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1.
J Cell Mol Med ; 28(6): e18161, 2024 03.
Article in English | MEDLINE | ID: mdl-38445787

ABSTRACT

Cisplatin is an antimitotic drug able to cause acute and chronic gastrointestinal side effects. Acute side effects are attributable to mucositis while chronic ones are due to neuropathy. Cisplatin has also antibiotic properties inducing dysbiosis which enhances the inflammatory response, worsening local damage. Thus, a treatment aimed at protecting the microbiota could prevent or reduce the toxicity of chemotherapy. Furthermore, since a healthy microbiota enhances the effects of some chemotherapeutic drugs, prebiotics could also improve this drug effectiveness. We investigated whether chronic cisplatin administration determined morphological and functional alterations in mouse proximal colon and whether a diet enriched in prebiotics had protective effects. The results showed that cisplatin caused lack of weight gain, increase in kaolin intake, decrease in stool production and mucus secretion. Prebiotics prevented increases in kaolin intake, changes in stool production and mucus secretion, but had no effect on the lack of weight gain. Moreover, cisplatin determined a reduction in amplitude of spontaneous muscular contractions and of Connexin (Cx)43 expression in the interstitial cells of Cajal, changes that were partially prevented by prebiotics. In conclusion, the present study shows that daily administration of prebiotics, likely protecting the microbiota, prevents most of the colonic cisplatin-induced alterations.


Subject(s)
Cisplatin , Prebiotics , Animals , Mice , Cisplatin/adverse effects , Kaolin , Weight Gain , Colon
2.
Environ Sci Technol ; 58(27): 12123-12134, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38934384

ABSTRACT

Clay minerals are ubiquitous in subsurface environments and have long been recognized as having a limited or negligible impact on the fate of arsenic (As) due to their negatively charged surfaces. Here, we demonstrate the significant role of kaolinite (Kln), a pervasive clay mineral, in enhancing As(V) immobilization during ferrous iron (Fe(II)) oxidation at near-neutral pH. Our results showed that Fe(II) oxidation alone was not capable of immobilizing As(V) at relatively low Fe/As molar ratios (≤2) due to the generation of Fe(III)-As(V) nanocolloids that could still migrate easily as truly dissolved As did. In the presence of kaolinite, dissolved As(V) was significantly immobilized on the kaolinite surfaces via forming Kln-Fe(III)-As(V) ternary precipitates, which had large sizes (at micrometer levels) to reduce the As mobility. The kaolinite-induced heterogeneous pathways for As(V) immobilization involved Fe(II) adsorption, heterogeneous oxidation of adsorbed Fe(II), and finally heterogeneous nucleation/precipitation of Fe(III)-As(V) phases on the edge surfaces of kaolinite. The surface precipitates were mixtures of amorphous basic Fe(III)-arsenate and As-rich hydrous ferric oxide. Our findings provide new insights into the role of clay minerals in As transformation, which is significant for the fate of As in natural and engineered systems.


Subject(s)
Arsenates , Kaolin , Oxidation-Reduction , Kaolin/chemistry , Arsenates/chemistry , Iron/chemistry , Ferrous Compounds/chemistry , Adsorption
3.
Anal Bioanal Chem ; 416(16): 3821-3833, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38777876

ABSTRACT

The use of a new nanomaterial in the feed chain requires a risk assessment that involves in vitro gastrointestinal digestions to predict its degradation and oral exposure to nanoparticles. In this study, a nanosilver-based material was incorporated into pig and chicken feed as a growth-promoting additive and subjected to the corresponding in vitro gastrointestinal digestions. An inductively coupled plasma mass spectroscopy (ICP-MS) analytical platform was used to obtain information about the silver released in the different digestion phases. It included conventional ICP-MS for total silver determination, but also single particle ICP-MS and coupling to hydrodynamic chromatography for detection of dissolved and particulate silver. The bioaccessible fraction in the intestinal phase accounted for 8-13% of the total silver, mainly in the form of dissolved Ag(I) species, with less than 0.1% as silver-containing particles. Despite the additive behaving differently in pig and chicken digestions, the feed matrix played a relevant role in the fate of the silver.


Subject(s)
Digestion , Gastrointestinal Tract , Metal Nanoparticles , Animal Feed , Chickens , Gastrointestinal Tract/metabolism , Kaolin/chemistry , Mass Spectrometry , Metal Nanoparticles/chemistry , Silver/chemistry , Swine , Animals
4.
Environ Res ; 247: 118257, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38262511

ABSTRACT

This study introduces the UV/glucose-oxidase@Kaolin (GOD@Kaolin) coupled organic green rust (OGR) system (UV/OGR/GOD@Kaolin) to investigate the promotion of glucose oxidase activity by UV light and its synergistic degradation mechanism for photosensitive pollutants, specifically targeting the efficient degradation of 4-chlorophenol (4-CP). The enzyme system demonstrates its ability to overcome drawbacks associated with traditional Fenton systems, including a narrow pH range and high localized concentration of H2O2, by gradually releasing hydrogen peroxide in situ within a neutral environment. In the presence of UV radiation under specific conditions, enhanced enzyme activity is observed, resulting in increased efficiency in pollutant removal. The gradual release of hydrogen peroxide plays a crucial role in preventing unwanted reactions among active substances. These unique features facilitate the generation of highly reactive species, such as Fe(IV)O, •OH, and •O2-, tailored to efficiently target the organic components of interest. Additionally, the system establishes a positive iron cycle, ensuring a sustained reactive capability throughout the degradation process. The results highlight the UV/OGR/GOD@Kaolin system as an effective and environmentally friendly approach for the degradation of 4-CP, and the resilience of the enzyme extends the system's applicability to a broader range of scenarios.


Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Ultraviolet Rays , Hydrogen Peroxide/chemistry , Glucose Oxidase/metabolism , Kaolin , Glucose , Oxidation-Reduction , Water Pollutants, Chemical/chemistry
5.
Environ Res ; 251(Pt 1): 118590, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38437900

ABSTRACT

Estuaries are fragile environment that are most affected by climate change. One of the major consequences of climate change on estuarine processes is the enhancement in salt intrusion leading to higher salinity values. This has several implications on the estuarine sediment dynamics. Of the various factors that affect the flocculation of cohesive sediments, salinity and turbulence have been recognized as to have great significance. Many of the estuaries are contaminated with heavy metals, of which, the concentration of Iron (Fe (II)) are generally on the higher range. However, the influence of Fe (II) on the flocculation of cohesive sediments at various estuarine mixing conditions is not well known. The present study investigated the influence of Fe (II) on the flocculation of kaolin at various concentration of Fe (II), salinity and turbulence shear. The results indicated that Fe (II) and salinity have a positive influence on kaolin flocculation. The increase in turbulence shear caused an initial increase and then a decrease in floc size. In case of sand-clay mixtures, that are observed in mixed sediment estuarine environments, a reduction in the floc size was observed, which is attributed to the breakage of flocs induced by the shear of sand. Breakage coefficient, which is a measure of break-up of flocs, is generally adopted as 0.5 assuming binary breakage. The present study revealed that the breakage coefficient can take values from 0 to 1 and is a direct function of Fe (II) and salinity and an inverse function of turbulence and sand concentration. Thus, a new model for breakage coefficient with the influencing parameters has been proposed, which is an improvement of existing model that is expressed in terms of turbulence alone. Sensitivity analysis showed that the proposed model can very well predict the breakage coefficient of Fe (II) - kaolin flocs. Thus, the model can quantify the breakage coefficient of flocs in estuaries contaminated with Fe (II) that is a vital parameter for population balance models.


Subject(s)
Clay , Estuaries , Flocculation , Geologic Sediments , Kaolin , Kaolin/chemistry , Clay/chemistry , Geologic Sediments/chemistry , Geologic Sediments/analysis , Sand/chemistry , Aluminum Silicates/chemistry , Salinity , Iron/chemistry , Ferrous Compounds/chemistry , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry
6.
Environ Res ; 260: 119604, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39002636

ABSTRACT

Fluoride pollution and water scarcity are urgent issues. Reducing fluoride concentration in water is crucial. Kaolinite has been used to study adsorption and fluoride removal in water and to characterize material properties. The experimental results showed that the adsorption capacity of kaolinite decreased with increasing pH. The highest adsorption of fluoride occurred at pH 2, with a capacity of 11.1 mg/g. The fluoride removal efficiency remained high after four regeneration cycles. The fitting results with the Freundlich isotherm model and the external diffusion model showed that the non-homogeneous adsorption of kaolinite fit the adsorption behavior better. Finally, the adsorption mechanism was analyzed by FT-IR and XPS. The binding energies of various adsorption sites and the chemical adsorption properties of atomic states were discussed in relation to DFT calculations. The results showed that Al and H sites were the main binding sites, and the bonding stability for different forms of fluoride varies, with the size of Al-F (-7.498 eV) > H-F (-6.04 eV) > H-HF (-3.439 eV) > Al-HF (-3.283 eV). Furthermore, the density of states and Mulliken charge distribution revealed that the 2p orbital of F was found to be active in the adsorption process and was the main orbital for charge transfer.


Subject(s)
Fluorides , Kaolin , Wastewater , Water Pollutants, Chemical , Fluorides/chemistry , Fluorides/analysis , Kaolin/chemistry , Wastewater/chemistry , Adsorption , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/analysis , Metallurgy , Density Functional Theory , Waste Disposal, Fluid/methods , Water Purification/methods , Hydrogen-Ion Concentration
7.
Environ Res ; 252(Pt 4): 119085, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38719067

ABSTRACT

Electrokinetic-Permeable Reaction Barrier (EK-PRB) coupled remediation technology can effectively treat heavy metal-contaminated soil near coal mines. This study was conducted on cadmium (Cd), a widely present element in the soil of the mining area. To investigate the impact of the voltage gradient on the remediation effect of EK-PRB, the changes in current, power consumption, pH, and Cd concentration content during the macroscopic experiment were analyzed. A three-dimensional visualized kaolinite-heavy metal-water simulation system was constructed and combined with the Molecular Dynamics (MD) simulations to elucidate the migration mechanism and binding active sites of Cd on the kaolinite (001) crystalline surface at the microscopic scale. The results showed that the voltage gradient positively correlates with the current, power consumption, and Cd concentration during EK-PRB remediation, and the average removal efficiency increases non-linearly with increasing voltage gradient. Considering power consumption, average removal efficiency, and cost-effectiveness, the voltage range is between 1.5 and 3.0 V/cm, with 2.5 V/cm being the optimal value. The results of MD simulations and experiments correspond to each other. Cd2+ formed a highly stable adsorption structure in contrast to the Al-O sheet on the kaolinite (001) crystalline surface. The mean square displacement (MSD) curve of Cd2+ under the electric field exhibits anisotropy, the total diffusion coefficient DTotal increases and the Cd2+ migration rate accelerates. The electric field influences the microstructure of Cd2+ complexes. With the enhancement of the voltage gradient, the complexation between Cd2+ and water molecules is enhanced, and the interaction between Cd2+ and Cl- in solution is weakened.


Subject(s)
Cadmium , Environmental Restoration and Remediation , Molecular Dynamics Simulation , Cadmium/chemistry , Environmental Restoration and Remediation/methods , Soil Pollutants/chemistry , Kaolin/chemistry
8.
BMC Pregnancy Childbirth ; 24(1): 39, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-38182997

ABSTRACT

BACKGROUND: Anaemia during pregnancy causes adverse outcomes to the woman and the foetus, including anaemic heart failure, prematurity, and intrauterine growth restriction. Iron deficiency anaemia (IDA) is the leading cause of anaemia and oral iron supplementation during pregnancy is widely recommended. However, little focus is directed to dietary intake. This study estimates the contribution of IDA among pregnant women and examines its risk factors (including dietary) in those with moderate or severe IDA in Lagos and Kano states, Nigeria. METHODS: In this cross-sectional study, 11,582 women were screened for anaemia at 20-32 weeks gestation. The 872 who had moderate or severe anaemia (haemoglobin concentration < 10 g/dL) were included in this study. Iron deficiency was defined as serum ferritin level < 30 ng/mL. We described the sociodemographic and obstetric characteristics of the sample and their self-report of consumption of common food items. We conducted bivariate and multivariable logistic regression analysis to identify risk factors associated with IDA. RESULTS: Iron deficiency was observed among 41% (95%CI: 38 - 45) of women with moderate or severe anaemia and the prevalence increased with gestational age. The odds for IDA reduces from aOR: 0.36 (95%CI: 0.13 - 0.98) among pregnant women who consume green leafy vegetables every 2-3 weeks, to 0.26 (95%CI: 0.09 - 0.73) among daily consumers, compared to those who do not eat it. Daily consumption of edible kaolin clay was associated with increased odds of having IDA compared to non-consumption, aOR 9.13 (95%CI: 3.27 - 25.48). Consumption of soybeans three to four times a week was associated with higher odds of IDA compared to non-consumption, aOR: 1.78 (95%CI: 1.12 - 2.82). CONCLUSION: About 4 in 10 women with moderate or severe anaemia during pregnancy had IDA. Our study provides evidence for the protective effect of green leafy vegetables against IDA while self-reported consumption of edible kaolin clay and soybeans appeared to increase the odds of having IDA during pregnancy. Health education on diet during pregnancy needs to be strengthened since this could potentially increase awareness and change behaviours that could reduce IDA among pregnant women with moderate or severe anaemia in Nigeria and other countries.


Subject(s)
Anemia , Iron Deficiencies , Pregnancy , Female , Humans , Cross-Sectional Studies , Nigeria/epidemiology , Pregnant Women , Prevalence , Clay , Kaolin , Iron , Anemia/epidemiology , Risk Factors
9.
J Water Health ; 22(9): 1704-1724, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39340383

ABSTRACT

The adsorption of trihalomethanes (THMs) from drinking water was investigated in the current study through comparison studies of kaolinite and ZnO@kaolinite nanocomposites. The clay structural network's successful immobilization on the zincite hexagonal structure of ZnO nanoparticles' lattice layers was verified by the SEM/EDX analysis. Under the optimum conditions, the maximum removal of THMs was achieved by kaolinite and ZnO@kaolinite nanocomposites after 60 min. The adsorption performance of the ZnO@kaolinite nanocomposites was greater than that of kaolinite because the former had a larger surface area than the latter. The Freundlich isotherm model best matched the adsorption experimental data, which also reveals the existence of multilayer adsorption on a diverse surface with the greatest correlation (R2 = 0.956 and 0.954, respectively) for both nanoadsorbents using the pseudo-first-order (PFO), pseudo-second-order (PSO), mixed 1, 2-order (MFSO), and intraparticle diffusion (IPD) models. The mechanism by which THMs in drinking water adsorb onto nanoadsorbents was examined. This revealed that both intraparticle and film diffusion were involved in the adsorption process. Kaolinite and ZnO@kaolinite nanocomposites can be used in water treatment to remove THMs due to their great recyclable and reusable properties, even after six cycles.


Subject(s)
Kaolin , Nanocomposites , Trihalomethanes , Water Pollutants, Chemical , Water Purification , Zinc Oxide , Zinc Oxide/chemistry , Kaolin/chemistry , Water Purification/methods , Water Pollutants, Chemical/chemistry , Adsorption , Trihalomethanes/chemistry , Nanocomposites/chemistry , Drinking Water/chemistry , Models, Chemical , Kinetics
10.
Childs Nerv Syst ; 40(5): 1533-1539, 2024 May.
Article in English | MEDLINE | ID: mdl-38194082

ABSTRACT

PURPOSE: Hydrocephalus is a brain disease prevalent in the pediatric population that presents complex pathophysiology and multiple etiologies. The best treatment is still ventricular shunting. Mechanical obstruction is the most frequent complication, but the resulting pathological effects are still unknown. OBJECTIVE: Evaluation and comparison of clinical, histopathological, and immunohistochemical aspects in the acute phase of experimental hydrocephalus induced by kaolin, after treatment with adapted shunt, and after shunt obstruction and posterior disobstruction. METHODS: Wistar rats aged 7 days were used and divided into 4 groups: control group without kaolin injection (n = 6), untreated hydrocephalic group (n = 5), hydrocephalic group treated with ventriculosubcutaneous shunt (DVSC) (n = 7), and hydrocephalic group treated with shunt, posteriorly obstructed and disobstructed (n = 5). The animals were submitted to memory and spatial learning evaluation through the Morris water maze test. The rats were sacrificed at 28 days of age and histological analysis of the brains was performed with luxol fast blue, in addition to immunohistochemical analysis in order to evaluate reactive astrocytosis, inflammation, neuronal labeling, and apoptotic activity. RESULTS: The group with shunt obstruction had worse performance in memory tests. Reactive astrocytosis was more evident in this group, as was the inflammatory response. CONCLUSIONS: Obstruction of the shunt results in impaired performance of behavioral tests and causes irreversible histopathological changes when compared to findings in the group with treated hydrocephalus, even after unblocking the system. The developed model is feasible and efficient in simulating the clinical context of shunt dysfunction.


Subject(s)
Hydrocephalus , Kaolin , Child , Humans , Rats , Animals , Rats, Wistar , Gliosis/pathology , Hydrocephalus/surgery , Brain/pathology
11.
Ecotoxicol Environ Saf ; 280: 116533, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38850697

ABSTRACT

The widespread utilization of plastic products ineluctably leads to the ubiquity of nanoplastics (NPs), causing potential risks for aquatic environments. Interactions of NPs with mineral surfaces may affect NPs transport, fate and ecotoxicity. This study aims to investigate systematically the deposition and aggregation behaviors of carboxylated polystyrene nanoplastics (COOH-PSNPs) by four types of clay minerals (illite, kaolinite, Na-montmorillonite, and Ca-montmorillonite) under various solution chemistry conditions (pH, temperature, ionic strength and type). Results demonstrate that the deposition process was dominated by electrostatic interactions. Divalent cations (i.e., Ca2+, Mg2+, Cd2+, or Pb2+) were more efficient for screening surface negative charges and compressing the electrical double layer (EDL). Hence, there were significant increases in deposition rates of COOH-PSNPs with clay minerals in suspension containing divalent cations, whereas only slight increases in deposition rates of COOH-PSNPs were observed in monovalent cations (Na+, K+). Negligible deposition occurred in the presence of anions (F-, Cl-, NO3-, CO32-, SO42-, or PO43-). Divalent Ca2+ could incrementally facilitate the deposition of COOH-PSNPs through Ca2+-assisted bridging with increasing CaCl2 concentrations (0-100 mM). The weakened deposition of COOH-PSNPs with increasing pH (2.0-10.0) was primarily attributed to the reduce in positive charge density at the edges of clay minerals. In suspensions containing 2 mM CaCl2, increased Na+ ionic strength (0-100 mM) and temperature (15-55 ◦C) also favored the deposition of COOH-PSNPs. The ability of COOH-PSNPs deposited by four types of clay minerals followed the sequence of kaolinite > Na-montmorillonite > Ca-montmorillonite > illite, which was related to their structural and surface charge properties. This study revealed the deposition behaviors and mechanisms between NPs and clay minerals under environmentally representative conditions, which provided novel insights into the transport and fate of NPs in natural aquatic environments.


Subject(s)
Calcium , Clay , Water Pollutants, Chemical , Clay/chemistry , Calcium/chemistry , Calcium/analysis , Water Pollutants, Chemical/chemistry , Osmolar Concentration , Hydrogen-Ion Concentration , Aluminum Silicates/chemistry , Polystyrenes/chemistry , Temperature , Minerals/chemistry , Bentonite/chemistry , Nanoparticles/chemistry , Kaolin/chemistry , Static Electricity
12.
Nano Lett ; 23(17): 8013-8021, 2023 09 13.
Article in English | MEDLINE | ID: mdl-37615624

ABSTRACT

The rapid proliferative biological behavior of primary foci of anaplastic thyroid cancer (ATC) makes it a lethal tumor. According to the specific iodine uptake capacity of thyroid cells and enhanced endocytosis of ATC cells, we designed a kind of nanoclay drug-loading system and showed a promising treatment strategy for ATC. Introducing potassium iodide (KI) improves the homoaggregation of clay nanoparticles and then affects the distribution of nanoparticles in vivo, which makes KI@DOX-KaolinMeOH enriched almost exclusively in thyroid tissue. Simultaneously, the improvement of dispersibility of KI@DOX-KaolinMeOH changes the target uptake of ATC cells by improving the endocytosis and nanoparticle-induced autophagy, which regulate the production of autolysosomes and autophagy-enhanced chemotherapy, eventually contributing to a tumor inhibition rate of more than 90% in the primary foci of ATC. Therefore, this facile strategy to improve the homoaggregation of nanoclay by introducing KI has the potential to become an advanced drug delivery vehicle in ATC treatment.


Subject(s)
Thyroid Carcinoma, Anaplastic , Thyroid Neoplasms , Humans , Thyroid Carcinoma, Anaplastic/drug therapy , Potassium Iodide/pharmacology , Potassium Iodide/therapeutic use , Kaolin , Endocytosis , Drug Delivery Systems , Thyroid Neoplasms/drug therapy
13.
Int J Mol Sci ; 25(4)2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38396728

ABSTRACT

Chronic Obstructive Pulmonary Disease (COPD) exacerbation is known for its substantial impact on morbidity and mortality among affected patients, creating a significant healthcare burden worldwide. Coagulation abnormalities have emerged as potential contributors to exacerbation pathogenesis, raising concerns about increased thrombotic events during exacerbation. The aim of this study was to explore the differences in thrombelastography (TEG) parameters and coagulation markers in COPD patients during admission with exacerbation and at a follow-up after discharge. This was a multi-center cohort study. COPD patients were enrolled within 72 h of hospitalization. The baseline assessments were Kaolin-TEG and blood samples. Statistical analysis involved using descriptive statistics; the main analysis was a paired t-test comparing coagulation parameters between exacerbation and follow-up. One hundred patients participated, 66% of whom were female, with a median age of 78.5 years and comorbidities including atrial fibrillation (18%) and essential arterial hypertension (45%), and sixty-five individuals completed a follow-up after discharge. No significant variations were observed in Kaolin-TEG or conventional coagulation markers between exacerbation and follow-up. The Activated Partial Thromboplastin Clotting Time (APTT) results were near-significant, with p = 0.08. In conclusion, TEG parameters displayed no significant alterations between exacerbation and follow-up.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Thrombelastography , Humans , Female , Aged , Male , Thrombelastography/methods , Cohort Studies , Prospective Studies , Kaolin
14.
J Environ Manage ; 355: 120506, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38447514

ABSTRACT

Plenty of heavy metals (HMs) that are adsorbed on clay minerals (such as kaolinite), in addition to low molecular-weight organic acids (such as oxalic acid (OA)) with high activities, are widespread in the natural environment. In the present study, the effects of OA on the environmental behaviors of Pb2+/Cd2+ adsorbed by kaolinite have been investigated. The effectiveness and mechanisms of calcium silicate (CS) and magnesium silicate (MS) in reducing the environmental risks of the HMs have also been studied. The results showed that the releases of Pb2+/Cd2+ increased with an increasing concentration of OA. When different dosages of CS/MS were added to the aging system, a redistribution of HMs took place and the free form of Pb2+/Cd2+ decreased to very low levels. Also, the unextractable Pb2+/Cd2+ increased to high levels. Furthermore, a series of characterizations showed that the released HMs were re-captured by the CS/MS. In addition, the CS immobilized the OA in the solution during the aging process, which also facilitated an immobilization of the carbon element in the environment. In general, the present study has contributed to a further understanding of the transport behaviors of the HMs in natural environments, and of the interactions between CS (or MS), the environmental media, and the heavy metal contaminants. In addition, this study has also provided an eco-friendly strategy for an effective remediation of heavy metal pollution.


Subject(s)
Metals, Heavy , Soil Pollutants , Kaolin , Cadmium , Lead , Metals, Heavy/analysis , Environmental Pollution , Soil Pollutants/analysis , Soil
15.
J Environ Manage ; 360: 121086, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38733841

ABSTRACT

This research focuses on the synthesis and application of a novel kaolin-supported g-C3N4/MoO3 nanocomposite for the degradation of tetracycline, an important antibiotic contaminant in water systems. The nanocomposite was prepared through a facile and environmentally friendly approach, leveraging the adsorption and photocatalytic properties of kaolin, g-C3N4 and MoO3 nanoparticles, respectively. Comprehensive characterization of the nanocomposite was conducted using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and optical spectra. The surface parameters were studied using N2 adsorption-desorption isotherm. The elemental composition was studied using X-ray photoelectron spectroscopy. The efficiency of the developed nanocomposite in tetracycline degradation was evaluated and the results revealed an efficient tetracycline degradation exhibiting the synergistic effects of adsorption and photocatalytic degradation in the removal process. The tetracycline degradation was achieved in 60 min. Kinetic studies and thermodynamic analyses provided insights into the degradation mechanism, suggesting potential applications for the nanocomposite in wastewater treatment. Additionally, the recyclability and stability of the nanocomposite were investigated, demonstrating its potential for sustainable and long-term application in water treatment.


Subject(s)
Kaolin , Nanocomposites , Tetracycline , Water Pollutants, Chemical , Water Purification , Tetracycline/chemistry , Nanocomposites/chemistry , Adsorption , Water Purification/methods , Kaolin/chemistry , Water Pollutants, Chemical/chemistry , Catalysis , Wastewater/chemistry , X-Ray Diffraction , Kinetics , Spectroscopy, Fourier Transform Infrared
16.
Molecules ; 29(10)2024 May 08.
Article in English | MEDLINE | ID: mdl-38792071

ABSTRACT

Every year, new compounds contained in consumer products, such as detergents, paints, products for personal hygiene, and drugs for human and veterinary use, are identified in wastewater and are added to the list of molecules that need monitoring. These compounds are indicated with the term emerging contaminants (or Contaminants of Emerging Concern, CECs) since they are potentially dangerous for the environment and human health. To date, among the most widely used methodologies for the removal of CECs from the aquatic environment, adsorption processes play a role of primary importance, as they have proven to be characterized by high removal efficiency, low operating and management costs, and an absence of undesirable by-products. In this paper, the adsorption of ibuprofen (IBU), a nonsteroidal anti-inflammatory drug widely used for treating inflammation or pain, was performed for the first time using two different types of geopolymer-based materials, i.e., a metakaolin-based (GMK) and an organic-inorganic hybrid (GMK-S) geopolymer. The proposed adsorbing matrices are characterized by a low environmental footprint and have been easily obtained as powders or as highly porous filters by direct foaming operated directly into the adsorption column. Preliminary results demonstrated that these materials can be effectively used for the removal of ibuprofen from contaminated water (showing a concentration decrease of IBU up to about 29% in batch, while an IBU removal percentage of about 90% has been reached in continuous), thus suggesting their potential practical application.


Subject(s)
Ibuprofen , Water Pollutants, Chemical , Water Purification , Ibuprofen/chemistry , Ibuprofen/isolation & purification , Water Pollutants, Chemical/isolation & purification , Water Pollutants, Chemical/chemistry , Adsorption , Water Purification/methods , Polymers/chemistry , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/isolation & purification , Wastewater/chemistry , Kaolin/chemistry
17.
Environ Geochem Health ; 46(10): 373, 2024 Aug 21.
Article in English | MEDLINE | ID: mdl-39167340

ABSTRACT

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 820.26 mg/L. Following the remediation process under optimal experimental conditions, the concentration was significantly reduced to 11.6 mg/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 0.05 mg/L, which is below the EPA's Safe Drinking Water Act standard for Cr(VI) content of 0.1 mg/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).


Subject(s)
Acetic Acid , Chromium , Electrodes , Environmental Restoration and Remediation , Iron , Kaolin , Soil Pollutants , Chromium/chemistry , Environmental Restoration and Remediation/methods , Kaolin/chemistry , Soil Pollutants/chemistry , Acetic Acid/chemistry , Iron/chemistry , Electrolytes/chemistry
18.
J Environ Sci (China) ; 139: 193-205, 2024 May.
Article in English | MEDLINE | ID: mdl-38105047

ABSTRACT

A series of novel chitosan-based magnetic flocculants FS@CTS-P(AM-DMC) was prepared by molecular structure control. The characterization results showed that FS@CTS-P(AM-DMC) had a uniform size of about 21.46 nm, featuring a typical core-shell structure, and the average coating layer thickness of CTS-P(AM-DMC) was about 5.03 nm. FS@CTS-P(AM-DMC) exhibited excellent flocculation performance for kaolin suspension, achieved 92.54% turbidity removal efficiency under dosage of 150 mg/L, pH 7.0, even at high turbidity (2000 NTU) with a removal efficiency of 96.96%. The flocculation mechanism was revealed to be dominated by charge neutralization under acidic and neutral conditions, while adsorption and bridging effects play an important role in alkaline environments. The properties of magnetic aggregates during flocculation, breakage, and regeneration were studied at different pH levels and dosages. In the process of magnetophoretic, magnetic particles collide and adsorb with kaolin particles continuously due to magnetic and electrostatic attraction, transform into magnetic chain clusters, and then further form three-dimensional network magnetic aggregates that can capture free kaolin particles and other chain clusters. Particle image velocimetry confirmed the formation of eddy current of magnetic flocs and experienced three stages: acceleration, stabilization, and deceleration.


Subject(s)
Chitosan , Water Purification , Chitosan/chemistry , Kaolin/chemistry , Flocculation , Magnetic Phenomena , Water Purification/methods
19.
Small ; 19(34): e2300842, 2023 08.
Article in English | MEDLINE | ID: mdl-37093210

ABSTRACT

Cancer is one of the deadliest diseases, and current treatment regimens suffer from limited efficacy, nonspecific toxicity, and chemoresistance. With the advantages of good biocompatibility, large specific surface area, excellent cation exchange capacity, and easy availability, clay minerals have been receiving ever-increasing interests in cancer treatment. They can act as carriers to reduce the toxic side effects of chemotherapeutic drugs, and some of their own properties can kill cancer cells, etc. Compared with other morphologies clays, layered clay minerals (LCM) have attracted more and more attention due to adjustable interlayer spacing, easier ion exchange, and stronger adsorption capacity. In this review, the structure, classification, physicochemical properties, and functionalization methods of LCM are summarized. The state-of-the-art progress of LCM in antitumor therapy is systematically described, with emphasis on the application of montmorillonite, kaolinite, and vermiculite. Furthermore, the property-function relationships of LCM are comprehensively illustrated to reveal the design principles of clay-based antitumor systems. Finally, foreseeable challenges and outlook in this field are discussed.


Subject(s)
Aluminum Silicates , Neoplasms , Clay/chemistry , Aluminum Silicates/chemistry , Minerals/chemistry , Kaolin/chemistry , Bentonite/chemistry , Adsorption , Neoplasms/drug therapy
20.
Physiol Plant ; 175(1): e13844, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36539940

ABSTRACT

High irradiance and increased air temperature during extreme weather conditions affect tree crops and impact the yield and quality of fruits. Moreover, flowering and fruit set of Citrus are likely impaired by UV radiation and/or reduced carbon assimilation, which increase reactive oxygen species production and damage the leaf photosynthetic apparatus. Particle coating films sprayed on leaves have been offered as a way to minimize crop losses due to the climate change scenario, even though the extent of leaf protection is not characterized. We evaluated the use of two protective films on the oxidative stress and leaf photosynthesis of sweet orange trees exposed to varying daylight levels. Trees were maintained under full sun light, sprayed or not (control) with kaolin or calcium carbonate, and under reduced irradiance using either aluminum shade cloth 50% or anti-UV transparent plastic. Kaolin or calcium carbonate reflected 20%-30% of the incident light on the leaf surface compared to leaves not sprayed and under full sunlight. Leaves with coating exhibited improved CO2 assimilation and photosystem II efficiency, and lower leaf temperatures over time. In addition, the coating protected leaves against excess irradiance due to dissipation of excess energy into the photosynthetic apparatus (NPQt). Nonenzymatic mechanisms for UV protection, such as carotenoids, were higher in full sun control plants than in leaf-coated plants. Comparable responses were observed on trees maintained covered either by the cloth or the plastic film. Finally, we conclude that the use of suspension particles mitigates the harmful effects of excess UV irradiance and temperature in sweet orange trees.


Subject(s)
Citrus , Trees , Trees/physiology , Temperature , Kaolin/pharmacology , Photosynthesis/radiation effects , Plant Leaves/physiology
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