Adsorptive removal of norfloxacin from aqueous solutions by Fe/Cu CNS-embedded alginate-carboxymethyl cellulose-chitosan beads.

The pervasive application of pharmaceuticals in aquatic environments has acquired much focus owing to their nonbiodegradability and eco-toxicity, which might readily destroy the ecological balance. Developed chitosan-coated Fe-Cu CNS alginate-CMC beads (NBs) were utilized in this study to adsorb the quinolone antibiotic norfloxacin (NOR) from water for the first time. Under ideal conditions (CNOR: 20 mg L-1; sorbent conc.: 2000 mg L-1; sorbent dosage: 0.15 g; interaction time: 300 min; solution pH: 6.0), about 86% NOR removal was achieved through batch mode. The removal performance for NOR was examined concerning pH, ionic strength, and coexisting micropollutants. The greatest NOR removal was attained on NBs with the greatest Langmuir adsorption capacity of 355 mg g-1 due to numerous mechanisms such as sorbent pore filling, electrostatic attraction, π-π attraction and hydrogen bonding. Studies using environmentally significant algae, such as Scenedesmus sp., to analyze the residual toxicity of treated NOR solution revealed a significant reduction in their toxic effects. Current research has demonstrated that nanocomposite beads are an excellent wastewater treatment material with promising industrial applications due to their ease of synthesis, exceptional surface adsorption properties, stability, and environmentally friendly reaction.

Application of green synthesized bimetallic nZVI-Cu nanoparticle as a sustainable alternative to chemical fertilizers to enhance growth and photosynthetic efficiency of rice seedlings.

Application of nanomaterials in agriculture has been extensively explored over the past decade leading to a wide ambit of nanoparticle-based agrochemicals. Metallic nanoparticles consisting of plant macro- and micro-nutrients have been used as nutritional supplements for plants through soil amendments, foliar sprays, or seed treatment. However, most of these studies emphasize monometallic nanoparticles which limit the range of usage and effectivity of such nanoparticles (NPs). Hence, we have employed a bimetallic nanoparticle (BNP) consisting of two different micro-nutrients (Cu & Fe) in rice plants to test its efficacy in terms of growth and photosynthesis. Several experiments were designed to assess growth (root-shoot length, relative water content) and photosynthetic parameters (pigment content, relative expression of rbcS, rbcL & ChlGetc.). To determine whether the treatment induced any oxidative stress or structural anomalies within the plant cells, histochemical staining, anti-oxidant enzyme activities, FTIR, and SEM micrographs were undertaken. Results indicated that foliar application of 5 mg L-1 BNP increased vigor and photosynthetic efficiency whereas 10 mg L-1 concentration induced oxidative stress to some extent. Furthermore, the BNP treatment did not perturb the structural integrity of the exposed plant parts and also did not induce any cytotoxicity. Application of BNPs in agriculture has not been explored extensively to date and this study is one of the first reports that not only documents the effectivity of Cu-Fe BNP but also critically explores the safety of its usage on rice plants making it a useful lead to design new BNPs and explore their efficacy.

Recent Developments in the Applications of GO/rGO-Based Biosensing Platforms for Pesticide Detection.

Pesticides are often used in different applications, including agriculture, forestry, aquaculture, food industry, etc., for the purpose of controlling insect pests and weeds. The indiscriminate usage of pesticides poses a massive threat to food, environmental, and human health safety. Hence, the fabrication of a sensitive and reliable sensor for the detection of pesticide residues in agro products and environmental samples is a critical subject to be considered. Recently, the graphene family including graphene oxide (GO) and reduced graphene oxide (rGO) have been frequently employed in the construction of sensors owing to their biocompatibility, high surface-area-to-volume ratio, and excellent physiochemical, optical, and electrical properties. The integration of biorecognition molecules with GO/rGO nanomaterials offers a promising detection strategy with outstanding repeatability, signal intensity, and low background noise. This review focuses on the latest developments (2018 to 2022) in the different types of GO/rGO-based biosensors, such as surface plasmon resonance (SPR), fluorescence resonance energy transfer (FRET), and electrochemical-based techniques, among other, for pesticide analysis. The critical discussions on the advantages, limitations, and sensing mechanisms of emerging GO/rGO-based biosensors are also highlighted. Additionally, we explore the existing hurdles in GO/rGO-based biosensors, such as handling difficult biological samples, reducing the total cost, and so on. This review also outlines the research gaps and viewpoints for future innovations in GO/rGO-based biosensors for pesticide determination mainly in areas with insufficient resources.

Fe3O4-urea nanocomposites as a novel nitrogen fertilizer for improving nutrient utilization efficiency and reducing environmental pollution.

Almost 81% of nitrogen fertilizers are applied in form of urea but most of it is lost due to volatilization and leaching leading to environmental pollution. In this regard, slow-release nano fertilizers can be an effective solution. Here, we have synthesized different Fe3O4-urea nanocomposites with Fe3O4 NPs: urea ratio (1:1, 1:2, 1:3) ie. NC-1, 2, and 3 respectively, and checked their efficacy for growth and yield enhancement. Oryza sativa L. cv. Swarna seedlings were treated with different NCs for 14 days in hydroponic conditions and significant up-regulation of photosynthetic efficiency and nitrogen metabolism were observed due to increased availability of nitrogen and iron. The discriminant functional analysis confirmed that the NC3 treatment yielded the best results so further gene expression studies were performed for NC-3 treated seedlings. Significant changes in expression profiles of ammonia and nitrate transporters indicated that NC-3 treatment enhanced nitrogen utilization efficiency (NUE) due to sustained slow release of urea. From pot experiments, we found significant enhancement of growth, grain nutrient content, and NUE in NC supplemented sets. 1.45 fold increase in crop yield was achieved when 50% N was supplemented in form of NC-3 and the rest in form of ammonium nitrate. NC supplementation can also play a vital role in minimizing the use of bulk N fertilizers because, when 75% of the recommended N dose was supplied in form of NC-3, 1.18 fold yield enhancement was found. Thus our results highlight that, slow-release NC-3 can play a major role in increasing the NUE of rice.

Nanopriming with zero-valent iron synthesized using pomegranate peel waste: A "green" approach for yield enhancement in Oryza sativa L. cv. Gonindobhog.

Nanopriming is a combination of nanoparticle treatment and a seed dressing technique that can increase seed quality, seedling vigour, yield and also imparts tolerance against biotic and abiotic stress. Here, nano-scale zero-valent iron (G-nZVI) was synthesized using fruit peel waste of Punica granatum L and their formation was validated from XRD and optical spectroscopic techniques. Later, the seeds were primed with G-nZVI at six different concentrations (0, 10, 20, 40, 80, and 160 mg L -1) to determine the dose which is optimum for increasing germination percentage and seedling vigour of rice (Oryza sativa L. cv. Gobindobhog). According to initial results, upon priming seeds with 40-80 mg L -1 G-nZVI highest growth rate was found. The early growth enhancement of seedlings was chiefly attributed to increased ROS generation, higher hydrolytic enzyme activities, and increased iron uptake in germinating seeds upon nanopriming. The effects of nanopriming were carried over to later stages of development. A field experiment was carried out where nanoprimed seeds and traditional hydroprimed control seeds were sown in plots and grown till maturity without the aid of any conventional fertilizers and pesticides and it was found that crop yield and grain nutrient concentrations were higher in nanoprimed sets. Compared to control hydroprimed sets, 1.53 folds higher crop yield was observed upon seed priming with 80 mg L -1 G-nZVI. Thus in the future, G-nZVI can be considered to be a novel low-cost, eco-friendly, food waste-derived seed treatment agent that has immense potential in increasing rice yield.

Iron-pulsing, a novel seed invigoration technique to enhance crop yield in rice: A journey from lab to field aiming towards sustainable agriculture.

Bulk fertilizer application is one of the easiest means of improving yield of crops however it comes with several environmental impediments and consumer health menace. In the wake of this situation, sustainable agricultural practices stand as pertinent agronomic tool to increase yield and ensure sufficient food supply from farm to fork. In the present study, efficacy of iron-pulsing in improving the rice yield has been elucidated. This technique involves seed treatment with different concentrations (2.5, 5 and 10 mM) of iron salts (FeCl3 and FeSO4) during germination. FeCl3 or FeSO4 was used to treat the sets and depending on the concentration of the salts, the sets were named as C2.5, C5, C10 and S2.5, S5, S10 (where C and S stands for FeCl3 and FeSO4 respectively and the numbers succeeding them denotes the concentration of salt in mM). Our investigation identified 72 h of treatment as ideal duration for iron-pulsing. At this time point, the seedling emergence attributes and activities of α-amylase and protease increased. The relative water uptake of the seeds also increased through upregulation of aquaporin expression. The treatment efficiently maintained the ROS balance with the aid of antioxidant enzymes and increased the iron content within the treated seeds. After transplantation in field, photosynthetic rate and chlorophyll content enhanced in the treated plants. Finally, the post-harvest agro-morphological traits (represented through panicle morphology, 1000 seed weight, harvest index) and yield showed significant improvement with treatment. Sets C5 and S5 showed optimum efficiency in terms of yield improvement. To our best knowledge, this study is the first report deciphering the efficacy of iron-pulsing as a safe, cost effective and promising technique to escalate the yield of rice crops without incurring an environmental cost. Thus, iron-pulsing is expected to serve as a potential tool to address global food security in years to come.

Differential growth and metabolic responses induced by nano-scale zero valent iron in germinating seeds and seedlings of Oryza sativa L. cv. Swarna.

Since development of antioxidant defence system is high energy demanding event, innate defence system and stress tolerance of plant is strictly governed by plant age. This study is aimed towards evaluating variation of tolerance in germinating seeds and seedlings of Oryza sativa L. cv. Swarna against nano-scale zero valent iron (nZVI). A comparative study of several physiological and biochemical parameters have been carried out among 2 distinct plant groups, Group I treated with variable concentrations of nZVI (50, 100, 150 and 200 mg L-1) during germination and Group II treated with similar nZVI doses on 7th day after germination. Upon treatment with higher nZVI concentrations, Group I seedlings showed susceptibility towards oxidative stress while Group II seedlings showed tolerance against these higher doses of nZVI. Significant growth enhancement was observed upon treatment with 50-150 mg L-1 nZVI, since up-regulation of plant's endogenous antioxidant system protected relatively aged Group II seedlings from oxidative damages. Hierarchical clustering based on overall physiological, biochemical and stress parameters confirmed that in Group I seedlings 100-200 mg L-1 nZVI treatments were toxic where as in Group II seedlings 50-150 mg L-1 nZVI treatments showed growth promoting effects. This differential response is due to developmental stage related resistance in plants.

Nanocomposites for Delivering Agrochemicals: A Comprehensive Review.

Excessive application of fertilizers negatively affects soil health, causes low nutrient utilization efficiency in plants, and leads to environmental pollution. The application of controlled-release fertilizer is gaining momentum to overcome this crisis. Engineered nanocomposites (ENCs) have shown tremendous promise for need-based delivery of agrochemicals (macro- and micronutrients, pesticides, and other agrochemicals). This review provides comprehensive coverage of synthesis of nanocomposites, their physical-chemical characterization, and techniques to achieve sustained release and targeted delivery to the crops, emphasizing their beneficial role in plant production and protection. Related aspects like feasibility of the application, commercialization of the nanoformulations, and biosafety concerns are also highlighted. This will be helpful to develop a critical understanding of the current state of the art in the controlled release of agrochemicals through nanocomposites. The pressing issues like scale up production, cost analyses, field-based trials, and environmental safety concerns should be given greater attention in future studies.

Tetracycline removal using green synthesized bimetallic nZVI-Cu and bentonite supported green nZVI-Cu nanocomposite: A comparative study.

Antibiotics, one of the most abundant contaminants in the natural water systems possess various difficulties to remediate through conventional water treatment methods. Tetracycline (TC) remains one of the most widely used antibiotics for human and veterinary applications because of its broad-spectrum antibacterial activity. In the current study, we have employed nano zero-valent technology-based antibiotic remediation. In a first of its kind work, we applied bimetallic nZVI-Cu nanoparticles synthesized using pomegranate rind extract for remediation. TC removal of 72 ±â€¯0.5% (initial TC concentration 10 mg/L) was obtained with the nZVI-Cu concentration of 750 mg/L at pH 7. To overcome the colloidal instability and enhance TC removal further, the bimetallic nanoparticles were formed in-situ over bentonite. The bentonite supported composite (B/nZVI-Cu) was used to treat TC an initial concentration of 10 mg/L and the results confirmed significant enhancement in removal with a substantially decreased nanoparticle loading. Using only 150 mg/L of B/nZVI-Cu at pH 7, 95 ±â€¯0.05% of TC could be removed. The nanoparticles and the composites were characterized by SEM, FT-IR, and XRD analyses. The removal process was followed by UV-Visible analyses in conjunction with TOC, ORP and LCMS measurements. For treatment using B/nZVI-Cu, the reusability of the composite was established up to three cycles of operation, and the process was validated in the real water systems. Substantially decreased residual toxicity of the composite treated TC solution lends credence to the environmental sustainability of the process.

A review on tetracycline removal from aqueous systems by advanced treatment techniques.

Tetracycline (TC), a frequently used drug for human and veterinary therapeutics, is among the most common antibiotic residues found in nature. Lack of advanced treatment techniques in the wastewater treatment plants (WWTPs) to remove residual TC from domestic and hospital wastewater poses a serious environmental risk. It is important to have an insight into the different advanced treatment techniques for efficient removal of TC from the surface water and in the WWTPs. The aim of this review is to discuss the nature and occurrence of TC in surface water and to present an overview of the various advanced treatment techniques for TC removal. The advanced treatment techniques include advanced oxidation processes (photolysis, ozonation, and catalytic/UV light-based degradation), membrane filtration, reverse osmosis, and adsorption techniques. Adsorption and integrated oxidation treatment techniques are the most widely studied methods, and they are widely accepted because of less cost, reusability, and toxic-free nature. Further, the uses of various types of catalysts for photodegradation and various sorbents for adsorption of TC are also presented. Finally, the importance of green nanocomposite for environmental sustainability in TC removal is emphasized.

Photo-Assisted Removal of Tetracycline Using Bio-Nanocomposite-Immobilized Alginate Beads.

In the present study, we report an efficient method for tetracycline (TC) removal from contaminated wastewater using alginate beads, immobilized with bio nanocomposite (BNC) consisting of Fe3O4 (iron oxide) and TiO2 (titanium dioxide) nanoparticles along with dead biomass of TC-resistant bacteria Acinetobacter sp. Chemically synthesized Fe3O4 nanoparticles and commercially available TiO2 (P25) nanoparticles were combined to form nanocomposite followed by encapsulation within alginate beads along with heat-killed biomass of Acinetobactersp. for the efficient degradation and adsorption of the target pollutant. The primary characterization of chemically synthesized nanoparticles was carried out with Fourier transform infrared, scanning electron microscopy-energy-dispersive X-ray spectrometry, transmission electron microscopy, and X-ray diffraction techniques. The batch studies for TC removal were performed by varying the reaction parameters such as bead weight, initial TC concentration, and pH in a photoreactor with UV-C irradiation. TC concentration of 10 mg/L, bead weight 10 g, and pH 6 were fixed as the optimum condition where 98 ± 0.5% of TC was removed from the solution. The possible removal mechanism was investigated with the help of UV-visible, total organic carbon, oxidation-reduction potential, Brunauer-Emmett-Teller, and liquid chromatography-mass spectroscopy analyses. The applicability of the process was successfully tested with the natural water systems spiked with TC at 10 mg/L. To assess the ecotoxic effects of the treated effluents, the cell viability assay was performed with the algal strains, Chlorella, and Scenedesmussp. and the bacterial strains, Pseudomonas aeruginosaand Escherichia coli. Finally, the reusability of the BNC bead was successfully established up to the 4th cycle.

Enhancement of nitrogen assimilation and photosynthetic efficiency by novel iron pulsing technique in Oryza sativa L. var Pankaj.

Rice is a major food crop. Due to urbanization and climate change, rice production is declining, posing a threat to the increasing food demand. For this, a modified technique of priming is used to enhance plant vigor. In the present study an endogenous rice cultivar was treated with two different iron salts for 72 h and grown for 14 days in nutrient solution. This increased the iron content of the samples which further escalated the photosynthetic efficiency and carbon assimilation in the treated plants. Photosynthesis being correlated to nitrogen assimilation, nitrogen assimilation intermediates and protein content were also elevated in treated plants. Plants showed no symptoms of stress as evident from low malondialdehyde content and increased antioxidant enzymes' activity. From this study it can be inferred that, treatment with iron during germination, helps to trigger growth by facilitating photosynthesis and nitrogen assimilation.

Enhanced tetracycline removal by in-situ NiFe nanoparticles coated sand in column reactor.

The occurrence of various antibiotics in natural waters poses an emerging environmental concern. Tetracycline (TC) is a frequently used antibiotic in human therapy, veterinary industry, and agricultural sectors. In the current study, TC removal from aqueous solutions was studied using binary Nickel/nano zero valent iron particles (NiFe nano particles) and in-situ NiFe nanoparticles coated sand (IS-NiFe). Removal of TC using bimetallic NiFe particles was optimized with help of response surface methodology (RSM). Using the optimized parameters (concentration of TC: 20 mg/L; NiFe dose: 120 mg/L; time of interaction: 90 min), 99.43 ±â€¯0.98% removal of TC was noted. Further, IS-NiFe was packed in the column reactors and effects of different parameters like flow rate (1-3 mL/min), bed height (3-10 cm) and inlet TC concentration (20-60 mg/L) on breakthrough characteristics were examined. Under the optimized conditions the removal capacity in the column reactor was 1198 ±â€¯40.2 mg/g using IS-NiFe. The column kinetic data were successfully fitted with Adams- Bohart and Thomas models. TC removal efficiency of IS-NiFe in column reactors was tested with TC (20 mg/L) spiked lake water, ground water, and tap water and the removal capacity was noted to be 698.55 ±â€¯11.21, 764.17 ±â€¯6.78, and 801.7 ±â€¯13.26 mg/g respectively.