100% removal for all 11 PFAS tested. The adsorption kinetics were best described by the pseudo-second-order model, indicating rapid adsorption. The isotherm data were well supported by the Toth model, suggesting that PFAS adsorption onto GO-CTAC involved complex interactions. Detailed characterization using scanning electron microscopy-energy dispersive X-ray spectroscopy, Fourier transform infrared, thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy confirmed the proposed adsorption mechanisms, including electrostatic and hydrophobic interactions. Interestingly, the performance of GO-CTAC was not influenced by the solution pH, ionic strength, or natural organic matter. Furthermore, the removal efficiency of PFAS at almost 100% in river water demonstrated that GO-CTAC could be a suitable adsorbent for capturing PFAS in real surface water.

Bead-Containing Superhydrophobic Nanofiber Membrane for Membrane Distillation.

This study introduces an innovative approach to enhancing membrane distillation (MD) performance by developing bead-containing superhydrophobic sulfonated polyethersulfone (SPES) nanofibers with S-MWCNTs. By leveraging SPES's inherent hydrophobicity and thermal stability, combined with a nanostructured fibrous configuration, we engineered beads designed to optimize the MD process for water purification applications. Here, oxidized hydrophobic S-MWCNTs were dispersed in a SPES solution at concentrations of 0.5% and 1.0% by weight. These bead membranes are fabricated using a novel electrospinning technique, followed by a post-treatment with the hydrophobic polyfluorinated grafting agent to augment nanofiber membrane surface properties, thereby achieving superhydrophobicity with a water contact angle (WCA) of 145 ± 2° and a higher surface roughness of 512 nm. The enhanced membrane demonstrated a water flux of 87.3 Lm-2 h-1 and achieved nearly 99% salt rejection efficiency at room temperature, using a 3 wt% sodium chloride (NaCl) solution as the feed. The results highlight the potential of superhydrophobic SPES nanofiber beads in revolutionizing MD technology, offering a scalable, efficient, and robust membrane for salt rejection.

Magnetic surfactant-modified clay for enhanced adsorption of mixtures of per- and polyfluoroalkyl substances (PFAS) in snowmelt: Improving practical applicability and efficiency.

The extensive use of per- and polyfluoroalkyl substances (PFAS) in many industrial and consumer contexts, along with their persistent nature and possible health hazards, has led to their recognition as a prevalent environmental issue. While various PFAS removal methods exist, adsorption remains a promising, cost-effective approach. This study evaluated the PFAS adsorption performance of a surfactant-modified clay by comparing it with commercial clay-based adsorbents. Furthermore, the impact of environmental factors, including pH, ionic strength, and natural organic matter, on PFAS adsorption by the modified clay (MC) was evaluated. After proving that the MC was regenerable and reusable, magnetic modified clay (MMC) was synthesized, characterized, and tested for removing a wide range of PFAS in pure water and snowmelt. The MMC was found to have similar adsorption performance as the MC and was able to remove > 90% of the PFAS spiked to the snowmelt. The superior and much better performance of the MMC than powdered activated carbon points to its potential use in removing PFAS from real water matrices at an industrial scale.

Insights into the structures and properties of dyes in the Fenton catalytic process for treating wastewater effluent.

A notable level of apprehension exists over the adverse impacts of dye pollution on aquatic ecosystems and human well-being. The primary objective of this research is to assess the effectiveness of Fenton catalytic reactions in degrading 14 different commercial azo dyes (both single and double) present in aqueous solutions. The investigation focused on the function of dye structures, using a combination of experimental data and examination of theoretical factors. Dye degradation process was carried out at pH 3, and the concentrations of Fe2+ (10-4 mol/L), H2 O2 (2 × 10-3 mol/L), and dye (0.05 g/L). The findings revealed that dyes with a larger molecular weight were more effective at degrading (D%), with the overall degradation efficiency varying from 0% to 94%. Functional groups played an important role in degradation efficiency; for example, dyes with higher aromatic rings led to less D%, while a higher number of sulfonic, methyl, and nitro groups was responsible for better D%. Notably, the presence of OH groups in the backbone of dyes (AB 24, ABE 113, and MB 9) formed the Fe complex during the catalytic process, and the D% was minimal. On the other hand, theoretical quantum calculations such as the greater the JCLogP, highest occupied molecular orbital, and Dipole moment value, the higher the degradation efficiency. And dyes with low lowest unoccupied molecular orbital tended to have a better degradation efficiency. To some extent, UV-Vis spectral analysis was investigated to determine the degradation pathway, and the pseudo-second-order kinetic model fitted better in the degradation process. The overall experimental and theoretical findings suggested that dye degradation efficiency by the Fenton process is structure-dependent. PRACTITIONER POINTS: Insights into the role of azo dye structures-properties on degradation efficiency. Higher molecular weight and sulfonic groups containing dyes showed better degradation efficiency. Hydroxyl groups play the formation of the Fe complex during the degradation process. Higher values of HOMO and lower values of LUMO enhanced degradation efficiency. The pseudo-second-order (PSO) kinetic model obeyed the Fenton process.

Effective stabilization of per- and polyfluoroalkyl substances (PFAS) precursors in wastewater treatment sludge by surfactant-modified clay.

The application of biosolids or treated sewage sludge containing per- and polyfluoroalkyl substances (PFAS) in agricultural lands and the disposal of sludge in landfills pose high risks to humans and the environment. Although PFAS precursors have not been regulated yet, their potential transformation to highly regulated perfluoroalkyl acids (PFAAs) may enable them to serve as a long-term source and make remediation of PFAAs a continuing task. Therefore, treating precursors in sewage sludge is even more, certainly not less, critical than treating or removing PFAAs. In this study, a green surfactant-modified clay sorbent was evaluated for its efficacy in stabilizing two representative PFAA precursors in sludge, e.g., N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) and 6:2 fluorotelomer sulfonic acid (6:2 FTSA), in comparison with unmodified clay and powdered activated carbon (PAC). Results showed N-EtFOSAA and 6:2 FTSA exhibited distinct adsorption behaviors in the sludge without sorbents due to their different physicochemical properties, such as hydrophobicity and functional groups. Among the three sorbents, the modified clay reduced the water leachability of N-EtFOSAA and 6:2 FTSA by 91.5% and 95.4%, respectively, compared to controls without amendments at the end of the experiment (47 days). Within the same duration, PAC decreased the water leachability of N-EtFOSAA and 6:2 FTSA by 60.6% and 37.3%, respectively. At the same time, the unmodified clay demonstrated a poor stabilization effect and even promoted the leaching of precursors. These findings suggested that the modified clay had the potential for stabilization of precursors, while negatively charged and/or hydrophilic sorbents, such as the unmodified clay, should be avoided in the stabilization process. These results could provide valuable information for developing effective amendments for stabilizing PFAS in sludge or biosolids. Future research should evaluate the long-term effect of the stabilization approach using actual sludge from wastewater treatment facilities.

Tuning the surface functionality of polyethylene glycol-modified graphene oxide/chitosan composite for efficient removal of dye.

There has been a lot of attention on water pollution by dyes in recent years because of their serious toxicological implications on human health and the environment. Therefore, the current study presented a novel polyethylene glycol-functionalized graphene oxide/chitosan composite (PEG-GO/CS) to remove dyes from aqueous solutions. Several characterization techniques, such as SEM, TEM, FTIR, TGA/DTG, XRD, and XPS, were employed to correlate the structure-property relationship between the adsorption performance and PEG-GO/CS composites. Taguchi's (L25) approach was used to optimize the batch adsorption process variables [pH, contact time, adsorbent dose, and initial concentration of methyl orange (MO)] for maximal adsorption capacity. pH = 2, contact time = 90 min, adsorbent dose = 10 mg/10 mL, and MO initial concentration = 200 mg/L were found to be optimal. The material has a maximum adsorption capacity of 271 mg/g for MO at room temperature. With the greatest R2 = 0.8930 values, the Langmuir isotherm model was shown to be the most appropriate. Compared to the pseudo-first-order model (R2 = 0.9685), the pseudo-second-order model (R2 = 0.9707) better fits the kinetic data. Electrostatic interactions were the dominant mechanism underlying MO sorption onto the PEG/GO-CS composite. The as-synthesized composite was reusable for up to three adsorption cycles. Thus, the PEG/GO-CS composite fabricated through a simple procedure may remove MO and other similar organic dyes in real contaminated water.

Optimization and prediction of the cotton fabric dyeing process using Taguchi design-integrated machine learning approach.

The typical textile dyeing process calls for a wide range of operational parameters, and it has always been difficult to pinpoint which of these qualities is the most important in dyeing performance. Consequently, this research used a combined design of experiments and machine learning prediction models' method to offer a sustainable and beneficial reactive cotton fabric dyeing process. To be more precise, we built a least square support vector regression (LSSVR) model based on Taguchi's statistical orthogonal design (L27) to predict exhaustion percentage (E%), fixation rate (F%), and total fixation efficiency (T%) and color strength (K/S) in the reactive cotton dyeing process. The model's prediction accuracy was assessed using many measures, including root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2). Principal component regression (PCR), partial least square regression (PLSR), and fuzzy modelling were some of the other types of regression models used to compare results. Our findings reveal that the LSSVR model greatly outperformed competing models in predicting the E%, F%, T%, and K/S. This is shown by the LSSVR model's much smaller RMSE and MAE values. Overall, it provided the highest possible R2 values, which reached 0.9819.

Electrospun nanofiber membrane diameter prediction using a combined response surface methodology and machine learning approach.

Despite the widespread interest in electrospinning technology, very few simulation studies have been conducted. Thus, the current research produced a system for providing a sustainable and effective electrospinning process by combining the design of experiments with machine learning prediction models. Specifically, in order to estimate the diameter of the electrospun nanofiber membrane, we developed a locally weighted kernel partial least squares regression (LW-KPLSR) model based on a response surface methodology (RSM). The accuracy of the model's predictions was evaluated based on its root mean square error (RMSE), its mean absolute error (MAE), and its coefficient of determination (R2). In addition to principal component regression (PCR), locally weighted partial least squares regression (LW-PLSR), partial least square regression (PLSR), and least square support vector regression model (LSSVR), some of the other types of regression models used to verify and compare the results were fuzzy modelling and least square support vector regression model (LSSVR). According to the results of our research, the LW-KPLSR model performed far better than other competing models when attempting to forecast the membrane's diameter. This is made clear by the much lower RMSE and MAE values of the LW-KPLSR model. In addition, it offered the highest R2 values that could be achieved, reaching 0.9989.

Microbial Fuel Cell Construction Features and Application for Sustainable Wastewater Treatment.

A microbial fuel cell (MFC) is a system that can generate electricity by harnessing microorganisms' metabolic activity. MFCs can be used in wastewater treatment plants since they can convert the organic matter in wastewater into electricity while also removing pollutants. The microorganisms in the anode electrode oxidize the organic matter, breaking down pollutants and generating electrons that flow through an electrical circuit to the cathode compartment. This process also generates clean water as a byproduct, which can be reused or released back into the environment. MFCs offer a more energy-efficient alternative to traditional wastewater treatment plants, as they can generate electricity from the organic matter in wastewater, offsetting the energy needs of the treatment plants. The energy requirements of conventional wastewater treatment plants can add to the overall cost of the treatment process and contribute to greenhouse gas emissions. MFCs in wastewater treatment plants can increase sustainability in wastewater treatment processes by increasing energy efficiency and reducing operational cost and greenhouse gas emissions. However, the build-up to the commercial-scale still needs a lot of study, as MFC research is still in its early stages. This study thoroughly describes the principles underlying MFCs, including their fundamental structure and types, construction materials and membrane, working mechanism, and significant process elements influencing their effectiveness in the workplace. The application of this technology in sustainable wastewater treatment, as well as the challenges involved in its widespread adoption, are discussed in this study.

Photo-aged non-biodegradable and biodegradable mulching film microplastics alter the interfacial behaviors between agricultural soil and inorganic arsenic.

The impacts of microplastics (MPs) prevalent in soil on the transport of pollutants were urged to be addressed, which has important implications for ecological risk assessment. Therefore, we investigated the influence of virgin/photo-aged biodegradable polylactic acid (PLA) and non-biodegradable black polyethylene (BPE) mulching films MPs on arsenic (As) transport behaviors in agricultural soil. Results showed that both virgin PLA (VPLA) and aged PLA (APLA) enhanced the adsorption of As(Ⅲ) (9.5%, 13.3%) and As(Ⅴ) (22.0%, 6.8%) due to the formation of abundant H-bonds. Conversely, virgin BPE (VBPE) reduced the adsorption of As(Ⅲ) (11.0%) and As(Ⅴ) (7.4%) in soil owing to the "dilution effect", while aged BPE (ABPE) improved arsenic adsorption amount to the level of pure soil due to newly generated O-containing functional groups being feasible to form H-bonds with arsenic. Site energy distribution analysis indicated that the dominant adsorption mechanism of arsenic, chemisorption, was not impacted by MPs. The occurrence of biodegradable VPLA/APLA MPs rather than non-biodegradable VBPE/ABPE MPs resulted in an increased risk of soil accumulating As(Ⅲ) (moderate) and As(Ⅴ) (considerable). This work uncovers the role of biodegradable/non-biodegradable mulching film MPs in arsenic migration and potential risks in the soil ecosystem, depending on the types and aging of MPs.

Environmental and health impacts of PFAS: Sources, distribution and sustainable management in North Carolina (USA).

Poly- and perfluoroalkyl substances (PFAS) are a class of manufactured chemicals that have recently attracted a great deal of attention from environmental regulators and the general public because of their high prevalence, resistance to degradation, and potential toxicity. This review summarizes the current state of PFAS and its effects on the environment of North Carolina, USA. Specific emphasis has been placed to identify i) the sources of PFAS in North Carolina ii) distribution of PFAS in different environmental segments of North Carolina, including surface water, groundwater, air, and sediment iii) drinking water contamination iv) impact of PFAS on human health v) PFAS accumulation in fish and other biota vi) status of PFAS removal from drinking water and finally vi) socioeconomic impact of PFAS uncertainties. Continuous discharges of PFAS occur in the North Carolina environment from direct and indirect sources, including manufacturing sites, firefighting foam, waste disposal and treatment plants, landfill leachate, and industrial emissions. PFAS are widespread in many environmental segments of North Carolina. They are more likely to be detected in surface and groundwater sediments and can enter aquatic bodies through direct discharge and wet and dry deposition of emissions. Eventually, some adverse effects of PFAS have already been reported in North Carolina residents who could have been exposed to the chemicals through contaminated drinking water. Furthermore, PFAS were also found in blood samples from fish and alligators. PFAS were confirmed to be present in water, sediment, organic compounds, and aquatic species at all levels of the food web. However, there is still a substantial amount of work to be done to understand the actual contamination by PFAS in North Carolina comprehensively.

The Advancement in Membrane Bioreactor (MBR) Technology toward Sustainable Industrial Wastewater Management.

The advancement in water treatment technology has revolutionized the progress of membrane bioreactor (MBR) technology in the modern era. The large space requirement, low efficiency, and high cost of the traditional activated sludge process have given the necessary space for the MBR system to come into action. The conventional activated sludge (CAS) process and tertiary filtration can be replaced by immersed and side-stream MBR. This article outlines the historical advancement of the MBR process in the treatment of industrial and municipal wastewaters. The structural features and design parameters of MBR, e.g., membrane surface properties, permeate flux, retention time, pH, alkalinity, temperature, cleaning frequency, etc., highly influence the efficiency of the MBR process. The submerged MBR can handle lower permeate flux (requires less power), whereas the side-stream MBR can handle higher permeate flux (requires more power). However, MBR has some operational issues with conventional water treatment technologies. The quality of sludge, equipment requirements, and fouling are major drawbacks of the MBR process. This review paper also deals with the approach to address these constraints. However, given the energy limitations, climatic changes, and resource depletion, conventional wastewater treatment systems face significant obstacles. When compared with CAS, MBR has better permeate quality, simpler operational management, and a reduced footprint requirement. Thus, for sustainable water treatment, MBR can be an efficient tool.

Sustainable fashion: Design of the experiment assisted machine learning for the environmental-friendly resin finishing of cotton fabric.

Given the carcinogenic properties of formaldehyde-based chemicals, an alternative method for resin-finishing cotton textiles is urgently needed. Therefore, the primary objective of this study is to introduce a sustainable resin-finishing process for cotton fabric via an industrial procedure. For this purpose, Bluesign® approved a formaldehyde-free Knittex RCT® resin was used, and the process parameters were designed and optimized according to the Taguchi L27 method. XRD analysis confirmed the crosslinking formation between resin and neighboring molecules of cotton fabric, as no change in the cellulose crystallization phase. Several machine learning models were built in a sequence to predict the crease recovery angle (CRA), tearing strength (TE) and whiteness index (WI). Assessment of modelling was evaluated through the use of various metrics such as root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2). Results were compared to those from other regression models, such as principal component regression (PCR), partial least squares regression (PLSR), and fuzzy modelling. Based on the results of our research, the LSSVR model predicted the CRA, TE, and WI with substantially more accuracy than other models, as shown by the fact that its RMSE and MAE values were significantly lower. In addition, it offered the greatest possible R2 values, reaching up to 0.9627.

Sustainable fashion: eco-friendly dyeing of wool fiber with novel mixtures of biodegradable natural dyes.

Natural materials, especially natural colorants, have achieved global prominence and might be regarded as an environmentally beneficial alternative to hazardous synthetic dyes. The color limitation of natural dyes hinders their application in textiles. The present work aims to prepare more color shades of wool yarns via dyeing with ternary natural dye mixtures without adding mordants. In this study, a sustainable dyeing approach for wool yarn was evaluated with three natural dyes, madder red (MR), gardenia blue (GB), and gardenia yellow (GY), by following an industrial dyeing procedure in the absence of a mordant. In the beginning, a preliminary assessment of dye stabilities was carried out, and it was found that the three natural dyes were sensitive to temperature and acid (degradation tendency). Then, the dyeing behavior was systematically evaluated, including a single natural dye, a binary natural dye mixture, and a ternary natural dye mixture. The results of wool yarn dyeing with a single natural dye show that the dye exhaustion percentage (E%) of MR, GY, and GB was in the ranges of 78.7-94.1%, 13.4-44.1%, and 54.8-68.5%, respectively. The dyeing results of wool yarns dyed with binary and ternary natural dye mixtures (a color triangle framework of dyed wool yarn) were characterized by colorimetric values (L*, a*, b*, C*, h, and K/S), and are presented to enlighten various colorful shades. Finally, color uniformity and colorfastness tests confirmed the vital contribution of natural dyes toward wool yarn coloration. Particularly, colorfastness to washing confirmed the stability of natural dyes with reference to the lower amount of dyes released into the effluent, which is beneficial for the environment. Overall, this study provides a good background for enhancing the industrialization trend of natural dyes by modulating their dyeing scheme.

Sustainable and eco-friendly dyeing of traditional grass cloth with a reactive dye in palm oil medium.

Traditional grass cloth has been used in China for a long time for the manufacturing of various household furnishing textiles and ladieswear. However, traditionally the grass cloth is dyed with reactive dyes in an aqueous medium, but the dyeing process is not sustainable because of high energy and water usage and the production of coloured effluent. In this work, the possibility of palm oil/water dual-phase dyeing of traditional grass cloth with a reactive dye, C.I. Reactive Blue 194 (Reactive Blue 194), was explored. The grass cloth soaked in an alkaline solution with 80-140% pick-up was dyed in a palm oil dyebath containing dye powder dispersed in a palm oil medium. The initial study confirmed that the pre-treatment of the fabric with an alkaline solution with 140% pick-up was beneficial for the uniform distribution of the dye in the fibres. The dyeing process parameters (e.g., fixation temperature, solution pH, and fixation time) for the grass cloth dyeing with the Reactive Blue 194 were optimised by using the Taguchi method. The pH of the alkali pre-treatment solution was found to be the most influential factor, as confirmed by the analysis of variance in terms of the percentage of contribution (94.41%), which was statistically significant (P < 0.05). The confirmation tests were carried out under optimal settings, and a higher K/S (24.06) was found compared with the initial condition (21.51). X-ray diffraction analysis indicated that the dyeing process did not affect the crystallinity of the grass cloth fibres. Furthermore, the recovery of palm oil from the spent dyebath was around 99%, and up to five times recycling and reuse of palm oil were studied for the dyeing of grass cloth. The colour strength of the grass cloths dyed in the palm oil recycled up to five times was similar to the cloth dyed in fresh palm oil. The results show that palm oil can be used as a dyeing medium for the sustainable dyeing of grass cloth with effluent reduction, which can be extended to the dyeing of other textile fibres.

Adsorption Behaviour of Reactive Blue 194 on Raw Ramie Yarn in Palm Oil and Water Media.

As an edible oil, palm oil is also safe and reliable in dyeing, and the residual palm oil after dyeing can be recycled and used continuously, which is green and environmentally friendly and has great research prospects. In this research, raw ramie yarn, used for traditional grass cloth, was dyed in a palm oil medium using Reactive Blue 194. Studying the adsorption and diffusion behaviour in the dyeing process is necessary. Additionally, the kinetics and isotherm model of dyeing raw ramie yarn with Reactive Blue 194 in palm oil is studied, and the adsorption behaviour between them is discussed. For a better understanding, the raw ramie yarn dyeing adsorption behaviour was also carried out in a water medium. It was found that the dyeing rates in palm oil are distinctly faster than in water. Kinetics data suggested that the pseudo-second-order model fitted for both dyeing mediums (palm oil and water) of the adsorption of the Reactive Blue 194 dye onto raw ramie yarn. Afterward, the adsorption isotherms' results denote that the Langmuir model was suitable for palm oil dyeing medium while the Freundlich model was suited for water medium. Overall, this study has demonstrated that raw ramie yarn dyeing in a palm oil medium could be a sustainable colouration route for textile fibres with a greater dye exhaustion percentage.

Sustainable traditional grass cloth fiber dyeing using the Taguchi L16 (44) orthogonal design.

For many centuries, traditional grass cloth has been used as an important raw material for home textiles in China, but its market can be expanded by incorporating color. Reactive Red 2 (R2), Reactive Blue 194 (B194), and Reactive Orange 5 (O5) were used in this work to explore the dyeing behavior of sustainable traditional grass fiber using industrial dyeing methods. Initially, an L16 (4^4) orthogonal design was schematically applied to carry out the dyeing process and it was determined that the total dye fixation rate (T%) of B194 dye was the best among the three dyes. Accordingly, a statistical Taguchi technique was analyzed on a larger scale to optimize the dyeing process parameters (salt concentration, fixation time, fixation temperature, and solution pH) of B194, in which solution pH was found to be the most influential factor in achieving the highest T%. This phenomenon was also verified using analysis of variance (ANOVA), where the solution pH was found to be the biggest contributor (50%) and statistically significant (p < 0.05). Finally, confirmation tests were conducted under optimized conditions and a higher T% (53.18%) was determined compared to initial conditions (48.40%). Later, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to analyze the structural characteristics and found that grass cloth was chemically stable, yet gummy materials were still observed on their surface, which was also confirmed from digital photographs. Generally, the color coordinates and fastness properties were also satisfactory.

Sustainable dyeing of ramie fiber with ternary reactive dye mixtures in liquid ammonia.

Liquid ammonia (LA) dyeing is a zero-effluent and sustainable dyeing technology investigated for textiles. In the present work, three bi-functional reactive dyes, Reactive Red 195 (R195), Reactive Yellow 145 (Y145), and Reactive Blue 194 (B194), were used to dye ramie fiber in liquid ammonia, and the dye exhaustion (%) and fixation (%) were compared with ramie fibers dyed with the same dyes in an aqueous dyeing method. Dyeing with a single reactive dye, a binary dye mixture, and a ternary dye mixture in liquid ammonia showed that all the dyes are highly compatible as they showed similar uptake. The total dye exhaustion percentage of dyeing with the ternary dye mixture was 22.6%. After dyeing, a cationic fixing agent (CFA)/decamethylcyclopentasiloxane (D5) micro-emulsion was applied and the dye fixation rate was 96.7% accompanied by high colorfastness to washing (Grade 4-5) and produced uniform shades. Finally, a color triangle of dyed ramie fibers was prepared to exhibit many colorful shades. This work demonstrates the viability of dyeing of textile fibers in liquid ammonia.

Tuning the structure of cerium-based metal-organic frameworks for efficient removal of arsenic species: The role of organic ligands.

The ability of organic ligands to change the structure of metal-organic frameworks (MOFs) in nature and influence their adsorption efficiency for arsenic species is enormous. The current work was designed to investigate the adsorption performance of cerium-based MOFs with tunable structures through the use of organic ligands (Ce-MOF-66 and Ce-MOF-808) towards arsenic species from water. The structural features of Ce-MOF-66 and Ce-MOF-808 with varying crystallinity, morphology, particle size, and surface area are considerably altered by organic ligands tuning, resulting in clearly distinct arsenate (As (V)) and arsenite (As (III)) adsorption capabilities. The experimental results showed that the Langmuir adsorption capacities of As (V) by Ce-MOF-66 and Ce-MOF-808 reached 355.67 and 217.80 mg/g, respectively, while for As (III) were 5.52 and 402.10 mg/g for Ce-MOF-66 and Ce-MOF-808, respectively. Except for the impact of PO43- on As (V), co-existing ions had no significant influence on adsorption, illustrating the high selectivity. Furthermore, to understand the structure and adsorption mechanism, two adsorbents were characterized by powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, specific surface area, Fourier transform infrared and X-ray photoelectron spectroscopy, in which identified that unsaturated sites and ligand exchange were the main adsorption mechanisms of As (V) and As (III). Overall, this research presents a novel approach for developing high-performance Ce-derived MOFs adsorbents to capture arsenic species.

One-Step Fabrication of Novel Polyethersulfone-Based Composite Electrospun Nanofiber Membranes for Food Industry Wastewater Treatment.

Using an environmentally friendly approach for eliminating methylene blue from an aqueous solution, the authors developed a unique electrospun nanofiber membrane made of a combination of polyethersulfone and hydroxypropyl cellulose (PES/HPC). SEM results confirmed the formation of a uniformly sized nanofiber membrane with an ultrathin diameter of 168.5 nm (for PES/HPC) and 261.5 nm (for pristine PES), which can be correlated by observing the absorption peaks in FTIR spectra and their amorphous/crystalline phases in the XRD pattern. Additionally, TGA analysis indicated that the addition of HPC plays a role in modulating their thermal stability. Moreover, the blended nanofiber membrane exhibited better mechanical strength and good hydrophilicity (measured by the contact angle). The highest adsorption capacity was achieved at a neutral pH under room temperature (259.74 mg/g), and the pseudo-second-order model was found to be accurate. In accordance with the Langmuir fitted model and MB adsorption data, it was revealed that the adsorption process occurred in a monolayer form on the membrane surface. The adsorption capacity of the MB was affected by the presence of various concentrations of NaCl (0.1-0.5 M). The satisfactory reusability of the PES/HPC nanofiber membrane was revealed for up to five cycles. According to the mechanism given for the adsorption process, the electrostatic attraction was shown to be the most dominant in increasing the adsorption capacity. Based on these findings, it can be concluded that this unique membrane may be used for wastewater treatment operations with high efficiency and performance.