• Journal of Life Science
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• v.22 no.5
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• pp.650-656
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• 2012

To reduce the production cost of $Pleurotus$ $ostreatus$, discarded medicinal sludge was collected from oriental medical clinics to develop the $Pleurotus$ $ostreatus$ culture medium. According to the analysis of the proximate composition of the materials used in Korean herb medicine, the crude ash contents of $Carthamus$ $tinctrius$ L stem and $Acanthopanax$ $chiisanensis$ were 11.6% and 10.1% respectively, which were relatively higher than the 9.6% of the control medium, waste cotton. Crude protein was detected in 9.8% of the waste cotton medium, whereas it was detected in 14.9%, 13.9%, 13.4%, and 11.5%, of wild mugwort, $Acanthopanax$ $\underline{chiisanensis}$, medicinal sludge, and $Carthamus$ $tinctrius$ L stem, respectively, which are all higher than the control. The pH of medicinal sludges, wild mugwort, and $Aacanthopanax$ $chiisanenses$ ranged from 5.27 to 5.72, which was similar to the 5.70 pH value of waste cotton. In the case of addition concentration of each Korean herb medicine material influencing mycelial growth of the $Pleurotus$ $ostreatus$, the 9% concentration was more favorable compared to that of 3% and 6%. However, the addition of Korean herb medicine materials did not significantly affect the growth of $P.$ $tolaassi$ and $Trichoderma$ $sp.$ According to a field experiment that added 9% of medicinal sludge into the waste cotton medium, the mycelial growth of mushrooms was facilitated by approximately 2 days, and the mushroom yield was increased by 10~15%. Furthermore, pileus and stipe of the mushrooms were even and superior in quality.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.5-12
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• 2014

Anaerobic digestion was investigated for the stabilization of sludge, decrease of volatile solids, production of biogas for wastewater sludge. In this study, total solids and volatile solids, elemental analysis were conducted to determine characteristics of various types of sludges and investigate the feasibility of biogas production of Municipal Wastewater Sludge (MWS), Industrial Wastewater Sludge (IWS), mixed sludge (Mix), and Municipal Wastewater Sludg Cake (MWSC). Total solids, volatile solids, and C/N ratio were determined in the range of 11.2~20.6 %, 62.1~83.1 % of TS and 4.96~8.33 %. Using the biochemical methane potential (BMP test), mixed sludge and wastewater sludge finished the methane production within approximately 20 day and 16~17 day. Sludge cake finished within 10 day. Mixed sludge produced 395.5 mL $CH_4$ per g of Volatile Solid (VS) and resulted in the highest methane production. For carbon dioxide production, five sludges had similar value of accumulated carbon dioxide production except for sludge cake.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.109-120
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• 2000

In the analysis of the common categories, moisture contents and organic concentrations were not much different according to the types of industry or treatment facilities. When heavy metals contribution of the sludge from domestic and industrial wastewater treatment facilities was analyzed, As, Hg and Cr concentrations were relatively high among 42 standards of the fertilizer law. As concentration war higher in 28 of 42 facilities (67%) than limits of the fertilizer law. Hg concentration was not acceptable in the 21 of 42 facilities (50%). Cr concentration was not acceptable in 9 of 42 facilities (21%). From these results, It is found that As is the most frequently detectable component and contaminant than any other heavy metals in sludges. The data from this experiment was also compared with the guidelines of harmful organics and the rest of heavy metals that are regulated by some of the foreign countries. Be, Se and Mo concentrations were lower than the limits. Among the organics, the average concentration of PCB (10 samples) was 26.2 ppb. The highest concentration was 162.6 ppb in the sludge of the municipal wastewater treatment facilities and the lowest concentration was 2.14 ppb from the skin manufacturing industry. From the leaching analysis of re-manufacturing goods from the sludge, most of them was acceptable on the regulation law but Cr concentration was over the limit.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.137-147
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• 2003

The objective of this experiment was to investigate the possibility on agricultural use of muncipal sewage sludge with respect to heavy metal contents in Korea. Metal contents (mg/kg) in 88 sludge samples were ranged from 0 to 54.3 for As, 1,7 to 197.3 for Cd, 7.3 to 2,854 for Cr, 87.4 to 5,730 for Cu, 129.3 to 10,289 for Mn 20.1 to 2,057 for Ni, 7.6 to 197.5 for Pb, and 523.5 to 6,349 for Zn. Heavy metal contents of sludges were compared with the regulation on raw material for compost. All sludges produced from sewage treatment plane in metropolis (over a million in population) and large cities ($500,00{\sim}1,000,000$) were not compatible with the regulation. In addition, 95% of sludge from small and mid-size cities ($100,00{\sim}500,000$) and 93% from rural area (below 100,000) were not suitable. On the basis of Cd, Cu, Ni and Zn contents, 41, 53, 47, and 89% of sludge samples were not compatible with the regulation on raw material for compost respectively.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.739-745
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• 2005

Simultaneous denitrification and methanogenesis at various influent COD/Nitrate-N(below C/N) ratio was investigated with two different anaerobic sludges of which one was inoculated with glucose only and the other was inoculated with glucose and nitrate. Three different C/N ratios of 30, 20, and 10 were applied with each anaerobic sludge in serum bottles agitated in a rotary shaker to monitor the time related changes of amount of gas production and gas composition. Glucose was used as a single carbon source, which was adjusted to 1,000 mg/L as COD and potassium nitrate was used as a nitrogen source to adjust the each C/N ratio. COD removal by methanogenesis was dominant at higher C/N ratios, while COD removal by denitrification was dominant at lower C/N ratios. With the sludges cultured at C/N ratios below 10, SMA and SDNR rising different carbon substrates were investigated. The most efficient carbon substrate was acetate and the highest SMA and SDNR were 0.76 g COD/g VSS day with pure anaerobic sludge and 1.38 g ${NO_3}^--N/g$ VSS day with sludge cultured at C/N ratio of 5, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.488-494
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• 2012

This study was conducted to determine the optimal ratio of sludges from milk processing industry (MPS), paper-mill industry (PMS) and night-soil treatment plant (NSS) for vermicomposting. Five different ratios, 0 : 80 : 20 (MPS-0), 25 : 60 : 15 (MPS-25), 50 : 40 : 10 (MPS-50), 75 : 20 : 5 (MPS-75), and 100 : 0 : 0 (MPS-100 : control) MPS : PMS : NSS by wet weight were tested in a small plot experiment. The experiment for each mixing ratio was performed for 2 weeks with the three replications. MPS-100 (100 : 0 : 0) only had the highest decomposition rate with 19.9%, followed by MPS-25, MPS-50, MPS-75 and MPS-0 with 19.5, 19.1, 17.6 and 16.7%, respectively. Except for MPS-100, Vermicomposting resulted in increase in ash, T-P, $NO_2{^-}-N$, $NO_3{^-}-N$, Mg, K, As, Cd and Cu, whereas moisture, VS (Volatile Substance), TKN (Total Kjeldahl Nitrogen), $NH_4{^+}-N$, Ca, Hg and Pb were lower in the final cast than the initial feed mixture. Meanwhile Zn showed very slight difference and Cr and Ni did not show any tendency between the feed mixture and the final cast. In the case of MPS-100, where the decomposition rate was the highest, all the heavy metals in the final cast except for Hg were increased. All the vermicomposts produced from five different mixing ratios of the vermicomposting sludges met the Korea Standard as by-product compost.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.107-113
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• 2006

Water treatment plant sludge occurred in sedimentation and inverse wash process is generally disposed by ocean dumping or reclamation after dehydration processing using mechanical or natural dry method. Recently, ocean dumping of sludge is limited actually by London Convention. Physical, chemical, and geotechnical characteristics of water treatment plant sludge were analyzed by experiments. The possibilities for recycling of the dehydration sludges as materials for covering sanitary landfill were examined. Experiments performed with sludges mixed with general soil to improved the sludge properties are the hydrometer analysis, the liquid and plastic limit test, the specific gravity test, the compaction test, and the unconfined compression test. The value of ${\gamma}_{dmax}$ is increased and OMC(Optimum Moisture Content) is lessened with mixed sludge. The value of maximum compressive strength and friction angle are increased and the cohesion is decreased with mixed sludge. The ratio between sludge and soil in mixed sludge was 3:7 and the strength of mixed sludge showed $3.6kg/cm^2$. These results satisfy the regulation of U.S. E.P.A regarding materials for covering sanitary landfill.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.189-192
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• 2005

We tested the field adaptation of Betula schmidtii on the abandoned coal-mine soil with sludge amendment methods for promoting physiological activity of B. schmidtii seedlings under several environmental stress. Sewage sludges were amended to coal-mine soil with B. schmidtii seedlings which grown in the mixture of artificial soil and composted sludge soil before transplanting (before-fertilized treatment, BF) and fertilized with composted sludge after transplanting (after-fertilized treatment, AF). The percent of establishment of seedlings for AF (80.7%) was lower than that for BF (92.7%). Nitrate reductase activity and photosynthetic pigment content were higher in AF than in BF, but malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were lower in AF than in BF These results represent that after-fertilized seedlings increase resistance against physiological stress at field condition using nitrogen source of composted sludge. On the contrary, before-fertilized seedlings were susceptible to environmental stress on abandoned coal-mine soil by exhausting of nitrogen source from composted sludge.

• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.80-86
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• 2009

This research was performed to evaluate heavy metal leaching characteristics of the sludge from paper mill process with sintering temperature. Heavy metal leaching of the sludge was characterized with Korean Leaching Test and Toxicity Characteristic Leaching Procedure. The test sludge was composed of 70.72% of moisture, 9.5% of volatile solids and 9.76% of fixed solids. As a result of XRF analysis, Fe was the highest inorganic element in approximately 83%, which implies the recycling possibility of the sludge in reuse of Fenton chemicals and artificial lightweight aggregate. Leaching of heavy metals from sintered sludge was lower than the dry ones. However, there was no significant difference in leaching characteristics between the sludges sintered at $350^{\circ}C$ and $650^{\circ}C$. Zn and Fe were leached more greatly in TCLP and KLT methods respectively.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.209-212
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• 2002

The heavy use of petroleum products in modern livings has brought ubiquitous environmental contaminants of aromatic compounds, which persist in aquatic and geo-environment without the substantial degradation. The persistence and accumulation of the aromatic compounds, which include xylene, phenol, toluene, phthalate, and so on are known to cause serious problems in our environments. Some of soil and aquatic microorganisms facilitate their growth by degrading aromatic compounds and utilizing degrading products as growth substrates, the biodegradation helps the reentry of carbons of aromatic compounds, preventing their accumulation in our environments. The metabolic studies on the degradation of aromatic compounds by microoganlsms were extensively carried out along with their genetic studies. A Rhodococcus sp. isolated in activated sludges has shown the excellent ability to grow on phenol as a sole carbon source. In the present study investigated a gene encoding phenol-degrading enzymes from a Rhodococcus sp.