Adsorption and Photocatalytic Degradation of Pesticides into Nanocomposites: A Review

Co3O4/CuO@C catalyst based on cobalt-doped HKUST-1 as an efficient peroxymonosulfate activator for pendimethalin degradation: Catalysis and mechanism

Pendimethalin (PM) is an organic pollutant (herbicide), and systematic studies on PM degradation are scarce. The efficient degradation of PM in water remains a challenge that requires to be addressed. Herein, for the first time, elemental Co was doped into HKUST-1 using a solvothermal method to generate Co3O4/CuO@C via pyrolysis. The as-prepared catalyst was used to activate peroxymonosulfate (PMS) for PM degradation, obtaining a PM degradation efficiency of 98.2 % after 30 min. The assessment of the effects of various factors on the degradation efficiency revealed that 1O2 dominated PM degradation, whereas the contribution of SO4•- was negligible. Although 3Co3O4/CuO@C exhibited a good degradation performance against other organic pollutants, its degradation performance in real water was poor. The carbon layer reduced metal-ion leaching (Co and Cu), and the synergistic interactions between Co3O4 and CuO promoted PMS activation. The roles of the components of 3Co3O4/CuO@C in PM degradation by activated PMS were investigated in the presence of CoIV and Co-OOSO3-. Two possible PM degradation pathways were systematically proposed, and the toxicity of the intermediates was analyzed. Finally, a mechanism for PM degradation by 3Co3O4/CuO@C-activated PMS was proposed.

Synergetic studies on the thermochemical activation and polyaniline integration on the adsorption properties of natural coal for chlorpyrifos pesticide: steric and energetic studies

Three types of synthetic coal-derived adsorbents were characterized as potential enhanced structurers during the removal of chlorpyrifos pesticide. The raw coal (CA) was activated into porous graphitic carbon (AC), and both CA and AC were blended with polyaniline polymers (PANI/CA and PANI/AC) forming two advanced composites. The adsorption performances of the modified structures in comparison with CA were evaluated based on both the steric and energetic parameters of the applied advanced isotherm model (the monolayer model of one energy). The uptake performances reflected higher capacities for the PANI hybridized form (235.8 mg/g (PANI/CA) and 309.75 mg/g (PANI/AC) as compared to AC (156.9 mg/g) and raw coal (135.8 mg/g). This signifies the impact of activation step and PANI blending on the surface and textural properties of coal. The steric investigation determined the saturation of the coal surface with extra active sites after the activation step (Nm(AC) = 62.05 mg/g) and the PANI integration (Nm(PANI/CA) = 113.5 mg/g and Nm(PANI/AC) = 169.7 mg/g) as compared to raw coal (Nm(CA) = 39.6 mg/g). This illustrated the reported uptake efficiencies of the modified samples, which can be attributed to the enhancement in the surface area and the incorporation of additional chemical groups. The results also reflect that each site can be loaded with 3-4 molecules of chlorpyrifos, which are arranged vertically and adsorbed by multi-molecular mechanisms. The energetic studies (< 40 kJ/mol) suggested the physical uptake of pesticide molecules by dipole bonding and hydrogen bonding processes. The thermodynamic functions donate the exothermic properties of 47reactions that occur spontaneously.

Efficient removal of organophosphate insecticide employing magnetic chitosan-derivatives

Herein, this work reports an efficient acephate adsorption using chitosan (CS) incorporating varying amounts of magnetite. A co-precipitation methodology was employed for the functionalization of chitosan with iron nanoparticles, using Fe2+ as the sole iron source and with a low energy requirement. The adsorbents were characterized by FTIR, XRD, VSM, and nitrogen porosimetry techniques. The CS∙Fe3O4 1:1 NPs showed the highest acephate removal percentage (74.96 %) at pH 9 and ambient temperatures. The adsorption process exhibited high dependencies on pH, adsorbent dosage, initial concentration of adsorbate, and ionic strength. Sips and pseudo-second-order kinetics models best adjusted the experimental data, suggesting that the process occurs on a heterogeneous surface. Thermodynamic evaluation showed that the adsorption was exothermic, favorable, and predominately through chemical interactions. Finally, the CS∙Fe3O4 showed no significant decrease after several cycles of adsorption/desorption, avoiding centrifugation-filtration steps.

Steric and energetic studies on the influence of cellulose on the adsorption effectiveness of Mg trapped hydroxyapatite for enhanced remediation of chlorpyrifos and omethoate pesticides

Magnesium-trapped hydroxyapatite (Mg.HP) was hybridized with cellulose fiber to produce a bio-composite (CLF/HP) with enhanced adsorption affinities for two types of toxic pesticides (chlorpyrifos (CF) and omethoate (OM)). The enhancement influence of the hybridized cellulose on the adsorption performances of Mg.HP was illustrated based on the determined steric and energetic factors. The computed CF and OM adsorption performances of CLF/HP during the saturation phases are 279.8 mg/g and 317.9 mg/g, respectively, which are significantly higher than the determined values using Mg/HP (143.4 mg/g (CF) and 145.3 mg/g (OM)). The steric analysis demonstrates a strong impact of the hybridization process on the reactivity of the surface of the composite. While CLF/HP reflects effective uptake site densities (Nm) of 93.3 mg/g (CF) and 135.3 mg/g (OM), the estimated values for Mg.HP are 51.2 mg/g (CF) and 46.11 mg/g (OM), which explain the reported enhancement in the adsorption performances of the composite. The capacity of each uptake site to be occupied with more than one molecule (n (CF) = 3-3.74 and n (OM) = 2.35-3.54) suggests multimolecular uptake. The energetic factors suggested physical mechanistic processes of spontaneous and exothermic behaviors either during the uptake of CF or OM.

An Updated Overview of Magnetic Composites for Water Decontamination

Water contamination by harmful organic and inorganic compounds seriously burdens human health and aquatic life. A series of conventional water purification methods can be employed, yet they come with certain disadvantages, including resulting sludge or solid waste, incomplete treatment process, and high costs. To overcome these limitations, attention has been drawn to nanotechnology for fabricating better-performing adsorbents for contaminant removal. In particular, magnetic nanostructures hold promise for water decontamination applications, benefiting from easy removal from aqueous solutions. In this respect, numerous researchers worldwide have reported incorporating magnetic particles into many composite materials. Therefore, this review aims to present the newest advancements in the field of magnetic composites for water decontamination, describing the appealing properties of a series of base materials and including the results of the most recent studies. In more detail, carbon-, polymer-, hydrogel-, aerogel-, silica-, clay-, biochar-, metal-organic framework-, and covalent organic framework-based magnetic composites are overviewed, which have displayed promising adsorption capacity for industrial pollutants.

Bio-based matrix photocatalysts for photodegradation of antibiotics

Antibiotics development during the last century permitted unprecedent medical advances. However, it is undeniable that there has been an abuse and misuse of antimicrobials in medicine and cosmetics, food production and food processing, in the last decades. The pay toll for human development and consumism is the emergence of extended antimicrobial resistance and omnipresent contamination of the biosphere. The One Health concept recognizes the interconnection of human, environmental and animal health, being impossible alter one without affecting the others. In this context, antibiotic decontamination from water-sources is of upmost importance, with new and more efficient strategies needed. In this framework, light-driven antibiotic degradation has gained interest in the last few years, strongly relying in semiconductor photocatalysts. To improve the semiconductor properties (i.e., efficiency, recovery, bandgap width, dispersibility, wavelength excitation, etc.), bio-based supporting material as photocatalysts matrices have been thoroughly studied, exploring synergetic effects as operating parameters that could improve the photodegradation of antibiotics. The present work describes some of the most relevant advances of the last 5 years on photodegradation of antibiotics and other antimicrobial molecules. It presents the conjugation of semiconductor photocatalysts to different organic scaffolds (biochar and biopolymers), then to describe hybrid systems based on g-C3N4 and finally addressing the emerging use of organic photocatalysts. These systems were developed for the degradation of several antibiotics and antimicrobials, and tested under different conditions, which are analyzed and thoroughly discussed along the work.

An investigation of Ca-doped MgO nanoparticles for the improved catalytic degradation of thiamethoxam pesticide subjected to visible light irradiation

The remediation of pesticides from the environment is one of the most important technology nowadays. Herein, magnesium oxide (MgO) nanoparticles and calcium-doped magnesium oxide (Ca-doped MgO) nanoparticles were synthesized by the co-precipitation method and were used for the degradation of thiamethoxam pesticide in aqueous media. Characterization of the MgO and Ca-doped MgO nanoparticles were performed by XRD, SEM, EDX, and FT-IR analysis to verify the synthesis and variations in chemical composition. The band gap energy and crystalline size of MgO and Ca-doped MgO nanoparticles were found to be 4.8 and 4.7 eV and 33 and 34 nm respectively. The degradation of thiamethoxam was accomplished regarding the impact of catalyst dosage, contact time, temperature, pH, and initial pesticide concentration. The pH study indicates that degradation of thiamethoxam depends on pH and maximum degradation (66%) was obtained at pH 5 using MgO nanoparticles. In contrast, maximum degradation (80%) of thiamethoxam was observed at pH 8 employing Ca-doped MgO nanoparticles. The percentage degradation of thiamethoxam was initially increasing but decreased at higher doses of the catalysts. The degradation of the pesticide was observed to be increased with an increase in contact time while high at room temperature but decreased with a temperature rise. The effect of the initial concertation of pesticide indicates that degradation of pesticide increases at low concentrations but declines at higher concentrations. This research study reveals that doping of MgO nanoparticles with calcium enhanced the degradation of thiamethoxam pesticide in aqueous media.

Prospects for application of microorganisms in bioremediation of soils contaminated with pesticides

The contamination of soil with residual amounts of pesticides remains an urgent challenge for human community. The most efficient approach to address this challenge is the direct microbial degradation of a pesticide in agricultural lands. To this end, the selected microorganisms, which quickly and completely utilize pesticides, are employed. In the present work, two herbicides belonging to different classes of chemical compounds, that is, imazamox and chlorsulfuron were used. The screening of promising microorganisms was carried out among different strains of bacteria and fungi in a liquid mineral medium containing a pesticide as the only source of carbon. It was found that the most active microorganisms were capable of utilizing up to 90% of the active substance for a short time. The dynamics of pesticides degradation indicated that the maximum destruction of the studied substances occurred during the first two weeks of cultivation. Further, the rate of degradation dramatically dropped or stopped at all. An increase in the concentration of pesticides in the cultivation medium almost completely suppressed their degradation. It is interesting that the bacteria were more suitable for the degradation of imazamox, while the fungi rendered the destruction of chlorsulfuron.

Removal of organic pollutants through hydroxyl radical-based advanced oxidation processes

The use of Advance Oxidation Process (AOPs) has been extensively examined in order to eradicate organic pollutants. This review assesses the efficacy of photolysis, O3 based (O3/UV, O3/H2O2, O3/H2O2/UV, H2O2/UV, Fenton, Fenton-like, hetero-system) and sonochemical and electro-oxidative AOPs in this regard. The main purpose of this review and some suggestions for the advancement of AOPs is to facilitate the elimination of toxic organic pollutants. Initially proposed for the purification of drinking water in 1980, AOPs have since been employed for various wastewater treatments. AOPs technologies are essentially a process intensification through the use of hybrid methods for wastewater treatment, which generate large amounts of hydroxyl (•OH) and sulfate (SO4·-) radicals, the ultimate oxidants for the remediation of organic pollutants. This review covers the use of AOPs and ozone or UV treatment in combination to create a powerful method of wastewater treatment. This novel approach has been demonstrated to be highly effective, with the acceleration of the oxidation process through Fenton reaction and photocatalytic oxidation technologies. It is clear that Advance Oxidation Process are a helpful for the degradation of organic toxic compounds. Additionally, other processes such as •OH and SO4·- radical-based oxidation may also arise during AOPs treatment and contribute to the reduction of target organic pollutants. This review summarizes the current development of AOPs treatment of wastewater organic pollutants.

An Overview of Renal Cell Carcinoma Hallmarks, Drug Resistance, and Adjuvant Therapies

Renal neoplasms are highlighted as one of the 10 most common types of cancer. Renal cell carcinoma (RCC) is the most common type of renal cancer, considered the seventh most common type of cancer in the Western world. The most frequently altered genes described as altered are VHL, PBRM1, SETD2, KDM5C, PTEN, BAP1, mTOR, TP53, TCEB1 (ELOC), SMARCA4, ARID1A, and PIK3CA. RCC therapies can be classified in three groups: monoclonal antibodies, tyrosine kinase inhibitors, and mTOR inhibitors. Besides, there are targeted agents to treat RCC. However, frequently patients present side effects and resistance. Even though many multidrug resistance mechanisms already have been reported to RCC, studies focused on revealing new biomarkers as well as more effective antitumor therapies with no or low side effects are very important. Some studies reported that natural products, such as honey, epigallocatechin-3-gallate (EGCG), curcumin, resveratrol, and englerin A showed antitumor activity against RCC. Moreover, nanoscience is another strategy to improve RCC treatment and reduce the side effects due to the improvement in pharmacokinetics and reduction of toxicities of chemotherapies. Taking this into account, we conducted a systemic review of recent research findings on RCC hallmarks, drug resistance, and adjuvant therapies. In conclusion, a range of studies reported that RCC is characterized by high incidence and increased mortality rates because of the development of resistance to standard therapies. Given the importance of improving RCC treatment and reducing adverse effects, nanoscience and natural products can be included in therapeutic strategies.

Using proteomics, q-PCR and biochemical methods complementing as a multiapproach to elicit the crucial responses of zebrafish liver exposed to neonicotinoid pesticide

Pesticides enter the environment through runoff and leaching and this raises public concern about effects on non-target organisms. Imidacloprid (IMI) a synthetic pesticide, has an unstable half-life, metabolized in minutes to weeks in the water. To evaluate the effects of IMI on the zebrafish liver, we conducted proteomic, molecular and biochemical analysis in a multi-level approach, to highlight the complementary features regarding the results of each method. Adult zebrafish were exposed to 60 mg/L IMI for 48 h and were evaluated using nLC-MS/MS for proteins, q-PCR analysis for expression of cat, gpx, pxr, ache, along with CAT and AChE enzyme activities and GSH and MDA assays. Based on proteomics, the regulation of antioxidant and immune responses, as well as gene transcription were significant processes affected. Apoptosis and ER stress pathways were upregulated and there was a down-regulation of cat and gpx genes. There was also elevated CAT activity and GSH and decreased MDA. Additionally, elevated AChE activity and up regulation of ache expression was observed. The multi-approach results included regulators of antioxidant, xenobiotic response and neuro-protective related proteins (genes and enzymes), which overall reflected harmful effects of IMI. Consequently, this study highlights the effects of IMI on zebrafish liver and reveals new potential biomarkers. In this respect, evaluated outcomes reveal the complementary features emphasizing the importance of studying chemicals using several methods. Our study provides deeper insights for future work in ecotoxicological studies regarding IMI and contribute to existing toxicity literature.

Photocatalytic degradation of imidacloprid using Ag2O/CuO composites

Imidacloprid is one of the most commonly used neonicotinoid pesticides that has been identified as a neurotoxin for various non-target organisms. It binds to the central nervous system of organisms, causing paralysis and eventually death. Thus, it is imperative to treat waterwaters contaminated with imidacloprid using an efficient and cost effective method. The present study presents Ag₂O/CuO composites as excellent catalysts for the photocatalytic degradation of imidacloprid. The Ag₂O/CuO composites were prepared in different compositions by adopting the co-precipitation method and used as a catalyst for the degradation of imidacloprid. The degradation process was monitored using UV-vis spectroscopy. The composition, structure, and morphologies of the composites were determined by FT-IR, XRD, TGA, and SEM analyses. The effect of different parameters i.e time, concentration of pesticide, concentration of catalyst, pH, and temperature on the degradation was studied under UV irradiation and dark conditions. The results of the study evidenced the 92.3% degradation of imidacloprid in only 180 minutes, which was 19.25 hours under natural conditions. The degradation followed first-order kinetics, with the half life of the pesticide being 3.7 hours. Thus, the Ag₂O/CuO composite was an excellent cost-effective catalyst. The non-toxic nature of the material adds further benefits to its use. The stability of the catalyst and its reusability for consecutive cycles make it more cost effective. The use of this material may help to ensure an immidacloprid free environment with minimal use of resources. Moreover, the potential of this material to degrade other environmental pollutants may also be explored.

Meta-analysis of metal nanoparticles degrading pesticides: what parameters are relevant?

The rise in the global population demands an increasing food supply and methods to boost agricultural production. Pesticides are necessary for agricultural production models, avoiding losses of close to 40%. Nevertheless, the extensive use of pesticides can cause their accumulation in the environment, causing problems for human health, biota, and ecosystems. Thus, new technologies have emerged to remove these wastes efficiently. In recent years, metal and metal oxide nanoparticles (MNPs) have been reported as promising catalysts to degrade pesticides; however, a systematic understanding of their effect on pesticide degradation is still required. Therefore, this study focused on a meta-analysis of articles available in Elsevier's Scopus and Thomas Reuters Web of Science, found by searching for "nanoparticle pesticide" and "pesticide contamination." After passing different filters, the meta-analysis was performed with 408 observations from 94 reviews, which comprise insecticides, herbicides, and fungicides, including organophosphates, organochlorines, carbamates, triazines, and neonicotinoids. Herein, 14 different MNPs (Ag, Ni, Pd, Co₃O₄, BiOBr, Au, ZnO, Fe, TiO₂, Cu, WO₃, ZnS, SnO₂, and Fe⁰), improved pesticide degradation, with the highest degradation rates achieved by Ag (85%) and Ni (82.5%). Additionally, the impact of the MNP functionalization, size, and concentration on pesticide degradation was quantified and compared. In general, the degradation rate increased when the MNPs were functionalized (~ 70%) compared to naked (~ 49%). Also, the particle size significantly affected the degradation of pesticides. To our knowledge, this study is the first meta-analysis performed about the impact of MNPs on pesticide degradation, providing an essential scientific basis for future studies.

Metal Oxides Nanoparticles: General Structural Description, Chemical, Physical, and Biological Synthesis Methods, Role in Pesticides and Heavy Metal Removal through Wastewater Treatment

Nanotechnology (NT) is now firmly established in both the private home and commercial markets. Due to its unique properties, NT has been fully applied within multiple sectors like pharmacy and medicine, as well as industries like chemical, electrical, food manufacturing, and military, besides other economic sectors. With the growing demand for environmental resources from an ever-growing world population, NT application is a very advanced new area in the environmental sector and offers several advantages. A novel template synthesis approach is being used for the promising metal oxide nanostructures preparation. Synthesis of template-assisted nanomaterials promotes a greener and more promising protocol compared to traditional synthesis methods such as sol-gel and hydrothermal synthesis, and endows products with desirable properties and applications. It provides a comprehensive general view of current developments in the areas of drinking water treatment, wastewater treatment, agriculture, and remediation. In the field of wastewater treatment, we focus on the adsorption of heavy metals and persistent substances and the improved photocatalytic decomposition of the most common wastewater pollutants. The drinking water treatment section covers enhanced pathogen disinfection and heavy metal removal, point-of-use treatment, and organic removal applications, including the latest advances in pesticide removal.

Efficient Uptake of Angiotensin-Converting Enzyme II Inhibitor Employing Graphene Oxide-Based Magnetic Nanoadsorbents

This paper reports a high efficiency uptake of captopril (CPT), employing magnetic graphene oxide (MGO) as the adsorbent. The graphene oxide (GO) was produced through an oxidation and exfoliation method, and the magnetization technique by the co-precipitation method. The nanomaterials were characterized by FTIR, XRD, SEM, Raman, and VSM analysis. The optimal condition was reached by employing GO·Fe3O4 at pH 3.0 (50 mg of adsorbent and 50 mg L−1 of CPT), presenting values of removal percentage and maximum adsorption capacity of 99.43% and 100.41 mg g−1, respectively. The CPT adsorption was dependent on adsorbent dosage, initial concentration of adsorbate, pH, and ionic strength. Sips and Elovich models showed the best adjustment for experimental data, suggesting that adsorption occurs in a heterogeneous surface. Thermodynamic parameters reveal a favorable, exothermic, involving a chemisorption process. The magnetic carbon nanomaterial exhibited a high efficiency after five adsorption/desorption cycles. Finally, the GO·Fe3O4 showed an excellent performance in CPT removal, allowing future application in waste management.

Biological Applications of Silica-Based Nanoparticles

Silica nanoparticles have been widely explored in biomedical applications, mainly related to drug delivery and cancer treatment. These nanoparticles have excellent properties, high biocompatibility, chemical and thermal stability, and ease of functionalization. Moreover, silica is used to coat magnetic nanoparticles protecting against acid leaching and aggregation as well as increasing cytocompatibility. This review reports the recent advances of silica-based magnetic nanoparticles focusing on drug delivery, drug target systems, and their use in magnetohyperthermia and magnetic resonance imaging. Notwithstanding, the application in other biomedical fields is also reported and discussed. Finally, this work provides an overview of the challenges and perspectives related to the use of silica-based magnetic nanoparticles in the biomedical field.