Sodium Trithiocarbonate Research Articles

Removal of copper, nickel and tin from model and reali ndustrial wastewater using sodium trithiocarbonate. The negative impact of complexing compounds

Removal of copper, nickel and tin from model and reali ndustrial wastewater using sodium trithiocarbonate. The negative impact of complexing compounds

Use of sodium trithiocarbonate for remove of chelated copper ions from industrial wastewater originating from the electroless copper plating process

Use of sodium trithiocarbonate for remove of chelated copper ions from industrial wastewater originating from the electroless copper plating process

Depression mechanism of Na2CS3 on pyrite in lime- CuSO4 system

The unavoidable presence of ionic substances in the ore pulp can adversely effects on the separation of pyrite from other valuable metal sulfide ores. Developing new reagents to eliminate this effect is of great significance. In this study, a novel approach was proposed to depress pyrite by utilizing sodium trithiocarbonate (Na2CS3) as a depressant in the lime-CuSO4 system. The results of the micro-flotation experiments showed that a low dosage of Na2CS3 in the lime-CuSO4 system could effectively depress pyrite. The presence of CuSO4 in the solution which improves the ability of BX to adsorb on the surface of the pyrite was also revealed by the analysis of LEIS, UV–Vis, and contact angle, while the addition of Na2CS3 effectively hindered the adsorption of BX. XPS and SEM-EDS analysis results showed that Na2CS3 forms a complex with Cu2+ and adsorbs onto the pyrite surface, thereby impeding the adsorption of the collector and effectively depressing pyrite.

Auxiliary depression of copper ion - strengthening the depression of sodium trithiocarbonate on chalcopyrite

Copper ions have been widely used as activators in mineral flotation. However, in this study, it was found that copper ions can be used as auxiliary depressant for chalcopyrite depression, reversing the traditional use of copper ions as activators. In addition, a chalcopyrite depressant called sodium trithiocarbonate (Na2CS3) has been proposed. Na2CS3 was used as the main depressant and copper ions as the auxiliary depressant in this paper. Copper ions could enhance the depression effect of Na2CS3 on chalcopyrite. The depression effect was reflected through micro-flotation tests, and the depression mechanisms were investigated by UV–Vis spectrophotometry determination, contact angle measurements, LEIS experiments, XPS tests, Zeta potential measurements and DFT simulation. The flotation results indicated that Na2CS3 can depress chalcopyrite, and copper ions could enhance the depression effect of Na2CS3 on chalcopyrite. UV–Vis spectrophotometry analysis shows that Na2CS3 can reduce adsorption capacity of BX on chalcopyrite surface. Contact angle measurements and LEIS experiments indicate that hydrophilicity substance is formed after the addition of Na2CS3. XPS tests confirm that the Cu(OH)2 produced by the addition of Na2CS3 was mainly responsible for the depression. Zeta potential measurements and DFT simulation reveal the synergistic mechanism between copper ions and Na2CS3. The enhanced depression effect of copper ion is mainly achieved by promoting the desorption of BX and the formation of Cu(OH)2 on chalcopyrite surface in the presence of Na2CS3.

Evaluation of the mobility of heavy metals in the sediments originating from the post-galvanic wastewater treatment processes.

The article presents the assessment of heavy metals mobility in sediments from the process of galvanic wastewater treatment (pH 2.5, Co 1.5mg/L, Cr6+ < 0.02mg/L, Cr(total) 62mg/L, Cu 110mg/L, Ni 129mg/L and Pb 59mg/L) based on the use of hydroxides (Ca(OH)2, NaOH) as well as inorganic and organic sulphur compounds (Na2S, sodium dimethyldithiocarbamate (DMDTC), sodium trithiocarbonate (Na2CS3), trimercapto-s-triazine trisodium salt, TMT). The leachability was assessed after 1, 7, 14 and 21days of sediment contact with the leaching agent (deionized water). FeCl3 was used as a coagulant. The efficiency of metal removal changed within a range of 99.67-99.94% (for NaOH), 98.80-99.75% (for TMT), 99.67-99.92% (for DMDTC), 99.67-99.91 (for Na2CS3). The heavy metal content in the obtained precipitates changed within the following ranges: 0.1-0.2g/kg (Co), 9.8-14.7g/kg (Cr), 23.6-39.8g/kg (Cu) 30.5-43.2g/kg (Ni), 24.3-33.1g/kg (Pb) and 12.2-18.7g/kg (Cd). The leachability tests revealed the release of 34-37% of Cd, 6.4-7.5% of Ni and 0.06-0.07% of Cu after using an excess of Na2CS3 as the precipitant. The use of NaOH resulted in the release of 0.42-0.46% of Cr from the sediment, and the use of TMT 0.03-0.34% of Ni. The best immobilization of heavy metals was observed in the case of the precipitate resulting from the use of DMDTC as a precipitating agent. The findings may be useful for predicting the mobility of heavy metals in the sludge and assessing the risk involved so as to support their removal and management.

Evaluation of the stability of heavy metal-containing sediments obtained in the wastewater treatment processes with the use of various precipitating agents

The article presents the results of research on the leachability of selected heavy metals (cadmium, nickel, chromium, cobalt, lead, and copper) from solid waste obtained in laboratory processes involved in the industrial treatment of wastewater generated in metal surface treatment plants. The test sludges were precipitated using sodium hydroxide solution, calcium hydroxide suspension, 45% solution sodium trithiocarbonate (Na2CS3), 15% solution trimercapto-s-triazine, sodium salt (TMT), and 40% solution sodium dimethyldithiocarbamate (DMDTC). The precipitates were treated with artificial acid rain and artificial salt water. After 1, 7, 14, and 21 days of leaching, the concentration of Cd, Co, Cr, Cu, Pb, and Ni in the leachate was determined. Artificial acid rain leached Ni and Cd to a maximum concentration of 724 mg/L and 1821 mg/L, respectively, from the sludge obtained after the application of Na2CS3, while artificial salt water leached Ni in the maximum amount of 466 mg/L and Cd—max. 1320 mg/L. When Ca(OH)2/NaOH was used, the leaching of Cr reached a similar level for both leaching agents, i.e., the maximum for artificial acid rain was 72.2 mg/L and the maximum for artificial salt water 71.8 mg/L. The use of Na2CS3 or Ca(OH)2/NaOH poses a risk of some heavy metals entering the environment, which may have a negative impact on living organisms, whereas the sludges obtained with the use of DMDTC and TMT as precipitants were the most stable under the experimental conditions and did not pose a potential environmental hazard.

Removal of Zinc from Concentrated Galvanic Wastewater by Sodium Trithiocarbonate: Process Optimization and Toxicity Assessment

In the present research, the removal of zinc from concentrated galvanic wastewater (pH 3.1, conductivity 20.31 mS/cm, salinity, 10.16 g/L, Chemical Oxygen Demand (COD) 2900 mg O2/L, Total Organic Carbon (TOC) 985 mg/L, zinc (Zn) 1534 mg/L and ethylenediaminetetraacetic acid (EDTA) 70 mg/L) by combination of lime (Ca(OH)2) and sodium trithiocarbonate (Na2CS3) as precipitation agents is studied. Central Composite Design (CCD) and response surface methodology (RSM) were applied for modelling and optimizing the designed wastewater treatment process. Analysis of Variance (ANOVA) and the experimental verification of the model confirmed the consistency of the experimental and estimated data calculated from the model (R2 = 0.9173, R2adj. = 0.8622). The use of Ca(OH)2 and Na2CS3 in the optimal condition calculated from the model (pH = 10.75 ± 0.10, V Na2CS3 dose 0.043 mL/L and time = 5 min) resulted in a decrease in the concentration of Zn in treated wastewater by 99.99%. Other physicochemical parameters of wastewater also improved. Simultaneously, the application of Ca(OH)2 and Na2CS3 reduced the inhibition of activated sludge dehydrogenase from total inhibition (for raw wastewater) to -70% (for treated wastewater). Under the same conditions the phytotoxicity tests revealed that the seed germination index for the raw and treated wastewater increased from 10% to 50% and from 90% to 100% for white mustard (Sinapis alba) and garden cress (Lepidium sativum L.), respectively. The parameters of root and shoot growth showed a statistically significant improvement. Treated wastewater (1:10) showed a stimulating effect (shoot growth) compared to the control sample (GI = -116.7 and -57.9 for S. alba and L. sativum L., respectively). Thus, the use of Na2CS3 is a viable option for the treatment of concentrated galvanic wastewater containing zinc.

Sodium trithiocarbonate cathode for high-performance sodium–sulfur batteries

A sodium trithiocarbonate cathode enables the formation of a protective layer in situ on both the cathode and anode, which greatly enhances the cell rate performance and cycle life of Na–S batteries.

Highly selective complexation of cadmium from wet phosphoric acid by organic coordination ligands

Recently, the application of organic coordination ligands for the cadmium removal from wet phosphoric acid (WPA) has shown a great interest, and a certain number of commercially available ligands have shown some affinity and selectivity for cadmium. This technic consists in making complexes between cadmium and ligands. It is easy to integrate industrially and does not require significant investment and maintenance overhead; the cost is driven by the organic ligand stability, efficiency and price. However, the challenge still the high cost of ligand and its insufficient world production capacity in comparison to the increasingly demand. The present research article aims to experiment new organic ligands potentially proved in various media for the cadmium removal. The cadmium removal tests from WPA were carried out under the industrial conditions of 25 % (w/w) P2O5, 14 ppm Cd, and 80 °C. A number of 21 organic ligands were carefully selected based on their potential removal of cadmium. The tests were separately performed under the stoichiometric conditions corresponding to a molar ratio R (nLigand/ncd) of 2, and the excess conditions corresponding to a molar ratio R (nLigand/ncd) of 10. Distinctly, the results relatively to R equaling 10 showed significant increase in cadmium removal specifically to DIBDPi (Diisobutyl dithiophosphinate), DEDTP (Diethyl dithiophosphate), ZDDP (Zinc dialkyl dithiophosphinate), TBAI (Tetrabutyl ammonium iodide), Na2CS3 (Sodium trithiocarbonate), and Aliquat 366 (Methyltrioctyl ammonium chloride), with an efficiency of 86 %, 71 %, 68 %, 29 %, 24 %, and 21 %, respectively. The other ligands still showed no affinity for cadmium removal from WPA.

Removal of Heavy Metal Ions from Wastewaters: An Application of Sodium Trithiocarbonate and Wastewater Toxicity Assessment.

The synthesis and application of sodium trithiocarbonate (Na2CS3) for the treatment of real galvanic wastewater in order to remove heavy metals (Cu, Cd and Zn) was investigated. A Central Composite Design/Response Surface Methodology (CCD/RSM) was employed to optimize the removal of heavy metals from industrial wastewater. Adequacy of approximated data was verified using Analysis of Variance (ANOVA). The calculated coefficients of determination (R2 and R2adj) were 0.9119 and 0.8532, respectively. Application of Na2CS3 conjugated with CCD/RSM allowed Cu, Cd and Zn levels to be decreased and, as a consequence, ∑Cu,Cd,Zn decreased by 99.80%, 97.78%, 99.78%, and 99.69%, respectively, by using Na2CS3 at 533 mg/L and pH 9.7, within 23 min. Implementation of conventional metal precipitation reagents (NaOH, Ca(OH)2 and CaO) at pH 11 within 23 min only decreased ∑Cu,Cd,Zn by 90.84%, 93.97% and 93.71%, respectively. Rotifer Brachionus plicatilis was used to conduct the assessment of wastewater toxicity. Following the application of Na2CS3, after 60 min the mortality of B. plicatilis was reduced from 90% to 25%. Engagement of Na2CS3 under optimal conditions caused the precipitation of heavy metals from the polluted wastewater and significantly decreased wastewater toxicity. In summary, Na2CS3 can be used as an effective heavy metal precipitating agent, especially for Cu, Cd and Zn.

Using Sodium Trithiocarbonate to Precipitate Heavy Metals from Industrial Wastewater – from the Laboratory to Industrial Scale

Using Sodium Trithiocarbonate to Precipitate Heavy Metals from Industrial Wastewater – from the Laboratory to Industrial Scale

Direct synthesis of α-thio aromatic acids from aromatic amino acids

Modified amino acids are useful synthetic components in both chemistry and biology. Here we describe a simple, scalable two-step procedure to generate α-thio aromatic acids from aromatic amino acids with yields of up to 96%. Diazotization and α-lactone mediated bromination efficiently form the α-bromo acid with retention of configuration. Thiol substitution with mild reagents such as sodium hydrosulfide or sodium trithiocarbonate provides the inverted, free α-thio acid. The mildly acidic soft nucleophile can then be utilized in many synthetic applications.

Investigation into the flotation response of refractory molybdenum ore to depressant mixtures: A case study

In this paper, bulk flotation followed by separation was investigated to concentrate purified molybdenite product from Jinduicheng molybdenum ores (Shanxi province, China). The bench scale tests mainly focussed on separation of molybdenite from other sulfide minerals using the new type of depressants. The effect of each single depressant, including organic depressant-modified dextrin (MD), P-Nokes reagent (PN) and sodium trithiocarbonate (ST), and their mixtures on galena, chalcopyrite and other sulfide ores, was examined in turn by changing the concentrations used in cleaner flotation tests. Closed circuit experiments were carried out under the optimal condition and satisfying recovery and grade of molybdenite concentrate could be achieved (86.294% and 53.157%, respectively). A potential reagent regime was developed, with more environmental friendly and more economical advantages due to the introduction of modified dextrin.

Simple Preparation of N-Protected Chiral β-Amino Alkyl Thiols from Corresponding Iodides Employing Sodium Trithiocarbonate

A simple protocol for the preparation of N-protected amino alkyl thiols is reported that employs a reaction of sodium trithiocarbonate (Na2CS3) with N-protected amino alkyl iodides. Na2CS3 is easy to prepare and the protocol circumvents the use of strong bases and multiple steps. All the thiol compounds made were obtained as enantiopure samples and were characterized employing NMR and mass spectrometry.

A Convenient Method for the Synthesis of Cyclic Trithiocarbonates on Carbohydrate Scaffolds.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Purines, pyrimidines, and related fused systems. 20. Heterocyclizations of 6-alkynyl-1,3-dimethyllumazines. Synthesis of pyrrole and thiophene analogs of some natural pteridines

Sonogashira cross-coupling of 6-chloro-1,3-dimethyllumazine with terminal alkynes gave 6-alkynyl derivatives in good yields. Oxidative amination of the latter with primary alkylamines was accompanied by the pyrrole-ring closure to form 1-R"-2-R-6,8-dimethylpyrrolo[3,2-g]pteridine-5,7(6H,8H)-diones. The addition of bromine to 6-alkynyllumazines afforded the corresponding dibromoalkenes whose treatment with sodium trithiocarbonate gave rise to 2-R-6,8-dimethylthieno[3,2-g]pteridine-5,7(6H,8H)-diones. The latter compounds are close analogs of the metabolite of molybdenum cofactor (molybdopterine).

A convenient method for the synthesis of cyclic trithiocarbonates on carbohydrate scaffolds

An efficient regio- and stereoselective method for the synthesis of cyclic trithiocarbonates on carbohydrate skeleton is described. A freshly prepared solution of sodium trithiocarbonate reacts with cis-oriented epoxytriflate pentoses 7– 11 to yield the corresponding cyclic trithiocarbonates 12– 16 . Structures of all new compounds are established through MS, 1H and 13C NMR techniques.

Matching the Composition of Viscose to the Composition of the Spinning Bath in Production of Viscose Fibre

The existence of optimality criteria for viscose and spinning bath compositions is advanced as a working hypothesis. The degree of preparation of viscose for spinning is expediently characterized not only by the ripeness index and viscosity, but also by the chemical composition: the ratio of sodium trithiocarbonate (TTC)/NaOHfr. A ratio of ∼2.0-2.1 should be considered optimum. Specific conductivity on the level of 32-33 S·m−1 is the criterion of spinning bath activity.

An Efficient Method for Synthesizing Substituted Naphtho-1,3-dithiole-2-thiones from Tetrachlorotetrathionaphthalene and Sodium Trithiocarbonate

Two types of naphtho-fused 1,3-dithiole-2-thiones (2a–f and 4a–d) were obtained by the reaction of 3,4,7,8-tetrachloro-naphtho[1,8-cd:5,6-c′d′]bis(1,2-dithiole) (1) and sodium trithiocarbonate. The dechalcogenization of the thiones, using mercury acetate, leads to the corresponding naphtho-1,3-dithiol-2-ones (3a–d and 5a–d). The structures of 3a and 4a were confirmed by X-ray investigation. The tetrathiafulvalenes (TTFs) 6 and 7 were synthesized from 2d and 3c by coupling of the starting compounds with the help of triethyl phosphite. Using 2,3-dichloro-5,6-dicyano-benzoquinone (DDQ) the TTFs were converted into semiconducting charge-transfer complexes.

Organic reagents for removing heavy metals from a 10-34-0 (N-P2O5-K2O) grade fertilizer solution and wet-process phosphoric acid

Fertilizer solutions and wet-process phosphoric acid (WPA) contain heavy metal impurities such as cadmium, zinc, lead, copper, manganese, and chromium. Trisodium trithiocyanuric acid (TMT-15), sodium trithiocarbonate (5% Na2CS3), and sodium polythiocarbonate (Thio-Red II) were evaluated as precipitating agents for heavy metals in a 10-34-0 (N-P2O5-K2O) grade fertilizer solution and WPA. A water-insoluble starch xanthate was also evaluated as an adsorbent for the heavy metals in 10-34-0 (N-P2O5-K2O) and WPA. Arsenic (24−99+%), cadmium (36−97+%), copper (98+%), mercury (96+%), lead (83−88+%), and zinc (8−83+%) precipitated from 10-34-0 (N-P2O5-K2O) upon the addition of each organic reagent, while levels of manganese and chromium were unaffected. Mercury (97+%), lead (75+%), cadmium (11−38%), copper (99+%), and chromium (3−35%) precipitated from WPA upon the addition of 5% Na2CS3 and Thio-Red II, while precipitation of manganese and zinc was negligible. The water-insoluble starch xanthate adsorbed mercury (96+%), copper (38−98+%), and lead (24−75%) from 10-34-0 (N-P2O5-K2O) and WPA while adsorption of arsenic, cadmium, manganese, chromium, and zinc was negligible.