• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.981-987
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• 2000

Upflow anaerobic sludge blanket(UASB) reactor was operated for treating swine wastewater containing high ammonia nitrogen to assess their performance and toxicity of free ammonia concentration. In the reactor, chemical oxygen demand(COD) removed about 70% at $2.6kgCOD/m^3.day$ of organic loading rate(OLR) and 3 days of hydraulic retention time (HRT), while it was decreased when OLR and HRT was maintained $7kg\;COD/m^3.day$ and 2 days, respectively. Also UASB reactor was evaluated the activity of methane producing bacteria(MPB) according to change of free ammonia concentrations, MPB activity of applied sludge in the 500 and $1000mg-N/{\ell}$ of free ammonia concentration was inhibited by 4% and 40%, respectively. This clearly showed that free ammonia concentration less than $500mg-N/{\ell}$ showed no inhibition to MPB in anaerobic treatment of organics, UASB reactor was stabilized easily less than $1000mgVSS/{\ell}$ due to degradation of organic solids by the high activities of anaerobes.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.75-86
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• 2003

In the near future, the capacity of conventional anaerobic digester is thought to be insufficient because of the increase of the total solids from expansion of intercepting sewer, sewage quantity and direct input of night soil from near apartment districts. The objectives of this study was to investigate the improvement of digestion efficiency using microbial agent(Bio-dh). The system was a pilot-scale, two-staged, anaerobic sludge digestion system. The first-stage digester was heated and mixed. The agitation velocity of the first-stage digester was 120rpm. The second-stage digester was neither heated nor mixed. The Digestion temperature was kept at $35{\pm}1^{\circ}C$ The detention time of digester was 19 days. The dosage of sewage sludge and microbial agent were $0.65m^3/day$ and $0.5{\ell}/day$, respectively. The experiments was run for 25days. Three times a week, $COD_{Mn}$ and SS of effluent, TS, VS, and biogas production rate were measured. Temperature, pH, and alkalinity were measured daily. The results were as follows ; Without microbial agent, digestion efficiencies ranged 46.0%~50.9%(mean=48.6%), with microbial agent(Bio-dh), digestion efficiencies ranged 52.8%~57.3%(mean=54.2%). Consequently, microbial agent(Bio-dh) increased the sludge digestion efficiency about 12%. Also, Without microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 1,639mg/L, 4,888mg/L respectively. With microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 859mg/L, 2,405mg/L respectively. Consequently, microbial agent(Bio-dh) increased the removal efficiency of $COD_{Mn}$ and SS about 47.6% and 50.8%, respectively.

• Korean Journal of Organic Agriculture
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• v.9 no.1
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• pp.37-49
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• 2001

This experiment was carried out to investigate the effects of application levels of nightsoil sludge compost(NSC) in 3 and 4 cuttings per annum on the dry matter yields and nutritive value of orchardgrass(Dactylis glomerata L.). Annual nightsoil sludge compost(NSC) were applied at levels of 0, 10, 20, 40 and 80 ton $㏊^{respectively}$ . Relative yields of each cut to annual dry matter yield were 29.9%, 46.% and 23.2% for 1st cut, 2nd cut and 3rd cut in 3 cutting system, 23.7%, 29.3%, 34.0% and 13.0% for 1st cut, 2nd cut, 3rd cut and 4th cut in 4 cutting system, respectively. Significantly higher dry matter yield of orchardgrass obtained were 8.11 ton $㏊^{-1}$ at level of 40 ton ㏊$^{-1}$ $yr^{-1}$ in 3 cutting systems, ranges of 7.50~10.71 ton $㏊^{-1}$ at level of 10~80 ton ㏊$^{-1}$ $yr^{-1}$ in 4 cutting systems than those of non application level of NSC, respectively(p〈0.05). The mean efficiency of dry matter production to application of NSC(kg DM/ton NSC) were 46 and 102 kg in 3 and 4 cutting systems, respectively. Although th contents of crude protein(CP, %) of orchardgrass were significantly higher at the application levels of 10~80 ton $㏊^{-1}$ $yr^{-1}$ -1/ by NSC than those of the application levels at the 0 ton $㏊^{-1}$ $yr^{-1}$ in 3 and 4 cutting systems(p〈0.05), the contents of neutral detergent fiber(NDF, %) and acid detergent fiber(ADF, %) were lower in NSC plots than those at the non-application plots of NSC. The contents of total digestible nutrient(TDN, %) and relative feed value(RFV) of orchardgrass were significantly increased with increase the applicaton levels of NSC(p〈0.05).

• Journal of Environmental Science International
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• v.7 no.6
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• pp.867-873
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• 1998

Laboratory study was conducted to provide basic data for operating anaerobic sequencing batch reactor(ASBR) process for treatment of nightsoil. The experiments were concerned with digestion characteristics, settleabiltity and dewaterability of digested sludge in ASBR system. Completely-mixed dally-fed control reactor without solid-liquid separation step was also operated to evaluate the baseline performance since the nature of nightsoil was changed with time. In all case, gas production from the ASBR shows 1.3 to 1.44 times higher than that from control, in spite of almost similar trend in organics removal. During thickening period, remarkable decrease in surface settling velocity was observed at the ASBRs compared with the control. In case of the ASBR run, flotation of mixed digested sludge was not occurred. Also, ultimate thickened volume of ASBRs increased 1.2~1.5 times compared with control. Dewaterability of digested sludge without conditioning decreased when the completely-mixed daily-fed reactor for ASBR run was converted to the ASBR. However, improvement of dewaterability of digested sludge from the ASBRs was observed as a result of addition of FeCl$_3$ to digested sludge for conditioning.

• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.101-109
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• 1999

In order to investigate the possibility of treating the different mixture ratios of apple pomace and nightsoil sludge by vermicomposting was performed and the stability of worm casts, and availability of worm casts as plant growth media was evaluated by the analysis of chemical composition. The results were obtained as follows ; 1. The value of cast production at 100% apple pomace treatment was higher than those of other mixture ratios of apple pomace and nightsoil sludge. 2. The highest values of increasing rate and reproductive efficiency were obtained at mixture ratios of 60% apple pomace with 40% nightsoil sludge. 3. The value of increasing rate at 100% nightsoil sludge treatment was lower that those of other mixture ratios of apple pomace and nightsoil sludge. 4. Organic matter, available inorganic nutrients and stability of worm casts showed high values in all treatments. It means that worm casts are an excellent plant growth media source with a high chemical composition and their stability.

• Journal of the Korean GEO-environmental Society
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• v.10 no.5
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• pp.33-39
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• 2009

This study was conducted to evaluate production of complex odor and 12 specific odorous compounds in a pilot-scale (capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each raw material was mixed with seed material and operated for two periods (1st : 50 days, 2nd : 60days). During composting, the temperature hit $90{\sim}95^{\circ}C$ after every mixing in both periods. Therefore, it was concluded that increasing temperature also saves the time which required for composting and high reduction of organics and water contents. The primary odorous compounds were ammonia, methyl mercaltan, dimethyl disulfide and trimethylamine. The concentration of the primary compounds and complex odor during the operation were higher than those on final day and most compounds did not exceed the allowable exhaust standard for odor. Also, it was found that optimal mixing time and control of high temperature are the most important parameters for odor control in ultra thermophilic aerobic composting.

• Journal of Animal Environmental Science
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• v.19 no.1
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• pp.47-54
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• 2013

Two types of reactors were set to investigate the change of characteristics of pig slurry by aeration during fertilization period. One system was equipped with air diffuser to supply oxygen to pig slurry for liquid fertilization, but there was no air diffuser in the other system. Air supply to the experimental systems was regulated by air flow meter. The reactors were set up in the laboratory to protect the pig slurry from external condition such as temperature and humidity changes. Maintaining optimal pH range in the experimental reactors is an important factor for liquid fertilization of pig slurry. In this study, pH ranges of aerobic reactor and anoxic reactor was 7.04~7.19 and 7.34~7.81, respectively. The temperature of aerobic reactors was $2{\sim}3^{\circ}C$ higher then indoor temperature. The amount of sludge accumulated at the bottom layer of non-aerated reactors was 4~5 times more than that of aerated reactors.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.27-36
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• 2010

This study was conducted to evaluate physicochemical parameters; temperature, pH, C/N ratio, water content, organic contents and volume in a pilot-scale(capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each target material was carried out by the first fermentation(organic waste + seed culture) and the second one(organic waste + seed culture + recycle compost), respectively. During composting, only with supply of air and mixing, the temperature increased $90{\sim}105^{\circ}C$ after every mixing in both periods. The changes of pH, $O_2$, $CO_2$ and $NH_3$ represented typical organic decomposition pattern by microorganisms. Also, all other physicochemical parameters of ultra thermophilic aerobic composting process showed similar or better performance than these of general aerobic composting. Heavy metal concentration of fermented compost adapted to compost fertilizer regulation standard in the heavy metal and hazardous analysis.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.391-396
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• 2010

In this research the characteristics of ammonia removal from malodorous waste-air were investigated under various operating condition of biofiilter packed with equal volume of rubber media and compost for the efficient removal of ammonia, representative source of malodor frequently generated at compost manufacturing factory and publicly owned facilities. Then the optimum conditions were constructed to treat waste-air containing ammonia with biofilter. Biofilter was run for 30 days(experimental frequency of 2 times/day makes 60 experimental times.) with the ammonia loading from $2.18g-N/m^3/h$ to $70g-N/m^3/h$ at $30^{\circ}C$. The ammonia removal efficiency reached almost 100% for I through IV stage of run to degrade up to the ammonia loading of $17g-N/m^3/h$. However the removal efficiency dropped to 80% when ammonia loading increased to $35g-N/m^3/h$, which makes the elimination capacity of ammonia $28g-N/m^3/h$ for V stage of run. However, the removal efficiency remained 80% and the maximum elimination capacity reached $55g-N/m^3/h$ when ammonia loading was doubled $70g-N/m^3/h$ for VI stage of run. Thus the maximum elimination capacity exceeded $1,200g-N/m^3/day$(i.e., $50g-N/m^3/h$) of the experiment of biofilter packed with rock wool inoculated with night soil sludge by Kim et al.. However, the critical loading did not exceed $810g-N/m^3/day$ (i.e., $33.75g-N/m^3/h$) of the biofilter experiment by Kim et al.. The reason to exceed the maximum elimination capacity of Kim et al. may be attributed to that the rubber media used as biofilter packing material provide the better environment for the fixation of nitrifying and denitrification bacteria to its surface coated with coconut based-activated carbon powder and well-developed inner-pores, respectively.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.101-110
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• 2004

A solid of Thermophilic Aerobic Oxidation(TAO) System was mixed with sawdust or a rice husks. After fermentation was finished, molding machine and a dryer were used, and pellet fertilizer was produced. The fertilizing experiment was carried out as five pieces by Bed soil, TAO solid(TAO-S), TAO pellet fertilizer(TAO-PF), Chemical fertilizer(NPK) and Control(no fertilizer). Growth rate of the Chinese cabbage by each treatment was examined. Analysis of microbe and soil characteristic before and after crop experiment were carried out. When the moisture contents of TAO-PF were $18\%$ and $25\%$, the occurrence rate of microbes for the storage time was increased to $80\%$ and $100\%$ respectively. However, in the $12\%$ of water content treatment was not increased microbes. The concentration of soil bacteria in TAO-PF and TAO-S for 15 day after treatment was $1.5\times10^7\~8.0\times10^7$ CFU/ml, and the concentration of bacteria for 50 day was increased to $6.3\times10^7$ and $8.3\times10^7$ CFU/ml. However, Fungus decreased. The concentration of Actinomycetes was increased in TAO solid, Bed soil and TAO-PF treatment. The TAO-S and TAO-PF treatment were normal to compare to the NPK treatment. In this experiment the height and width of the Chinese cabbage were 22.3 cm, 16.8 cm in Bed soil and 28.8 cm, 21.3 cm in TAO solid. The leaf number of TAO-S, TAO-PF and NPK treatment were similar to 39.8, 38.3, 40.3 sheet. As the result, the TAO-PF knew that use was possible with fertilizer.