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Purines are the building blocks of DNA/RNA, energy substrates, and cofactors. Purine metabolites, including ATP, GTP, NADH, and coenzyme A, are essential molecules in diverse biological processes such as energy metabolism, signal transduction, and enzyme activity. When purine levels increase, excess purines are either recycled to synthesize purine metabolites or catabolized to the end product uric acid. Purine catabolism increases during states of low oxygen tension (hypoxia and ischemia), but this metabolic pathway is incompletely understood in the context of histotoxic hypoxia (i.e., inhibition of oxygen utilization despite normal oxygen tension). In rabbits exposed to cyanide-a classical histotoxic hypoxia agent-we demonstrated significant increases in several concordant metabolites in the purine catabolic pathway (including plasma levels of uric acid, xanthosine, xanthine, hypoxanthine, and inosine) via mass spectrometry-based metabolite profiling. Pharmacological inhibition of the purine catabolic pathway with oxypurinol mitigated the deleterious effects of cyanide on skeletal muscle cytochrome c oxidase redox state, measured by non-invasive diffuse optical spectroscopy. Finally, plasma uric acid levels correlated strongly with those of lactic acid, an established clinical biomarker of cyanide exposure, in addition to a tissue biomarker of cyanide exposure (skeletal muscle cytochrome c oxidase redox state). Cumulatively, these findings not only shed light on the in vivo role(s) of cyanide but also have implications in the field of medical countermeasure (MCM) development.

The toxic cyanides in cyanide residues produced from cyanidation process for gold extraction are harmful to the environment. Pyrite is one of the main minerals existing in cyanide residues. In this work, the interaction of cyanide with pyrite and the decyanation of pyrite cyanide residue were analyzed. Results revealed that high pH value, high cyanide concentration, and high pyrite dosage promoted the interaction of cyanide with pyrite. The cyanidation of pyrite was pseudo-second-order with respect to cyanide. The decyanation of pyrite cyanide residue by Na2SO3/air oxidation was performed. The cyanide removal efficiency was 83.9% after 1 h of reaction time under the optimal conditions of pH value of 11.2, dosage of 22 mg·g−1, and air flow rate of 1.46 L·min−1. X-ray photoelectron spectroscopy analysis of the pyrite samples showed the formation of Fe(III) and FeSO4 during the cyanidation process. The cyanide that adsorbed on the pyrite surface after cyanidation mainly existed in the forms of free cyanide (CN−) and ferrocyanide (Fe(CN)64−), which were effectively removed by Na2SO3/air oxidation. During the decyanation process, air intake promoted pyrite oxidation and weakened cyanide adsorption on the pyrite surface. This study has practical significance for gold enterprises aiming to mitigate the environmental impact related to cyanide residues. [ABSTRACT FROM AUTHOR]

AbstractCyanide is increasingly released into the environment as a result of human activities. Once ingested into the body, it blocks vital functions and can lead to death. The aim of this work is to detect cyanide using cathodic stripping voltammetry employing a carbon paste electrode modified with 5% Agban Bingerville clay. Two electrochemical sensors were developed for the detection of cyanide: one with a bare carbon paste electrode and the other with a clay-modified carbon paste electrode. The modified electrode detects cyanide in a hydrochloric acid (pH 1) supporting electrolyte seven times more effectively than the bare carbon paste electrode. Its detection limit is 1.41 µmol/L or 0.04 mg/L, and its sensitivity is 4458 μA cm−2μM−1. This value is below the cyanide concentration limit set by the World Health Organization (WHO) for drinking water. This sensor can therefore contribute to the routine monitoring of environmental matrices. After detection, Moringa oleifera seed powder helps eliminate the cyanide from the solution. The optimum mass of seed powder, which removes 77% of cyanide, is 0.08 g for a 10 mL cell after stirring for 10 min. The elimination occurs as a result of electrostatic interactions between positively charged Moringa proteins and cyanide. [ABSTRACT FROM AUTHOR]

Globally, environmental pollution continues to be a significant public health problem, and according to the World Health Organisation, pollution-induced deaths account for 23% of deaths yearly, which could be prevented if people lived in healthier environments. Despite implementing multilateral agreements and international treaties such as the Bamako, Basel, Rotterdam, Minamata, and Stockholm conventions, the United Nations Sustainable Development Goals, and national laws, toxic pollutants remain a serious environmental and public health problem in low-income countries. In the specific context of Kwekwe City, an industrial and mining area in Zimbabwe, where environmental and pollution-induced health problems associated with industries have been widely reported, this study was conducted in close collaboration with the local community. The study aimed to assess community members' perceptions regarding health risks associated with potentially toxic elements and cyanide pollution in Kwekwe City. An explorative cross-sectional study was conducted with key stakeholders and industrial settlements' residents. Face-to-face interviews with key informants and focus group discussions with residents and workers were used to gather data. A thematic approach was utilised in data analysis. Study participants, who played a crucial role in the research process, perceived that industrial pollution principally linked to cyanide, mercury and chromium posed significant environmental and health risks. This participatory approach in risk perception assessment is critical in providing insight into the scope of the problem and formulating intervention strategies. However, given that qualitative study results lack generalisability and replicability, quantitative studies need to be undertaken to determine environmental levels of toxic chemical pollutants as a complementary and validative measure. [ABSTRACT FROM AUTHOR]

Pakistan is an agricultural country producing plenty of fruits, like: mango, banana, apple, peaches, grapes, plums, variety of citrus fruits including lemon, grapefruit, and oranges. So far the peels of most of the fruits are usually wasted and not properly utilized anywhere. In this work, the peels of banana and grapefruit are converted into biochar by slow pyrolysis under controlled supply of air and used for sequestering cyanide ions from aqueous medium after chemical modification with ZnCl2 and sodium dodecyl sulfate (SDS). The modified biochar was characterized by various instrumental techniques, like: SEM, FTIR, TGA, and CHNS. Different parameters, like: time, temperature, pH, and dose of adsorbent affecting the adsorption of cyanide ions, onto prepared biochar were optimized and to understand the adsorption phenomenon, kinetic and thermodynamic studies were performed. Concentration of cyanide ions was estimated by employing standard ion selective electrode system and it is found that Sodium Dodecyl Sulfate treated biochar of banana peels shown more adsorption capacity, i.e.,: 17.080 mg/g as compared to all samples. Present work revealed that the biochar produced from the fruit waste has sufficient potential to eliminate trace quantities of cyanide from water, especially after treatment with sodium dodecyl sulfate. An industrial area in Asian and African countries where mining is done using traditional techniques is the major cause of cyanide toxicity in wastewater streams. So, here chemically fabricated biochar made by peels of banana and grape fruit is employed for removal of cyanide ion for controlling aquatic pollution using local resources in green way. Favorable results indicated the feasibility of this process, which is cost effective, convenient, ecofriendly, and sustainable. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The first example of a bis(cyaphido) complex, trans‐[Ru(dppe)2(C≡P)2], is described, unequivocally demonstrating the synthetic accessibility and stability of complexes that feature more than one cyaphido ligand. Synthesis is achieved from the precedent cation [Ru(dppe)2(C≡P)]+ via sequential coordination and desilylation of the phosphaalkyne Me3SiC≡P. The heteroleptic analogue trans‐[Ru(dppe)2(C≡N)(C≡P)] is also prepared from the same cation and NaCN; both cyaphido complexes are structurally characterized, enabling the first direct comparison of cyaphide with cyanide, its isoelectronic and isolobal counterpart. This demonstrates an enhanced π‐acidity for −C≡P over −C≡N, while computational studies reveal also a higher π‐donor character for the cyaphido ligand. [ABSTRACT FROM AUTHOR]

This study utilized water-soluble fluorescein isothiocyanate (FITC) to cover graphene loaded gold nanoparticle composites, and the fluorescence of the probe molecule FITC was quenched. Then, by adding cyanide to the system, the strong complexation of cyanide ions (CN-) with gold nanoparticles formed a stable complex Au (CN)3-x, gradually restoring the fluorescence of the probe molecules, thereby achieving rapid detection of cyanide. The pH value of the experimental solution, reaction time, and interfering ions were optimized. The experimental results indicated that the FITC-Au NPs fluorescence probe had a minimum detection limit of 0.036 μmol/L for CN- in the presence of an H2O2 environment. There was a good linear relationship within the 0.05-80 μmol/L concentration range. The high stability and selectivity of FITC-Au NPs probes were utilized to achieve rapid detection of CN- in complex samples. This simple, fast, and economical fluorescence sensing system shows great practical potential in the detection of anions in actual samples. [ABSTRACT FROM AUTHOR]

This study assesses cyanide and cyanidation wastes management practices among small, medium and large-scale gold leaching plants in Siaya County, Kenya. The socio-economic benefits of gold extraction through cyanidation of mercury-contaminated tailings notwithstanding, the study establishes inadequate cyanide and cyanidation wastes management practices which could potentially cause significant environmental and human health impacts. Through structured key-informant interviews with operators from 15 selected gold leaching plants of varying scales of operation, along with field observations, and quantitative analysis utilizing both bivariate and inferential statistical tools, the study reveals inadequacies in cyanide, cyanidation wastewater, and tailings management practices. Key findings highlight widespread contravention of the international cyanide management standards and lack of adoption of advanced cyanidation wastes treatment technologies. Moreover, the study examines Political, Economic, Social, Technological, Environmental, and Legal factors as external factors affecting the management of cyanidation wastes. Consequently, the study recommends adoption of comprehensive cyanide management practices as outlined in the Cyanide Code and technological upgrades to mitigate potential environmental and human health impacts, and enhance regulatory compliance in gold cyanidation. In a nutshell, this study underscores the urgent need for stringent enforcement of environmental and mining industry laws and regulations in order to protect the environment and public health in gold mining regions. These measures are vitally important to ensure responsible mining practices and uphold environmental stewardship while promoting economic growth. [ABSTRACT FROM AUTHOR]

Ecuador is a developing country that relies on mining as a significant source of economic income every year; however, there needs to be more studies on the soil pollution caused by mining over time. Biological remediation as an alternative to the use of physical and chemical methods offers a more cost-effective and environmentally friendly means to counteract the negative impacts that the presence of heavy metals in mining tailings soils can cause. This study focused on soil sampling from the mining tailings of the San Carlos de las Minas sector, in the Zamora Chinchipe province in Ecuador, to find potential bacterial strains that can degrade two specific contaminants, mercury (Hg) and cyanide (CN-). For this purpose, 68 soil subsamples were collected. pH, electrical conductivity, moisture, and the concentration of the contaminants were analyzed and measured. The initial concentration of CN- was 0.14 mg/kg, and of Hg was 88.76 mg/kg. From the soil samples, eight bacterial strains were isolated, characterized at macroscopic and microscopic levels, and identified at the molecular level. The bacteria were then subjected to degradability tests for CN- and Hg, obtaining interesting results. The degradation capacity of CN- stood out for the strains Micrococcus aloeverae and Pseudomonas alcaliphila, and for the degradation of Hg, the strains Hydrogenophaga laconesensis and Micrococcus aloeverae were highlighted, achieving degradation percentages of up to 98.80%. These results emphasize the discovery of these bacterial species with potential use in cyanide and mercury remediation processes.

Background: Cassava roots are widely consumed in tropical regions of Asia, Africa, and Latin America. Although the protein, vitamin, carotenoid, and mineral content in the leaves makes them a nutritionally attractive option, their consumption is limited due to their high levels of cyanogenic compounds (CCs). In this study, the CC content in different parts of the plant (leaves, storage root cortex, and parenchyma) was assessed at harvest for 50 landrace genotypes representative of cassava diversity in Latin America. The changes in CC in leaves at different physiological ages (3, 6, 9, and 11 months after planting) were also investigated. Results: The average CC was higher in the cortex (804 ppm) and leaves (655 ppm) than in root parenchyma (305 ppm). Genotypes from different regions of Latin America, as identified by seven genetic diversity groups, differed significantly in CC levels. The Andean and Amazon groups had, respectively, the lowest (P = 0.0008) and highest (P < 0.0001) CC levels in all three parts of the plants. Cyanogenic compound concentrations were higher in leaves from young plants (P < 0.0001) and decreased with increasing physiological age. Conclusion: The results help to guide the selection of parental lines with low CC levels for breeding and to contribute to the expanded use of cassava and its by‐products for food and feed. Cassava for fresh consumption, especially, requires varieties with low total CC content, especially in the root cortex and parenchyma. COL1108 (204, 213, and 174 ppm, respectively, in the parenchyma, cortex, and leaves) and PER297 (83, 238, and 299 ppm, respectively, in the parenchyma, cortex, and leaves) can fulfill this requirement. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Simple and efficient sample pretreatment methods are important for analysis and detection of chemical warfare agents (CWAs) in environmental and biological samples. Despite many commercial materials or reagents that have been already applied in sample preparation, such as SPE columns, few materials with specificity have been utilized for purification or enrichment. In this study, ionic magnetic mesoporous nanomaterials such as poly(4-VB)@M-MSNs (magnetic mesoporous silicon nanoparticles modified by 4-vinyl benzene sulfonic acid) and Co2+@M-MSNs (magnetic mesoporous silicon nanoparticles modified by cobalt ions) with high absorptivity for ethanol amines (EAs, nitrogen mustard degradation products) and cyanide were successfully synthesized. The special nanomaterials were obtained by modification of magnetic mesoporous particles prepared based on co-precipitation using -SO3H and Co2+. The materials were fully characterized in terms of their composition and structure. The results indicated that poly(4-VB)@M-MSNs or Co2+@M-MSNs had an unambiguous core-shell structure with a BET of 341.7 m2·g−1 and a saturation magnetization intensity of 60.66 emu·g−1 which indicated the good thermal stability. Poly(4-VB)@M-MSNs showed selective adsorption for EAs while the Co2+@M-MSNs were for cyanide, respectively. The adsorption capacity quickly reached the adsorption equilibrium within the 90 s. The saturated adsorption amounts were MDEA = 35.83 mg·g−1, EDEA = 35.00 mg·g−1, TEA = 17.90 mg·g−1 and CN−= 31.48 mg·g−1, respectively. Meanwhile, the adsorption capacities could be maintained at 50–70% after three adsorption–desorption cycles. The adsorption isotherms were confirmed as the Langmuir equation and the Freundlich equation, respectively, and the adsorption mechanism was determined by DFT calculation. The adsorbents were applied for enrichment of targets in actual samples, which showed great potential for the verification of chemical weapons and the destruction of toxic chemicals. [ABSTRACT FROM AUTHOR]

Reactions of uranium tri‐ and tetrahalides, UBr3, UI3, UCl4, and UI4, with different cyanides MCN (M=K, Ag) in liquid anhydrous ammonia led to three novel uranium(IV) cyanide compounds. The reaction of UCl4 in the presence of KCN resulted in the compound [U(CN)(NH3)8]Cl3 ⋅ 3NH3, while UBr3 and UI3 were oxidized in the presence of AgCN to form the compounds ∞1[ ${{}_{\infty }{}^{1}[}$ (μ‐CN){(H3N)5U(μ‐NH2)3U(NH3)5}]Br4 ⋅ 2NH3, and ∞1[ ${{}_{\infty }{}^{1}[}$ (μ‐CN){(H3N)5U(μ‐NH2)3U(NH3)5}]I4 ⋅ 2NH3. The reaction of UI4 with KCN in aNH3 also yielded the compound ∞1[ ${{}_{\infty }{}^{1}[}$ (μ‐CN){(H3N)5U(μ‐NH2)3U(NH3)5}]I4 ⋅ 2NH3. The compounds ∞1[ ${{}_{\infty }{}^{1}[}$ (μ‐CN){(H3N)5U(μ‐NH2)3U(NH3)5}]X4 ⋅ 2NH3 (X=Br, I) crystallize in different space groups, Pmn21 (no. 31) and Imm2 (no. 44), respectively. In both cases, the ∞1[ ${{}_{\infty }{}^{1}[}$ (μ‐CN){(H3N)5U(μ‐NH2)3U(NH3)5}]4+ cation forms infinite strands. We conducted quantum‐chemical calculations and Intrinsic Bond Orbital analyses on the observed [U(CN)(NH3)8]3+ cation and the [(μ‐CN)2{(H3N)5U(μ‐NH2)3U(NH3)5}]3+ model cation to gain insight into the bonding situation. [ABSTRACT FROM AUTHOR]

Cyanides and nitriles, characterized by their R-CN chains, are known for their toxicity, mutagenicity, and carcinogenicity, posing significant threats to environmental and human health. This study aims to explore the biodegradation capabilities of Rhodococcus sp. in breaking down cyanide and nitrile bonds. Rhodococcus pyridinivorans strain I-benzo was isolated from tanning waste and cultured in mineral media with a 20 mM benzonitrile substrate. The activity of this strain was tested using substrates such as benzonitrile, acetonitrile, acrylonitrile, benzamide, acetamide, and acrylamide, revealing positive reactions of nitrile hydratase and amidase enzymes through the Nessler measurement method, which indicated the production of ammonia and carboxylic acids. Furthermore, the degradation tests showed that the Vmax values for the biodegradation of potassium cyanide and sodium cyanide were 0.56 ppm/minute and 0.21 ppm/minute, respectively. These findings highlight the potential application of Rhodococcus pyridinivorans strain I-benzo in mitigating the environmental impact of cyanide and nitrile pollutants through efficient biodegradation. [ABSTRACT FROM AUTHOR]

Chemosensor A, (E)-(4-(2-((2-hydroxynaphthalene-1-yl)methylene)hydrazinyl)benzonitrile has been synthesized by condensation of 4-cyanophenylhydrazine hydrochloride with 2-hydroxy-1-naphthaldehyde in ethanol solvent at ∼80°C. The chemosensor A, has been characterized by FT-IR, ESI-MS and 1H-NMR spectroscopic techniques. The chemosensor A has been investigated for selective cyanide ion sensing ability through UV–visible and fluorescence spectra. Further the chemosensor A was also employed as live cell imaging reagent for intra-cellular detection of cyanide ion in SW480 cells. [ABSTRACT FROM AUTHOR]

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Metal–organic frameworks (MOFs) are frequently utilized as sensing materials. Unfortunately, the low conductivity of MOFs hinder their further application in electrochemical determination. To overcome this limitation, a novel modification strategy for MOFs was proposed, establishing an electrochemical determination method for cyanides in Baijiu. Co and Ni were synergistically used as the metal active centers, with meso−Tetra(4−carboxyphenyl)porphine (TCPP) and Ferrocenecarboxylic acid (Fc−COOH) serving as the main ligands, synthesizing Ni/Co−MOF−TCPP−Fc through a hydrothermal method. The prepared MOF exhibited improved conductivity and stable ratio signals, enabling rapid and sensitive determination of cyanides. The screen−printed carbon electrodes (SPCE) were suitable for in situ and real−time determination of cyanide by electrochemical sensors due to their portability, low cost, and ease of mass production. A logarithmic linear response in the range of 0.196~44 ng/mL was demonstrated by this method, and the limit of detection (LOD) was 0.052 ng/mL. Compared with other methods, the sensor was constructed by a one−step synthesis method, which greatly simplifies the analysis process, and the determination time required was only 4 min. During natural cyanide determinations, recommended readouts match well with GC−MS with less than 5.9% relative error. Moreover, this electrochemical sensor presented a promising method for assessing the safety of cyanides in Baijiu. [ABSTRACT FROM AUTHOR]

AbstractKlebsiella oxytoca JCM 1665 was subjected to extracellular rhodanese production using a submerged fermentation technique. The organism was further engineered for higher cyanide tolerance and rhodanese yield using ethylmethanesulfonate as a mutagen. Mutagenesis resulted in an improved mutant with high cyanide tolerance (100 mM) and rhodanese yield (26.7 ± 0.67 U/mL). This yield was 4.34-fold higher than the wild strain (6.15 ± 0.65 U/mL). At temperatures ranging from 30 to 80 °C, the first-order thermal denaturation constant (Kd) for free enzyme increases from 0.00818 to 0.0333 min−1 while the immobilized enzyme increases from 0.003 to 0.0204 min−1. The equivalent half-life reduces from 99 to 21 minutes and 231 to 35 minutes, respectively. Residual activity tests were used to assess the thermodynamic parameters for both enzyme preparations. For the free enzyme, the parameters obtained were enthalpy (29.40 to 29.06 kJ.mol−1), entropy (−194.24 to −197.50 J.mol−1K−1) and Gibbs free energy (90.20 to 98.80 kJ.mol-1). In addition, for immobilized rhodanese, we obtained enthalpy (40.40 to 40.07 kJ.mol−1), entropy (−164.21 to − 165.20 J.mol−1K−1) and Gibbs free energy (91.80 to 98.40 kJ.mol−1. Regarding its operational stability, the enzyme was able to maintain 63% of its activity after being used for five cycles. Immobilized K. oxytoca rhodanese showed a marked resistance to heat inactivation compared to free enzyme forms; making it of utmost significance in many biotechnological applications. [ABSTRACT FROM AUTHOR]

The release of cyanide from cyanogenic precursors is the central core of the plant defences based on the cyanogenesis process. Although cyanide is formed as a coproduct of some metabolic routes, its production is mostly due to the degradation of cyanohydrins originating from cyanogenic glycosides in cyanogenic plants and the 4-OH-ICN route in Brassicaceae. Cyanohydrins are then hydrolysed in a reversible reaction generating cyanide, being both, cyanohydrins and cyanide, toxic compounds with potential defensive properties against pests and pathogens. Based on the production of cyanogenic-derived molecules in response to the damage caused by herbivore infestation, in this review, we compile the actual knowledge of plant cyanogenic events in the plant–pest context. Besides the defensive potential, the mode of action, and the targets of the cyanogenic compounds to combat phytophagous insects and acari, special attention has been paid to arthropod responses and the strategies to overcome the impact of cyanogenesis. Physiological and behavioural adaptations, as well as cyanide detoxification by β-cyanoalanine synthases, rhodaneses, and cyanases are common ways of phytophagous arthropods defences against the cyanide produced by plants. Much experimental work is needed to further understand the complexities and specificities of the defence–counter-defence system to be applied in breeding programs. [ABSTRACT FROM AUTHOR]

A novel indolium-based fluorescent probe for the detection of CN− was developed based on the conjugation of 1, 2, 3, 3-Tetramethyl-3H-indolium iodide and 2-acetyl benzothiophene. The introduction of external CN− caused a nucleophilic attack to the quaternary amine salt structure in the probe and resulted in the departure of iodide ions and the steric rotation of the index salt group, which caused fluorescence quenching. The titration experiments showed that the probe had rapid qualitative and quantitative analysis capabilities for CN−. Moreover, the relevant biocompatibility experiments also demonstrated the potential application value of the probe. [ABSTRACT FROM AUTHOR]

Ecuador is a developing country that relies on mining as a significant source of economic income every year; however, there needs to be more studies on the soil pollution caused by mining over time. Biological remediation as an alternative to the use of physical and chemical methods offers a more cost-effective and environmentally friendly means to counteract the negative impacts that the presence of heavy metals in mining tailings soils can cause. This study focused on soil sampling from the mining tailings of the San Carlos de las Minas sector, in the Zamora Chinchipe province in Ecuador, to find potential bacterial strains that can degrade two specific contaminants, mercury (Hg) and cyanide (CN-). For this purpose, 68 soil subsamples were collected. pH, electrical conductivity, moisture, and the concentration of the contaminants were analyzed and measured. The initial concentration of CN- was 0.14 mg/kg, and of Hg was 88.76 mg/kg. From the soil samples, eight bacterial strains were isolated, characterized at macroscopic and microscopic levels, and identified at the molecular level. The bacteria were then subjected to degradability tests for CN- and Hg, obtaining interesting results. The degradation capacity of CN- stood out for the strains Micrococcus aloeverae and Pseudomonas alcaliphila , and for the degradation of Hg, the strains Hydrogenophaga laconesensis and Micrococcus aloeverae were highlighted, achieving degradation percentages of up to 98.80%. These results emphasize the discovery of these bacterial species with potential use in cyanide and mercury remediation processes. [ABSTRACT FROM AUTHOR]

Molecular studies about cyanide biodegradation have been mainly focused on the hydrolytic pathways catalyzed by the cyanide dihydratase CynD or the nitrilase NitC. In some Pseudomonas strains, the assimilation of cyanide has been linked to NitC, such as the cyanotrophic model strain Pseudomonas pseudoalcaligenes CECT 5344, which has been recently reclassified as Pseudomonas oleovorans CECT 5344. In this work, a phylogenomic approach established a more precise taxonomic position of the strain CECT 5344 within the species P. oleovorans. Furthermore, a pan-genomic analysis of P. oleovorans and other species with cyanotrophic strains, such as P. fluorescens and P. monteilii, allowed for the comparison and identification of the cioAB and mqoAB genes involved in cyanide resistance, and the nitC and cynS genes required for the assimilation of cyanide or cyanate, respectively. While cyanide resistance genes presented a high frequency among the analyzed genomes, genes responsible for cyanide or cyanate assimilation were identified in a considerably lower proportion. According to the results obtained in this work, an in silico approach based on a comparative genomic approach can be considered as an agile strategy for the bioprospection of putative cyanotrophic bacteria and for the identification of new genes putatively involved in cyanide biodegradation. [ABSTRACT FROM AUTHOR]

AbstractThe rise in cyanide concentration in groundwater in many developing countries is linked to the indiscriminate discharge of cyanide-bearing wastewater from cassava processing industries. This research synthesized a super-active activated carbon (AC) from a novel biomass precursor, Raphia hookeri kernel, functionalized with phosphoric acid via in-situ and ex-situ methods. Morphological and functional characterizations were performed, and the influence of some key process variables on cyanide adsorption was also investigated for the two derived ACs to study the impact of the activation method used. The optimal conditions for cyanide adsorption for the in-situ and ex-situ–derived ACs were identified as pH 8, AC dose of 0.15 g, temperature of 40 °C, and initial cyanide concentration of 100 mgL−1 at different equilibrium times of 100 min and 120 min, respectively. The kinetic studies revealed that the pseudo-second-order kinetic model fitted the adsorption data better for the two ACs based on the high correlation coefficients (r2), suggesting that the adsorption process is chemisorption. The equilibrium studies showed that the in-situ-derived AC followed the Langmuir isotherm with a maximum adsorption capacity (qm) of 93.821 mgg−1 indicating monolayer adsorption for the in-situ-derived AC. The ex-situ-derived AC, however, followed the Sips isotherm with a maximum adsorption capacity (qm) of 79.381 mgg−1 indicating a heterogeneous surface for the ex-situ-derived AC. The ACs showed decreasing cyanide adsorption after five cycles but maintained significant adsorption capacity after desorption-adsorption cycles. [ABSTRACT FROM AUTHOR]

Key message: Pepper fruits contain two leucine aminopeptidase (LAP) genes which are differentially modulated during ripening and by nitric oxide. The LAP activity increases during ripening but is negatively modulated by nitration. Leucine aminopeptidase (LAP) is an essential metalloenzyme that cleaves N-terminal leucine residues from proteins but also metabolizes dipeptides and tripeptides. LAPs play a fundamental role in cell protein turnover and participate in physiological processes such as defense mechanisms against biotic and abiotic stresses, but little is known about their involvement in fruit physiology. This study aims to identify and characterize genes encoding LAP and evaluate their role during the ripening of pepper (Capsicum annuum L.) fruits and under a nitric oxide (NO)-enriched environment. Using a data-mining approach of the pepper plant genome and fruit transcriptome (RNA-seq), two LAP genes, designated CaLAP1 and CaLAP2, were identified. The time course expression analysis of these genes during different fruit ripening stages showed that whereas CaLAP1 decreased, CaLAP2 was upregulated. However, under an exogenous NO treatment of fruits, both genes were downregulated. On the contrary, it was shown that during fruit ripening LAP activity increased by 81%. An in vitro assay of the LAP activity in the presence of different modulating compounds including peroxynitrite (ONOO−), NO donors (S-nitrosoglutathione and nitrosocyteine), reducing agents such as reduced glutathione (GSH), l-cysteine (l-Cys), and cyanide triggered a differential response. Thus, peroxynitrite and reducing compounds provoked around 50% inhibition of the LAP activity in green immature fruits, whereas cyanide upregulated it 1.5 folds. To our knowledge, this is the first characterization of LAP in pepper fruits as well as of its regulation by diverse modulating compounds. Based on the capacity of LAP to metabolize dipeptides and tripeptides, it could be hypothesized that the LAP might be involved in the GSH recycling during the ripening process. [ABSTRACT FROM AUTHOR]

Copyright of Forensic Science & Technology is the property of Institute of Forensic Science, Ministry of Public Security and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Background: Cyanide is a very toxic chemical that reacts with the ferric cytochrome oxidase in the mitochondrial system to form a stable complex. This complex inhibits the process of oxidative phosphorylation, thereby interrupting aerobic respiration in the organism. It is postulated that activated charcoal (AC) intercepts the ingested cyanide in the gastrointestinal tract before it is absorbed into the system. Methods: A single dose of 3 mg/kg body weight of potassium cyanide (KCN) was orally administered to the rats in each of the five groups, each consisting of 6 rats. After 15 minutes, all rats in each group were given AC from different agro-based materials. The control group (group 1) received standard commercial AC orally at 1 g/kg. group 2 received AC from plantain peels, group 3 received AC from castor oil seed shell, group 4 received AC from coconut shell and group 5 received a combination of AC from plantain peels, castor oil seed shell, and coconut shell. Blood samples were collected sequentially from rats in each group for biochemical assays using standard procedures. Results: The control group, which received KCN and standard commercial AC, exhibited the highest alanine transaminase (ALT) value (60.09±0.10 U/L) on day seven. Similarly, the highest aspartate transaminase (AST) value (196.28±0.72 U/L) was observed in the control group. Alkaline phosphate (ALP) levels followed a similar pattern. On day seven, the serum creatinine levels were 3.81±0.11 mg/dL for group 1 and 3.45±0.05 mg/dL for group 5. Subsequently, all biochemical parameters decreased after day 7, with the lowest levels recorded in rats that received AC derived from coconut shells. Conclusion: The administration of locally prepared agro-based adsorbents to Wistar rats after exposure to sublethal doses of cyanide significantly mitigated the effects of the cyanide on the liver, kidneys, and heart, as indicated by the biochemical parameters of the albino Wistar rats in the study.

Nanoparticles of TiO2 doped with low amount of Fe were synthesized from natural ilmenite obtained from alluvial gold mine wastes. The obtained TiO2 were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance, thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), N2 adsorption-desorption isotherms, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results confirm the formation of mesoporous TiO2 nanoparticles in anatase phase with 0.05 wt.% of iron possibly replacing some titanium places. All the characterizations were performed to the synthesized solid and the reference materials (TiO2 anatase and Degussa P25). The photocatalytic activity of both the synthesized solid and references were evaluated in the photo-oxidation of cyanide in aqueous medium under UV illumination. An experimental design type Box-Behnken was performed choosing three different parameters: the initial concentration of cyanide (50, 150 and 250 ppm) the catalyst load (0.1, 0.5 and 1.0 g L-1) and the oxygen source. The percentage of cyanide conversion was chosen as response in the design obtaining as optimal conditions [CN-]0 = 50 ppm, catalyst load = 0.6 g L-1 and air bubbling. Under these conditions it was reached 32, 32 and 89% of cyanide conversion for Fe-TiO2 synthesized, TiO2 anatase and Degussa P25, respectively.

In addition to its role as a toxic environmental contaminant, cyanide has been hypothesized to play a key role in prebiotic chemistry and early biogeochemical evolution. While cyanide-hydrolyzing enzymes have been studied and engineered for bioremediation, the extant diversity of these enzymes remains underexplored. Additionally, the age and evolution of microbial cyanide metabolisms is poorly constrained. Here we provide comprehensive phylogenetic and molecular clock analyses of the distribution and evolution of the Class I nitrilases, thiocyanate hydrolases, and nitrile hydratases. Molecular clock analyses indicate that bacterial cyanide-reducing nitrilases were present by the Paleo- to Mesoproterozoic, and were subsequently horizontally transferred into eukaryotes. These results present a broad diversity of microbial enzymes that could be optimized for cyanide bioremediation.

Abstract Background Basal energetic metabolism in sperm, particularly oxidative phosphorylation, is known to condition not only their oocyte fertilising ability, but also the subsequent embryo development. While the molecular pathways underlying these events still need to be elucidated, reactive oxygen species (ROS) could have a relevant role. We, therefore, aimed to describe the mechanisms through which mitochondrial activity can influence the first stages of embryo development. Results We first show that embryo development is tightly influenced by both intracellular ROS and mitochondrial activity. In addition, we depict that the inhibition of mitochondrial activity dramatically decreases intracellular ROS levels. Finally, we also demonstrate that the inhibition of mitochondrial respiration positively influences sperm DNA integrity, most likely because of the depletion of intracellular ROS formation. Conclusion Collectively, the data presented in this work reveals that impairment of early embryo development may result from the accumulation of sperm DNA damage caused by mitochondrial-derived ROS.

The threat to groundwater by toxic wastewater in the vicinity of cassava processing mills has not been taken seriously in the Niger delta region. Consequently, the fate of cyanide from the surficial surface into underlying aquifers was modelled by MODFLOW and MT3DMS. The vulnerability is influenced by subsurface geology, vertical hydraulic conductivity and sorptive characteristics of the unsaturated zones, seasonal recharge and depth to water levels. The migration of cyanide is considerably not different from the direction of groundwater flow. Its migration is significantly affected by the geology and constituents of the unsaturated zones which retard the spread of cyanide plume into the underlying aquifers. The study has successfully demonstrated the effectiveness of MODFLOW and MT3DMS in determining the vulnerability of aquifers to cassava wastewater from processing mills and associated contaminants. The pumped-and- treat technique is specifically suggested for the remediation of cyanide contaminated aquifers characterized by high hydraulic conductivity.

Cyanide poisoning remains a significant concern for both civilian and military personnel worldwide. Rhodanese, a cyanide detoxify enzyme produced by the wild (KOJCM1665) and two selected mutant strains (KOJCM1665c and KOJCM1665d) of Klebsiella oxytoca JCM 1665 was purified and characterized using a combination of standard techniques. Extracellular rhodanese yield of the wild and selected mutants were 6.2 ± 0.6, 26.7 ± 0.7 and 18.3 ± 0.3 U/mL respectively. The overall levels of recovery of rhodanese activity and fold after purification were 49 %, 66 %, and 58 % and 2.6, 2.6, and 2.3 % for the wild, KOJCM 1665c, and KOJCM 1665d, respectively. The native molecular weights of the three enzyme preparations were 35.1, 34.9, and 34.8 kDa, while the subunit molecular weight was 35 kDa for all the enzymes. The optimum activity of the enzymes was observed at 50 °C and pH 6.0. The real km of the three enzyme preparations for KCN as a substrate were 1.03 × 10−3, 0.95 × 10−3, and 0.80 × 10−3 M, respectively, while the km for the second substrate (Na2S2O3) were 0.59 × 10−3, 0.49 × 10−3, and 0.69 × 10−3 M, respectively. The substrate specificity study showed that the enzyme preferred sodium thiosulfate as the substrate. Metal ions such as Na+ and K+ had significantly greater inhibitory effects on enzyme activity. This study demonstrated the potential of enhancing K. oxytoca JCM 1665 to overexpress extracellular rhodanese, and the physicochemical properties of the enzyme hold significant promise as a target for improving the efficiency of cyanide bioremediation processes.

Konzo, a disease characterized by sudden, irreversible spastic paraparesis, affecting up to 10% of the population in some regions of Sub-Saharan Africa during outbreaks, is strongly associated with dietary exposure to cyanogenic bitter cassava. The molecular mechanisms underlying the development of konzo remain largely unknown. Here, through an analysis of 16 individuals with konzo and matched healthy controls from the same outbreak zones, we identified 117 differentially methylated loci involved in numerous biological processes that may identify cyanogenic-sensitive regions of the genome, providing the first study of epigenomic alterations associated with a clinical phenotype of konzo.

Ethyl carbamate (EC) is a 2A classified carcinogen in Chinese liquor that has raised many problems regarding food safety. Applying microorganisms to control the content of EC precursors in fermented grains has been proven as an effective method to reduce EC in alcoholic beverages. However, the utilization of microorganisms to decrease the precursors of EC (urea and cyanide) is still incomplete in regard to Chinese liquor. Thus, it is necessary to isolate strains with the degradative activities of urea and cyanide. Herein, Bacillus sonorensis F3 and Bacillus licheniformis YA2 strains were isolated from the fermented grains through multiple rounds of high-throughput screening, and the degradative abilities in urea and cyanide reached 95.72% and 75.48%, respectively. In addition, the urease from the B. sonorensis F3 strain and the carbon nitrogen hydrolase from the B. licheniformis YA2 strain were identified by the heterogeneous expression in Escherichia coli. Then, both F3 and YA2 strains were combined at a ratio of 5:1 and applied to eliminate the EC in the simulated fermentation of Chinese liquor; as a result, 51.10% of EC was reduced without affecting the main composition of flavor substances. The obtained strains have great potential in terms of the improvement of quality and safety of Chinese liquor. [ABSTRACT FROM AUTHOR]

Tajikistan possesses large reserves of dump tailings characterized by a high gold content. The formation of these dump tailings is associated with the low cost of gold in the past, since rich ores with a gold content above 6–8 g/t were more often involved in processing. At recovery of ≈ 70–75%, tailings with a gold content below 1.8 g/t were disposed of. The paper studies the material composition and carries out an assessment of the degree of refractoriness of the studied dump tailings to leaching. It was established that the main components of tailings are SiO2 and Al2O3. The dump tailings contain 2.4 g/t of gold and 7 g/t of silver. In terms of material composition, the sample of the dump tailings belongs to a readily cyanidable type. Gold finely disseminated in acid-soluble minerals represents 6–6.5%, while minerals insoluble in acids and quartz contain 15% of gold. In addition, the tailing sample contains gold encapsulated in minerals soluble in sulfuric acid. In terms of gold form, the dump tailings are classified as medium refractory to leaching processes. The diagnostic leaching test results for gold showed that the use of thiourea as a lixivant in the further development of the leaching process is promising. Gold recovery by thiourea leaching was 78%. [ABSTRACT FROM AUTHOR]

Microbial treatment of free-cyanide-polluted wastewater is a cost-effective, efficient, and eco-friendly method. Free-cyanide-degrading microbial cultures were isolated from different sources using batch-enrichment culture techniques, with acetate as the carbon source. Five microbial cultures were able to tolerate and grow at 1500 mg/L free cyanide, which was used as the only nitrogen source under strongly alkaline conditions (pH = 11). Among them, one bacterial strain (B11) was selected for further study because of its high free-cyanide-biodegradation efficiency. Bacterial strain B11 was molecularly identified as Bacillus licheniformis CDBB B11. Free cyanide inhibited the growth rate of B. licheniformis CDBB B11 at initial cyanide concentrations >75 mg/L. Despite this, the bacterial strain demonstrated 100% cyanide-biodegradation efficiency at initial cyanide concentrations ranging from 25 to 75 mg/L, which decreased to 32% as the initial cyanide concentration increased from 75 to 1500 mg/L. Free-cyanide biodegradation corresponds to bacterial growth and ammonia accumulation in the culture medium. The alkaliphilic B. licheniformis CDBB B11 strain is a robust candidate for the detoxification of free-cyanide-laden wastewater because it tolerates and efficiently degrades free cyanide at concentrations of up to 1500 mg/L. [ABSTRACT FROM AUTHOR]

Cyanide represents a persistent threat for accidental or malicious misuse due to easy conversion into a toxic gas and access to large quantities through several industries. The high safety index of hydroxocobalamin is a cornerstone quality as a cyanide scavenger. Unfortunately, intravenous infusion of hydroxocobalamin limits the utility in a mass casualty setting. We previously reported platinum(II) [Pt(II)] complexes with trans-directing sulfur ligands as an efficacious alternative to hydroxocobalamin when delivered by a bolus intramuscular (IM) injection in mice and rabbits. Thus, to enable Pt(II) as an alternative to hydroxocobalamin, a high safety factor is needed. The objective is to maintain efficacy and mitigate the risk of nephrotoxicity. Platinum amino acid complexes with the ability to form 5- or 6-membered rings and possessing either carboxylates or carboxamides are evaluated in vitro for cyanide scavenging. In vivo efficacy wa s evaluated in the zebrafish and mice cyanide exposure models. In addition, Pt(II) complex toxicity and pharmacokinetics were evaluated in a cyanide naive Sprague Dawley model. Doses for toxicity are escalated to 5× from the efficacious dose in mice using a body surface area adjustment. The results show the carboxamide ligands display a time and pH dependence on cyanide scavenging in vitro and efficacy in vivo. Additionally, exchanging the carboxylate for carboxamide showed reduced indications of renal injury. A pharmacokinetic analysis of the larger bidentate complexes displayed rapid absorption by IM administration and having similar plasma exposure. These findings point to the importance of pH and ligand structures for methionine carboxamide complexes with Pt(II). [ABSTRACT FROM AUTHOR]

In this study, we synthesized a coumarin–hemicyanine-based deep red fluorescent dye that exhibits an intramolecular charge transfer (ICT). The probe had a large Stokes shift of 287 nm and a large molar absorption coefficient (ε = 7.5 × 105 L·mol−1·cm−1) and is best described as a deep red luminescent fluorescent probe with λem = 667 nm. The color of probe W changed significantly when it encountered cyanide ions (CN−). The absorption peak (585 nm) decreased gradually, and the absorption peak (428 nm) increased gradually, so that cyanide (CN−) could be identified by the naked eye. Moreover, an obvious fluorescence change was evident before and after the reaction under irradiation using 365 nm UV light. The maximum emission peak (667 nm) decreased gradually, whilst the emission peak (495 nm) increased gradually, which allowed for the proportional fluorescence detection of cyanide (CN−). Using fluorescence spectrometry, the fluorescent probe W could linearly detect CN− over the concentration range of 1–9 μM (R2 = 9913, RSD = 0.534) with a detection limit of 0.24 μM. Using UV-Vis spectrophotometry, the linear detection range for CN− was found to be 1–27 μM (R2 = 0.99583, RSD = 0.675) with a detection limit of 0.13 μM. The sensing mechanism was confirmed by 1H NMR spectroscopic titrations, 13C NMR spectroscopy, X-ray crystallographic analysis and HRMS. The recognition and detection of CN− by probe W was characterized by a rapid response, high selectivity, and high sensitivity. Therefore, this probe provides a convenient, effective and economical method for synthesizing and detecting cyanide efficiently and sensitively. [ABSTRACT FROM AUTHOR]

Background: Basal energetic metabolism in sperm, particularly oxidative phosphorylation, is known to condition not only their oocyte fertilising ability, but also the subsequent embryo development. While the molecular pathways underlying these events still need to be elucidated, reactive oxygen species (ROS) could have a relevant role. We, therefore, aimed to describe the mechanisms through which mitochondrial activity can influence the first stages of embryo development. Results: We first show that embryo development is tightly influenced by both intracellular ROS and mitochondrial activity. In addition, we depict that the inhibition of mitochondrial activity dramatically decreases intracellular ROS levels. Finally, we also demonstrate that the inhibition of mitochondrial respiration positively influences sperm DNA integrity, most likely because of the depletion of intracellular ROS formation. Conclusion: Collectively, the data presented in this work reveals that impairment of early embryo development may result from the accumulation of sperm DNA damage caused by mitochondrial-derived ROS. [ABSTRACT FROM AUTHOR]

A silylated chalcone based sensing probe was designed and synthesized for both simultaneous as well as discriminative detection of fluoride and cyanide ions. The probe showed chromogenic response after the addition of either fluoride or cyanide ion. However, addition of water caused discoloration of the probe solution in case of fluoride ion only while no such change was observed in case of cyanide ions. The probe was found to be selective for the colorimetric detection of F‐ and CN‐ions as it did not generate any chromogenic response in presence of other analyte. For fluoride ions, the detection limit of sensor was calculated to be 0.075 μM while in case of cyanide ions; the detection limit was determined to be 0.23 and 0.44 μM in absence and in presence of water respectively. Practical utility of the proposed method was also demonstrated by testing the real water samples. [ABSTRACT FROM AUTHOR]

Cyanide and heavy metals pose significant risks as contaminants in certain industrial effluents. This study aims to concurrently eliminate cyanide and specific heavy metals from synthetic wastewater resembling gold processing effluent, employing an improved electrocoagulation method incorporating ozone and UV-LED. The investigation delves into the effects of pH, electrode type, current density, reaction time, and ozonation. The findings revealed notable removal efficiencies: 98% for cyanide, 76% for nickel, 85% for copper, and 84% for zinc when utilizing a stainless steel electrode as the cathode. Optimal removal rates were achieved at 94% for cyanide, 93% for copper, 92% for zinc, and 83% for nickel, employing the UV-LED-ozone technique with an ozonation flow rate of 4 mg/s at pH = 10. Notably, when Al-Gr-SS-Fe electrodes and a current of 15 mA/cm2 were applied, these removal efficiencies were observed. Therefore, the most favorable conditions for the concurrent removal of pollutants from synthetic wastewater involved maintaining a pH of 10, utilizing SS-Fe as anode and Al-Gr as cathode electrodes, and employing a current density of 15 mA/cm2. The addition of ozonation with a flow rate of 4 mg/s, along with UV-LED, further enhanced the removal process. In summary, it can be inferred that the enhanced electrocoagulation method outperformed conventional electrocoagulation, leading to increased elimination of cyanide and selected heavy metals. [ABSTRACT FROM AUTHOR]

The presence of cyanide compounds in soil can lead to the formation and evaporation of hydrogen cyanide (HCN), while some of these compounds can undergo conversion by microorganisms present in the soil. However, high concentrations of cyanide can be toxic to soil microorganisms. During the gold extraction of mines, sodium cyanide (NaCN) solution is commonly used which results in a significant amount of cyanide waste that is regarded as an environmental pollutant. Previous studies have proposed physical, chemical, and biological methods to eliminate cyanide, but they have not achieved optimal efficiency. Unfortunately, the potential of artificial intelligence (AI) in this domain has been overlooked. Artificial Neural Network (ANN) models, specifically the multilayer perceptron (MLP) and simple linear regression, can significantly enhance and expedite the cyanide remediation process due to their remarkable predictive capabilities. In this study, an MLP and simple linear regression were employed to predict the biodegradation procedures of cyanide in soil. The study focused on cyanide waste generated by gold extraction factories and utilized environmental factors such as initial waste cyanide concentration, pH, soil and environmental temperature, humidity, chloride concentration, alkaline, electrical conductivity, precipitation, evaporation intensity, cyanide concentration, and initial pH as input data for the artificial neural network. The results of the MLP model revealed that electrical conductivity is the most influential factor in predicting the cyanide rate and initial pH of the waste soil. Conversely, the results of the simple linear regression indicated that the variables with the greatest impact on cyanide concentration are electrical conductivity (0.881), time (0.862), and alkalinity (0.724). By leveraging AI techniques such as ANN, this study demonstrates the potential for improved cyanide remediation. The integration of environmental factors and predictive models can contribute to more effective strategies for addressing cyanide pollution in soil. [ABSTRACT FROM AUTHOR]

The following paper is the second part of an article dealing with the mining accident that took place in 2000 in the Romanian town of Baia Mare, which has been described as one of the worst environmental disasters since the Chernobyl accident. The first part focused on the circumstances of the accident, its consequences, and an analysis of the international legal framework in force at the time of the incident. The authors also describe the changes in international law adopted in response to the accident in Baia Mare and analyse the relevant case-law of the ECtHR related to the Baia Mare accident, Tătar v. Romania case. In the second part of the article, the authors discuss the response to the accident at the level of the European Union and the key changes in EU legislation adopted as a result of the accident. The article also points to changes made in national law in the Czech Republic, which directly or indirectly responded to the accident in Baia Mare. In conclusion, the authors relate this mine accident to the accident on the Bečva River that occurred in 2020. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) and cyanide poisoning are frequent causes of morbidity and mortality in cases of house and industrial fires. The 14th edition of guidelines from the Undersea and Hyperbaric Medical Society does not recommend hyperbaric oxygen (HBO2) treatment in those patients who have suffered a cardiac arrest and had to receive cardiopulmonary resuscitation [1]. In this paper, we describe the case of a 31-year-old patient who received HBO treatment in the setting of cardiac arrest and survived. [ABSTRACT FROM AUTHOR]

A new fluorescent sensor for the detection of CN− was developed based on the conjugation of phenothiazine fluorophore and benzofuran unit. By the nucleophilic attacking of CN− to the fluoroacetylamino group in the sensor, the additional reaction of CN− and carbonyl group induced the ICT (intramolecular charge transfer) effect in the molecule and caused the fluorescence quenching sensor. The titration experiments show that the sensor has good sensitivity, selectivity and quick response for CN−. In addition, the fluorescent detection of CN− in the living cell and zebrafish experiments demonstrated the value of the sensor in tracing the CN− in biological systems. [ABSTRACT FROM AUTHOR]

Microbial treatment of free-cyanide-polluted wastewater is a cost-effective, efficient, and eco-friendly method. Free-cyanide-degrading microbial cultures were isolated from different sources using batch-enrichment culture techniques, with acetate as the carbon source. Five microbial cultures were able to tolerate and grow at 1500 mg/L free cyanide, which was used as the only nitrogen source under strongly alkaline conditions (pH = 11). Among them, one bacterial strain (B11) was selected for further study because of its high free-cyanide-biodegradation efficiency. Bacterial strain B11 was molecularly identified as Bacillus licheniformis CDBB B11. Free cyanide inhibited the growth rate of B. licheniformis CDBB B11 at initial cyanide concentrations >75 mg/L. Despite this, the bacterial strain demonstrated 100% cyanide-biodegradation efficiency at initial cyanide concentrations ranging from 25 to 75 mg/L, which decreased to 32% as the initial cyanide concentration increased from 75 to 1500 mg/L. Free-cyanide biodegradation corresponds to bacterial growth and ammonia accumulation in the culture medium. The alkaliphilic B. licheniformis CDBB B11 strain is a robust candidate for the detoxification of free-cyanide-laden wastewater because it tolerates and efficiently degrades free cyanide at concentrations of up to 1500 mg/L.

In this research, the adsorption rates of cyanide and palladium onto Fe3O4/alginate/diatomite nano-adsorbent (FADA) were evaluated. The co-precipitation technique was applied to synthesis of FADA. The response surface methodology (RSM) was employed to investigate the relation between input-independent factors (initial pollutant concentration, contact time, FADA dosage and pH) and one dependent output response (removal efficiency). The best model was selected based on the results of the ANOVA analysis.SO model due to R2 of 0.929 and the insignificant lack of fit (0.12) for cyanide and also R2 of 0.98 and the insignificant lack of fit (0.12) for palladium was selected as an appropriate model for adsorption of both pollutants. Therefore, prediction and optimisation of the adsorption of the pollutants onto FADAwere done based on SO model. The best conditions for the adsorption of cyanide (95.65%) and palladium (92.66%) onto FADA were obtainedat (pH, 5.45; palladium concentration, 15.13 mg L−1; contact time, 104.8 min and FADA dosage, 0.98 g L−1) and (pH,7.0; cyanide concentration, 4.88 mg L−1; contact time, 91.06 min and FADA dosage, 2.05 g L−1), respectively. Investigation of the non-linear isotherm models indicated adsorptions of cyanide (R2 = 0.995) and palladium (R2 = 0.999) ontoFADA have reasonably fit to the Sips model.The maximum adsorption capacities of cyanide and palladium per mass unit of FADA were 208.55 mg g−1 and 60.2 mg g−1, respectively.The pseudo-first-order (R2 = 0.99) and the intra-particle diffusion (R2 = 0.96) were found to agreement well with the adsorption experimental data obtained for cyanide and palladium, respectively. Results indicated the sorption reactions of cyanide and palladium onto FADA were endothermic and exothermic, respectively.The present study indicated diatomite magnano composite boosted with alginate polymer beads due to high operating groups and also a high surface-to-volume ratio and porosity can be applied as an efficient adsorbent for the removal of cyanide and palladium from aqueous solutions. [ABSTRACT FROM AUTHOR]

The rate of cyanide reduction in the aqueous solutions by adsorption onto the diatomite magnano composite boosted with alginate polymer beads (DMBA) was evaluated. The R software using RSM was used as an experimental technique to design a statistical equation. Based on statistical results obtained, second order model due to insignificant lack of fit (0.12) and the higher value of correlation coefficient (0.92) was selected as a suitable model to design of the adsorption process. Based on the stationary points, the maximum adsorption of cyanide (98.11%) was achieved under selected conditions (initial cyanide concentration, 4.88 mg L−1; contact time, 91.06 min and DMBA dosage, 2.05 g L−1). The Sips nonlinear model indicated the best compatibility with the experimental data. It was found to be a successful model for predicting the heterogeneity of surfaces. The maximum adsorption capacity of cyanide onto DMBA was determined 208.55 mg g−1. The pseudo-first-order model was found to agree well with the adsorption experimental data obtained for cyanide. The thermodynamic data revealed the spontaneous sorption and endothermic for the adsorption of cyanide onto DMBA. [ABSTRACT FROM AUTHOR]