Adsorption Of Triclosan Research Articles

Kinetic modeling and optimization of triclosan adsorption onto coconut shell activated carbon

This study investigates the efficacy of activated carbon derived from coconut shells for the removal of Triclosan (TCS) from aqueous solutions. Experimental results demonstrate the impressive efficiency of coconut shell-derived activated carbon in eliminating TCS from water. Statistical analysis underscores the significant role of agitation in enhancing adsorption efficiency, with increased agitation leading to higher contaminant removal rates. Equilibrium is rapidly achieved, with removal efficiencies exceeding 85 %. Kinetic analysis reveals rapid adsorption kinetics, predominantly following the pseudo-second-order model. Additionally, intraparticle diffusion analyses provide insights into TCS diffusion within activated carbon pores, highlighting its dependence on solute concentration. These findings underscore the potential of coconut shell-derived activated carbon as a viable solution for mitigating TCS contamination in water sources, contributing to the development of effective water treatment strategies.

Performance evaluation of sugarcane bagasse biochar based fixed bed column for removal of triclosan from aqueous solution in presence of humic acid: Mechanism, kinetics and safety

Triclosan (TCS), an emerging pollutant emerges as a notable contributor to adverse impacts on aquatic organisms owing to its widespread use during COVID19. The current study aims to investigate the efficiency of sugarcane bagasse biochar (SBB) for removal of triclosan (TCS), an emerging pollutant in aquatic ecosystems in presence of humic acid from aqueous solution through batch and column studies. In batch study, SBB prepared at pyrolysis temperature of 400 °C showed highest adsorption of TCS. Langmuir isotherm model showed highest adsorption of 68.49 mg g−1 at pH 7.0. A 90 % reduction in TCS was accomplished with 0.625 g L−1 of SBB-400 °C. Adsorption kinetic modelling was well fitted to pseudo-second order model signifying that rate of adsorption on SBB-400 °C mainly depends on chemisorption. TCS removal was not significantly inhibited in presence of 5, 10 and 25 mg L−1humic acid concentrations. Column experiments of continuous flow biochar-bed column with the aqueous solution spiked with TCS (100 mg L−1) at a flow rate of 50 mL min−1 showed 99 % removal efficiency. Thomas model and Yoon-Nelson model signified the breakthrough behaviour of TCS adsorption on the column and the experimental data were in good agreement with the expected values. Bioassay studies on Chlorella vulgaris exhibited that percentage inhibition (8 %) in algal cell counts was significantly less in the SBB treated TCS water when compared with control (untreated water containing TCS). The designed column is highly efficient, effective and eco-friendly approach for TCS removal.

Effects of reduced graphene oxide nanomaterials on transformation of 14C-triclosan in soils

Increasing use and release of graphene nanomaterials and pharmaceutical and personal care products (PPCPs) in soil environment have polluted the environment and posed high ecological risks. However, little is understood about the interactive effects and mechanism of graphene on the behaviors of PPCPs in soil. In the present study, the effects of reduced graphene oxide nanomaterials (RGO) on the fate of triclosan in two typical soils (S1: silty loam; S2: silty clay loam) were investigated with 14C-triclosan, high-resolution mass spectrometry, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), density functional theory (DFT) calculations, and microbial community structure analysis. The results showed that RGO prolonged the half-life of triclosan by 23.6–51.3 %, but delayed the formation of transformed products such as methyl triclosan and dechlorinated dimer of triclosan in the two typical soils. Mineralization of triclosan to 14CO2 was inhibited by 48.2–79.3 % in 500 mg kg−1 RGO in comparison with that in the control, whereas the bound residue was 54.2–56.4 % greater than the control. RGO also reduced the relative abundances of triclosan-degrading bacteria (Pseudomonas and Sphingomonas) in soils. Compared to silty loam, RGO more effectively inhibited triclosan degradation in silty clay loam. Furthermore, the DFT calculations suggested a strong association of the adsorption of triclosan on RGO with the van der Waals forces and π-π interactions. These results revealed that RGO inhibited the transformation of 14C-triclosan in soil through strong adsorption and triclosan-degrading bacteria inhibition in soils. Therefore, the presence of RGO may potentially enhance persistence of triclosan in soil. Overall, our study provides valuable insights into the risk assessment of triclosan in the presence of GNs in soil environment.

Comparative impact of pristine and aged microplastics with triclosan on lipid metabolism in larval zebrafish: Unveiling the regulatory role of miR-217

The prevalence of microplastics (MPs), especially aged particles, interacting with contaminants like triclosan (TCS), raises concerns about their toxicological effects on aquatic life. This study focused on the impact of aged polyamide (APA) MPs and TCS on zebrafish lipid metabolism. APA MPs, with rougher surfaces and lower hydrophobicity, exhibited reduced TCS adsorption than unaged polyamide (PA) MPs. Co-exposure to PA/APA MPs and TCS resulted in higher TCS accumulation in zebrafish larvae, notably more with PA than APA. Larvae exposed to PA + TCS exhibited greater oxidative stress, disrupted lipid metabolism, and altered insulin pathway genes than those exposed to TCS. However, these negative effects were lessened in the APA + TCS group. Through miRNA-seq and miR-217 microinjection, it was revealed that PA + TCS co-exposure upregulated miR-217, linked to lipid metabolic disorders in zebrafish. Moreover, molecular docking showed stable interactions formed between PA, TCS, and the insulin signaling protein Pik3r2. This study demonstrated that PA and TCS co-exposure significantly inhibited the insulin signaling in zebrafish, triggering lipid metabolism dysregulation mediated by miR-217 upregulation, while APA and TCS co-exposure alleviated these disruptions. This research underscored the ecological and toxicological risks of aged MPs and pollutants in aquatic environments, providing crucial insights into the wider implications of MPs pollution.

Synthesis of recyclable and light-weight graphene oxide/chitosan/genipin sponges for the adsorption of diclofenac, triclosan, and microplastics

Emerging micropollutants, such as pharmaceuticals and microplastics (MPs), have become a pressing water environmental concern. The aim of this study is to synthesize chitosan sponges using graphene oxide (GO) and genipin (GP) for the removal of pharmaceuticals (diclofenac (DCF) and triclosan (TCS)) and MPs, verify their adsorption mechanisms, evaluate the effects of temperature, pH, and salinity on their adsorption capacities, and determine their reusability. The GO5/CS/GP sponge exhibited a macroporous nature (porosity = 95%, density = 32.6 mg/cm3). GO and cross-linker GP enhanced the adsorption of DCF, TCS, and polystyrene (PS) MPs onto the CS sponges. The adsorption of DCF, TCS, and PS MPs involved multiple steps: surface diffusion and pore diffusion of the sponge. The adsorption isotherms demonstrated that Langmuir model was the most fitted well model to explain adsorption of TCS (qm = 7.08 mg/g) and PS MPs (qm = 7.42 mg/g) on GO5/CS/GP sponge, while Freundlich model suited for DCF adsorption (qm = 48.58 mg/g). DCF adsorption was thermodynamically spontaneous and endothermic; however, the adsorption of TCS and PS MPs was exothermic (283–313 K). The optimal pH was 5.5–7 due to the surface charge of the GO5/CS/GP sponge (pHzpc = 5.76) and ionization of DCF, TCS, and PS MPs. As the salinity increased, DCF removal efficiency drastically decreased due to the weakening of electrostatic interactions; however, TCS removal efficiency remained stable because TCS adsorption was mainly caused by hydrophobic and π–π interactions rather than electrostatic interaction. The removal of PS MPs was enhanced by the electrostatic screening effects of high Na+ ions. PS nanoplastics (average size = 26 nm) were removed by the GO5/CS/GP sponge at a rate of 73.0%, which was better than that of PS MPs (41.5%). In addition, the GO5/CS/GP sponge could be recycled over five adsorption–desorption cycles.

Natural aging and adsorption/desorption behaviors of polyethylene mulch films: Roles of film types and exposure patterns

Polyethylene (PE) mulch films are an important source of microplastics (MPs) in agricultural soils, which may further affect the bioavailability of coexisting pollutants. In this study, white (WM), black (BM), and silver-black (SM) PE mulch films were aged on the soil surface and under soil burial to simulate the two exposure patterns of abandoned mulch films in the field. Results indicated that the soil-surface exposure induced more pronounced aging characteristics, and WM seemed the most susceptible. Serious surface deterioration by aging led to a drastic decrease in the tensile properties of the films, suggesting the tendency to fragment. Oxygen-containing functional groups were generated on the film surfaces, with oxygen/carbon ratios increasing by up to 29 times, which contributed to the prominent increase in Pb adsorption on the film-derived MPs. Additionally, the film surface became more hydrophobic when exposed to the soil surface but more hydrophilic in the soil-burial exposure, which was in agreement with the change in triclosan adsorption, i.e., promotion and suppression, respectively. Aging generally decreased the desorption potential of the adsorbed pollutants in simulated gastrointestinal solutions due to increased interactions. By comparison, exposure patterns were revealed to be the critical factor for these changes, regardless of film types.

Effective triclosan removal by using porous aromatic frameworks in continuous fixed-bed column studies.

Triclosan (TCS) has been regarded as an emerging contaminant in aquatic systems, making its efficient removal of great significance. In this study, NPVMo@iPAF-1, with a specific surface area of 665 m2/g, was prepared by incorporating (NH4)5H6PV8Mo4O40 into porous aromatic frameworks (PAF). The maximum adsorption capacity of TCS on NPVMo@iPAF-1 reached 917.1mg/g, as calculated from the Langmuir model. Fixed-bed columns packed with NPVMo@iPAF-1 were employed for TCS removal; the experiment data strongly correlated with the Thomas and Yoon-Nelson models under different operational conditions. Pore preservation, electrostatic effects, and the synergistic effect of π-π interactions contributed to the effective adsorption of TCS onto NPVMo@iPAF-1. The NPVMo@iPAF-1 fixed-bed column could be effectively regenerated through in-situ ozonation for more than 10 regeneration cycles. NPVMo@iPAF-1 turned out to be a promising adsorbent for removing TCS not only from pure water but also from reclaimed water and surface water samples.

Emerging Contaminants Removal from Wastewater Using Organo-Modified Bentonite Clay

Organo-modified bentonite clay locally sourced from Bauchi State, Nigeria was prepared and used as an adsorbent for Emerging Contaminants (EC) capture from Kaduna Polytechnic female hostel wastewater. The produced adsorbent was characterized to determine the functional groups, surface area and crystal structure. Surface area for directly modified bentonite clay produced adsorbents and oxalic acid-pretreated bentonite clay adsorbent was found to be 625 m2/g and 349.2 m2/g respectively and the morphology of the produced acid-pretreated organo-modified bentonite clay adsorbents has better pore development with a higher amorphous structure. The wastewater compositions were found to contain major ECs identified to be Diclofenac, Triclosan, Methylparaben, and Bisphenol A, which account for 76.206% of the ECs that are detrimental to human and the environment. The impact of the adsorption factors; contact time, adsorbent dosage, and temperature on uptake behavior were all examined. Effect of adsorbent dosage was established which shows that all ECs removed rise rapidly from 0.5 – 1.0 g adsorbent dosage and then slowly reach a maximum of 98.65% Triclosan, 95.83% Diclofenac, 91.49% BPA, and 62.16% Methyl-Paraben removal as adsorbent dosage increases to 2g. On the other hand, as the adsorbent dosage increases to 3g, the removal rate of all ECs was observed to drop slightly and then attain maximum removal as the dosage rises to 4g. In contrast, a rise in adsorbent dosage of 2.5g gives a sudden drop in removal of Triclosane to 92.41% and Methyl-Paraben to 53.01% as well as a sharp drop in Methyl-Paraben to 33.33% and slightly drop in the removal of all other ECs. Langmuir and Freundlich isotherms models were fitted to the adsorption data and Freundlich showed best fit indicating chemisorption. The adsorption of triclosan, diclofenac, bisphenol A, and methylparaben followed pseudo second-order kinetic model.

Adsorption of triclosan on the reusable graphene oxide with cobalt ferrite from aqueous solution

With the increase in personal hygiene care due to the COVID-19 pandemic, antibacterial soaps have also increased. Triclosan (TCS) is one of the main chemical residuals from these products and its presence can compromise aquatic ecosystems due to its adverse effects. Therefore, it is important to monitor triclosan that may be present in contaminated water and propose conventional and advanced treatments to remove this contaminant from the environment. The characterization by physicochemical and spectroscopic techniques indicated that the proposed functionalization was accomplished, obtaining a specific surface area of 27.32 m2/g, the morphology images demonstrate a heterogeneous material that facilitates the removal and functional groups in the material that help this adsorption process. In addition, GO-CoFe2O4 reached a maximum adsorption capacity of 134.25 mg g−1 at 318 K with an equilibrium time of 2 h, being highly efficient for TCS removal from aqueous solutions (93 %), obtaining a correlation factor of 0.914. The experimental data was better adjusted to the pseudo-second-order kinetic and Langmuir and Temkin's isotherm models, with maximum correlation factor values of 0.986 and 0.992 respectively. The adsorbent proved to be sustainable since it was able to maintain 92 % using 0.01 g of adsorbent and an initial concentration of triclosan of 30 mg L-1 the initial adsorption capacity after 10 reuse cycles. Therefore, the proposed adsorbent demonstrates an operational advantage in wastewater treatment. The present study aimed to develop an adsorbent material based on graphene oxide functionalized with cobalt ferrite to remove triclosan present in water.

Photodegradation of Triclosan on the Kaolinite Surface: Kinetic, Mechanistic, and Molecular Modeling Approach.

The photodegradation of triclosan (TCS) was investigated on the kaolinite surface. The quantum yield was evaluated, and the photoproducts were identified by HPLC/MS (LC/Q-TOF), showing that the phototransformation is completely different from that reported in aqueous solutions. In particular, the formation of dioxin derivatives was fostered and occurred with a higher efficiency when compared to aqueous solutions. This suggests that TCS has specific interactions with the clay that clearly modifies its photochemical behavior. Moreover, it has also been shown that higher concentrations of TCS, namely, higher than 1.0 μmol g-1 of kaolinite, lead to a significant decrease of the photodegradation rate constant and enhance the formation yield of dimer-type photoproducts. This suggests that the distribution of TCS is clearly not homogeneous at the clay surface and the formation of aggregates is more likely occurring. To get a better insight into this specific interaction, a molecular dynamic modeling of TCS adsorption at the surface of kaolinite was carried out. This clearly shows that when equilibrium is reached, TCS binds to the kaolinite surface by hydrogen bonds involving the phenol function of TCS and the hydroxyl groups of the kaolinite surface. Such behavior confers a particular conformation to the adsorbed TCS that is different from that obtained in water and which could be a key step to partially explain the specific photochemical reactivity in both media. In addition, several TCS molecules appear to interact with each other through the π-stacking (aromatic stacking) process while retaining this hydrogen bond with the kaolinite surface. This is clearly in favor of cluster formation on the clay surface and promotes dimer-type photoproducts.

Adsorption behavior of triclosan on polystyrene nanoplastics: The roles of particle size, surface functionalization, and environmental factors

Nanoplastics (NPs) contribute substantially to the transport of waterborne pollutants. Triclosan (TCS) has a high potential to contact with NPs because of their prevalence in natural waters. Herein, this study investigated the adsorption behavior of TCS on differently sized and functionalized polystyrene (PS) NPs. The effects of environmental factors such as pH, salinity, and dissolved organic matter (DOM) were also evaluated. Results suggest that the adsorption equilibrium constant (kd) of TCS in pristine PSNP suspensions followed the order as: PSNPs-50 nm (4.39 L·g−1) > PSNPs-100 nm (2.78 L·g−1) > PSNPs-200 nm (2.59 L·g−1) > PSNPs-500 nm (1.36 L·g−1) ≈ PSNPs-900 nm (1.36 L·g−1). For the functionalized PSNPs (i.e., PSNPs-COOH, PSNPs-NH2), the values of specific surface area normalized kd called kd, SSA were higher than those of pristine PSNPs. Meanwhile, TCS adsorption on two functionalized PSNPs remained stable and then decreased as salinity increased, while an opposite trend was observed toward pristine PSNPs. All these suggested that physicochemical properties of PSNPs (e.g., particle size and surface functional groups) are important factors influencing their adsorption capacity. When the solution pH raised, the adsorbed amounts of TCS on all tested PSNPs prone to decline. However, DOM only affected the adsorption behavior of PSNPs-50 nm, probably owing to its aggregation with tiny PSNPs and the induced secondary adsorption.

Investigation of the Adsorption Process of Triclosan from an Aqueous Solution, Using Nanoporous Carbon Adsorbents, Obtained after Treatment of Organic Household and Vegetable Waste

The absorption of triclosan on the surface of four different carbon adsorbents, obtained on the base of plant and household waste (RDF), provided by Sofia Waste Plant, was investigated. The obtained results indicate that the most important parameters, which determine the process of triclosan adsorption by adsorbent surface are pore texture, the size of the accessible surface for the molecules of triclosan, and the chemical nature of the adsorbent surface. It was found that the obtained adsorbents can be successfully applied for the extraction of triclosan from waste and drinking water. The possibilities for solid products, obtained by thermal treatment of household and vegetable waste, to be applied successfully in a water purification technique are discussed.

Effects of triclosan adsorption on intestinal toxicity and resistance gene expression in Xenopus tropicalis with different particle sizes of polystyrene

Microplastics (MPs) are commonly found with hydrophobic contaminants in the water column and pose a serious threat to aquatic organisms. The effects of polystyrene microplastics of different particle sizes on the accumulation of triclosan in the gut of Xenopus tropicalis, its toxic effects, and the transmission of resistance genes were evaluated. The results showed that co-exposure to polystyrene (PS-MPs) adsorbed with triclosan (TCS) caused the accumulation of triclosan in the intestine with the following accumulation capacity: TCS + 5 µm PS group > TCS group > TCS + 20 µm PS group > TCS + 0.1 µm PS group. All experimental groups showed increased intestinal inflammation and antioxidant enzyme activity after 28 days of exposure to PS-MPs and TCS of different particle sizes. The TCS + 20 µm PS group exhibited the highest upregulated expression of pro-inflammatory factors (IL-10, IL-1β). The TCS + 20 µm group showed the highest increase in enzyme activity compared to the control group. PS-MPs and TCS, either alone or together, altered the composition of the intestinal microbial community. In addition, the presence of more antibiotic resistance genes than triclosan resistance genes significantly increased the expression of tetracycline resistance and sulfonamide resistance genes, which may be associated with the development of intestinal inflammation and oxidative stress. This study refines the aquatic ecotoxicity assessment of TCS adsorbed by MPs and provides informative information for the management and control of microplastics and non-antibiotic bacterial inhibitors.

Effects of weathering on the properties and fate of secondary microplastics from a polystyrene single-use cup

In this work, we probed the changes to some physicochemical properties of polystyrene microplastics generated from a disposable cup as a result of UV-weathering, using a range of spectroscopy, microscopy, and profilometry techniques. Thereafter, we aimed to understand how these physicochemical changes affect the microplastic transport potential and contaminant sorption ability in model freshwaters. Exposure to UV led to measured changes in microplastic hydrophobicity (20–23 % decrease), density (3% increase), carbonyl index (up to 746 % increase), and microscale roughness (24–86 % increase). The settling velocity of the microplastics increased by 53 % after weathering which suggests that UV aging can increase microplastic deposition to sediments. This impact of aging was greater than the effect of the water temperature. Weathered microplastics exhibited reduced sorption capacity (up to 52 % decrease) to a model hydrophobic contaminant (triclosan) compared to unaged ones. The adsorption of triclosan to both microplastics was slightly reversible with notable desorption hysteresis. These combined effects of weathering could potentially increase the transport potential while decreasing the contaminant transport abilities of microplastics. This work provides new insights on the sorption capacity and mobility of a secondary microplastic, advances our knowledge about their risks in aquatic environments, and the need to use environmentally relevant microplastics.

Equilibrium, thermodynamic and kinetic modeling of triclosan adsorption on mesoporous carbon nanosphere: Optimization using Box-Behnken design

In this study, a high-potential nanoadsorbent from mesoporous carbon nanospheres (MCNS) was synthesized and characterized by TEM, XRD, SEM, Raman, and BET analysis. The novel MCNS nanoadsorbent was found to has high efficiency for adsorbing triclosan (TCS) form an aqueous solution. An investigation was done on how the pH of the solution affects the adsorption equilibrium. On the other hand, adsorption isotherm models were fitted to a Langmuir model, showing that chemisorption was the technique of adsorption. The total rate of TCS adsorption on MCNS was determined using kinetic models, which were fitted to a pseudo-second-order model. Using the response surface methodology (RSM), the four adsorption process parameters of time, temperature, solution pH, and adsorbent dosage were adjusted. According to the (ΔH°), (ΔS°), and (ΔG°), TCS was endothermically and spontaneously extracted utilizing MCNS as an adsorbent. The synthesized MCNS adsorbent exhibits remarkable render ability and reusability for up to five cycles of adsorption–desorption. As a proof of concept, the produced adsorbent's efficiency was assessed for filtering wastewater samples on a lab scale. Investigate the mechanism by which the MCNS and TCS interact, since this process may include electrostatic interaction, pore filling, π-π interaction, or H-bonding. Water filtration and industrial wastewater treatment were made easy and efficient with the MCNS adsorbent. Our research indicates that our work is the first to describe how to extract TCS using MCNS adsorbent from wastewater samples. The findings show that a pH value of 6 yields a maximum TCS adsorption capability onto MCNS of 607.95 mg g−1.

Interaction mechanism of triclosan on pristine microplastics

Urban wastewaters comprise different hydrophobic pollutants such as microplastics (MPs), pharmaceuticals, and personal care products. Among these pollutants, triclosan (TCS) shows a worrying interaction ability with MPs; recent studies show MPs serve as a vector between TCS and aquatic environments, whose interaction is still being studied to understand their combined toxicity and transport ability. Using computational chemistry tools, this work evaluates the TCS-MPs interaction mechanism, including pristine polymers, i.e., aliphatic polyamides (PA), polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). Our results show that TCS adsorption on MPs solely occurs via physisorption, where PA reaches the higher adsorption ability. Remarkably, MPs reach higher or comparable adsorption stability than carbon-based materials, boron nitrides, and minerals, indicating their worrying transport properties. Also, the adsorption capacity is strongly influenced by entropy changes rather than thermal effects, which determine the different sorption capacities among polymers and agree well with reported sorption capacities from adsorption kinetic experiments in the literature. MPs show a polar and highly susceptible surface to establish electrostatics and dispersion effects on TCS. Accordingly, the TCS-MPs interaction mechanism arises from the interplay between electrostatics and dispersion forces, with a combined contribution of 81–93 %. Specifically, PA and PET maximize the electrostatic effects, while PE, PP, PVC, and PS maximize the dispersion effects. From the chemical viewpoint, TCS-MPs complexes interact by a series of pairwise interactions such as Van der Waals, hydrogen bonding, C-H⋯π, C-H⋯C-H, C-Cl⋯C-H, and C-Cl⋯Cl-C. Finally, the mechanistic information explains the effects of temperature, pressure, aging, pH, and salinity on TCS adsorption. This study quantitatively elucidates the interaction mechanism of TCS-MP systems, which were hard to quantify to date, and explains the TCS-MPs sorption performance for sorption/kinetic studies.

Adsorption of Triclosan on Nylon 66 Membrane: Preconcentration and Ultrasensitive Colorimetric Detection.

In this work, adsorption of triclosan (TCS) on nylon 66 membrane is explored to develop a preconcentration and sensing platform. Nylon 66 membrane exhibits superior sorption ability even for trace amounts of TCS (10 μg/L). Investigating the surface adsorption chemistry by XPS analysis revealed the formation of a hydrogen bond between the hydroxyl group of TCS and the amide group of nylon 66. In the absence of TCS, the amphiprotic water molecule forms a multilayer OH group on the membrane surface. However, TCS showed preferential adsorption on the membrane-replacing water molecule due to its higher hydrophobic partition coefficient. We validated the effective preconcentration of TCS on the membrane using LC-MS analysis. Performing colorimetry directly on the TCS-enriched membrane surface showed a visible color change for concentrations as low as 10 μg/L. The relative blue intensity was found to vary linearly over a concentration range of 10-100 μg/L, and we achieved a detection limit of 7 μg/L for a 5 mL sample. This method utilizes easy-to-use resources which drastically reduce the cost and complexity of analysis.

Adsorption of triclosan from aqueous solutions via novel metal–organic framework: Adsorption isotherms, kinetics, and optimization via Box-Behnken design

Utilizing Lanthanum/Palladium -Metal organic framework (La/Pd-MOF), this study sought to analyze the efficacy of removing triclosan (TCS) from aqueous solutions. Through compelling experimentation, we demonstrated that La/Pd-MOF is an effective adsorbent for eliminating TCS from water. Characterization of the material was conducted using SEM, XRD, BET analysis, and surface characterization to determine the point of zero charge. Through batch experiments, we investigated how pH levels impacted adsorption equilibrium. Fascinatingly, our results show that changes in solution pH drastically altered adsorption behavior. The effectiveness of TCS adsorption on La/Pd-MOF was thoroughly examined using kinetic models, adhering to the pseudo-second-order model. Furthermore, Langmuir isotherm model fitted the adsorption process accordingly. It was identified that a chemisorption process was involved in the overall process. To further customize the parameters like absorbent dosage, solution pH, temperature and time, Box-Behnken design (BBD) with Response Surface Methodology (RSM) were implemented. According to the instructions, the (ΔH°), (ΔS°), and (ΔG°) of TCS were endothermically and spontaneously extracted using La/Pd-MOF as an adsorbent. The synthesized La/Pd-MOF adsorbent exhibits remarkable render ability and cyclability for up to five cycles of adsorption–desorption. The effectiveness of the created adsorbent was evaluated as a proof of concept for cleaning wastewater samples at a lab scale. Study the mechanism of interaction between the La/Pd-MOF and TCS as it could be taking place through π-π interaction, pore filling, H-Bonding or electrostatic interaction. The La/Pd-MOF adsorbent provided a straightforward and efficient method for managing industrial effluent and water filtration. Our research indicates that our work is the first to describe how to remove TCS using La/Pd-MOF adsorbent from wastewater samples. The results showed that a maximum adsorption capacity of TCS onto La/Pd-MOF is obtained at a pH value of 6, which is 610.845 mg·g−1.

Adsorption behavior of triclosan on microplastics and their combined acute toxicity to D. magna

Microplastics (MP) have been recently identified as emerging water contaminants in worldwide. Owing to its physicochemical properties, MP have been considered as a vector of other micropollutants and may affect their fate and ecological toxicity in the water environment. In this study, triclosan (TCS), which is a widely-used bactericide, and three frequently found types of MP (PS-MP, PE-MP, and PP-MP) were investigated. The adsorption behavior of TCS on MP was investigated by the effect of reaction time, initial concentration of TCS, and other water chemistry factors. Elovich model and Temkin model are the most fitted well with kinetics and adsorption isotherms, respectively. The maximum TCS adsorption capacities were calculated for PS-MP (9.36 mg/g), PP-MP (8.23 mg/g), and PE-MP (6.47 mg/g). PS-MP had higher affinity to TCS owing to hydrophobic and π-π interaction. The TCS adsorption on PS-MP was inhibited by decreasing concentrations of cations, and increasing concentration of anion, pH, and NOM concentration. At pH 10, only 0.22 mg/g of adsorption capacity was obtained because of the isoelectric point (3.75) of PS-MP and pKa (7.9) of TCS. And almost no TCS adsorption occurred at NOM concentration of 11.8 mg/L. Only PS-MP had no acute toxic effect on D. magna, whereas TCS showed acute toxicity (EC50,24h of TCS = 0.36 ± 0.4 mg/L). Although survival rate increased when TCS with PS-MP due to lower the TCS concentration in solution via adsorption, PS-MP was observed in intestine and body surface of D. magna. Our findings can contribute to understanding the combined potential effects of MP fragment and TCS to aquatic biota.

Evaluation of the black soybean hulls agro-industrial waste for chloroquine removal from aqueous medium and treatment of multi-components

The COVID-19 pandemic increased the pollution of water resources by some contaminants, e.g., chloroquine (CQN), due to its probable benefit in the treatment of the virus. Thus, is necessary the removal of CQN from water through advanced techniques. Black soybeans have been widely used due to their benefits to human health, and as a result, there was an increase in soybean husk residue, the main by-product of the soybean processing industry. Given the current scenario and the need to develop new uses for this agricultural residue, this study aimed to establish an economical and environmental biotechnology by the CQN adsorption process onto black soybean hulls (BSH) for the first time. BSH was characterized by physicochemical and spectroscopic techniques that demonstrated porosity, organic functional groups and negative surface charges. The pH study did not affect CQN adsorption pronouncedly, indicating that π-interactions and hydrogen bonds are the main mechanisms of the adsorption process. The maximum adsorption capacity was 75.06 ± 2.24 mg g−1 with 240 min of contact time at 288 K. In order to verify the biosorbent applicability, the safranin orange dye and triclosan adsorption were also evaluated onto BSH. The absorption peaks of the contaminants used in the synthetic mixture demonstrated a removal rate of 90.81 ± 0.80% for safranin orange, 66.79 ± 1.12% for triclosan and 70.62 ± 0.67% for CQN. The satisfactory removal of other contaminants indicates that BSH is a promising, affordable and environmentally friendly biosorbent with applicability potential for alternative treatment of contaminated water.