Journal articles on the topic 'Cyanide'
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Sáez, Lara Paloma, Purificación Cabello, María Isabel Ibáñez, Víctor Manuel Luque-Almagro, María Dolores Roldán, and Conrado Moreno-Vivián. "Cyanate Assimilation by the Alkaliphilic Cyanide-Degrading Bacterium Pseudomonas pseudoalcaligenes CECT5344: Mutational Analysis of the cyn Gene Cluster." International Journal of Molecular Sciences 20, no. 12 (June 20, 2019): 3008. http://dx.doi.org/10.3390/ijms20123008.
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The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 can grow with cyanate, cyanide, or cyanide-containing industrial residues as the sole nitrogen source, but the assimilation of cyanide and cyanate takes place through independent pathways. Therefore, cyanide degradation involves a chemical reaction between cyanide and oxaloacetate to form a nitrile that is hydrolyzed to ammonium by the nitrilase NitC, whereas cyanate assimilation requires a cyanase that catalyzes cyanate decomposition to ammonium and carbon dioxide. The P. pseudoalcaligenes CECT5344 cynFABDS gene cluster codes for the putative transcriptional regulator CynF, the ABC-type cyanate transporter CynABD, and the cyanase CynS. In this study, transcriptional analysis revealed that the structural cynABDS genes constitute a single transcriptional unit, which was induced by cyanate and repressed by ammonium. Mutational characterization of the cyn genes indicated that CynF was essential for cynABDS gene expression and that nitrate/nitrite transporters may be involved in cyanate uptake, in addition to the CynABD transport system. Biodegradation of hazardous jewelry wastewater containing high amounts of cyanide and metals was achieved in a batch reactor operating at an alkaline pH after chemical treatment with hydrogen peroxide to oxidize cyanide to cyanate.
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Luque-Almagro, Víctor M., María-J. Huertas, Lara P. Sáez, Manuel Martínez Luque-Romero, Conrado Moreno-Vivián, Francisco Castillo, M. Dolores Roldán, and Rafael Blasco. "Characterization of the Pseudomonas pseudoalcaligenes CECT5344 Cyanase, an Enzyme That Is Not Essential for Cyanide Assimilation." Applied and Environmental Microbiology 74, no. 20 (August 15, 2008): 6280–88. http://dx.doi.org/10.1128/aem.00916-08.
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ABSTRACT Cyanase catalyzes the decomposition of cyanate into CO2 and ammonium, with carbamate as an unstable intermediate. The cyanase of Pseudomonas pseudoalcaligenes CECT5344 was negatively regulated by ammonium and positively regulated by cyanate, cyanide, and some cyanometallic complexes. Cyanase activity was not detected in cell extracts from cells grown with ammonium, even in the presence of cyanate. Nevertheless, a low level of cyanase activity was detected in nitrogen-starved cells. The cyn gene cluster of P. pseudoalcaligenes CECT5344 was cloned and analyzed. The cynA, cynB, and cynD genes encode an ABC-type transporter, the cynS gene codes for the cyanase, and the cynF gene encodes a novel σ54-dependent transcriptional regulator which is not present in other bacterial cyn gene clusters. The CynS protein was expressed in Escherichia coli and purified by following a simple and rapid protocol. The P. pseudoalcaligenes cyanase showed an optimal pH of 8.5°C and a temperature of 65°C. An insertion mutation was generated in the cynS gene. The resulting mutant was unable to use cyanate as the sole nitrogen source but showed the same resistance to cyanate as the wild-type strain. These results, in conjunction with the induction pattern of the enzymatic activity, suggest that the enzyme has an assimilatory function. Although the induction of cyanase activity in cyanide-degrading cells suggests that some cyanate may be generated from cyanide, the cynS mutant was not affected in its ability to degrade cyanide, which unambiguously indicates that cyanate is not a central metabolite in cyanide assimilation.
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Luque-Almagro, V. M., R. Blasco, M. J. Huertas, M. Martínez-Luque, C. Moreno-Vivián, F. Castillo, and M. D. Roldán. "Alkaline cyanide biodegradation by Pseudomonas pseudoalcaligenes CECT5344." Biochemical Society Transactions 33, no. 1 (February 1, 2005): 168–69. http://dx.doi.org/10.1042/bst0330168.
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Pseudomonas pseudoalcaligenes CECT5344 uses cyanide, cyanate, β-cyanoalanine, and other cyanoderivatives as nitrogen sources under alkaline conditions, which prevents volatile HCN (pKa 9.2) formation. The cyanide consumed by this strain is stoichiometrically converted into ammonium. In addition, this bacterium grows with the heavy metal, cyanide-containing waste water generated by the jewellery industry, and is also a cyanide-resistant strain which induces an alternative oxidase and a siderophore-based mechanism for iron acquisition in the presence of cyanide. The detection of cyanase and β-cyanoalanine nitrilase activities in cyanide-induced cells suggests their implication in the cyanide degradation pathway.
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Luque-Almagro, Víctor M., María-J. Huertas, Manuel Martínez-Luque, Conrado Moreno-Vivián, M. Dolores Roldán, L. Jesús García-Gil, Francisco Castillo, and Rafael Blasco. "Bacterial Degradation of Cyanide and Its Metal Complexes under Alkaline Conditions." Applied and Environmental Microbiology 71, no. 2 (February 2005): 940–47. http://dx.doi.org/10.1128/aem.71.2.940-947.2005.
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ABSTRACT A bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. The bacterium was classified as Pseudomonas pseudoalcaligenes by comparison of its 16S RNA gene sequence to those of existing strains and deposited in the Colección Española de Cultivos Tipo (Spanish Type Culture Collection) as strain CECT5344. Cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) the bacterium stoichiometrically converted cyanide into ammonium in the presence of l-methionine-d,l-sulfoximine, a glutamine synthetase inhibitor. The bacterium was able to grow in alkaline media, up to an initial pH of 11.5, and tolerated free cyanide in concentrations of up to 30 mM, which makes it a good candidate for the biological treatment of cyanide-contaminated residues. Both acetate and d,l-malate were suitable carbon sources for cyanotrophic growth, but no growth was detected in media with cyanide as the sole carbon source. In addition to cyanide, P. pseudoalcaligenes CECT5344 used other nitrogen sources, namely ammonium, nitrate, cyanate, cyanoacetamide, nitroferricyanide (nitroprusside), and a variety of cyanide-metal complexes. Cyanide and ammonium were assimilated simultaneously, whereas cyanide strongly inhibited nitrate and nitrite assimilation. Cyanase activity was induced during growth with cyanide or cyanate, but not with ammonium or nitrate as the nitrogen source. This result suggests that cyanate could be an intermediate in the cyanide degradation pathway, but alternative routes cannot be excluded.
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Harborth, P., M. Thieme, and K. Fricke. "Bioremediation of a Cyanide-Contaminated Site Using EH-/PH-Controlled Conditions (ENA)." Advanced Materials Research 71-73 (May 2009): 717–20. http://dx.doi.org/10.4028/www.scientific.net/amr.71-73.717.
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In the course of remedial investigations for a former gasworks site, high cyanide pollution of the soil (74.6 - 101.7 mg/kgDS total cyanide) and of the groundwater (3,840 µg/l total cyanide /approx. 300 µg/l free cyanides) were particularly problematic. Extensive investigations in the laboratory as well as in field studies finally resulted in a 2-step oxic/anoxic concept. Both the free cyanides as well as the complex bound cyanides could be biodegraded at more than 90% through a combination of H2O2-treatment (ISCO) and denitrification by in situ conditions. Furthermore a destruction of the iron cyanide complexes under fermentative conditions could be observed for the first time.
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Корабельников, Д. В., И. А. Федоров, and Ю. Н. Журавлев. "Сжимаемость и электронные свойства цианидов металлов." Физика твердого тела 63, no. 7 (2021): 874. http://dx.doi.org/10.21883/ftt.2021.07.51036.044.
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The compressibility and electronic properties of metal cyanides are investigated within the density functional theory taking into account the dispersion van der Waals interaction. It was shown that gold cyanide has a low linear compressibility (less than 0.1% at a pressure of 1 GPa) and a high linear modulus (~ 1200 GPa) along the -Au-CN-Au-CN- chains. Silver cyanide exhibits negative linear compressibility, which correlates with the compressibility of Ag-N coordination bonds. For sodium cyanide, the linear compressibility along the C - N covalent bonds is greater than for gold and silver cyanides, while the elastic anisotropy is less. Unlike sodium cyanide, for gold and silver cyanides, cation-anionic bonds (Au-N, Au-C and Ag-N, Ag-C) are partially covalent in nature, and the upper valence states correspond mainly to the states of cations. The band gap of gold cyanide is smaller than that of silver and sodium cyanides. The band gap widths of gold and silver cyanides significantly decrease with increasing pressure, which indicates the possibility of metallization at sufficiently high pressures.
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Skowroń, Jolanta, and Katarzyna Konieczko. "Hydrogen cynide and cyanide salts: sodium, potassium, calcium, as CN-. Documentation of proposed values of occupational exposure limits (OELs)." Podstawy i Metody Oceny Środowiska Pracy 33, no. 1(91) (March 30, 2017): 5–62. http://dx.doi.org/10.5604/1231868x.1232633.
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Hydrogen cyanide (HCN) and its salts: potassium cyanide (KCN), sodium cyanide (NaCN) and calcium cyanide [Ca(CN2)] are very toxic. Hydrogen cyanide at ambient conditions is a colourless liquid or a colourless gas with the characteristic odour of bitter almonds. Sodium, potassium and calcium cyanides are white hygroscopic, crystalline solids with a slight HCN odour. Hydrogen cyanide is used mainly in a fumigation of ships, buildings, orchards and various foods, in electroplating, in the production of chelating agents such as EDTA, and in metal treatment processes. It is also used as a chemical intermediate. Cyanides are used in the extraction and recovery of gold and silver from ores, the heat treatment of metals, and electroplating. They are also precursors in chemical syntheses. Workers from metal, electrochemical, plastics, pharmaceutical, textile, chemical and food industries are exposed to these compounds. In 2008–2013, there were no workers exposed to the concentration of hydrogen cyanide and sodium, potassium and calcium cyanides exceeding the maximum admissible ceiling concentration MAC(C) 5 mg/m3 (the national database maintained by the Regional Sanitary Station in Bydgoszcz). Hydrogen cyanide and cyanides are irritating to mucous membranes and skin. They are absorbed by inhalation, dermal and oral exposure. The acute hydrogen cyanide and cyanides poisoning indicate a great danger and hazard, because these compounds are quickly absorbed into the body and their effects are present within a few minutes after the start of exposure. Exposure to sodium cyanide at a concentration of 286 mg/m3 or to hydrogen cyanide at a concentration greater than 300 mg/m3 for 1 min may be fatal. Sodium, potassium or calcium cyanides at concentrations of 25 mg/m3 are direct hazards to life and health of workers if exposure lasts about 30 min and without respiratory protection. For hydrogen cyanide this value was established as 56 mg/m3. The development of symptoms of acute poisoning by hydrogen cyanide or cyanides in humans occurs in three phases: breathlessness and excitement, convulsions and paralysis. The results of studies of subchronic and chronic exposures of workers to cyanides by inhalation indicate that symptoms of exposure were associated with changes in the central nervous system (headache, weakness, changes in the sensation of taste and smell) and damage to the thyroid (enlargement, changes in uptake of iodine, elevated concentration of thyroid stimulating hormone TSH and a reduction of thyroid hormones T3 and T4). Other studies suggest that chronic exposure to hydrogen cyanide in the hardening plant of metals caused decrements in lung functions among workers. Hydrogen cyanide and cyanides, both in aqueous solution, applied to the conjunctival sac or on the skin is quickly absorbed into the body of animals in amounts sufficient to cause toxic effects and death. In rats and mice treated with sodium cyanide in drinking water at a dose of 4.5 mg/kg bw/day for 13 weeks, no significant changes in biochemical and haematological parameters of peripheral blood and histopathological findings in the internal organs were observed. There were no pathological changes in the respiratory, cardiovascular, nervous system and kidneys in rats which were feed with hydrogen cyanide over two years. Calculated NOAEL was approximately 10.4 mg/kg body weight. There is no available data on the carcinogenicity of hydrogen cyanide and cyanides in human and animals. Positive effects were obtained in one study only, in which hydrogen cyanide was tested with Salmonella typhimurium strain TA 100 in the absence of metabolic activation, while the other strains employed in this study yielded negative results. Cyanides did not show mutagenic activity in the tests in vitro and in vivo. On the basis of the studies on hamsters, teratogenic effects of sodium cyanide were observed. This compound was toxic for pregnant mothers and caused an increase in fatal resorption and malformations in an offspring. The results of the study of workers exposed to hydrogen cyanide and cyanides and with changes in thyroid were the basis for calculating MAC (NDS) value. The LOAEL value was establishes as a concentration of 4.7 mg/m3. The MAC of 1 mg/m3 (calculated CN–) was established for hydrogen cyanide and the inhalable fraction of sodium, potassium, calcium cyanides was accepted. Due to totally different mechanism of action of hydrogen cyanide and cyanides (sodium, potassium, calcium) in chronic exposure (effects on the thyroid gland) and in the acute exposure, which is primarily associated with inhibition enzymatic system of cytochrome c oxidase, which prevents cells from using oxygen (histotoxic hypoxia), for these compounds the ceiling value MAC(C) of 5 mg/m3 was not changed. Such an approach is a deviation from the basic methodology adopted by the Group of Expert and the Interdepartmental Commission for MAC and MAI. MAC and ceiling MAC(C) values for these substances should be establish due to the different effects of critical action and mechanisms of action in the acute and chronic condition. This approach is consistent with the DECOS Committee (Dutch Expert Committee on Occupational Standards) from 2002. According to the committee, the acute human data show the most sensitive effect, i.e., death. The steepness of the dose-response relationship and the severity of the acute effects in humans imply at the same time that utmost care should be taken to prevent this exposure level from being exceeded, not even for a short time. Therefore, the committee proposed to establish a ceiling value for the acute health effects of 10 mg/m3 for hydrogen cyanide. The Scientific Committee on Occupational Exposure Limit Values (SCOEL) proposed an OEL value of 1 mg/m3. However, since the acute effects in humans are severe (i.e., death) and show a rather steep dose-response relationship, peak exposures should be avoided. Based on the steepness of the dose-response relationship and the severity of the acute effects in humans a STEL of 5 mg/m3 is recommended as CN– from any combination of the three compounds. Based on the very high skin permeability measured for hydrogen cyanide and cyanide anions in aqueous solutions, a skin notation is recommended for hydrogen cyanide and sodium, potassium, calcium cyanides.
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Han, Wenwen, Hongying Yang, and Linlin Tong. "Removal of Cyanide in Gold Cyanide Residues through Persulfate-Advanced Oxidation Process." Minerals 13, no. 5 (April 28, 2023): 613. http://dx.doi.org/10.3390/min13050613.
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The toxic cyanides in gold cyanide residues produced in the cyanidation process of gold extraction threaten environmental safety and inhibit the recovery of valuable metals. In this study, the removal of cyanide through the persulfate-advanced oxidation process was investigated, and heat activation and ultrasonic activation were tested for cyanide removal. The results showed that cyanide in cyanide residue could be removed by 2.0 wt.% potassium persulfate at pH 10.0 after 60 min reaction with a removal efficiency of 53.47%. The removal efficiency increased to 62.18% at T = 60 °C for heat activation and 74.76% with an ultrasonic power of 100% for ultrasonic activation. The cyanide content in the toxic leaching solution of the residue after the ultrasonic-activated persulfate-advanced oxidation process (3.84 mg/L) reached the national standard of China. Two kinds of free radical scavengers, tert-butanol and methanol, were used to investigate the generation of free radicals. The results showed that both SO4•− and HO• were produced and accelerated the oxidation of cyanide, and HO• played a major role under alkaline conditions. According to XPS analysis, the oxidation of ultrasonic-activated persulfate focused on cyanide removal rather than pyrite in cyanide residue. More cyanides were transferred from the cyanide residue to the liquid phase, leading to the high efficiency of ultrasonic activation. The ultrasonic-activated persulfate-advanced oxidation process has potential application prospects for the treatment of gold cyanide residues.
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Suryono, Chrisna Adhi. "Uji Lethal Concentration (LC) Senyawa Cyanida pada Karang Tingkat Laboratatorium dalam Kaitannya sebagai Bahan Penangkap Ikan Hias." Jurnal Kelautan Tropis 18, no. 3 (May 27, 2016): 160. http://dx.doi.org/10.14710/jkt.v18i3.529.
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Salah satu cara menagkap ikan hias yang efektip adalah dengan cara membius dengan menggunakan cyanida. Tujuan dari penelitian ini adalah untuk mengetahui letathal concetration senyawa cyanida terhadap karang Porites lutea dan Galaxea fascicularis. Rancangan penelitian yang digunakan adalah split plot RAK dengan ulangan 3 kali. Jenis karang merupakan kelompok utama dan konsentrasi cyanida merupakan sub-kelompok. Pengamatan yang diamati adalah jumlah zooxanthellae dan prosentase kematian karang. Hasil penelitian menunjukan semakin tinggi konsentrasi cyanida menunjukan semakin tinggi prosentase kematian karang. Demikain pengaruhnya terhadap zooxanthellae, semakin tinggi konsentrasi cyanida semakin kecil jumlah zooxanthellae pada karang. Hasil uji anova terhadap tingkat kematian karang dan jumlah zooxanthellae.menunjukan pengaruh yang sangat nyata (P<0,001).Kata kunci : Cyanida, LC, karang, dan ikan hiasOne of the most effective to capture ornamental fishes by using cyanide unconscious. The purpose of this study was to conduct LC of cyanide compound on coral Porites lutea and Galaxea fascicularis. The split plot randomized block design with 3 replicate was use on this study. While the kind of corals as the main block and the cyanide concentration as the sub-block. The study focusing on the analyzed of the number of zooxanthellae and the percentage mortality of corals. The results of the study shows, increasing cyanide concentration affected increasing percentage mortality of coral and decreasing the number of zooxanthellae on the coral. The result of ANOVA test showed highly differences significantly (p<0.001).Keywords: Cyanide, LC, coral and artistic fishes
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Muderawan, I. Wayan, I. Wayan Karyasa, I. Nyoman Tika, and Gede Agus Beni Widana. "Chemistry and Biology of Cyanides: A Literature Review." Indonesian Journal of Chemistry and Environment 6, no. 2 (December 6, 2023): 63–82. http://dx.doi.org/10.21831/ijoce.v6i2.67030.
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The term cyanide is used to describe compounds that contain the cyano, -C≡N, group. The cyanides exist in nature as inorganic as well as organic compounds in the forms of gas or liquid such as HCN, CNCl and acetonitrile, or solids such as NaCN, KCN, and Ca(CN)2. Cyanide compounds are also found in addible plants as cyanogenic glycosides. Compounds that can release cyanide are known as cyanogenic compounds. HCN has a low boiling point (25.63 oC) and is as weakly acidic with a pKa 9.2. It partially ionizes in water to give the cyanide anion, -CN. Cyanide ion from salt reacts with acid to give HCN, but at high pH (8-10), it remains as cyanide ion even if the temperature of the water is 80.0-100.0 °C. Cyanide is one of the deadliest poisons, LC50 is 1.1 and 5.0 mg/kg for HCN and NaCN, which can cause death to those who come into contact within a few minutes or hours of exposure, depending on the level and route of exposure. It is a rapidly acting, potentially deadly chemical that interferes with the body’s ability to use oxygen. Due to its toxicity, cyanide has many roles in industry such as pesticides and medicines as nitrile-containing pharmaceuticals. Organic compounds that have a −C≡N functional group are called nitriles. Over 30 nitrile-containing pharmaceuticals are currently marketed for a diverse variety of medicinal indications with more than 20 additional nitrile-containing leads in clinical development. In addition, over 120 naturally occurring nitriles have been isolated from terrestrial and marine sources. In plants, cyanides are usually bound to sugar molecules in the form of cyanogenic glycosides. Hydrogen cyanide can be released from hydrolysis of cyanogenic glycosides which are commonly present in edible plants. Because it is a relatively common toxin in the environment, the body can detoxify a small amount of cyanide. The major route of metabolism for cyanides is detoxification in the liver by the mitochondrial enzyme rhodanese, which catalyzes the transfer of the sulfane sulfur of thiosulfate to the cyanide ion to form thiocyanate. Ingested cyanide may be countered by administering antidotes, such as natural vitamin B12 and sodium thiosulfate, that detoxify cyanide or bind to it.
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Parmar, Prachi, Ajai Kumar Pillai, and Vinay Kumar Gupta. "Rapid Spectrophotometric Determination of Trace Amounts of Cyanide and Hydrogen Cyanide Using p-Aminoacetanilide in Various Samples." Journal of the Korean Chemical Society 54, no. 1 (February 20, 2010): 165–68. http://dx.doi.org/10.5012/jkcs.2010.54.01.165.
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Hosetti, B. B., P. N. Dube, M. S. Prashanth, and A. Shwetha. "Acute toxicity of metal cyanides to Indian major carp Labeo rohita (Hamilton)." Biotehnologija u stocarstvu 26, no. 3-4 (2010): 267–77. http://dx.doi.org/10.2298/bah1004267h.
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Static renewal bioassay tests were carried out to determine the acute toxicity (LC50) of metal cyanides to the Indian major carp Labeo rohita. The 96 hour LC50 value for the sodium cyanide, zinc cyanide and copper cyanide to the fish L. rohita were 0.32 mg/L 0.35 mg/L, and 1.1 mg/L respectively. Among the metal cyanide tested, sodium cyanide is found to be more toxic than the other cyanide complexes. In general behavioral responses of the fishes exposed to cyanide included uncontrolled swimming, erratic movements, loss of balance, moving spiral fashion with sudden jerky movements, vertical movements lying on the sides of the test chamber and rapid flapping of the opercular movements with opened mouth finally settles to the bottom.
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Hargono, Hargono, Andri Cahyo Kumoro, and Bakti Jos. "Inhibitory Effects of Cyanide on the Activity of Granular Starch Hydrolyzing Enzyme (GSHE) during Hydrolysis of Cassava (Manihot Esculenta Crantz) Starch." Periodica Polytechnica Chemical Engineering 63, no. 1 (May 16, 2018): 11–17. http://dx.doi.org/10.3311/ppch.12006.
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The kinetics and inhibitory effects of cyanide on the granular starch hydrolyzing enzyme (GSHE) activity during hydrolysis of cassava (Manihot esculenta Crantz) starch at low temperature were studied. The substrates included native cassava starch at various concentrations (100-400 g/L) and native cassava starches with added cyanide at various concentrations (50-150 mg/kg), while the concentration of enzyme was 1.5% (w/w). A decrease in reducing sugar concentration during hydrolysis of cassava starch indicated that the cyanide reduced the enzyme activity. Lineweaver-Burk plot of Michaelis-Menten equation was used to study the inhibition kinetics. The maximum velocity (Vmax) value was higher for native cassava starch than that of native cassava starch with added cyanides. The presence of cyanide was found to reduce the Vmax values. No significant different of the saturation constant (Km) value between native cassava starch and native cassava starch with added cyanides was observed. Based on the inhibition type analysis, the effect of cyanide in the cassava starch can be classified as a noncompetitive inhibition, with the Ki value of 0.33 mg/L.
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Simovic, L., and W. J. Snodgrass. "Natural Removal of Cyanide in Gold Milling Effluents - Evaluation of Removal Kinetics." Water Quality Research Journal 20, no. 2 (May 1, 1985): 120–35. http://dx.doi.org/10.2166/wqrj.1985.023.
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Abstract Research using synthetic solutions was conducted to examine factors influencing the natural removal of cyanides from gold mill lagoons. Factors examined included: pH, temperature, ultraviolet irradiation and degree of aeration. Temperature was the principal factor affecting the rate of cyanide loss from solution. UV irradiation had some effect while the effect of aeration was limited. The dominant mechanism for cyanide removal from solution was volatilization. Cyanide degradation was found to follow a first order reaction with respect to free cyanide and metallo-cyanide complexes of Zn, Ni, Cu and Fe. Data from each single metallo-cyanide solution were fitted to a mathematical model which considered volatilization of free cyanide, dissociation of the metallo-cyanide species, and one cyanide complex per metal. The best estimates of the rate constants found for the single metallo-cyanide solutions were used to simulate the removal characteristics of cyanide in a synthetic mixed solution of four metals. The coefficient of determination ranged from 0.93 to 0.99 for model predictions fitted to data from single metallo-cyanide solutions. Estimates for volatilization coefficients varied widely with some of the variation resulting from data which did not completely describe the decay process. The simulation of cyanide removal from the synthetic mixed solution suggested the need to recalibrate the model or to examine the formation of more than one metallo-cyanide species.
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Sáez, Lara P., Gema Rodríguez-Caballero, Alfonso Olaya-Abril, Purificación Cabello, Conrado Moreno-Vivián, María Dolores Roldán, and Víctor M. Luque-Almagro. "Genomic Insights into Cyanide Biodegradation in the Pseudomonas Genus." International Journal of Molecular Sciences 25, no. 8 (April 18, 2024): 4456. http://dx.doi.org/10.3390/ijms25084456.
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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.
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Corfield, Peter W. R., and Alexander Sabatino. "Crystal structures of two mixed-valence copper cyanide complexes withN-methylethylenediamine." Acta Crystallographica Section E Crystallographic Communications 73, no. 2 (January 10, 2017): 141–46. http://dx.doi.org/10.1107/s2056989017000111.
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The crystal structures of two mixed-valence copper cyanide compounds involvingN-methylethylenediamine (meen), are described. In compound (I), poly[bis(μ3-cyanido-κ3C:C:N)tris(μ2-cyanido-κ2C:N)bis(N-methylethane-1,2-diamine-κ2N,N′)tricopper(I)copper(II)], [Cu4(CN)5(C3H10N2)2] or Cu4(CN)5meen2, cyanide groups link CuIatoms into a three-dimensional network containing open channels parallel to thebaxis. In the network, two tetrahedrally bound CuIatoms are bonded by the C atoms of two end-on bridging CN groups to form Cu2(CN)6moieties with the Cu atoms in close contact at 2.560 (1) Å. Other trigonally bound CuIatoms link these units together to form the network. The CuIIatoms, coordinated by two meen units, are covalently linked to the networkviaa cyanide bridge, and project into the open network channels. In the molecular compound (II), [(N-methylethylenediamine-κ2N,N′)copper(II)]-μ2-cyanido-κ2C:N-[bis(cyanido-κC)copper(I)] monohydrate, [Cu2(CN)3(C3H10N2)2]·H2O or Cu2(CN)3meen2·H2O, a CN group connects a CuIIatom coordinated by two meen groups with a trigonal–planar CuIatom coordinated by CN groups. The molecules are linked into centrosymmetric dimersviahydrogen bonds to two water molecules. In both compounds, the bridging cyanide between the CuIIand CuIatoms has the N atom bonded to CuIIand the C atom bonded to CuI, and the CuIIatoms are in a square-pyramidal coordination.
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Beattie, JK, and GA Polyblank. "Copper-Catalyzed Oxidation of Cyanide by Peroxide in Alkaline Aqueous Solution." Australian Journal of Chemistry 48, no. 4 (1995): 861. http://dx.doi.org/10.1071/ch9950861.
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The oxidation of cyanide by peroxide in alkaline aqueous solution is catalysed by copper complexes. In the presence of excess cyanide, copper(II) is reduced to form the tricyanocuprate (I) complex. The cyanogen oxidation product is hydrolysed with disproportionation to cyanate and cyanide:2CuII+2CN-→ 2CuI+(CN)2(CN)2+2OH- → OCN-+CN-+H2OCuI+3CN- ↔ Cu(CN)32-The stoichiometry and kinetics of the catalysed oxidation have been investigated. Hydrogen peroxide oxidizes coordinated cyanide with a rate that is first order in peroxide and first order in copper but independent of cyanide concentration in the presence of excess cyanide. Cu(CN)32-+H2O2→ Cu(CN)2-+OCN-+H2O Cu(CN)2-+CN-↔ Cu(CN)32- When the excess cyanide is consumed and Cu(CN)2- becomes the dominant species, the reaction becomes more complex and less efficient. Under certain conditions the stoichiometry revealed a peroxide-to-Cu(CN)2- ratio of about 6 : 1, instead of the minimum of 2.5:1 required for the oxidation of the coordinated cyanide to cyanate and the CuI to Cu(OH)2. This suggests that peroxide is consumed by a copper- catalysed disproportionation, in competition with oxidation of the coordinated cyanide. An intermediate yellow complex forms while peroxide is present, before Cu(OH)2 finally precipitates. The consequence of this mechanism is that the most efficient process for the destructive oxidation of cyanide has a high cyanide-to-copper ratio, to minimize the final concentration of Cu(CN)2- which consumes peroxide inefficiently. The rate of the reaction depends on the concentration of copper, however, which must be large enough for a satisfactory turnover.
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Koenigsmann, Christopher, Leena N. Rachid, Christina M. Sheedy, and Peter W. R. Corfield. "Synthesis, decomposition studies and crystal structure of a three-dimensional CuCN network structure with protonated N-methylethanolamine as the guest cation." Acta Crystallographica Section C Structural Chemistry 76, no. 5 (April 17, 2020): 405–11. http://dx.doi.org/10.1107/s2053229620004477.
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The compound poly[2-hydroxy-N-methylethan-1-aminium [μ3-cyanido-κ3 C:C:N-di-μ-cyanido-κ4 C:N-dicuprate(I)]], {(C3H10NO)[Cu2(CN)3]} n or [meoenH]Cu2(CN)3, crystallizes in the tetragonal space group P43. The structure consists of a three-dimensional (3D) anionic CuICN network with noncoordinated protonated N-methylethanolamine cations providing charge neutrality. Pairs of cuprophilic Cu atoms are bridged by the C atoms of μ3-cyanide ligands, which link these units into a 43 spiral along the c axis. The spirals are linked together into a 3D anionic network by the two other cyanide groups. The cationic moieties are linked into their own 43 spiral via N—H...O and O—H...O hydrogen bonds, and the cations interact with the 3D network via an unusual pair of N—H...N hydrogen bonds to one of the μ2-cyanide groups. Thermogravimetric analysis indicates an initial loss of the base cation and one cyanide as HCN at temperatures in the range 130–250 °C to form CuCN. We show how loss of a specific cyanide group from the 3D CuCN structure could form the linear CuCN structure. Further heating leaves a residue of elemental copper, isolated as the oxide.
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Ibebunjo, C., Beryl P. Kamalu, and E. C. Ihemelandu. "Comparison of the effects of cassava (Manihot esculenta Crantz) organic cyanide and inorganic cyanide on muscle and bone development in a Nigerian breed of dog." British Journal of Nutrition 68, no. 2 (September 1992): 483–91. http://dx.doi.org/10.1079/bjn19920106.
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Effects of cassava (Manihot esculenta Crantz)-borne organic cyanide and inorganic cyanide in the form of sodium cyanide on bone and muscle development were investigated in eighteen dogs of Nigerian breed. After 16 weeks of stabilization in the laboratory from the time of purchase when the dogs were fed on the same diet, they were randomly assigned to three experimental groups of six dogs each. The control group was fed on rice while the other two groups were fed on either cassava (gari) or rice plus cyanide. The three diets were made isoenergetic and isonitrogenous by varying the quantity of meat incorporated into them. The results obtained after 14 weeks of feeding the respective diets indicated that there was retardation of muscle development in the gari-fed dogs. This may have resulted from gluconeogenesis from muscle protein associated with suppression of production of insulin by the pancreas in this group. The results indicated also that the effects of inorganic dietary cyanides on muscle development were different. Both forms of dietary cyanides, however, had no adverse effect on bone development
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Sereda, Olha, and Helen Stoeckli-Evans. "Crystal structures of {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O}nand {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n[where Lpn = (R)-propane-1,2-diamine]: two heterometallic chiral cyanide-bridged coordination polymers." Acta Crystallographica Section E Crystallographic Communications 71, no. 4 (March 21, 2015): 392–97. http://dx.doi.org/10.1107/s2056989015005253.
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The title compounds,catena-poly[[[bis[(R)-propane-1,2-diamine-κ2N,N′]copper(II)]-μ-cyanido-κ2N:C-[tris(cyanido-κC)(nitroso-κN)iron(III)]-μ-cyanido-κ2C:N] monohydrate], {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O}n, (I), and poly[[hexa-μ-cyanido-κ12C:N-hexacyanido-κ6C-hexakis[(R)-propane-1,2-diamine-κ2N,N′]dichromium(III)tricopper(II)] pentahydrate], {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n, (II) [where Lpn = (R)-propane-1,2-diamine, C3H10N2], are new chiral cyanide-bridged bimetallic coordination polymers. The asymmetric unit of compound (I) is composed of two independent cation–anion units of {[Cu(Lpn)2][Fe(CN)5)(NO)]} and two water molecules. The FeIIIatoms have distorted octahedral geometries, while the CuIIatoms can be considered to be pentacoordinate. In the crystal, however, the units align to form zigzag cyanide-bridged chains propagating along [101]. Hence, the CuIIatoms have distorted octahedral coordination spheres with extremely long semicoordination Cu—N(cyanido) bridging bonds. The chains are linked by O—H...N and N—H...N hydrogen bonds, forming two-dimensional networks parallel to (010), and the networks are linkedviaN—H...O and N—H...N hydrogen bonds, forming a three-dimensional framework. Compound (II) is a two-dimensional cyanide-bridged coordination polymer. The asymmetric unit is composed of two chiral {[Cu(Lpn)2][Cr(CN)6]}−anions bridged by a chiral [Cu(Lpn)2]2+cation and five water molecules of crystallization. Both the CrIIIatoms and the central CuIIatom have distorted octahedral geometries. The coordination spheres of the outer CuIIatoms of the asymmetric unit can be considered to be pentacoordinate. In the crystal, these units are bridged by long semicoordination Cu—N(cyanide) bridging bonds forming a two-dimensional network, hence these CuIIatoms now have distorted octahedral geometries. The networks, which lie parallel to (10-1), are linkedviaO—H...O, O—H...N, N—H...O and N—H...N hydrogen bonds involving all five non-coordinating water molecules, the cyanide N atoms and the NH2groups of the Lpn ligands, forming a three-dimensional framework.
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Dong, Kaiwei, Feng Xie, Wei Wang, Yongfeng Chang, Chunlin Chen, and Xiaowei Gu. "Calcination of Calcium Sulphoaluminate Cement Using Pyrite-Rich Cyanide Tailings." Crystals 10, no. 11 (October 26, 2020): 971. http://dx.doi.org/10.3390/cryst10110971.
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Pyrite-rich cyanide tailings (CTs) are industrial hazardous solid wastes arising from the gold mining industry. Every year, hundreds of millions of tons of cyanide tailings are produced and discharged to tailings dams. It is of great significance to dispose of cyanide tailings harmlessly and resourcefully. The feasibility of calcination of calcium sulphoaluminate (CSA) cement clinker using pyrite-rich cyanide tailings as Fe2O3 and SO3 sources was investigated for this paper. The behavior of pyrite during the calcination of cyanide tailings under various calcination conditions and the properties of calcium sulphoaluminate cement clinker were examined. The results show that it is feasible to produce calcium sulphoaluminate cement clinker using pyrite-rich cyanide tailings. The optimal conditions for the calcination of calcium sulphoaluminate cement using pyrite-rich cyanide tailings are confirmed. During the calcination process, the cyanides decompose into carbonate, CO2, and N2. The pyrite decomposes into Fe2O3 and SO2, and they react with CaO and Al2O3 to form the intermediates of CaSO4, 2CaO·Fe2O3, and CaO·2Al2O3, which further react to form 3CaO·3Al2O3·CaSO4, 4CaO·Al2O3·Fe2O3, and 12CaO·7Al2O3. The calcium sulphoaluminate cement prepared by pyrite-rich cyanide tailings exhibits excellent mechanical properties and meets the compressive strength criteria of 42.5 grade calcium sulphoaluminate cement.
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Sobieh, Shaimaa S., Rasha Abed El-Gammal, Wafaa S. Abu El-Kheir, Alia A. El-Sheimy, Alaa A. Said, and Yassein M. El-Ayouty. "Heterologous Expression of Cyanobacterial Cyanase Gene (CYN) in Microalga Chlamydomonas reinhardtii for Bioremediation of Cyanide Pollution." Biology 11, no. 10 (September 29, 2022): 1420. http://dx.doi.org/10.3390/biology11101420.
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Recombinant DNA technology offered the creation of new combinations of DNA segments that are not found together in nature. The present study aimed to produce an ecofriendly bioremediation model to remediate cyanide pollution from a polluted marine system. Cyanide is a known toxic compound produced through natural and anthropogenic activities. An Agrobacterium-tumefaciens-mediated genetic transformation technique was used to generate transformed Chlamydomonas reinhardtii using plant expression vector pTRA-K-cTp carries isolated coding sequence of the cyanobacterial cyanase gene (CYN) isolated from Synechococcus elongatus (PCC6803). qRT-PCR analysis showed the overexpression of CYN in transgenic C. reinhardtii, as compared with the respective wild type. Growth parameters and biochemical analyses were performed under cyanide stress conditions using transgenic and wild C. reinhardtii for evaluating the effect of the presence of the cyanobacterial cyanase gene in algae. The transgenic C. reinhardtii strain (TC. reinhardtii-2) showed promising results for cyanide bioremediation in polluted water samples. Cyanide depletion assays and algal growth showed a significant resistance in the transgenic type against cyanide stress, as compared to the wild type. Genetically modified alga showed the ability to phytoremediate a high level of potassium cyanide (up to150 mg/L), as compared to the wild type. The presence of the CYN gene has induced a protection response in TC. Reinhardtii-2, which was shown in the results of growth parameter analyses. Therefore, the present study affirms that transgenic C. reinhardtii by the CYN coding gene is a potential effective ecofriendly bioremediator model for the remediation of cyanide pollutants in fresh water.
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Qin, Ying-Lian, Hong Sun, Yan Jing, Xiu-Ping Jiang, Gao-Feng Wang, and Jian-Fang Qin. "A novel three-dimensional copper(I) cyanide coordination polymer constructed from various bridging ligands: synthesis, crystal structure and characterization." Acta Crystallographica Section C Structural Chemistry 75, no. 11 (October 23, 2019): 1517–23. http://dx.doi.org/10.1107/s2053229619014025.
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The cyanide ligand can act as a strong σ-donor and an effective π-electron acceptor that exhibits versatile bridging abilities, such as terminal, μ2-C:N, μ3-C:C:N and μ4-C:C:N:N modes. These ligands play a key role in the formation of various copper(I) cyanide systems, including one-dimensional (1D) chains, two-dimensional (2D) layers and three-dimensional (3D) frameworks. According to the literature, numerous coordination polymers based on terminal, μ2-C:N and μ3-C,C,N bridging modes have been documented so far. However, systems based on the μ4-C:C:N:N bridging mode are relatively rare. In this work, a novel cyanide-bridged 3D CuI coordination framework, namely poly[(μ2-2,2′-biimidazole-κ2 N 3:N 3′)(μ4-cyanido-κ4 C:C:N:N)(μ2-cyanido-κ2 C:N)dicopper(I)], [Cu2(CN)2(C6H6N4)] n , (I), was synthesized hydrothermally by reaction of environmentally friendly K3[Fe(CN)6], CuCl2·2H2O and 2,2′-biimidazole (H2biim). It should be noted that cyanide ligands may act as reducing agents to reduce CuII to CuI under hydrothermal conditions. Compound (I) contains diverse types of bridging ligands, such as μ4-C:C:N:N-cyanide, μ2-C:N-cyanide and μ2-biimidazole. Interestingly, the [Cu2] dimers are bridged by rare μ4-C:C:N:N-mode cyanide ligands giving rise to the first example of a 1D dimeric {[Cu2(μ4-C:C:N:N)] n+} n infinite chain. Furthermore, adjacent dimer-based chains are linked by μ2-C:N bridging cyanide ligands, generating a neutral 2D wave-like (4,4) layer structure. Finally, the 2D layers are joined together via bidentate bridging H2biim to create a 3D cuprous cyanide network. This arrangement leads to a systematic variation in dimensionality from 1D chain→2D sheet→3D framework by different types of bridging ligands. Compound (I) was further characterized by thermal analysis, solid-state UV–Vis diffuse-reflectance and photoluminescence studies. The solid-state UV–Vis diffuse-reflectance spectra show that compound (I) is a wide-gap semiconductor with band gaps of 3.18 eV. The photoluminescence study shows a strong blue–green photoluminescence at room temperature, which may be associated with metal-to-ligand charge transfer.
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Liu, Ying, Baogang Sun, Wenting Jia, Yuan Wang, Lijia Huang, Pengge Ning, and Shaojun Yuan. "Study on Removal Mechanism for Copper Cyanide Complex Ions in Water: Ion Species Differences and Evolution Process." International Journal of Molecular Sciences 24, no. 6 (March 7, 2023): 5066. http://dx.doi.org/10.3390/ijms24065066.
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A large amount of cyanide-containing wastewater is discharged during electrode material synthesis. Among them, cyanides will form metal–cyanide complex ions which possess high stability, making it challenging to separate them from these wastewaters. Therefore, it is imperative to understand the complexation mechanism of cyanide ions and heavy metal ions from wastewater in order to obtain a deep insight into the process of cyanide removal. This study employs Density Functional Theory (DFT) calculations to reveal the complexation mechanism of metal–cyanide complex ions formed by the interaction of Cu+ and CN− in copper cyanide systems and its transformation patterns. Quantum chemical calculations show that the precipitation properties of Cu(CN)43− can assist in the removal of CN−. Therefore, transferring other metal–cyanide complex ions to Cu(CN)43− can achieve deep removal. OLI studio 11.0 analyzed the optimal process parameters of Cu(CN)43− under different conditions and determined the optimal process parameters of the removal depth of CN−. This work has the potential to contribute to the future preparation of related materials such as CN− removal adsorbents and catalysts and provide theoretical foundations for the development of more efficient, stable, and environmentally friendly next-generation energy storage electrode materials.
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Randi, Elisa B., Karim Zuhra, Laszlo Pecze, Theodora Panagaki, and Csaba Szabo. "Physiological concentrations of cyanide stimulate mitochondrial Complex IV and enhance cellular bioenergetics." Proceedings of the National Academy of Sciences 118, no. 20 (May 10, 2021): e2026245118. http://dx.doi.org/10.1073/pnas.2026245118.
Full textAbstract:
In mammalian cells, cyanide is viewed as a cytotoxic agent, which exerts its effects through inhibition of mitochondrial Complex IV (Cytochrome C oxidase [CCOx]). However, the current report demonstrates that cyanide’s effect on CCOx is biphasic; low (nanomolar to low-micromolar) concentrations stimulate CCOx activity, while higher (high-micromolar) concentrations produce the “classic” inhibitory effect. Low concentrations of cyanide stimulated mitochondrial electron transport and elevated intracellular adenosine triphosphate (ATP), resulting in the stimulation of cell proliferation. The stimulatory effect of cyanide on CCOx was associated with the removal of the constitutive, inhibitory glutathionylation on its catalytic 30- and 57-kDa subunits. Transfer of diluted Pseudomonas aeruginosa (a cyanide-producing bacterium) supernatants to mammalian cells stimulated cellular bioenergetics, while concentrated supernatants were inhibitory. These effects were absent with supernatants from mutant Pseudomonas lacking its cyanide-producing enzyme. These results raise the possibility that cyanide at low, endogenous levels serves regulatory purposes in mammals. Indeed, the expression of six putative mammalian cyanide-producing and/or -metabolizing enzymes was confirmed in HepG2 cells; one of them (myeloperoxidase) showed a biphasic regulation after cyanide exposure. Cyanide shares features with “classical” mammalian gasotransmitters NO, CO, and H2S and may be considered the fourth mammalian gasotransmitter.
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Da Cruz, Abby, María Daza, Sandra Zavala, Steve Camargo, and Nadia Balbin. "Detoxification of effluents with cyanide. Application on a cyanide gossan mineral." E3S Web of Conferences 433 (2023): 01005. http://dx.doi.org/10.1051/e3sconf/202343301005.
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The process of cyanidation is employed to extract the gold and silver components from minerals. As a result of this procedure, the production of effluents and solid waste occurs, wherein the presence of free cyanide is observed as the most hazardous form. The application of degrading processes can facilitate the transformation of cyanides in solution into forms that are less hazardous. The aim of this study is to investigate the degradation of cyanide effluents using either sodium hypochlorite or ozone. The primary purpose is to identify the optimal conditions for the degradation of total cyanide while ensuring the absence of any other pollutants. The cyanidation process will be implemented under optimal conditions for the purpose of recovering gold and silver from Gossan ore. The gossan ore sourced from Rio Tinto in Huelva, Spain, finds application in the detoxification of cyanide effluents. Characterization techniques are employed to identify the predominant elements present in the ore, namely iron (25.0%) and silicon (21.2%). The process of cyanide breakdown with ozone treatment yields carbonates, which are significantly more ecologically sustainable in comparison to cyanates formed by hypochlorite. Nevertheless, the utilization of ozone in mining is limited due to some disadvantages, namely its exorbitant cost and excessive consumption.
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Meillier, Andrew, and Cara Heller. "Acute Cyanide Poisoning: Hydroxocobalamin and Sodium Thiosulfate Treatments with Two Outcomes following One Exposure Event." Case Reports in Medicine 2015 (2015): 1–4. http://dx.doi.org/10.1155/2015/217951.
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Cyanide is rapidly reacting and causes arrest of aerobic metabolism. The symptoms are diffuse and lethal and require high clinical suspicion. Remediation of symptoms and mortality is highly dependent on quick treatment with a cyanide antidote. Presently, there are two widely accepted antidotes: sodium thiosulfate and hydroxocobalamin. These treatments act on different components of cyanide’s metabolism. Here, we present two cases resulting from the same source of cyanide poisoning and the use of both antidotes separately used with differing outcomes.
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Ofori-Sarpong, G., A. S. Adam, and R. K. Amankwah. "Detoxification of Cyanide Wastewater by Cyanotrophic Organisms: the case of Phanerochaete chrysosporium." Ghana Mining Journal 20, no. 1 (July 7, 2020): 34–44. http://dx.doi.org/10.4314/gm.v20i1.4.
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Abstract
Cyanide, a carbon-nitrogen radical, is a major building block in many industries including pharmaceuticals, petrochemical and gold processing. In the gold extraction industry, cyanide has been the universal lixiviant for over a century due to better understood process chemistry, among others. Industries that discharge cyanide-laden effluents are mandated to keep concentrations below 0.2 mg/L to prevent death by cyanide-intoxification, which occurs when cyanide binds to key iron-containing enzymes and prevent them from supplying oxygen-containing blood to the tissues. Techniques used to attenuate cyanide in wastewater can broadly be grouped into chemical, physical and biological methods. In recent times, attention has been placed on biotechnological methods, which make use of cyanotrophic microorganisms to clean up cyanide-contaminated environments. This paper reports on studies set out to assess the ability of Phanerochaete chrysosporium to degrade cyanide under different conditions including changes in cyanide concentration, culture mass, time, closed system and open system. At the end of 24-hour contact in an open agitated system with initial pH of 11.5, a control experiment using 100 mg/L cyanide revealed a natural attenuation of 15% with pH decreasing to 9.88, while the best myco-detoxification of 85% was achieved by contacting 100 mg/L cyanide with 0.5 g culture mass, translating into degradation capacity of 17.2 mg/g (milligram of cyanide per gram of culture) with pH reducing to 8.4 in 24 hours. The degradation could be based on a number of mechanisms including hydrolysis to HCN, oxidation to cyanyl radical and cyanate due to natural attenuation through atmospheric contact, and secretion of organic acid, oxidative enzymes, and hydrogen peroxide by the fungus.
Keywords: Cyanotrophic Organism, Myco-Detoxification, Cyanide-Laden Effluents, pH
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Afianisa, Salma, Endang Saepudin, Bambang Sunarko, and Nunik Sulistinah. "Biodegradation Potential of Cyanide and Nitrile using Bacteria of The Genus Rhodococcus." Syntax Literate ; Jurnal Ilmiah Indonesia 9, no. 6 (July 3, 2024): 3765–75. http://dx.doi.org/10.36418/syntax-literate.v9i6.16689.
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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.
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Watanabe, A., K. Yano, K. Ikebukuro, and I. Karube. "Cyanide hydrolysis in a cyanide-degrading bacterium, Pseudomonas stutzeri AK61, by cyanidase." Microbiology 144, no. 6 (June 1, 1998): 1677–82. http://dx.doi.org/10.1099/00221287-144-6-1677.
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Shao, Xiu-Dan, and Chun-Hua Yu. "An organic–inorganic hybrid compound containing imidazolium cations and a one-dimensional lithium hexacyanidocobaltate-based anionic framework." Acta Crystallographica Section C Structural Chemistry 70, no. 6 (May 23, 2014): 603–5. http://dx.doi.org/10.1107/s2053229614011541.
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An organic–inorganic hybrid compound,catena-poly[bis(3H-imidazol-1-ium) [[tetracyanido-κ4C-cobalt(III)]-μ-cyanido-κ2C:N-[diaqualithium(I)]-μ-cyanido-κ2N:C]], {(C3H5N2)2[CoLi(CN)6(H2O)2]}n, was synthesized by the reaction of Li3[Co(CN)6] with imidazolium chloride in aqueous solution. The compound crystallizes in the monoclinic space groupC2/c(data collected at 273 K). In the crystal structure, neighbouring [Co(CN)6]3−anionic units are linked by Li+cations through the cyanide groups in atransmode, forming a one-dimensional zigzag chain structure extending along thecaxis. A three-dimensional supramolecular network is formed through hydrogen-bonding interactions and is further stabilized by weak CN...π interactions between the cyanide groups and the imidazolium cations.
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RAMIREZ, CARLOS DARIO LOPEZ, DAIRO E. CHAVERRA, and OSCAR JAIME RESTREPO BAENA. "Obtaining Urea from Effluents of Gold Cyanidation Process." Material Science Research India 16, no. 1 (April 23, 2019): 43–47. http://dx.doi.org/10.13005/msri/160106.
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Cyanide is one of the most used reagents in the precious metal extraction process; as well as the most efficient from the point of view of the dissolution process, but it is also a toxic product that requires a lot of care in handling. Likewise, the residual solutions of the process must be followed because they can be a risk of contamination of water, animals and human health. In the artisanal processes of obtaining gold and silver, neutralization of the residual solutions is used to passivate the present cyanide. During this process ammonium cyanate is formed which decomposes rapidly in the presence of air and sunlight in carbon dioxide and ammonia gas, contributing to the greenhouse effect. In this work, the use of the ammonium cyanate obtained in the process of neutralization of the cyanide solutions as a reagent to obtain urea is proposed. Urea was obtained indirectly through the use of the reagent kit UREA/BUN-COLOR. The process is effective at pH ≤ 4.5 with a rapid increase in solution temperature and the addition of hydrogen peroxide. The urea crystals begin to form at 50°C. The cyanide/urea ratio obtained was 1/7.5.
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Christoffers, Jens, and David Kieslich. "Cyanide Anions as Nucleophilic Catalysts in Organic Synthesis." Synthesis 53, no. 19 (May 5, 2021): 3485–96. http://dx.doi.org/10.1055/a-1499-8943.
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AbstractThe nucleophilic addition of a cyanide anion to a carbonyl group is the basis for several cyanide-catalyzed organic reactions, which are summarized in this review. Since cyanide is also a good leaving group, it is an excellent catalyst for transacylation reactions. As an electron-withdrawing group, it also stabilizes a negative charge in its α-position, thus allowing the umpolung of aldehydes to formyl anion equivalents. The two leading examples are the benzoin condensation and the Michael–Stetter reaction furnishing α-hydroxy ketones and 1,4-dicarbonyl compounds, which are both catalyzed by cyanides. The review also covers variants like the silyl-benzoin coupling, the aldimine coupling and the imino-Stetter reaction. Moreover, some cyanide-catalyzed heterocyclic syntheses are reviewed.1 Introduction2 Nucleophilic Additions2.1 Cyanohydrin Formation2.2 Corey–Gilman–Ganem and Related Oxidation Reactions2.3 Conjugate Addition2.4 Intramolecular Carbocyanation3 Transacylation Reactions3.1 Ester Hydrolysis and Transesterification3.2 Formation of Amides3.3 Ketones from Esters3.4 Esters from Ketones4 Transformations Involving an Umpolung4.1 Benzoin Condensation4.2 Aldimine Coupling4.3 Michael–Stetter Reaction4.4 Imino-Stetter Reaction5 Formation of Heterocycles5.1 Oxazolines from Isocyanoacetates5.2 Imidazoles from TosMIC via Oxazolines5.3 Bargellini Reaction6 Conclusion
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Connors, Richard, Elisabeth Tran, and Tony Durst. "Acyl cyanides as carbonyl heterodienophiles: application to the synthesis of naphthols, isoquinolones, and isocoumarins." Canadian Journal of Chemistry 74, no. 2 (February 1, 1996): 221–26. http://dx.doi.org/10.1139/v96-024.
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Irradiation of 2-methylbenzoyl cyanide (3a) in acetonitrile solution results in the formation of its dimer, which upon loss of HCN gives rise to the cycloadduct 7a. The dimerization also proceeds efficiently with derivatives of 3a giving adducts 7b and 7c. When 2-methylaroyl cyanides are photolyzed in the presence of a more reactive acyl cyanide the mixed adducts 8a–e are obtained in excellent yields. The cycloadducts 7a–c and 8a–e react with carbon and nitrogen nucleophiles by a tandem addition–cyclization sequence furnishing substituted naphthols (10a and 10b) and isoquinolones (11a–d), respectively. Isocoumarins 12a and 12b were prepared from the adducts 8a and 8e by treatment with potassium tert-butoxide in THF. Key words: naphthols, isoquinolones, isocoumarins, synthesis of; acyl cyanides; hetero Diels–Alder.
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Asnaashari, Solmaz, Simin Keshavarz, Abbas Delazar, Yaser Sarvari, and Parina Asgharian. "GC-MS Analysis, Antioxidant and Antimicrobial Screening of Volatile Oil of Lepidium vesicarium." Pharmaceutical Sciences 24, no. 3 (September 23, 2018): 246–49. http://dx.doi.org/10.15171/ps.2018.36.
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Background: Lepidium vesicarium (Cruciferae), one of the important medicinal plants with a long history of medicinal use. The current study was designed to evaluate the free radical scavenging and antimicrobial activities of the L. vesicarium EO as one of the Iranian plant species. Methods: The compositions of the EO from the aerial parts of L. vesicarium were analyzed by GC-MS and GC-FID. Furthermore, anti-oxidant and anti-microbial potentials were investigated via DPPH reagent and disk diffusion procedure, respectively. Results: A total of 18 compounds amounting 97.70% of the oil have been identified, while Benzyl cyanide (43.94%), Isothio cyanic acid (22.69%) and Benzyl isothio cyanate (20.69%) were the main constituents. The EO showed no activity against the free radicals and studied microbial strains (gram positive and gram negative and also fungi species). Conclusion: On the whole, the presence of cyanide derivatives in studied EO revealed the rational use of this plant in medicine. Comparing with other genesis of Lepidium, anti-oxidant and anti -microbial properties of L. vesicarium essential oil were not noticeable.
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Kwon, Sung-Hyun, and Dae-Chul Cho. "Cyanide Degradation by Two Recombinant Cyanide Hydratases." Journal of the Korea Academia-Industrial cooperation Society 10, no. 6 (June 30, 2009): 1287–91. http://dx.doi.org/10.5762/kais.2009.10.6.1287.
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Jobe, David J., and Kenneth Charles Westaway. "Fourier transform infrared spectroscopy studies of cyanide ion solutions of dimethylformamide and aqueous dimethylformamide." Canadian Journal of Chemistry 71, no. 9 (September 1, 1993): 1353–61. http://dx.doi.org/10.1139/v93-175.
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Fourier transform infrared spectroscopy has been used to investigate the behaviour of HCN and alkali metal and tetraethylammonium cyanides in DMF and aqueous DMF. The cyanide ion exists as free ions and ion pairs in pure DMF but as water-solvated and DMF-solvated ions in aqueous DMF. The aqueous DMF solutions can be treated as a pseudo two-phase system with a distribution coefficient of 0.018 between the aqueous and DMF-rich pseudo phases. A kinetic analysis of the cyanide ion – benzyl chloride reaction in DMF and aqueous DMF has shown that the rate constant for the SN2 reaction is markedly decreased with the addition of as little as 2.5% water. This decrease is primarily due to changes in transition state solvation. The SN2 reactions between cyanide ion and benzylmethyl-4-substituted phenylsulphonium perchlorates in 20% aqueous DMF have also been investigated.
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Srivastav, Satyam, Milan Sil, Prasanta Gorai, Amit Pathak, Bhalamurugan Sivaraman, and Ankan Das. "Astrochemical model to study the abundances of branched carbon-chain molecules in a hot molecular core with realistic binding energies." Monthly Notices of the Royal Astronomical Society 515, no. 3 (August 3, 2022): 3524–38. http://dx.doi.org/10.1093/mnras/stac1904.
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ABSTRACT Straight-chain (normal-propyl cyanide, $\rm {n-C_3H_7CN}$) and branched-chain (iso-propyl cyanide, $\rm {i-C_3H_7CN}$) alkyl cyanides are recently identified in the massive star-forming regions (Sgr B2(N) and Orion). These branched-chain molecules indicate that the key amino acids (side-chain structures) may also be present in a similar region. The process by which this branching could propagate towards the higher order (butyl cyanide, $\rm {C_4H_9CN}$) is an active field of research. Since the grain catalysis process could have formed a major portion of these species, considering a realistic set of binding energies are indeed essential. We employ quantum chemical calculations to estimate the binding energy of these species considering water as a substrate because water is the principal constituent of this interstellar ice. We find significantly lower binding energy values for these species than were previously used. It is noticed that the use of realistic binding energy values can significantly change the abundance of these species. The branching is more favourable for the higher order alkyl cyanides with the new binding energies. With the inclusion of our new binding energy values and one essential destruction reaction ($\rm {i-C_3H_7CN+H \rightarrow CH_3C(CH_3)CN + H_2}$, having an activation barrier of 947 K), abundances of $\rm {t-C_4H_9CN}$ dramatically increased.
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Zalesov, M. V., V. A. Grigoreva, V. S. Trubilov, and A. Ya Boduen. "Designing of engineering solutions to enhance efficiency of high-copper gold-bearing ore processing." Mining Industry Journal (Gornay Promishlennost), no. 5/2021 (November 12, 2021): 51–56. http://dx.doi.org/10.30686/1609-9192-2021-5-51-56.
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The modern metals industry is characterised by a downward trend in the quality of ores involved in processing, and conventional methods of extracting useful components are inefficient for raw materials with complex composition. To maintain the growing level of metal production it is required to introduce new efficient technologies for processing of low-grade and refractory ores as well as man-made deposits. The article describes processing methods of refractory raw materials with high cyanide content using copper-gold ores as an example, where gold is the primary commodity, and copper is the accompanying useful component. The most common method of processing copper-gold ores is preconcentration followed by selective leaching of copper and gold. In some cases, technologies involving copper by-products and cyanide recovery from the cyanide leaching solutions offer equally effective options for processing of the copper-gold ores and concentrates. Copper-gold ores are processed at gold mines using the cyanide procedures, supplemented if required by gravity and flotation concentration. In all variations of the cyanide treatment, most of copper minerals actively react with cyanides of alkali metals, binding the CN– ions into the copper complex of [Cu(CN3)]2–. This reaction results in an increased solvent consumption, as well as in number of challenges related to cleaning tailings and slurries from highly toxic cyanide compounds and dissolved copper. In addition to technological complications associated with the need to meet strict requirements for the maximum permissible concentrations, copper accumulated in the cycling solutions also causes a decrease in gold extraction from the processed ores.
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Rader, W. Scott, Ljiljana Solujic, E. B. Milosavljevic, J. L. Hendrix, and J. H. Nelson. "Photochemistry of Aqueous Solutions of Dicyanomercury(II) and Potassium Tetracyanomercurate(II)." Journal of Solar Energy Engineering 116, no. 3 (August 1, 1994): 125–29. http://dx.doi.org/10.1115/1.2930070.
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Photochemically induced reactions of dicyanomercury(II) and potassium tetracyanomercurate(II) in alkaline aqueous solutions were investigated in detail. The studies were conducted in the presence or absence of a titanium(IV) oxide semiconductor photocatalyst utilizing sunlight as the irradiation source. It was established that the cyanide ion liberated from the thermodynamically stable mercury-cyano species can be photocatalytically oxidized via cyanate and nitrite to nitrate. In addition, the process removes over 99 mol% of mercury from the solution. In the absence of the photocatalyst, no photoproducts were detected and mercury remained in solution. The results obtained may have ramifications for the use of solar power for the efficient treatment of large quantities of precious metals mill tailings wastes containing various cyanide species. In addition, in order to follow the fate of cyanide in these experiments, a novel gas-diffusion flow injection analysis system for the determination of cyanide from the thermodynamically stable mercury-cyano complexes was utilized.
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Mitsudo, Koichi, Kazuki Yoshioka, Takayuki Hirata, Hiroki Mandai, Koji Midorikawa, and Seiji Suga. "1,10-Phenanthroline- or Electron-Promoted Cyanation of Aryl Iodides." Synlett 30, no. 10 (April 11, 2019): 1209–14. http://dx.doi.org/10.1055/s-0037-1611793.
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A 1,10-phenanthroline-promoted cyanation of aryl iodides has been developed. 1,10-Phenanthroline worked as an organocatalyst for the reaction of aryl iodides with tetraalkylammonium cyanide to afford aryl cyanides. A similar reaction occurred through an electroreductive process.
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Qin, Ying-Lian, Jian-Fang Qin, and Hong Sun. "A novel tetrazolate- and cyanide-bridged three-dimensional heterometallic coordination polymer: crystal structure, thermal stability and magnetic properties." Acta Crystallographica Section C Structural Chemistry 73, no. 11 (October 19, 2017): 968–74. http://dx.doi.org/10.1107/s2053229617014760.
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By using environmentally friendly K3[Co(CN)6] as a cyanide source, the solvothermal reaction of CuCl2 and tetrazole (Htta) led to a novel tetrazolate- and cyanide-bridged three-dimensional heterometallic CuII–CoIII complex, namely poly[[hexa-μ2-cyanido-κ12 C:N-pentakis(μ3-tetrazolato-κ3 N 1:N 2:N 4)cobalt(III)tetracopper(II)] monohydrate], {[CoIIICuII 4(CHN4)5(CN)6]·H2O} n , (I). The crystal structure analysis reveals that it is the first example of a (6,8,8)-connected three-dimensional framework with a unique topology, constructed from anionic [Co(CN)6]3− and cationic [(Cu1)2(tta)2]2+ and [(Cu2Cu3)(tta)3]+ units through μ2-cyanide and μ3-tetrazolate linkers. The compound was further characterized by thermal analysis, vibrational spectroscopy (FT–IR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM–EDS) and magnetic measurements. The magnetic investigation indicates that the complex exhibits antiferromagnetic coupling between adjacent CuII cations.
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Gosi, Mahesh, Nagaraju Marepu, and Yeturu Sunandamma. "Cyanine-based Fluorescent Probe for Cyanide Ion Detection." Journal of Fluorescence 31, no. 5 (July 9, 2021): 1409–15. http://dx.doi.org/10.1007/s10895-021-02771-8.
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Singh, Hariraj, and Brijesh Kumar Mishra. "Degradation of cyanide, aniline and phenol in pre-treated coke oven wastewater by peroxide assisted electro-oxidation process." Water Science and Technology 78, no. 10 (December 10, 2018): 2214–27. http://dx.doi.org/10.2166/wst.2018.503.
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Abstract The present study explored the feasibility of using graphite electrodes for the electrochemical oxidation of cyanide, thiocyanate, phenol and aniline with hydrogen peroxide. The dosing effects of hydrogen peroxide and current density were examined in the pre-treated coke oven wastewater. It was found that 0.025 M hydrogen peroxide and 13.63 mA/cm2 of current density were more favorable for the removal of 100%, 90%, 71% and 40% cyanide, thiocyanate, phenol and aniline respectively. The increased removal of phenol in the coke oven wastewater was attributed to the pre-treatment of wastewater. Initially, 28% phenol was converted to phenolate ion by air stripping process, which increased the removal rate of phenol by the electro-oxidation process as the removal of phenolate is quite easy compared to phenol. The advanced oxidation process degrades the more toxic cyanide into less toxic intermediate cyanate ions (CNO─), which further cut down into nontoxic end products such as N2, HCO3 and CO2. The experimental results show that the primary mechanisms in the oxidation of cyanide and phenol are mediated electro-oxidation by hydroxyl radicals and hypochlorite ions. The operating cost under the optimized conditions for the removal of 100% cyanide and 71% phenol was estimated to be 616.95 INR/m3.
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Mediavilla, Juan Jose Viña, Begoña Fernandez Perez, Maria C. Fernandez de Cordoba, Julia Ayala Espina, and Conchi O. Ania. "Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater." Molecules 24, no. 7 (April 8, 2019): 1373. http://dx.doi.org/10.3390/molecules24071373.
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We have explored the simultaneous degradation of cyanides and thiocyanate present in wastewaters from a cokemaking factory using photoassisted methods under varied illumination conditions (from simulated solar light to UV light). Overall, the photochemical degradation of cyanides was more efficient than that of thiocyanates, regardless of the illumination conditions, the effect being more pronounced in the absence of a photocatalyst. This is due to their different degradation mechanism that in the case of thiocyanates is dominated by fast recombination reactions and/or charge transfer reactions to electron scavengers. In all cases, cyanate, ammonia, nitrates, and nitrites were formed at different amounts depending on the illumination conditions. The conversion yield under simulated solar light was almost complete for cyanides and quite high for thiocyanates after 6 h of illumination. Regarding toxicity, photochemical oxidation at 254 nm and under simulated solar light decreased significantly the toxicity of the pristine wastewater, showing a correlation with the intensity of the irradiation source. This indicate that simulated light can be effectively used to reduce the toxicity of industrial effluents, opening an interesting perspective for optimizing cyanide detoxification systems based on natural light.
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Ciaccafava, Alexandre, Daria Tombolelli, Lilith Domnik, Jae-Hun Jeoung, Holger Dobbek, Maria-Andrea Mroginski, Ingo Zebger, and Peter Hildebrandt. "Carbon Monoxide Dehydrogenase Reduces Cyanate to Cyanide." Angewandte Chemie International Edition 56, no. 26 (May 23, 2017): 7398–401. http://dx.doi.org/10.1002/anie.201703225.
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Hsieh, Chia-Jung, and Chi-Yang Yu. "Cyanate Degradation in Different Matrices Using Heat-Purified Enzymes." Catalysts 13, no. 1 (December 30, 2022): 76. http://dx.doi.org/10.3390/catal13010076.
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A green and low-cost removal method for cyanate, a toxic byproduct from the treatment of cyanide, is still needed. Cyanase converts cyanate to CO2 and NH3, but its industrial practicality is limited because the reaction requires HCO3− as a substrate. In this study, we used carbonic anhydrase from Sulfurihydrogenibium azorense (SazCA) to provide HCO3− for cyanase from Thermomyces lanuginosus (TlCyn); both TlCyn and SazCA were purified by one-step heating without prior cell lysis. The heat treatment resulted in higher activities of both enzymes than the conventional two-step process. From a 50 mL-culture, the highest total activity of 147 U and 47,174 WAU was obtained from 5 min of heating at 60 and 80 °C for TlCyn and SazCA, respectively. The coupled enzymatic system was used to degrade cyanate in three different matrices: 50 mM Tris-HCl (pH 8), industrial wastewater, and artificial wastewater. In the industrial wastewater, with the addition of 0.75 WAU (Wilbur-Anderson unit) of SazCA, cyanate degradation using 0.5 mM NaHCO3 was similar to that using 3 mM NaHCO3, indicating an 83% reduction in NaHCO3. We have demonstrated that the dependence on HCO3− of cyanate degradation can be effectively alleviated by using low-cost heat-purified TlCyn and SazCA; the industrial practicality of the coupled enzymatic system is therefore improved.
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Khota, Waroon, Chatchai Kaewpila, Rattikan Suwannasing, Nikom Srikacha, Julasinee Maensathit, Kessara Ampaporn, Pairote Patarapreecha, et al. "Ensiling Cyanide Residue and In Vitro Rumen Fermentation of Cassava Root Silage Treated with Cyanide-Utilizing Bacteria and Cellulase." Fermentation 9, no. 2 (February 3, 2023): 151. http://dx.doi.org/10.3390/fermentation9020151.
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Cyanide is a strong toxin in many tropical forage plants that can negatively affect ruminants. The aim of this study is to determine the cyanide removal efficiency, silage quality, and in vitro rumen fermentation of fresh cassava roots ensiled without an additive (control) and with Acremonium cellulase (AC), two cyanide-utilizing bacterial inoculants (Enterococcus feacium KKU-BF7 (BF7) and E. gallinarum KKU-BC10 (BC10)), and their combinations (BF7 + BC10, AC + BF7, AC + BC10 and AC + BF7 + BC10). A completely randomized design was used with eight treatments × four small-scale silo replicates. Additionally, extra silage samples (seven silos/treatment for individually opening after 0, 1, 3, 5, 7, 15, and 30 days of ensiling) were added to observe the changes in the total cyanide concentration and pH value. The fresh cassava root contained an optimal number of lactic acid bacteria (105 colony forming units/g fresh matter), and the contents of dry matter (DM) and total cyanides were 30.1% and 1304 mg/kg DM, respectively. After 30 days of ensiling, all silages demonstrated a low pH (<3.95; p < 0.01). Cyanide content ranged from 638 to 790 mg/kg DM and was highest in the control (p < 0.01). The addition of BF7 + BC10 increased the crude protein (CP) content (p < 0.01). The addition of AC decreased the fibrous contents (p < 0.01). The control had less acetic acid and propionic acid contents (p < 0.01) and a greater butyric acid content (p < 0.01). However, the degrees of in vitro DM digestibility (IVDMD) and gas production were similar among treatments. Methane production ranged between 29.2 and 33.3 L/kg IVDMD (p < 0.05), which were observed in the AC + BC10 and BF7 + BC10 treatments, respectively. Overall, our results suggested that the cyanide removal efficiency after 30 days of ensiling with good-quality cassava-root silage was approximately 39% of the initial value. The enterococci inoculants and/or AC could improve the ensiling process and cyanide removal efficiency (increasing it to between 47 and 51% of the initial value). The novel enterococci inoculants (BF7 + BC10) were associated with a decreased cyanide content and an increased CP content. They appeared to promote the methanogenesis potential of the cassava root silage. More research is required to validate the use of cyanide-utilizing bacterial inoculants in cyanogenetic plants, bioenergy fermentation, and livestock.
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Sekisov, A. G., T. G. Konareva, A. Yu Lavrov, V. Yu Burov, and E. S. Emirziadi. "Efficiency of using peroxide-carbonate compounds in reagent complexes for leaching gold hard to recover from placer." IOP Conference Series: Earth and Environmental Science 962, no. 1 (January 1, 2022): 012058. http://dx.doi.org/10.1088/1755-1315/962/1/012058.
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Abstract The article deals with the data of theoretical and experimental studies of the processes of activation gold leaching using reactive peroxide carbonate compounds, obtained by electrophotochemical treatment of solutions of initial reagents of the corresponding composition, in the composition of reagent complexes. The obtained results of the experiments on the interaction of various carbonate and peroxide-carbonate compounds with sodium cyanide in the process of mixing activated and non-activated solutions with aqueous cyanide solutions in different order definitely prove that supramolecular percarbonate-cyanide compounds are being formed in them. It has been established that these activated solutions, prepared on the basis of the initial hydrocarbonate ones, contain metastable compounds that provide a higher rate of gold extraction from crude minerals than standard aqueous cyanic solutions of the same initial concentration.
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Permana, Rizki Dimas, Sunarto Sunarto, Syawalludin Alisyahbana Harahap, Indah Riyantini, and Yuwanda Ilham. "Potassium Cyanide (KCN) Content in Coral Reefs and Its Effect on The Abundance of Indicator-Fishes in The Anambas Islands." Journal of Science and Applicative Technology 5, no. 1 (May 28, 2021): 214. http://dx.doi.org/10.35472/jsat.v5i1.381.
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The coral reef ecosystem has been continuously degraded in various parts of Indonesia, including the Anambas Islands. This research aimed to discover the content of Potassium Cyanide (KCN) accumulated on corals and the effect on indicator fishes abundance in the Anambas Islands. This research was conducted at 25 observation stations in the Anambas Islands National Marine Protected Area. The potassium cyanide (KCN) content was tested with the principle of titration and distillation. The coral samples used ranged from 10-20 g diluted in 100-200 ml distilled water. The method used to determine the abundance of indicator fish was underwater visual census or UVC, which recorded fish in every station. This research recorded 307 fish individuals from 14 species of the Chaetodontidae family. Potassium Cyanide's content on corals was high ranging from 0,009-0,032 mg/L with an average 0,0205 mg/L. We concluded that there was a negative correlation between the content of Potassium Cyanide (KCN) on corals and indicator fishes abundance, which means the higher the Potassium Cyanide content (KCN) is on corals, the lower the indicator fishes abundance will point out.