• Clean Technology
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• v.18 no.4
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• pp.379-389
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• 2012

Environmental issues are being paid more attention due to income growth, urban overcrowding, and population growth in Korea. Among the various environmental problems, odor damage is the one of the serious factors. To take example for food waste combination treatment in Su-young wastewater treatment plant in Busan, many complaints occurred because this plant locate around residential areas. The purpose of this work is not only to analyze odorous elements and their contributions but also to evaluate odor quotient (OQ), sum of odor quotient (SOQ), and treatment efficiency of bio-filter. The results of dilution sensory test of complex odor, grinder, leachate, hopper indicated higher order complex odors happen in July and August. The main odorous elements consisted of hydrogen sulfide, ammonia, methly mercaptan and acetaldehyde, which were analyzed by instrumental detection method, and methyl mercaptan was exceeded over 3,571 times of threshold. In addition, result of contribution of odor was methyl mercaptan (49.95 to 59.08%), hydrogen sulfide (20.43 to 29.27%), trimethylamine (8.82 to 13.42%) and acetaldehyde (9.17 to 11.35%). Other facilities were compared with the contribution of the odor using OQ and SOQ during the process. Sulfur compounds, acetaldehyde, and trimethylamine are high contribution of odor using OQ as well as odor intensity of grinding process is highest. As a result, sulfur compounds (e.g., methyl mercaptan and hydrogen sulfide) are highest for OQ and SOQ of grinding process is highest as 7,067. The removal efficiency of deodorization equipment was more than 90.00% in ammonia and amines, but the average efficiency of sulfur compounds was 53.51%. Thus, this facility is more higher contribution of acetaldehyde and trimethylamine than other treatment facilities. And food waste treatment in environmental area needs to consider appropriate capacity and refers to other bio-filter operating conditions.

• Analytical Science and Technology
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• v.15 no.1
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• pp.80-86
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• 2002

The simultaneous analysis of the odorous compounds designated by law in Korea and Japan was examined with the thermal desorber gas chromatography-mass spectrometry using one column. The approximate concentrations of trimethyl amine, acetaldehyde, methyl mercaptan and dimethyl sulfide were estimated. Styrene, dimethyl disulfide, propionaldehyde, n-butyl aldehyde, i-butyl aldehyde, n-valeraldehyde, i-valeraldehyde, ethyl acetate, toluene, xylene, methyl i-butyl ketone and i-butanol were detected at concentrations of the detection limits of their threshold values. As a typical example of simultaneous analysis of the odorous compounds, the volatile organic compounds emitted from compost procedure of food waste were concentrated and analyzed with thermal desorber/GC/MSD, and major malodorous compounds were estimated from the concentrations and threshold values of the detected components. From the result of analysis, 34 compounds were confirmed and among them, trimethyl amine, i-valeraldehyde, methyl mercaptan, methyl allyl sulfide, dimethyl sulfide, acetaldehyde, ethanol, n-butyaldehyde were expected to attribute to the odor in order of strength.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.663-669
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• 2017

Activated carbons were prepared from waste citrus peels using KOH, NaOH, and $ZnCl_2$ as activating chemicals. They were prepared at optimal conditions including the chemical ratio of 300%, activation time of 1.5h, and activation temperature of $900^{\circ}C$ for KOH, $700^{\circ}C$ for NaOH, and $600^{\circ}C$ for $ZnCl_2$, which were named as ACK, ACN, and ACZ, respectively. Using the activated carbons, their adsorption characteristics for three target gases such as acetone, benzene, and methylmercaptan (MM) were carried out in a batch reactor. The adsorption behavior of activated carbons for three target gases followed the Freundlich model better than the Langmuir. And the experimental kinetic data followed a pseudo-second-order kinetic model more than pseudo-first-order one. Following the intraparticle diffusion model suggested that the external mass transfer and particle diffusion were occurred simultaneously during the adsorption process.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.646-651
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• 1998

The molecular structure of sulfur compounds and the retention relationship are studied by gas chromatography. Analyzed sulfur compounds are, hydrogen sulfide, sulfur dioxide, carbon disulfide, ethyl mercaptan, dimethyl sulfide, iso-propyl mercaptan, normal propyl mercaptan, ethyl methyl sulfide, tert-butyl mercaptan, tetrahydrothiophene, thiophene, and 2-chlorothiophene. Multiple linear regression explains the retention relationship of molecular descriptors. In GC the temperature program is 30$^{\circ}C$ held for 10.5 min, and then increased to 150$^{\circ}C$ at a rate 15$^{\circ}C$/min. Predicted equation for relative retention time (RRT) using SAS program is as follows; $RRT=0.121bp+14.39dp-8.94dp^2+0.0741sqmw-35.78\; (N=8,\; R^2=0.989, \;Variance=0.175,\;F=66.21)$. RRTs are function of boiling point, the square root of molecular weight, molecular dipole moment, and boiling point effects mostly on RRT. The RRT is maximized at the molecular dipole moment of 0.805D, when using nonpolar columns. The planar and highly symmetric compounds are eluted slowly. The square, of correlation coefficient $(R^2)$ using SAS program, is 0.989, and the variance is 0.175 in training sets. For three sulfur compounds, the variance between observed RRTs and predicted RRTs is 0.432 in testing sets.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.277-285
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• 2014

The usage of efficient microorganism (EM) is increasing in concern for server purposes including odor removal during carcasses degradation. In this study, we have studied the type of soil and its effect on efficient microorganisms for the removal of odorous gases during buried carcasses degradation in lab-scale reactor. The carcasses are buried in the reactor with various soil types such as normal soil, 20% sandy and 20% clay soil with the efficient microorganism KEM. The efficient microorganisms KEM have the ability to stabilize the degradation of carcasses of the burial site. We have focused on the analysis of odorous gases such tri-methylamine (TMA), hydrogen sulfide ($H_2S$), methyl mercaptan (MM), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), carbon dioxide ($CO_2$), and methane ($CH_4$) along with the changes of microbial community changed during complete degradation of buried carcasses for a year. The results suggested that the 20% sandy soil contain lesser level of $H_2S$ and MM (0.09 and 0.35 mg) but 20% clay has higher nitrogen compound removing effect and leave only less amount of ammonia and TMA (0.31 and 2.06 mg). The 20% sandy soil also has the ability to breakdown the carcasses more quality compared with other types of soil. Based on the data obtained in this study suggesting that, the use of 20% sandy soil can effectively control sulfur compounds whereas 20% clay soil controls nitrogen compounds in the buried soil. Depending on the type of the soil, the dominant of microbial communities and the distribution was change.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.28-36
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• 2018

Adsorption experiments of three target gases such as acetone, benzene, and methyl mercaptan (MM) were carried in a continuous reactor using the activated carbon prepared from waste citrus peel. In a single gas system, the breakthrough time obtained from using the activated carbon (WCAC) prepared from waste citrus peel. In a single gas system, the breakthrough time obtained from the breakthrough curve decreased with increasing the inlet concentration and flow rate, but increased with respect to the aspect ratio (L/D). Adsorbed amounts of the target gases by WCAC increased as a function of the inlet concentration and aspect ratio. However, adsorbed amounts with the increase of the flow rate were different depending upon target gases. Results from the breakthrough time and adsorbed amount showed that the affinity for WCAC was the highest in benzene, followed by acetone and then MM. On the other hand, in the binary and ternary systems, the breakthrough curve showed a roll-up phenomenon where the adsorbate having a small affinity for WCAC was replaced with the adsorbate with a high affinity. The adsorption of acetone on WCAC was more strongly affected when mixing with the nonpolar benzene than that of using sulfur compound MM.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.237-243
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• 2018

The surface chemistry of WCK-AC, WCN-AC and WCZ-AC which are activated carbons prepared from waste citrus peel using KOH, NaOH, and $ZnCl_2$ as activating chemicals were investigated. Also the relationships between the adsorption capacities of the target gases such as acetone, benzene and methyl mercaptan (MM) by the prepared activated carbons and the pore characteristics of each activated carbon were examined. According to XPS analysis of the prepared activated carbons, graphite and phenolic were the main surface functional groups of C1, and the sum of phenol, carbonyl and carboxyl groups increased in the order of WCK-AC > WCN-AC > WCZ-AC. The breakthrough curves obtained from the adsorption experiments for the three target gases in the fixed bed adsorption reactor were well simulated by the empirical equations proposed by Yoon and Nelson. The adsorption capacity for acetone, benzene and MM was larger for activated carbons with the larger sum of surface functional groups. The larger the specific surface area and the pore volume of activated carbons and the smaller the pore size, the better the adsorption performance. In particular, the specific surface area was the best criterion for the adsorption performance of activated carbons used in this study.

• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.296-300
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• 2007

This paper presents applicability of photocatalytic decomposition of methyl mercaptan using $TiO_2$. A quartz reactor was used in order to elucidate reaction pathway in photocatalytic decomposition of methyl mercaptan. Experimental results showed that more than 99.9% of methyl mercaptan was decomposed within 30 minutes. It was found that the photocatalytic decomposition of methyl mercaptan followed pseudo first order and its reaction coefficient was $0.05min^{-1}$ During 30 minutes in the photocatalytic reaction, the concentration of methyl mercaptan, dimethyl disulfide, $SO_2$, $H_2SO_4$, COS, $H_2S$ were determined. These results showed that 64% of methyl mercaptan were compensated for the increase in sulfur after 30 minutes through the mineralization. The proposed main photocatalytic decomposition pathway of methyl mercaptan was methyl $mercaptan{\rightarrow}dimethyl$ $disulfide{\rightarrow}SO_2{\rightarrow}H_2SO_4$.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.1971-1976
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• 2014

In this study, the photocatalytic decomposition characteristics of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed methyl mercaptan (MM) by UV reactor installed with $TiO_2$-coated perforated plate were studied. The photocatalytic decomposition rate of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed with MM fitted well on Langmuir-Hinshelwood (L-H) kinetics equation. The maximum elimination capacity was obtained to be $628g/m^3{\cdot}d$ for single toluene, $499g/m^3{\cdot}d$ for toluene mixed with benzene, $318g/m^3{\cdot}d$ for toluene mixed with acetone, and $513g/m^3{\cdot}d$ for toluene mixed with MM, respectively. The negative effect in photocatalytic decomposition of toluene are found to be in the order of acetone>benzene>MM.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.321-328
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• 2004

Nano silica ball and nano carbon ball are developed commercially by template synthesis method. Adsorption of unpleasant smelling substances such as ammonia, trimethylamine, acetaldehyde and methyl mercaptane onto nano carbon ball with hollow macroporous core/mesoporous shell structures, nano carbon ball, was investigated and compared with that onto odor adsorbent materials, activated carbon, commercially available. The adsorption and decomposition of malodor at nano carbon ball exhibited superior than those onto activated carbon. The physicochemical properties such as mesopore size distributions, large nitrogen BET specific surface area and large pore volume and decomposition of malodor were studied to interpret the predominant adsorption performance. The nano carbon ball is expected to be useful in many applications such as deodorizers, adsorbent of pollutants.