• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.681-686
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• 2019

In this work, the effect of the culture medium composition on microbial growth and ethanol production in Clostridium autoethanogenum culture was investigated to enhance the ethanol productivity. D-Ca-pantothenate, vitamin B₁₂ (as vitamins), and sodium sulfide (as sulfur source) were selected as examined components, and the effects of components' concentration on cell growth and ethanol production was investigated. For D-Ca-pantothenate concentrations varing from 0.5, 5, 50 and 500 mg/L, a slight increase in the ethanol production was observed at the 0.5 mg/L, but negligible differences in microbial growth and ethanol production were measured for the concentration ranges examined. The effect of vitamin B₁₂ concentrations from 0.1, 1.0, 10, and 100 mg/L on the microbial growth and ethanol production was investigated, and it was found that the ethanol production using a 0.1 mg/L of vitamin B₁₂ concentration increased by 245% compared to that of using the basic medium concentration (10 mg/L). The effect of sodium sulfide concentrations (0.5, 5, and 10 g/L) on the microbial growth and ethanol production was also studied, and the inhibition of microbial growth was observed when the sodium sulfide usage was over 0.5 g/L. In conclusion, changes in D-Ca-pantothenate and sodium sulfide concentrations did not affect the ethanol production, whereas even a 100 times lower concentration of vitamin B₁₂ than that of the basic medium improved the production.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1887-1890
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• 2014

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.545-552
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• 2022

Tin-antimony sulfide nanocomposites were prepared via hydrothermal synthesis and a N₂ reduction process for use as a negative electrode in a sodium ion battery. The electrochemical energy storage performance of the battery was analyzed according to the tin-antimony composition. The optimized sulfides exhibited superior charge/discharge capacity (770 mAh g^-1 at a current density of 100 mA g^-1) and stable lifespan characteristics (71.2 % after 200 cycles at a current density of 500 mA g^-1). It exhibited a reversible characteristic, continuously participating in the charge-discharge process. The improved electrochemical energy storage performance and cycle stability was attributed to the small particle size, by controlling the composition of the tin-antimony sulfide. By optimizing the tin-antimony ratio during the synthesis process, it did not deviate from the solubility limit. Graphene oxide also acts to suppress volume expansion during reversible electrochemical reaction. Based on these results, tin-antimony sulfide is considered a promising anode material for a sodium ion battery used as a medium-to-large energy storage source.

• Clean Technology
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• v.23 no.1
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• pp.113-117
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• 2017

We prepared sodium carbonate impregnated activated carbon fiber and evaluated its availability for hydrogen sulfide removal by the comparison with the counterpart, sodium carbonate granular impregnated activated carbon. The sodium carbonate impregnated concentration and immersion duration were chosen as two primary parameters. First, the hydrogen sulfide adsorption capacity increased in proportion to the impregnated concentration up to 3 wt%, above which the sodium carbonate impregnated amount rarely showed an increase due to the pore filling effect for both cases. The optimal impregnated concentration was thus set to 3 wt%. Meanwhile, impregnated activated carbon fiber required only half of the immersion duration compared with granular impregnated activated carbon, while showing a 30% increase on the hydrogen sulfide removal capacity. The greater specific area of impregnated activated carbon fiber explained it. In conclusion, we evaluated advantage of preparation time and improved hydrogen sulfide adsorption capacity by impregnate sodium carbonate, which is capable of reacting with hydrogen sulfide chemically, onto the activated carbon fiber with improved specific area.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.6
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• pp.518-523
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• 2013

This paper describes the reduction of a hydrogen sulfide ($H_2S$) generated from a biogas plant. Micro bubble system is adopted to supply air into the water in the reaction chamber, which can increase the contact area of the supplied air to the reserving water. Two stage reaction chambers having two reaction rooms are designed and manufactured to enhance the reduction rate of a hydrogen sulfide. Sodium hydroxide (NaOH) is also considered to get rid of a hydrogen sulfide. Air volume rate to the water in a reaction chamber is maintained between 0.5 and $1.0m^3/min$. Throughout experimental measurement of the concentration of a hydrogen sulfide by changing the volume of supplied air into the water, reduction rate of a hydrogen sulfide increases as air volume increases. Adding sodium hydroxide to the water with the air supply can reduce effectively a hydrogen sulfide up to 99.5% from biogas. It is noted that a hydrogen sulfide generated by a biogas plant can reduce by supplying micro bubble air and sodium hydroxide effectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.203-209
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• 2023

Cobalt sulfide nanocomposites were synthesized through a simple hydrothermal method as anode materials for sodium ion batteries (SIBs). In this work, a cobalt sulfide nanoparticle (CoS-NF) and a cobalt sulfide nanocomposite integrated with reduced graphene oxide (CoS@G-NC) were fabricated for electrochemical energy storage performance of battery. The as-prepared CoS@G-NC electrode exhibited reversible and stable cycle performance (62 % after 30 cycles at current density of 200 mA g^-1). The improved electrochemical property was attributed to the small grain growth and uniform distribution of cobalt sulfide during synthesis, which maximized the diffusion pathway for sodium ions and effectively suppressed the delamination and volume expansion of cobalt sulfide during the conversion reaction. The results provide promising anode materials for next-generation SIBs.

• Archives of Pharmacal Research
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• v.2 no.1
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• pp.9-16
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• 1979

3-Amino-2-phenylthietane derivatives were considered as a useful tool to elusidate the mechanism of inhibiton of MAO by tranylcypromine-type inhitors. The synthesis of 3-benzoylamino-2-phenylthieetane, 3-amino-2-phenylthietane, and 3-N, N-dimentylamino-2-p-nitrophenythietane was attempted using the reaction between 1, 3 dihalogeno alkanes with alkali sulfide. When 1-pheny1-1, 3-dihalo-2-benzolaminopropane was treated with sodium sulfide, 2-pheny 1-4 benzylidene-2-oxazoline was isolated, indicating the case of elimination reaction compared to ring formation. The reaction of 1-p-nitropheny1-1, 3-dichloro-2-N, N-dimethylaminopropane with sodium sulfide gave bis (1-p-nitropheny1-2-N, N-dimethylamino-3-chloropropane)sulfide. The mechanism of reaction was discussed.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.143-146
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• 1996

A continuous potential pulse is applied to a silver-working electrode on a pulsed amperometric detector (PAD) for detection of free cyanide and sulfide. The moving phase is 0.1 M sodium hydroxide, 0.5 M sodium acetate and 5% (v/v) ethylenediamine mixture, and the flow rate is 0.7 mL/min. Optimized pulse conditions include a -200 mV (vs. Ag/AgCl reference electrode) detection potential(Ed) for 60 msec and 50 mV cleaning potential (Ec) for 120 msec. The silver working electrode surface is not poisoned by cyanide or sulfide, and the PAD maintains long-term stability without loss of sensitivity and reproducibility at these pulse conditions. The detection limit of cyanide and sulfide separated by ion chromatography using an anion exchange column is 0.1 ppm and 0.05 ppm, respectively.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.22-27
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• 2004

The activated paper mill sludge was treated with WF and some additives (sodium sulfide, nickel nitrate, ethyl acetate) for methane fermentation at $35^{\circ}C$. Optmum C/N ratio was 60 out of three conditions (20, 30 and 60). The Period of 40% of methane content possibly ignition, was 2 days shorter than with non-treatment during 10 days. Nevertheless, the total amount of methane production showed the 1/8 level of control far the same period. The yield and content of methane were increased by the addition of sodium Sulfur and ethyl acetate. Sulfur was an essential factor in methane fermentation of paper mill sludge.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.437-441
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• 2000

A study on the removal of Pb ion from Pb-contaminated soil was carried out using ex-site extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt(IDA) as a washing agent were evaluated as a function of concentration reaction time mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1:15 and 1:20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction were 368.8 ppm and 267.5 ppm respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide form the precipitation of lead hydroxide and lead sulfide and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/$\ell$ for the TA washing solution and 4 g/$\ell$, 5g/$\ell$ for the IDA washing solution respectively. The efficiency of recycle for TA and IDA washing solution were 78.8% , 95.1%, and 89.2%, 96.6% at third extractions under $Na_2S$ and $Ca(OH)_2$, respectively.