Ratio Of Cd Research Articles

EXTRACTION OF CADMIUM (II), COMPLEX WITH 2- MERCAPTOBENZOTHIAZOLE AND ITS STABILITY REGARDING GAMMA RAYS AND STUDY OF BIOLOGICAL ACTIVITY OF THE COMPLEX

The study in volve the temperature effect on the extraction process for some chelate systems through study of extraction of Cd (II) by 2- mercaptobenzothiazole. The work include the calculations of thermodynamics parameters (_Hex, _Gex , _Sex) for the extraction processes to Cd (II). The results were indicated that _Hex has a negative value (exothermic process). The obtained negative values of _G ex indicated to the spontaneous extraction processes. The results were shown that D values decrease with increase of temperature while D increase with increase of ethanol concentration as catalyst. Mole ratio method was employed for expected determination of the stoichiometry of the complex. The results showed that the ratio of Cd (II) to the reagent is ( 1 : 2) respectively.

Emerging insights of NK cells immunosurveillance in histomorphologic prognostic indicators of oral squamous cell carcinoma.

IFN-gamma and natural killer (NK) cells have been considered the most effective cells in the combat of cancer, contributing to better prognosis and longer survival. The aim of the study was to analyze and correlate the CD 57 immunopositive NK cell-mediated Interferon-γ pathway in regulating immune mechanisms in Oral Squamous Cell Carcinoma. The study sample was composed of a total of 40 cases of histopathologically confirmed cases of Oral Squamous cell carcinoma (OSCC). Clinical data such as age, gender, habit history, signs and symptoms, and TNM staging were obtained for each case. The biopsy specimens of the cases obtained were fixed with 10% neutral buffered formalin and processed and embedded in paraffin wax. 3-4 μ thick sections were taken for hematoxylin and eosin staining and immunohistochemistry procedure. A saliva sample was collected from each patient and stored at 20 degree Celsius for estimation of salivary interferon-gamma levels using the sandwich ELISA technique. CD 57 NK cells quantitative assessment was significantly associated with tumor budding, cell nest size, the pattern of invasion, lymphocytic host response, NK cell morphology, Depth of invasion, and Tumor thickness. The ratio of CD 57 immunopositive NK cells to salivary IFN-γ levels showed a significant association with histopathological grades, tumor size, and lymph node status. Adoptive cellular transfer therapy with NK cells has been advocated in both experimental models and clinical trials in treating hematopoietic malignancies. The strategy is based on reviving the patient innate immune surveillance and control of tumor invasion by the infusion of activated NK cells. The IFN-gamma and NK cell infiltration in oral squamous cell carcinoma might show a distinctive tumor microenvironment with a favorable local cytotoxic immune response against neoplastic cells.

Compositionally engineered Cd-Mo-Se alloyed QDs toward photocatalytic H2O2 production and Cr(VI) reduction with a detailed mechanism and influencing parameters.

With the exceptional advantages of safety, greenness, and low cost, photocatalytic H2O2 generation has kindled a wonderful spark, although being severely hampered by the terrible photoinduced exciton recombination, migration, and surface decomposition. Here, employing reflux method, the Cd-Mo-Se quantum dots of varying molar ratios of Cd and Mo were synthesized using thioglycolic acid as the capping ligand to regulate their growth. This type of metal alloying promotes rapid charge migration, improves light harvesting, and reduces the rate of charge recombination. The improved optoelectronic properties and boosted activity of Cd-rich ternary CMSe-1 QDs led to the observed exceptional photocatalytic H2O2 yield of 1403.5 μmol g-1 h-1 (solar to chemical conversion efficiency, 0.27%) under visible light, outperforming the other ternary and Se-based QD photocatalysts. Additionally, CMSe-1 shows 93.6% (2 h) hazardous Cr(VI) photoreduction. The enhanced catalytic performance of CMSe-1 corresponds to effective charge carrier separation and transfer efficiency, well supported by PL, TRPL, and electrochemical measurements. Photocatalytic H2O2 production was also studied under varying experimental conditions and the scavenger test suggests a superoxide radical intermediate 2-step single electron reduction pathway. The catalyst-assisted Cr(VI) reduction is substantiated by the zero-order kinetics as well as the determination of the pHPZC value. The catalyst can be employed for a maximum of four times while retaining its activity, according to the photostability and reusability test outcomes. This research presents interesting approaches for producing ternary QDs and modified systems for efficient photocatalytic H2O2 production and Cr(VI) reduction.

Experimental study on the redistribution law of heavy metals in sludge disintegration

Aiming at the problems of large output of excess sludge, difficulty in treatment and disposal, and the potential toxicity of heavy metals restricting its resource utilization, this paper studies the redistribution law of heavy metals in the process of sludge disintegration. The dissertation investigates the distribution law of typical heavy metals such as Cu, Pb, Cd, Zn in the process of microwave and citric acid-microwave cracking sludge under different specific energy and fixed specific energy conditions. The Tessier five-step continuous extraction method was used to extract heavy metals, and the changes in their content and chemical forms were analyzed, which provided certain technical support for the subsequent harmless treatment and resource utilization of excess sludge. The main findings of this paper are as follows: The dissolution rate of heavy metals Cu, Pb, Cd, and Zn increased rapidly during the citric acid-microwave cracking process in the TS specific energy range of 0–45000 kJ/kg, and then gradually tended to be gradual. The maximum dissolution rates of Cu, Pb, Cd, Zn were 8.06%, 16.58%, 14.69%, and 24.11%, respectively. The concentrations of Cu, Pb, Cd, and Zn in the sludge were mainly F4; F3, F4; F2, F3. The proportions of stable states of Cu, Pb, Cd, and Zn in sludge increased to 88.6%, 55.91%, 35.7%, and 31.35%, respectively. When the specific energy was 45000 kJ/kg TS, the concentrations of Pb, Zn, and Cd in the solid phase of the sludge appeared to increase under microwave cracking alone and decrease under the combined action of citric acid and microwave. The concentration of Cu in the solid phase of the sludge increased slightly. The dissolution rates of Pb, Cd, and Zn by microwave alone and citric acid-microwave method were 14.23% and 16.58%, 10.34% and 14.69%, 17.53%, and 24.11%, respectively. The dissolution rates of Cu by both methods were lower. The steady state ratios of Pb and Zn in the citric acid-microwave method increased to 55.91% and 31.25%, respectively; the steady state ratio of Cd in the microwave alone method increased to 39.51%; both methods had no significant effect on the stability of Cu.

Quantitative analysis of heavy metals by laser-induced breakdown spectroscopy technique in association with temperature control and KCl additive

In order to avoid the spectral signal instability and low detection accuracy originating from “transient plasma” produced by laser-induced breakdown (LIBS) technology, the LIBS system based on three-dimensional scaffold was developed to optimize the optical fiber detection position. The spectral signal quality of samples with different contents of KCl additives (0%–100%) at 20–280 °C was analyzed. The double spectral line internal standard model of Cd and Pb elements in sediment was established. The experimental results show that the signal-to-noise ratio of Cd and Al in the sediment with 15% KCl additive at 180 °C is 1.78 and 1.39 times higher than that without additive at room temperature. The R2 of the calibration model for Cd and Pb in sediment with the double enhancement method increased from 0.938 08 and 0.948 80 to 0.963 41 and 0.952 61. The spectral line integral area bispectral line internal scale model R2 is improved to 0.990 34 and 0.988 83. The results showed that the sample heating combined with KCl additive could improve the quality of the spectral signal and increase the detection sensitivity.

Enhanced washing of cadmium and lead from polluted river sediment using horizontal electroosmosis

Sediments are an important sink for heavy metals in river and lake waters, and their chemical compositions affects the circulation of these elements in the ecosystem. Therefore, the remediation of polluted sediments is critical for the health of the ecological environment. This work proposes a facile method for the enhancement of heavy metals extraction from contaminated sediment. In this work, horizontal electroosmosis was applied to improve extraction efficiency of Cd and Pb from river sediment. The effect of the washing reagent (distilled water, citric acid, nitric acid, acetic acid and EDTA) on remediation was investigated, and optimization of the operational parameters of remediation time, washing reagent concentration, electrode spacing, and applied voltage were also studied. Citric acid and EDTA were found to give rise to the greatest removal ratio for Cd and Pb, respectively, with electroosmosis enhancement. After electrokinetic washing for 13 days at cell voltage of 30 V, the removal ratio of Cd by citric acid was 77.0%, and that of Pb by EDTA was 88.3%, at the initial concentrations of 30.2 and 304.2 mg kg (dry solids), respectively. Decreases in exchangeable, carbonate-bound and iron-manganese oxide-bound fractions of the heavy metals were apparent upon their removal from the polluted river sediment.

The effect of changing ratios of Cd:S films on the properties Optical prepared by chemical spraying

ﺘــم ﺘﺤﻀــﻴر اﻏﺸــﻴﺔ ﻛﺒرﻴﺘﻴــد اﻟﻛــﺎدﻤﻴوم Cd:S ﺒطرﻴﻘــﺔ اﻟــرش اﻟﻛﻴﻤﻴــﺎﺌﻲ اﻟﺤــ ارري ودرﺴــت ﺨواﺼﻪ اﻟﺒﺼرﻴﺔ. ﻫذﻩ اﻻﻏﺸﻴﺔ ﺘﺤﺘوي ﻋﻠﻰ ﻨﺴب ﻤﺨﺘﻠﻔﺔ ﻤن اﻴوﻨﺎت اﻟﻛﺎدﻤﻴوم اﻟﻰ اﻟﻛﺒرﻴت. ﻓﺠـوة اﻟطﺎﻗﺔ اﻟﺒﺼرﻴﺔ ﻟﻬذﻩ اﻻﻏﺸﻴﺔ ﺘﻘﻝ ﻋﻨد ﻨﻘﺼﺎن ﻨﺴﺒﺔ اﻴوﻨﺎت اﻟﻛﺒرﻴت اﻟﻰ اﻟﻛﺎدﻤﻴوم.ﻛـذﻟك ﺘـم د ارﺴـﺔ ﺘﺄﺜﻴر اﻟﻨﺴب ﻋﻠﻰ ﺤﺎﻓﺔ اﻻﻤﺘﺼﺎص أﻷﺴـﻴﺔ (اورﺒـﺎخ) وﺠـد ﺒـﺎن ﻋـرض اﻟﺤـﺎﻻت اﻟﻤوﻀـﻌﻴﺔ (∆E) ﺘزداد ﻋﻨد ﺘﻘﻠﻴﻝ ﺘرﻛﻴز اﻴوﻨﺎت اﻟﻛﺒرﻴت ﻟﻸﻏﺸﻴﺔ اﻟﻤﺤﻀرة.

Electric field-enhanced immobilization of Cd and Pb in contaminated river sediments

The immobilization of heavy metal pollutants in river and lake sediments is critical for environmental health and safety. In this study, combined electrokinetic and chemical immobilization were used to remediate Cd and Pb polluted river sediments. The effect of the concentrations of the immobilization reagents and the applied voltage were investigated. Immobilization ratios for Cd and Pb of 98.6% and 84.3%, respectively, was achieved at 7.5 V cm−1 using seven successive rounds of recycling of the immobilization solution of mixed 1.0 g L−1 CO32− and 3.0 g L−1 H2PO4− at the volume ratio of 1:9 with 100 mL immobilization solution to 100 g sediment. The enhancement effect of the electric field is mainly attributed to the increased contact between the immobilization reagents and the heavy metals due to electroosmosis. This study provides a new method for the treatment of heavy metal-polluted sediments.

Comparative study on changes in Cd accumulation and ionome between rice and spinach: Impact of zinc ion activity.

Excessive Cd accumulation in rice grain has caused chronic Cd diseases in humans. In most crops, 100 times more Zn than Cd strongly inhibits Cd uptake and translocation. However, this response is not found for rice (Oryza sativa L.), which was found to have an unusual Cd uptake pattern compared with other crops, such as spinach (Spinacia oleracea L.). Moreover, studies on shared transporters between Zn and Cd using normal solution experiments with traditional high concentrations of metal ions may result in irrelevant interactions. Therefore, we developed ethyleneglycoltetraacetate-buffered nutrient solutions in this work. Rice and spinach seedlings were grown under calibrated low Cd2+ activity and low to phytotoxic Zn2+ activity levels while buffering other micronutrient cations at sufficient levels. Results showed that as rice grew with pZn2+ =8.1-5.4, root Cd and shoot Ni decreased significantly and gradually. However, shoot Cd and Mn in rice decreased slightly with the increase of solution Zn2+ from deficiency to sufficiency and then increased at toxic Zn2+ solution (pZn2+ =5.4). The shoot/root ratios of Cd in rice under toxic pZn2+ (5.6 and 5.4 pZn2+ activity) were significantly increased (p<.05). It could be concluded that rice absorption of Cd is not inhibited by co-contaminating (toxic) Zn. For spinach, with Zn varying from pZn2+ =8.1-5.7, both shoot and root Cd substantially decreased, as did shoot Ni. This work revealed that, to understand food chain Cd risks, one needs to consider the inhibitory role of Zn in limiting Cd absorption in all crops studied except rice.

Analysis of annexin V levels and cytokine status in patients with acute myocardial infarction

Aim. Study of annexin V levels and cytokine status in patients with acute myocardial infarction. Materials and methods. We examined 27 patients with Q-forming myocardial infarction who were admitted 12–24 hours after the development of the clinic, and 20 individuals in the control group. The lipid spectrum was determined using an automatic analyzer Humalizer-3000 (Human, Germany). Immunological studies were performed on a flow cytofluorimeter Navios (Beckman Coulter, USA). Lymphocyte subpopulations were evaluated using monoclonal antibodies produced by Immunotech (Coulter Corporation, USA). A set of ANNEXIN V-FITC/7 AAD (Beckman Coulter, USA) was used to isolate cells that had undergone apoptosis. Isolation of peripheral blood mononuclears was performed by centrifugation on a density gradient Ficol-hypac (Pharmacia Fine Chemicals, Sweden), interleukin-1β was determined using the Vector-Best test system (Vector-Best, Russia), and the tumor necrosis factor was determined using the RayBio Human TNF-alpha ELISA Kit (USA). Statistical data processing was performed using the program package Statistica 10.0. Results. In patients with acute myocardial infarction on the background of dyslipidemia (total cholesterol and LDL cholesterol increased, cholesterol-HDL reduced) showed a significant decrease in the total number of T-lymphocytes (СD 3+) (p &lt; 0.05), T-suppressor (СD 8+) (p &lt; 0.01), B-cells number (СD 19+) and the ratio of CD 4+/CD 8+ lymphocytes increased (p &lt; 0.05). In patients with myocardial infarction there was a significant increase of apoptotic cells and рro-inflammatory cytokines involved in apoptosis (IL-1β and TNF-α) in the blood compared with the control. Conclusion. Increased spontaneous apoptosis of peripheral blood lymphocytes in patients with acute myocardial infarction indicates the systemic nature of apoptosis in acute coronary pathology, due to increased annexin-dependent apoptosis of T-lymphocytes as a result of immune disorders, which leads to activation of the cytokine system with an increased concentration of рro-inflammatory mediators (TNF-α, IL-1β). The identified dependencies require further study with the prospect of developing predictive algorithms for myocardial infarction outcomes based on indicators of annexin V and pro-inflammatory cytokines.

Soil inorganic amendments produce safe rice by reducing the transfer of Cd and increasing key amino acids in brown rice

The digestibility of cadmium (Cd) in brown rice is directly related to amino acid metabolism in rice and human health. In our field study, three kinds of alkaline calcium-rich soil inorganic amendments (SIAs) at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy. With the increased application of SIA, Cd content in iron plaque on rice root significantly increased, the transfer of Cd from rice root to grain significantly decreased, and then Cd content in brown rice decreased synchronously. The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test. Results showed that more than 70% of Cd in brown rice could be digested by simulated gastrointestinal juice. Based on the total and digestible Cd contents in brown rice to evaluate the health risk, the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils. The amino acids (AAs) in brown rice were determined by high-performance liquid chromatography. The contents of 5 key AAs (KAAs) that actively respond to environmental changes increased significantly with the increased application of SIA. The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain, and consequently altered the ratio of indigestible Cd in brown rice. The formation of indigestible KAAs-Cd complexes by combining KAAs (phenylalanine, leucine, histidine, glutamine, and asparagine) with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.

Metabolome-wide association study suggests antagonistic responses to cadmium and selenium in diseased human lungs

Background and Aim: Cadmium (Cd) is a toxic environmental metal that binds selenium (Se) and contributes to many lung diseases. Humans have widespread exposures to Cd through diet and cigarette smoking, and studies in rodent models show that Se can protect against Cd toxicities. We performed metabolome-wide association study (MWAS) of Cd and Se in diseased and non-diseased human lungs to test for possible Cd-Se interactions. Methods: We analyzed tissue from 31 human lung explants, including 25 from patients with end-stage lung diseases, including idiopathic pulmonary fibrosis, cystic fibrosis, and chronic obstructive lung disease (COPD)/emphysema. We used ICP-MS (Inductively Coupled Plasma Mass Spectrometry) to measure Cd and Se, and liquid chromatography-high-resolution mass spectrometry (LC-HRMS) to conduct metabolomics analysis. Results: Metabolic pathway associations with Cd were similar to those previously observed in experimental models, including amino acid, lipid and energy-related pathways, many of which were also associated with Se. Two-way hierarchical cluster analysis (HCA) of metabolites associated with Cd revealed separation of individuals according to disease, with COPD/emphysema in the highest Cd cluster, and non-diseased individuals in the lowest Cd cluster. HCA of Se-associated metabolites revealed that COPD/emphysema also clustered by lower Se compared to others. More pathway associations occurred for the ratio of Cd:Se than either Cd or Se alone, suggesting an antagonistic relationship, and network analysis showed that most metabolites were associated with either Cd or Se. A relatively small number of polyunsaturated fatty acids and metabolites associated with inflammatory signaling had high Eigenvector centrality scores, suggesting a central mechanism of antagonistic interaction. Conclusions: Overall, the data show that metabolic pathway responses in human lung vary with Cd:Se ratio in a pattern suggesting that Se is antagonistic to Cd toxicity. Keyword: Human lung disease, environmental metals, metabolic disruption, high-resolution metabolomics.

Electronic properties of heterometallic zeolitic imidazolate framework and its encapsulation with Ni, Pd and Pt

The electronic properties of heterometallic zeolitic imidazolate frameworks (ZIF-8) containing Cd and Zn metal centres have been examined using density functional theory to reveal the nature of metal to ligand interaction, band gap, density of states and charge distribution. The band gap energy of mixed-metal ZIF-8(Zn/Cd) has been calculated for each ratio of Cd and Zn in the mixed-metals showing a small window of possible alternating the electronic states of this material. The band gap energy shifts from 4.84 eV in pristine ZIF-8(Zn) to 4.33 eV when all the Zn2+ metal centres were replaced by Cd2+ ions. Increasing the ratio of Cd to Zn decreases the band gap energy due to the shifting of the electronic states of Cd at the edge of the conductance band. Modification of the electronic structure was also examined when several metals of Ni, Pd, and Pt were dopped in the mixed-metal ZIF-8(Zn/Cd) to give band gap energies of 2.19, 3.35, and 3.41 eV, respectively. The presence of mixed-metal seems to fine tune the band gap energy than doping the metals in ZIF-8(Zn) only. Density of states have been evaluated to reveal the coordination nature in the mixed-metal ZIF-8(Zn/Cd) as well as after doping with the metals. Additional electronic parameter of the net atomic charge distribution based on the repeating electrostatic potential extracted atomic method was also determined in a range of van der Waals (vdW) radius to see the effect of mixed metals in ZIF-8(Zn/Cd). The net atomic charge of each metal centre is observed to be convergence when the vdW radius scale was set to 0.8, 0.9 and 1.0.

Effective and stable adsorptive removal of Cadmium(II) and Lead(II) using selenium nanoparticles modified by microbial SmtA metallothionein

Metallothionein SmtA-modified selenium nanoparticles (SmtA-SeNPs), efficient adsorbents for Cd(II) and Pb(II), were synthesized in the present work. The ligand, microbial SmtA protein, was synthesized using an engineered strain Escherichia coli, posing the benefits of simplicity, safety, and high production. SmtA-SeNPs were spheres with diameters between 68.1 and 122.4 nm, containing amino, hydroxyl, and sulfhydryl functional groups with negatively charged (pH > 5). SmtA-SeNPs displayed better adsorption performance than dissociative SmtA and SeNPs. The adsorption of Cd(II) and Pb(II) mainly depends on the electrostatic attractions and the metal chelation of abundant functional groups. The maximum adsorption capacity was 506.3 mg/g for Cd(II) and 346.7 mg/g for Pb(II), which were higher than the values of most nanoparticles. In addition, SmtA-SeNPs were immobilized with a membrane filter to produce a SmtA-SeNPs filter, and the percentage removal of Cd(II) and Pb(II) increased from 26.75% to 98.13% for Cd(II) and from 9.95% to 99.20% compared with the blank filter. Moreover, the SmtA-SeNPs filter was regenerated using subacid deionized water, and the filter exhibited a stable removal ratio of Cd(II) and Pb(II) in ten continuous cycles of Cd(II)- or Pb(II)-containing wastewater treatment. The residual amounts of Cd and Pb met national standard levels of wastewater discharge.

High-performance MoS2/CdS nanodiamonds for photocatalytic hydrogen evolution under visible light irradiation

This study demonstrates high-performance visible-light-driven H2-evolution photocatalysts based on novel CdS nanodiamonds. The CdS nanodiamonds (~100 nm) were prepared by optimizing the molar ratios of Cd to S (Cd/S = 1:8) via a hydrothermal method. Various amounts of MoS2 nanosheets were decorated on the surface of the CdS nanodiamonds. The 6 wt% MoS2/CdS nanocomposites exhibited the highest H2 evolution rate (32.94 mmol g−1 h−1), which was 3 times (10.37 mmol g−1 h−1) higher than that of the pristine CdS nanodiamonds under visible light irradiation. The underlying reasons for the enhanced photocatalytic performances were investigated by measuring the electro-chemical properties of the composites, suggesting that the improved performances were attributed to suitable optical adsorption range, low recombination rate of the photo-generated electrons and holes, extra generated charges, excellent charge transfer ability, and increased donor density. This study offers new insights for preparing the CdS nanoparticles with novel structures and high-photocatalytic performances for solar‑hydrogen energy conversion.

Extraction of Cd(II) picrate with benzo-18-crown-6 ether into benzene under the presence of nitric acid in water phases.

Cd(II) picrate was extracted at 298K into benzene (Bz) using benzo-18-crown-6 ether (B18C6) under the presence of HNO3 in water (w) phases. Extraction constants, such as Kex, Kex±, and Kex2±, and a conditional distribution constant (KD,A) of A- = Pic- were determined, where their extraction and distribution constants were defined as [CdLA2]Bz/P, [CdLA+]Bz[A-]Bz/P, and [CdL2+]Bz([A-]Bz)2/P with P = [Cd2+][L]Bz[A-]2 at L = B18C6 and [A-]Bz/[A-], respectively. A [HNO3]t dependence of log Kex was discussed, while ionic strength dependences of log Kex± and log Kex2± were done. Here, [HNO3]t denotes a total concentration of HNO3 added to the w phases. Also, among the eight conditions of [HNO3]t, comparing Kex with an experimental distribution ratio of Cd(II) indicated that the Kex values do not function as a measure for extraction ability of L to the present systems. Moreover, the composition of Cd(II): Pic(-I) in the extracted species was shown by changing [HNO3]t.

Biochar Alleviates Phytotoxicity by Minimizing Bioavailability and Oxidative Stress in Foxtail Millet (Setaria italica L.) Cultivated in Cd- and Zn-Contaminated Soil.

Soil contamination with multiple heavy metals is a global environmental issue that poses a serious threat to public health and ecological safety. Biochar passivation is an efficient and economical technology to prevent heavy metal contamination of Cd; however, its effects on compound-contaminated and weakly alkaline soil remain unclear. Further, the mechanisms mediating the immobilization effects of biochar have not been evaluated. In this study, three biochar treated at different pyrolytic temperatures [300°C (BC300), 400°C (BC400), and 500°C (BC500)] were applied to Cd-/Zn-contaminated soils, and their effects on plant growth, photosynthetic characteristics, Cd/Zn accumulation and distribution in foxtail millet were evaluated. Further, the effect of biochar application on the soil physicochemical characteristics, as well as the diversity and composition of the soil microbiota were investigated. Biochar significantly alleviated the phytotoxicity of Cd and Zn. DTPA (diethylenetriamine pentaacetic acid)-Cd and DTPA-Zn content was significantly reduced following biochar treatment via the transformation of exchangeable components to stable forms. BC500 had a lower DTPA-Cd content than BC300 and BC400 by 42.87% and 39.29%, respectively. The BC500 passivation ratio of Cd was significantly higher than that of Zn. Biochar application also promoted the growth of foxtail millet, alleviated oxidative stress, and reduced heavy metal bioaccumulation in shoots, and transport of Cd from the roots to the shoots in the foxtail millet. The plant height, stem diameter, biomass, and photosynthetic rates of the foxtail millet were the highest in BC500, whereas the Cd and Zn content in each organ and malondialdehyde and hydrogen peroxide content in the leaves were the lowest. Moreover, biochar application significantly increased the abundance of soil bacteria and fungi, as well as increasing the fungal species richness compared to no-biochar treatment. Overall, biochar was an effective agent for the remediation of heavy metal-contaminated soil. The passivation effect of biochar exerted on heavy metals in soil was affected by the biochar pyrolysis temperature, with BC500 showing the best passivation effect.

Enhanced structural, optical, and photocatalytic activity of novel Cd–Zn co-doped Mg0.25 Fe1.75O4 for degradation of RhB dye under visible light irradiation

CdxZn1-xMg0.25Fe1.75O4 (where x = 0.00, 0.25, 0.50, 0.75, 1.00) have been successfully produced by a facile hydrothermal technique for a thorough comparison of structural, optical, and photocatalytic properties (degradation of Rhodamine B -RhB dye under visible light irradiation). X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) confirmed the formation of cubic spinel structure for all of the samples. Fourier transform infrared (FTIR) spectroscopy verified the presence of metal-oxygen (M–O) bonding in the prepared samples with two frequency bands corresponding to phonon vibrational stretching in both the octahedral and tetrahedral lattice positions. UV–Visible Spectrophotometer and photoluminescence (PL) spectroscopy investigated the bandgap variation (2.7 eV-1.7 eV) and emission spectrum peaks appearing in the range of 405–471 nm region. The comparison in the photo-degradation of Rhodamine B (RhB) revealed the superior performance (98% degradation of RhB dye in 80 min having a K value of 0.04966 with excellent reusability) of Cd0.50Zn0.50Mg0.25Fe1.75O4 sample having 50/50 dopant ratio of Cd and Zn in the parent Mg Ferrite, attributed to the lowest bandgap, longer lifetime of charge carriers, active octahedral lattice site, electron/hole pair recombination preventions, and the least value of ohmic impedance at higher frequency.

Synthesis of CdS nanomaterials and their photocatalytic activity under visible light

CdS nanomaterial was hydrothermally synthesized at 160 oC for 6 hours from a dispersed mixture of Cd(NO3)2.4H2O and CH3CSNH2 in 50 mL ethylenediamine and denoted as Cw-m, where w-m is the weight ratio of Cd(NO3)2.4H2O/CH3CSNH2 and equals to 1-2, 1-1 and 3-2. The obtained materials were characterized by X-Ray Diffraction (XRD), Infrared spectra (IR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray (EDX), and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-Vis-DRS). The UV-vis DRS showed that the CdS materials possess bandgap of around 2.24 eV. The photocatalytic activity of the CdS was assessed by degradation of methylene blue (MB) under visible light. The experiments indicated that CdS semiconductor materials can be active under visible light. The MB degradation over the CdS was mainly attributed to the photoreduction process induced by the superoxide radical anions (O2• -) and hydroxyl radicals (•OH).

Microstructures and optical properties of PVA encapsulated cadmium selenide QD synthesized in non-stoichiometric ratio by green chemical route

Cadmium Selenide core quantum dots and rods nanoparticles in polyvinyl alcohol matrix were synthesized in a green chemical route using aqueous solutions of cadmium chloride, selenium, sodium sulfite and PVA, in the non-stoichiometric ratio of Cd:Se (1: 1.8, 1:2.00 and 1:2.20) at pH near 9 in the three samples thermalized at 110°C,140°C and 160°C. XRD spectra confirmed mostly zinc blende unit cell with lattice parameters determined by Nelson-Riley plots (0.5840 nm, 0.5910 nm and 0.5914 nm for the three samples), along with some Wurtzite unit cells whose parameters were determined by the Cohen method. The micro-strains and mean particle sizes were determined by Williamson-Hall plots and found to agree with structural analysis. For zinc blende contents, these were −0.03814 for 1.72 nm, −0.03748 for 1.75 nm and −0.01712 for 3.02 nm particles respectively. The surface morphology as observed by SEM exhibited nano-rods, dots and their agglomerations. Absorption bands were found in the ultraviolet region with meagre values in the visible range. Tauc plots were traced to get optical band gaps of 5.08 eV, 4.90 eV and 4.84 eV for the three sizes of nanoparticles reflecting its dependency on particle size, which indicated a blue shift arising out of quantum confinement. Photoluminescence spectra indicated strong emissions in the ultraviolet range (at 255 nm, 295 nm and 350 nm) and multiple bands in the visible region near 555 nm, 650 nm and 825 nm. Such micro-structural and optical properties as these are suited for applications in solar, electric, photo-physical and bio-imaging devices.