Calcium Oxide Nanoparticles Research Articles

In Vitro Evaluation of the Influence of Biosynthesized Calcium Oxide Nanoparticles on the Antibacterial Activity, pH, Microleakage and Cytotoxicity of Conventional Intracanal Medicaments

Intracanal medicaments are an important adjunct to the effective disinfection of the root canal system. However, conventional intracanal medicaments do not provide adequate protection against Enterococcus faecalis, which is the organism of interest in many cases of root canal failures. This study aimed to evaluate the influence of biosynthesized calcium oxide nanoparticles (CaO NPs) on the antibacterial activity, pH, microleakage and cytotoxicity of intracanal medicaments. CaO NPs were biosynthesized by the direct thermal decomposition of eggshells (EGS) and the reduction of calcium nitrate with papaya leaf extract (PLE). These nanoparticles were mixed with a proprietary calcium hydroxide powder in 10% and 25% (w/w) concentrations and blended in analytical-grade coconut oil to formulate the experimental medicaments. These were then evaluated for antibacterial activity, pH, microleakage and cytotoxicity at 1 day, 7 days and 15 days. A proprietary calcium hydroxide paste formulation (MX) was used as the control. Means and standard deviations were calculated and analyzed using repeated-measures ANOVA for pH and three-way ANOVA for the antibacterial effect, microleakage and cytotoxicity, followed by LSD post hoc analysis. Significant antibacterial activity was noted against Enterococcus faecalis at all times, with zones of inhibition (ZOI) up to 19.60 ± 2.30 mm. pH levels up to 13.13 ± 0.35 were observed for the experimental groups. Microleakage remained comparable to the control, while cytotoxicity was not observed in any of the groups at any time. Intracanal medicaments formulated with 10% and 25% (w/w) of biosynthesized CaO NPs could be promising candidates for the disinfection of the root canal system compared to conventional counterparts.

Synthesis and Characterization of CaO nanoparticles from Periwinkle shell for the Treatment of Tetracycline-contaminated Water by Adsorption and Photocatalyzed Degradation

Due to the ever-increasing discharge of antibiotic residues into different water bodies, there is a significant need to improve existing water treatment methods. In this study, we synthesized calcium oxide nanoparticles from periwinkle shells using the sol-gel method for applications in the adsorption and photodegradation of tetracycline from wastewater. The nanoparticles were characterized using FTIR, UV-Visble spectroscopy, XRD, SEM-EDX, TEM, BET and TGA/DTA. The nanostructure produced showed strong crystalline, optical, structural and surface properties. With an average crystallite size of 25 nm, particle size of 2.09 nm, BET surface area of 582.68 m2/g, specific surface area of 90.08 m2/g, bandgap of 4.8 eV and other properties that supported their functionality as adsorbent and photocatalyst for the removal of tetracycline residue from water. The adsorption experiment gave a maximum efficiency of about 80% while the photodegradation catalysed by the nanoparticles indicated efficiency up to 97%. Both adsorption and photodegradation showed strong dependency on pH, tetracycline concentration, catalyst load and concentration of KI. Response surface analysis and subsequent experimental validation indicated that degradation approaching 100% for tetracycline is feasible under optimum conditions involving concentration = 500 ppm, time = 50 min, catalyst load = 1.25 g and KI concentration = 0.25 M. Computational calculations gave results that are in good match with experimental data and further proved that the degradation is limited by adsorption and is majorly controlled by oxidation facilitated by O2*.

Synthesis and characterization of calcium oxide nanoparticles and evaluating their diverse effects on plant growth and development of Trigonella foenum-graecum L.

Synthesis and characterization of calcium oxide nanoparticles and evaluating their diverse effects on plant growth and development of Trigonella foenum-graecum L.

Calcium oxide nanoparticles ameliorate cadmium toxicity in alfalfa seedlings by depriving its bioaccumulation, enhancing photosystem II functionality and antioxidant gene expression

Cadmium (Cd) is a highly toxic and carcinogenic pollutant that poses significant risks to living organisms and the environment, as it is absorbed by the plant roots and accumulates in different parts of crop during its production. A promising sustainable strategy to counteract these threats to use calcium oxide nanoparticles (CaO-NPs) as soil supplements in fodder crops. This approach has shown notable morpho-physiological and biochemical improvements under metal toxicity conditions. However, the specific mechanisms driving Cd tolerance, particularly at physio-biochemical level and antioxidant related genes expression in fodder crops including alfalfa remain unexplored. CaO-NPs supplementation can trigger various signaling pathways that lead to enhance the photosynthetic pigments formation, stomatal conductance, CO2 assimilation rate and quantum yield of photosystem II. In this study, we evaluated various doses of CaO-NPs (0, 25, 50, and 100 mg kg−1) for their efficacy in reducing Cd bioavailability and toxicity in alfalfa plants. Our results demonstrated that Ca2+ and Cd2+, which share the same ionic radius, compete for ion transport through channels. The small size and high availability of CaO-NPs facilitate their rapid translocation within plant tissues, reducing metal uptake by 61 % in shoots and 30 % in roots. Notably, application of CaO-NPs at 100 mg kg−1 significantly increased shoot length (44 %) and root lengths (35 %) as compared to Cd-treated control plants. The highest dose of CaO-NPs also improved photosynthetic efficiency and gas exchange attributes including (gs, Tr, Pn and Ci) by 66 %, 27 %, 33 % and Ci 21 %, respectively, compared with the Cd treated control. Moreover, CaO-NPs (at 100 mg kg−1) alleviated metal-induced oxidative stress by boosting antioxidant enzyme activity like SOD (25 %) POD (42 %), CAT (72 %) and APX (87 %) and diminishing reactive oxygen species (ROS) production when compared with sole Cd treatment. Scanning and transmission electron microscopy revealed that CaO-NPs positively impacted stomatal conductance and mitigated Cd toxicity in leaf ultrastructure. Additionally, the highest dose of CaO-NPs markedly upregulated the expression of antioxidant-related genes, MsCu/Zn SOD, MtPOD, MtCAT, and MtAPX in roots and shoots by 0.67 and 1.03 fold-change (FC), 0.61 and 0.53 FC, 0.54 and 0.88 FC, and 0.46 and 0.66 FC, respectively. In conclusion, CaO-NPs demonstrate significant potential for environmentally friendly mitigation of Cd stress in alfalfa by reducing its uptake, thereby supporting sustainable agriculture.

Eco-Friendly Facile Conversion of Waste Eggshells into CaO Nanoparticles for Environmental Applications.

Amongst the many types of food waste, eggshells contain various minerals and bioactive materials, and they can become hazardous if not properly disposed of. However, they can be made useful for the environment and people by being converted to environmentally friendly catalytic materials or environmental purification agents. Simple calcination can enhance their properties and thereby render them suitable for catalytic and environmental applications. This work aimed to prepare CaO from waste eggshells and examine its effectiveness in photocatalytic pollution remediation, electrocatalytic activity, optical sensing, and antibacterial activities. As opposed to other techniques, this calcination process does not require any chemical reagents due to the high purity of CaCO3 in eggshells. Calcium oxide nanoparticles were prepared by subjecting waste eggshells (ES) to high-temperature calcination, and the synthesized CaO nanoparticles were characterized for their structural, morphological, chemical, optical, and other properties. Furthermore, their photocatalytic degradation of methylene blue dye and antibacterial efficiency against Escherichia coli and Staphylococcus aureus were investigated. It was found that the green-converted CaO can be efficiently used in environmental applications, showing good catalytic properties.

Biosynthesis of calcium oxide nanoparticles by employing Mulberry (Morus nigra) leaf extract as an efficient source for Rhodamine B remediation

Green processes for synthesizing nanocomposites are a hot area of research today as traditional processes are expensive, inefficient, harmful for synthesizing organic and inorganic molecules, and unsuitable for large-scale operations. The present study investigates the capacity of green synthesized Calcium oxide nanoparticles (CaO NPs) for efficiently removing Rhodamine B. Chemical reduction was replaced with Mulberry (Morus nigera) leaf extract as an environmentally friendly reaction mechanism. CaO NPs are characterized by various analytical techniques including EDX, BET, SEM, FTIR, TGA, Zeta Potential, Point of Zero Charge (PZC), and XRD. Maximum adsorption of Rhodamine B by CaO NPs is revealed at an initial concentration of Rhodamine B of 80 ppm, a temperature of 343 K, and contact time of 60 min, 0.4 g of adsorbent at a pH value of 7. Maximum removal of Rhodamine B by CaO NPs was found to be 98.2% which is promising with this small amount of adsorbent (0.4 g). Diverse Kinetic and adsorption isotherms are employed in this study to determine the requirement and significance of the adsorption process. Various adsorption isotherms such as Freundlich, Temkin, Dubinin–Radushkevich (D–R), and Langmuir models have been employed. Among the kinetic adsorption isotherms Elovich, Intraparticle kinetic model, pseudo 1st order, and pseudo 2nd order models were applied. The current study investigates the thorough understanding of the Rhodamine B adsorption process including the mechanism of adsorption using condition optimization, characterization, and model applications. The proposed adsorbent can be employed for the green removal of Rhodamine B from wastewater of industry with maximum efficiency and favorable regeneration properties.

Calcium nanoparticles produced by Acacia arabica leaf extract and their influence on fresh-cut fruit quality features

Calcium oxide nanoparticles have possessed unique structural and numerous applications, including the food preservative, antimicrobial, and chemotherapeutic properties. The study’s goal was to identify and create calcium oxide-derived leaf extract nanoparticles from Acacia arabica (AA) and assess their effectiveness on fresh-cut fruit quality attributes. The calcium oxide nanoparticles (AACaN) produced using AA leaf extract by the simple precipitation method and the AACaN obtained were characterised and confirmed using various analytical techniques. Freshly sliced apple fruit as well as unsliced blueberry and blackberry were immersed in AACaN (10 and 20 µg/mL) at two different concentrations for five minutes before being put in packed polypropylene plastic bags and maintained at 5 °C. According to the quality evaluations of pH, DPPH, 2,2-diphenylpicrylhydrazyl (DPPH), hardness, total soluble solid content (TSS), and sensory analysis. AACaN at 20 µg/mL has the ability to preserve freshly cut fruits of apples as well as unsliced blueberries and blackberries, thereby effectively extending fruits 20-day shelf life in comparison to control (untreated) fruits. This study has concluded that the AA is an ideal source to synthesis calcium oxide nanoparticles, and it was proved by materially characterizing. Moreover, the AACaN at 20 µg/mL proved the apples, blueberry, and blackberry fruits shelf life, which also added a large nutritional value while maintaining a storage quality.

Green synthesis of CaO nanoparticles from chicken eggshells: antibacterial, antifungal, and heavy metal (Pb2⁺, Cr2⁺, Cd2⁺ and Hg2⁺) adsorption properties

BackgroundChicken eggshells, a common poultry byproduct, are rich in calcium and provide a sustainable source for producing calcium oxide nanoparticles (CaO NPs). Their use in eco-friendly synthesis aligns with the growing emphasis on sustainable materials for environmental and biomedical applications. Objectives: This study develops an eco-friendly method for synthesizing CaO NPs from chicken eggshells, characterizes their physicochemical properties, and evaluates their antibacterial and antifungal activities. It also tests their effectiveness in removing heavy metal ions (Pb2⁺, Cr2⁺, Cd2⁺, and Hg2⁺) from aqueous solutions.MethodsCaO NPs were synthesized by calcining chicken eggshells at 700°C for 7 h. Comprehensive characterization included analysis of crystalline structure, morphology, optical properties, bandgap energy, chemical composition, and thermal stability. Antibacterial and antifungal activities were tested using the well-agar diffusion method. Batch adsorption experiments evaluated heavy metal ion removal under varying conditions of pH, temperature, stirring time, and adsorbent concentrationResultsThe synthesis produced spherical, single-crystal CaO NPs with diameters ranging from 5 to 30 nm and a crystalline size of approximately 20 nm. The nanoparticles had a bandgap energy of about 4.7 eV. Significant antibacterial activity was observed against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli, with increasing inhibition zones correlating with nanoparticle concentration. The CaO NPs also effectively inhibited Candida albicans. For efficient metal ion removal, the optimal conditions were found to be 30 min at pH 6 with 40 mg of CaO NPs at 25°C, achieving recovery rates of 98% for Pb2⁺, 97% for Cd2⁺, 97% for Cr2⁺, and 97% for Hg2⁺. For near-complete removal, extending the process to 70 min at pH 6 with 40 mg of CaO NPs at 45°C achieved the highest recovery rates: 99% for Pb2⁺, 98% for Cd2⁺, 99% for Cr2⁺, and 99% for Hg2⁺, though this approach involves higher energy and cost.ConclusionCaO NPs derived from chicken eggshells are effective antibacterial agents and adsorbents for heavy metal removal. These findings highlight their potential for sustainable applications in environmental and biomedical fields.

In vitro safety profile and phyto-ecotoxicity assessment of the eco-friendly calcium oxide nanoparticles

The present study aims to evaluate the toxicity of the green calcium oxide nanoparticles (CaO-NPs) from golden linseed extract (Linum usitatissimum L.) by phytotoxicity in seeds (Daucus carota, Beet shankar, Lactuca sativa and Brassica oleracea), in vitro safety profile and soil toxicity for CaO-NPs solutions from 12.5 to 100 μg mL−1. Ecotoxicity analysis of the soil was conducted using XRD diffractograms, which revealed characteristic peaks of the nanoparticles at 37.35° (12.5, 25, 50, and 100 μg mL−1), as well as a peak at 67.34° (25 and 100 μg mL−1). Additionally, the in vitro safety assessment indicated favorable cell specification and regulation within the first 24 h, demonstrating reductions of 15.9 ± 0.2%, 17.9 ± 0.2%, 17.6 ± 0.2%, and 32.9 ± 0.2% to 12.5, 25, 50, and 100 μg mL−1, respectively. The dsDNA assay revealed initial protection and controlled release within the cells for 48 h. However, after 72 h, there was an increase of 20 ± 0.2%, 16 ± 0.2%, 32 ± 0.2%, and 43 ± 0.2% to 12.5, 25, and 50 μg mL−1. The analysis of ROS generation demonstrated a reduction of 40 ± 0.2%, 33 ± 0.2%, 20 ± 0.2%, and 9 ± 0.2% to 12.5, 25, 50, and 100 μg mL−1, respectively, within 72 h. When compared to the negative control (NC), there was an increase of 50 ± 0.2%, 56 ± 0.2%, 77 ± 0.2%, and 92 ± 0.2% at the same concentrations, suggesting that the nanoparticles generated free radicals, leading to cellular inflammation. This was attributed to the positive surface charge of the nanoparticles, resulting in reduced interaction with the cell membrane and the subsequent release of hydroxyl (•OH), which caused inflammatory processes in the cells. Therefore, CaO-NPs exhibited a low phytotoxicity and high cytocompatibility, while also promoting plant germination and growth.

Remediation of wastewater and innovative cheap cost filter for microbial and heavy metal removal using calcium oxide nanoparticles

Remediation of wastewater and innovative cheap cost filter for microbial and heavy metal removal using calcium oxide nanoparticles

Oryza glumaepatula and calcium oxide nanoparticles enhanced Cr stress tolerance by maintaining antioxidant defense, chlorophyll and gene expression levels in rice

Chromium (Cr), a potent heavy metal, threatens rice cultivation due to its escalating presence in soil from human activities. Wild rice contains useful genes for phytoremediation; however, it is difficult to use directly for metal mitigation. Here, a single segment substitution line (SSSL), SG001, was developed by crossing O. glumaepatula and Huajingxian74 (HJX) to evaluate the survival ability of plants against Cr. Further, we explored the potential effect of calcium oxide nanoparticles (CaO-NPs) (50 μM) to minimize the toxic effect of Cr (100 μM) in rice cultivars, SG001 and HJX. The findings of this study indicated that Cr toxicity led to increased oxidative stress. This was shown by higher levels of hydrogen peroxide (H2O2), which was increased by 104% in SG001 and 177% in HJX, and malondialdehyde (MDA) increased by 79% in SG001 and 135% in HJX. Furthermore, it also depicted that Cr toxicity considerably declined shoot and root length, shoot and root fresh weight by 30%, 27%, 25%, and 20% in SG001 and 44%, 51%, 42%, and 45% in HJX, respectively. This mitigation was evidenced by decreased Cr contents, increased calcium (Ca) levels in SG001, and the maintenance of chlorophyll, antioxidant defense, and gene expression levels. Moreover, there was a notable reduction in MDA and H2O2, while the defense mechanisms of key antioxidants, including ascorbate peroxidase, superoxide dismutase, glutathione, catalase, and peroxidase were upregulated, along with an increase in soluble protein contents in both rice cultivars after applying CaO-NPs. CaO-NPs effectively restored cellular and subcellular structural integrity and growth in both lines, which had been seriously disrupted by Cr toxicity. Overall, our findings suggest that SG001, in combination with CaO-NPs, could serve as an effective strategy to mitigate Cr toxicity in plants.

Single-layer encapsulation film with CaO absorbent by solution process

A method for preparing a single-layer encapsulation film using an organic-inorganic hybrid precursor solution processing was investigated. The film was created using a commodity epoxy and graphene oxide to ensure cost-effectiveness. Fast curing and annealing techniques, including microwave and intense pulsed light exposure, were employed. Calcium oxide nanoparticles were incorporated as a special moisture absorbent to improve the film's barrier properties. The barrier performance of the single layer encapsulation film was considerably enhanced by post-treatment of these nanoparticles. The characterization of the calcium oxide nanoparticles after post-treatment was performed using transmission electron microscopy with energy-dispersive X-ray spectroscopy, FT-IR, Brunauer-Emmett-Teller test. The composite epoxy encapsulation film, incorporating graphene oxide and post-treated calcium oxide nanoparticles, reduced water permeability approximately 400 times compared to the neat epoxy encapsulation film. This substantial improvement makes it suitable for use in flexible disposable electronics. The enhanced water vapor blocking efficiency is attributed to the combined effect of pathway block by graphene oxide and moisture absorption by calcium oxide.

Comparative role of calcium oxide nanoparticles and calcium bulk fertilizer to alleviate cadmium toxicity by modulating oxidative stress, photosynthetic performance and antioxidant-defense genes expression in alfalfa

Cadmium (Cd) toxicity poses a significant threat to soil health and sustainable food production. Its bioaccumulation in plant tissues induces phytotoxicity by affecting physiological and biochemical attributes, leading to a reduction in plant biomass and production. Recently, nanotechnology has emerged as a promising approach for addressing heavy metal toxicity in an eco-friendly manner to enhance crop production. However, the comparative role of foliar applied calcium oxide nanoparticles (CaO-NPs) and bulk calcium fertilizer under Cd stress in alfalfa remains unexplored. Herein, we studied the ameliorative role of CaO-NPs and bulk calcium (50 and 100 mg L−1) to alleviate Cd stress (30 mg kg−1) in alfalfa seedlings. Plants exposed to Cd exhibited significant decreases in morpho-physiological traits, gas exchange attributes, and pigment contents as well as increase in Cd bioaccumulation in plant tissues. Notably, exogenous application of CaO-NPs ameliorates the toxic impact of Cd by enhancing plant biomass (45%), fluorescence efficiency and gaseous exchange attributes. The maximum dose of CaO-NPs induced Cd-tolerance response accompanied by a significant increase in antioxidative enzyme activities, such as superoxide dismutase (SOD; 29%), peroxidase (POD; 41%), catalase (CAT; 36%) and ascorbate peroxidase (APX; 49%), which play positive roles in ROS scavenging. TEM examination further revealed the protective role of these NPs in averting Cd-induced damage to leaf ultrastructure and mesophyll cells. Furthermore, CaO-NPs had a substantial influence on both Cd and Ca2+ accumulation in plant tissues, while qRT‒PCR analysis demonstrated higher expression of antioxidant defense genes viz. Cu/ZnSOD (0.38 fold change (FC)), MtPOD (0.51 FC), MtCAT (0.61 FC) and MtAPX (0.79 FC) under CaO-NPs application, over Cd control. Overall, our findings suggested that exogenous CaO-NPs could be effective in alleviating the adverse effects of Cd on alfalfa seedlings to ensure food safety and support sustainable agriculture.

Synthesis of calcium-based nanofertilizer and its efficacy towards reduction of oxidative stress and fluoride uptake in rice (Oryza sativa L.)

The phytotoxicity of fluoride and its build-up in agricultural plants and subsequently the entry into the food chain is a serious threat to human health. The present study highlighted the green synthesis of calcium oxide nanoparticles (CaO NPs) and characterization using UV-Vis spectrophotometer, TEM, SEM, EDX, XRD, and FTIR. Further, synthesized CaO NPs (0, 10, and 50 mg/L) were applied on fluoride-stressed (10 mg/L) rice seedlings to check its possible ameliorative effects towards growth and fluoride accumulation in different parts of rice seedlings. Characterization revealed that nanoparticles were crystalline (46.72 %) and spherical in shape, with an average diameter of 20–25 nm. Results of the seedling growth analysis revealed that CaO NPs inhibited the translocation of fluoride in rice plants, which in turn decreased the phytotoxicity caused by fluoride, including lipid peroxidation and chlorosis, and enhanced the overall growth of seedlings. The co-exposure of CaO NPs with fluoride also showed a reduction in the fluoride-induced oxidative stress, as demonstrated by lower MDA, O2•- contents, and activity of antioxidant enzymes (CAT, SOD, and POD) as compared to fluoride treatment alone. The application of CaO NPs also restored potassium content in seedlings grown under fluoride stress. Furthermore, the highest reduction of fluoride accumulation by 65 and 76 % in roots and shoots was recorded at 50 mg/L of CaO NPs treatment, respectively. Therefore, the present study clearly indicated the ameliorative potential of CaO NPs towards fluoride stress in rice. However, a field study is needed to establish the social acceptance of this valuable nanofertilizer in fluoride-contaminated areas.

Free Radical Scavenging Activity of Commelina Benghalensis Mediated Calcium Oxide Nanoparticles

Free Radical Scavenging Activity of Commelina Benghalensis Mediated Calcium Oxide Nanoparticles

Antimicrobial Activity of Calcium Oxide Nanoparticles Synthesized using CommelinaBenghalensis against Clinical Pathogens

Antimicrobial Activity of Calcium Oxide Nanoparticles Synthesized using CommelinaBenghalensis against Clinical Pathogens

Bio-fabrication of calcium oxide nanoparticles from Coccinia grandis as a potential photocatalyst for dye degradation with antimicrobial activity

In the current study, Coccinia grandis fruit extract was used to synthesize calcium oxide nanoparticles (CaO NPs) in an economical and environmentally friendly manner. UV–Vis spectroscopy and Fourier transform infrared spectroscopy revealed that the phytoconstituents found in Coccinia grandis fruit extract facilitated the production of CaO NPs by acting as better stabilizing, biodegradable, and reducing agents. The synthesized CG-CaO NPs were also tested for photocatalytic activity in the breakdown of selective dyes such as methyl red, methyl orange, and methylene blue in the presence of sunlight. The degradation percentage was determined by analyzing the color removal rates for all dye components. After 6 h of reaction, the IC50 values for methyl red, methyl orange, as well as methylene blue dyes were 73, 107, and 133, respectively. The CG-CaO NPs were further evaluated for their antimicrobial activity against specific bacteria and fungi using the agar-well diffusion method. 200 μg/mL CG-CaO NPs inhibited Aspergillus niger, Escherichia coli, Salmonella typhi, Streptococcus mutans, and Staphylococcus aureus at zones of 13, 14, 16, 14, and 15 mM, respectively. Further checkerboard assay confirmed the antagonism effect with gentamicin. Also, Artemia salina toxicity assay showed that the LD50 value of CaO NPs was 400 μg/mL of CaO NPs. The findings confirm that Coccinia grandis-mediated CG-CaO NPs can be used effectively in antimicrobial and environmental settings.

Sustainable and eco-friendly production of biodiesel from Chlorella vulgaris supplemented with biogenic calcium oxide nanoparticles derived from Ulva intestinalis and eggshell as precursors

Biodiesel derived from microalgae has the potential to be a sustainable fuel. Eggshell waste is rich in vital compounds, but still creates pollution problems, due to being discarded in the landfills without any treatment. This study aims to convert eggshells to CaCl2 and use CaCl2 derived from eggshells to biogenic CaO-NPs. Tested the impact of CaCl2, CaCl2 derived from eggshells, and biogenic CaO-NPs, as supplementation to the BG11 media on the growth and lipids yield of Chlorella vulgaris green alga. This study used Ulva intestinalis green alga to synthesize (Ui-CaO-NPs). The characterizations of Ui-Ca-ONPs were analyzed by EDS, XRD, zeta potential, FT-IR, and TEM. Chlorella vulgaris cultivated in modified BG11 media that was supplemented by different concentrations of CaCl2, CaCl2 derived from eggshell, and Ui-CaO-NPs as eggshell precursors (0.009, 0.018, and 0.036 g/L). The low concentrations of CaCl2 as eggshell precursors possessed high optical density, dry weight, and lipids contents of C. vulgaris. The best Chlorophyll a and b contents were obtained with Ui-CaO-NPs (0.018 g/L). The highest carotenoid content was obtained with alga grown in a medium containing 0.036 g/L CaCL2 the GC.Ms. analysis possessed the high-quality lipids profile obtained with C. vulgaris cultivated in media containing 0.018 g/L Ui-CaO-NPs. Eggshells can be used as sources of CaCl2 and CaO-NPs for different applications as eco-friendly and economical materials.

A comparative study of calcium oxide nanoparticle and its ferrite (CaO/Fe2O3) nanocomposite for removal of zinc and nickel from electroplating effluent

Electroplating effluent contains many heavy metals including Zinc (Zn) and Nickel (Ni) are some of the crucial metals which exist in high concentrations. Calcium Oxide nanoparticles (CaONPs) and CaO/Fe2O3 nanocomposite (CaO/Fe2O3NC) were synthesized to evaluate the feasibility of Zn (II) and Ni (II) removal from wastewater. CaO NPs were successfully synthesized from waste eggshells by the sol–gel process while the chemical precipitation method was used for the synthesis of CaO NC. The morphology of the prepared material was characterized by X-ray diffraction (XRD), DLS, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analysis. Batch studies were performed to assess the effect of pH, time, and adsorbent dose on the adsorption efficiency of the nanoparticle and nanocomposite for Zn (II) and Ni (II) removal. Inductively coupled plasma mass spectroscopy (ICP-MS) was used to monitor the amount of Zn (II) and Ni (II) ions in the aqueous solutions. The adsorption capacity of both metal ions increases with an increase in pH, with maximum adsorption occurring at pH 8. An optimum dose of 75 mg/L was observed with both CaO nanoparticle and CaO/Fe2O3 nanocomposite to remove Zn (II) and Ni (II) while equilibrium was achieved after 1 h. The high adsorption capacity makes these adsorbents a promising candidate for removal of metal ions from electroplating effluent.

Synthesis and Characterization of Calcium Oxide Nanoparticles and Their Application in the Adsorption of Indigo Carmine

Synthesis and Characterization of Calcium Oxide Nanoparticles and Their Application in the Adsorption of Indigo Carmine