• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.51-65
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• 2002

This study was carried out to apply some basic physical and chemical treatment options including Fenton's oxidation, and to evaluate the performances and the characteristics of organic and nitrogen removal using lab-scale biological treatment system such as complete-mixing activated sludge and sequencing batch reactor(SBR) processes for the treatment of leachate from a municipal waste landfill in Gyeongnam province. The results were as follows: Chemical coagulation experiments using aluminium sulfate, ferrous sulfate and ferric chloride resulted in leachate CO $D_{Cr}$ removal of 32%, 23% and 21 % with optimum reaction dose ranges of 10,000～15,000 mg/$\ell$, 1,000 mg/$\ell$ and 500～2,000 mg/$\ell$, respectively. Fenton's oxidation required the optimum conditions including pH 3.5, 6 hours of reaction time, and hydrogen peroxide and ferrous sulfate concentrations of 2,000 ～ 3,000 mg/$\ell$ each with 1:1 weight ratio to remove more than 50% of COD in the leachate containing CO $D_{Cr}$ between 2,000 ～ 3,000 mg/$\ell$. Air-stripping achieved to remove more than 97% of N $H_3$-N in the leachate in spite of requiring high cost of chemicals and extensive stripping time, and, however, zeolite treatment removing 94% of N $H_3$-N showed high selectivity to N $H^{+}$ ion and much faster removal rate than air-stripping. The result from lab-scale experiment using a complete-mixing activated sludge process showed that biological treatability tended to increase more or less as HRT increased or F/M ratio decreased, and, however, COD removal efficiency was very poor by showing only 36% at HRT of 29 days. While COD removal was achieved more during Fenton's oxidation as compared to alum treatment for the landfill leachate, the ratio of BOD/COD after Fenton's oxidation considerably increased, and the consecutive activated sludge process significantly reduced organic strength to remove 50% of CO $D_{Cr}$ and 95% of BO $D_{5}$ . The SBR process was generally more capable of removing organics and nitrogen in the leachate than complete-mixing activated sludge process to achieve 74% removal of influent CO $D_{Cr}$ , 98% of BO $D_{5}$ and especially 99% of N $H_3$-N. However, organic removal rates of the SBR processes pre-treated with air-stripping and with zeolite were not much different with those without pre-treatment, and the SBR process treated with powdered activated carbon showed a little higher rate of CO $D_{Cr}$ removal than the process without any treatment. In conclusion, the biological treatment process using SBR proved to be the most applicable for the treatment of organic contents and nitrogen simultaneously and effectively in the landfill leachate.e.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.363-370
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• 2015

The production of polyhydroxyalkanoates (PHAs) using Sequencing Batch Reactor (SBR) was investigated. The experiments were performed in two fabricated SBRs (4 L) of different oxidation state. Synthetic wastewater was used as substrate, using C/N/P ratio of 42:10:1. SBR 1 and SBR 2 were operated in aerobic dynamic feeding (ADF) and anaerobic/oxic dynamic feeding (AODF) condition, respectively. ADF provide feast and famine in aerobic condition, while AODF in anaerobic/oxic condition. PHAs production was found high in AODF than AOF. Maximum PHAs content of 40.0% (w/w)of biomass were produced in AODF mode. Produced PHAs structural and thermal property were good.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.284-290
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• 1993

The soap-free emulsion polymerization was carried out for Styrene/Butadiene system with Acrylonitrile as hydrophilic comonomer and KPS as initiator. Under the condition of below 50% conversion, the dependence of Rp on $[AN]^n$ and $[KPS]^n$ was found to be n=1.617-1.050 and n=0.83-0.96 for [AN] and [KPS], respectively. The effect of $[AN]^n$ and $[KPS]^n$ on particle number density (Np) was determined to be n=1.533 and n=0.733, respectively. The highest conversion was obtained under the conditions of pH=5 and ratio of total monomer (g) to water (g)=0.5. The mechanical properties of SBR obtained in this experiment were shown to be inferior to commercial SBR in terms of tensile strength, 300% modulus and elongation. It was found that cure rate of SBR prepared in this experiment was faster than that of commercial SBR.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.113-118
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• 2002

Laboratory experiments were aimed to evaluate the effect of nitrate as a electron acceptor during the biological phosphorus uptake and to investigate the microbial community. Anaerobic-anoxic sequencing batch reactor (SBR) compared the removal behaviour to anaerobic-oxic SBR, both SBRs maintained lower effluent quality with 1.0 mgp/1. Anaerobic-anoxic SBR was able to remove additional 5.0 to 7.0 mg (P+N)/ι than other biological nutrient removal (BM) system. Therefore, it was proposed that the anaerobic-anoxic SBR was more effective at weak sewage. From the results of the maicrobial community analysis, it can be inferred that denitrifying bacteria and polyphosphate accumulating bacteria coexist in anaerobic-anoxic SBR during stable condition for removing the nitrogen and phosphorus. Particularly, it was suggested that the Zoogloea ramigera in the $\beta$-subclass of proteobacteria and the Alcaligenes defragrans of the Rhodocyclus group in the $\beta$-subclass of proteobacteria played a major role for removing the nitrogen and phosphorus as dPAOs (denitrifying phosphate accumulating organisms).

• Journal of Korean Society on Water Environment
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• v.37 no.1
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• pp.47-54
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• 2021

Aerobic granular sludge (AGS) can be classified as a type of self-immobilized microbial aggregates measuring more than 0.2 mm. It offers the option to simultaneously remove COD, N, and P that occur in different zones inside a granule. Also, AGS is characterized by high precipitability, treatability with high organic loading, and high tolerance to low temperature. In this study, a sequencing batch reactor inoculated with AGS (AGS-SBR) is a new advanced wastewater treatment process that was proven to grow AGS with integrated nutrient removal and low C/N ratio. A pilot plant, AGS-SBR with a capacity of 225 ㎥/d was installed at an S sewage treatment plant in Gyeonggi-do. The results of the operation showed that the water quality of the effluent indicated that the value of BOD5 was 1.5 mg/L, CODMn was 11.4 mg/L, SS was 6.2 mg/L, T-N was 13.2 mg/L, and T-P was 0.197 mg/L, and all of these values reliably satisfied an effluent standard (I Area). In winter, the T-N treatment efficiency at a lower temperature of less than 11℃ also showed reliability to meet the effluent standard of the I Area (20 mg/L or less). Analysis of microbial community in AGS showed a higher preponderance of beneficial microorganisms involved in denitrification and phosphorus accumulation compared with activated sludge. The power consumption and sludge disposal cost were reduced by 34.7% and 54.9%, respectively, compared to the domestic SBR type sewage treatment plant with a processing capacity of 1,000 ㎥/d or less.

• The tire
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• s.134
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• pp.22-27
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• 1988

• Elastomers and Composites
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• v.29 no.1
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• pp.18-29
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• 1994

The purpose of this study is to investigate reinforced effect between silica treated by coupling agents and rubber matrix under the configuration chemical bonds, and the effect of silica particles coated by organic polymers using aluminum chloride as the catalyst. In vulcanization characteristies were tested by Curastometer. The M-series vulcanizates were reached to the fastest optimum cure $time(t_{90})$ and R-series vulcanizates with the same formula had the shorted optimum cure times. Tensile characteristics measuring with a tensile tester revealed that the M-series vulcanizate was the best in the physical properties, such as tensile strength. In 100% modulus, however, the S-series vulcanizates appeared to be better than the other vulcanizates. Also, hardness showed the following order : S-series>R-series>M-series with the order of elongation R-series>M-series>S-series. In SEM test, shapes of chemical treated silicas were observed. The dispersion of filler in the SBR composite appeard uniformly. In RDS test for the dynamic characteristics, G' indicates that S-3 shows the highest value with the next order M-3>R-3, and the order of damping values are as followe: M-3>M-3>R-3.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.3
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• pp.399-408
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• 2012

The overall goal of this study was to characterize and quantify ammonia-oxidizing bacteria (AOB) in four different full-scale sequence batch reactor (SBR) wastewater treatment plants. Also, this study focused on assessing the occurrence of the alternative ammonia-oxidizing microbes such as anammox (anaerobic ammonia oxidation) bacteria (AMX) and ammonia-oxidizing archaea (AOA) in these systems. Based on total AOB numbers and the estimated cell density in the mixed liquor samples, AOB constituted 0.3 - 1.8% of the total bacterial population in the four WWTPs. Based on clone library, Nitrosomonas ureae-like AOB were dominant in plant A and B, while plant C and D had Nitrosomonas nitrosa-like AOB as major AOB group. The four different AMX primer sets targeting AMX 16S rRNA gene produced PCR amplicons distantly related to Chlamydia and Planctomycetales group bacteria. However, it was not clear these groups of bacteria perform anammox reaction in the SBR plants. Also, molecular evidence of AOA was found in one of the SBR plants, with a sequence located in the deep branch of the sediment creanarchaeota group.

• Journal of Korean Association for Spatial Structures
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• v.9 no.4
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• pp.61-72
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• 2009

As a trend of construction has become high-rise and larger, it is necessary to reduce the self-weight of structures and buildings. One of the most effective methods to reduce the self-weight of structures and buildings is to use the lightweight aggregate concrete. To complement the strength of the lightweight aggregate concrete, polymer was added to concrete's mixing. In this study, experiments to make the moderate mixing proportion of polymer modified lightweight concrete were performed. Also the hardened concrete tests were performed to investigate the physical characteristics of the polymer-modified lightweight aggregate concrete. As a result, the flexural strength was increased by a small quantity of SBR Latex. Based on the test results the estimating equation was proposed through the regression analysis.

• Elastomers and Composites
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• v.6 no.2
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• pp.47-63
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• 1971

We have studied the blending effects of Diene 33R and styrenebutadiene rubber at various blending ratios of 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black HAF and ISAF at various compounding ratios of 55 PHR, 65 PHR, 75 PHR for tyre tread rubber. As the results, it was found that ; 1. For tyre tread rubber, when the blending ratio, Diene NF 35R/SBR 1778, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 65 PHR. The compounding of ISAF made better result than that of HAF for abrasion quantity, tearing strength, and tensile strength. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved. And as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to SBR than to Diene Rubber. 5. It is a shortage that elongation revealed low price.