• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.93-101
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• 2000

The objective of this study was to evaluate the possibility of co-digestion of food waste and sewage sludge mixture using anaerobic system. The Biochemical methane Potentials of cabbage and food waste were $297ml\;CH_4/g$ VS and $306.7ml\;CH_4/g$ VS, respectively. The biodegradability of food waste was 60%. The concentrations of acetate, propionate, and isobutyrate produced during the aerobic acidogenesis of food waste for 36 hours were 7,000~7,200 ppm, 260~280 ppm, 380~400 ppm, and 40~50 ppm, respectively, of which acetate was over 85%. The concentrations of acetate, propionate, and isobutyrate produced during the anaerobic acidogenesis for 36 hours were 1,400~1,600 ppm, 30~40 ppm, 220~250 ppm, and 260~300 ppm, respectively, of which acetate was over 70%. The biodegradabilities of aerobic and anaerobic acidogenesis were 30% and 25%, respectively. Methanogensis could be activated under 1 % of NaCl and 1,000 ppm of volatile fatty acids at the range of pH 6.8~7.2. The maximum mixture ratio of food waste and sewage sludge in the present study was 2:8 by the result of VS removal rate and Methane production.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.79-89
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• 2003

The purpose of this study is to investigate appropriate environmental factors when domestic waste is decomposed as aerobic digestion. So stabilization degree was measured after the waste is mixed as certain rates and water content was controlled by 55% and 60%. Variation of VS showed food waste in reactors of number 1, 2, 3, 4 and 5 was decomposed fully except reactor of number 6. Decomposition degree of VS in reactors of number 1, 2, 3 and 4 was not different high because Vinyl and plastic inserted played role bulking agent in reactor number 1, 2, 3 and 4. In reactors, maximum temperature indicated $57{\sim}59^{\circ}C$ and temperatures in reactors 1, 2, 3 and 4 were higher and remained longer than in reactor 5 and 6 for 2~4 days. Variation of $CO_2$ was similar to that of VS. The reduction rate of water content was low because moisture generated by oxidation fever of microorganism did not evaporated well. pH was low in the beginning of the reaction however, as time passed, it increased slightly and remained regular pattern. EC and C/N showed the same pattern as pH. Settlement and weight reduction rates were similar to the factors above. Reactor 1, 2, 3, and 4 showed higher settlement and weight reduction rate than reactor 5 and 6.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.3
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• pp.33-40
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• 2014

This study were conducted to evaluate the N mineralization and nitrification rates and to estimate the losses of total carbon and nitrogen by runoff water in soils cooperated with organic composts and bio-char during corn cultivation. For the experiment, the soil texture used in this study was clay loam, and application rates of chemical fertilizer and bio-char were $230-107-190kg\;ha^{-1}$($N-P_2O_5-K_2O$) as recommended amount after soil test and 0.2% to soil weight. The soil samples were periodically taken at every 15 day intervals during the experimental periods. The treatments were consisted of cow compost, pig compost, swine digestate from aerobic digestion system, and their bio-char cooperation. For N mineralization and nitrification rates, it was shown that there were generally low in the soil cooperated with bio-char as compared to the only application plots of different organic composts except for 47 days after sowing. Also, they were observed to be highest in the application plot of swine digestate from aerobic digestion system. For loss of total carbon by run-off water, it was ranged from 1.5 to $3.0kg\;ha^{-1}$ in the different organic compost treatment plots. However, Loss of total carbon with bio-char could be reduced at $0.4kg\;ha^{-1}$ in PC treatment plot. Also, with application of bio-char, total nitrogen was estimated to be reduced at 4.2 (15.1%) and $3.8(11.8%)kg\;ha^{-1}$ in application plots of pig compost and swine aerobic digestate, respectively.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.155-160
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• 2009

This study was carried out to investigate the feasibility of Multi Process of Aerobic Digestion (MPAD) for recycling of swine manure slurry as fertilizer. MPAD consisted of three kinds of difference process which are thermophilic aerobic oxidation (TAO) system, lime solidification system, and reverse osmosis (R/O) membrane system. TAO system was studied well previously for decade. The chemical composition of the lime-treated solid fertilizer was as like that organic matter 17.4%, moisture 34.1%, N 0.9%, P 1.7%, K 0.3%, Ca 12.7%, and which was expected to be useful as acid soil amendment material. The concentrated liquid material produced by R/O membrane system was also expected as a good fertilizer for crops production and soil fertility improvement.

• KSBB Journal
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• v.23 no.1
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• pp.90-95
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• 2008

In this study, a combined process of sequential anaerobic-aerobic digestion (SAAD), fluidized-bed bioreactor (FBBR), and ultrafiltration (UF) for the treatment of small scale food waste leachate was developed and evaluated. The SAAD process was tested for performance and stability by subjecting leachate from food waste to a two-phase anaerobic digestion. The main process used FBBR composed of aerators for oxygen supply and fluidization, three 5 ton reaction chambers containing an aerobic mesophilic microorganism immobilized in PE (polyethylene), and a sedimentation chamber. The HRTs (hydraulic retention time) of the combined SAAD-FBBR-UF process were 30, 7, and 1 day, and the operation temperature was set to the optimal one for microbial growth. The pilot process maintained its performance even when the CODcr of input leachate fluctuated largely. During the operation, average CODcr, TKN, TP, and salt of the effluent were 1,207mg/L, 100mg/L, 50 mg/L, and 0.01 %, which corresponded to the removal efficiencies of 99.4%, 98.6%, 89.6%, and 98.5%, respectively. These results show that the developed process is able to manage high concentration leachate from food waste and remove CODcr, TKN, TP, and salt effectively.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.613-619
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• 2018

In this study, various influent sludge pre-treatment methods and the internal recirculation of thickened sludge from effluents using a liquid/solid separation unit were adopted to investigate their effects on the sludge digestion and methane production in a combined mesophilic anaerobic and thermophilic aerobic sludge digestion process. A lab-scale combined sludge digestion process was operated during 5 phases using different feed sludge pre-treatment strategies. In phase 1, the feed sludge was pre-treated with a thermal-alkaline method. In contrast, in phases 2, 3 and 4, the internal recirculation of thickened sludge from the effluent and thermal-alkaline, thermal, and alkaline pre-treatment (7 days) were applied to the combined process. In phase 5, the raw sludge without any pre-treatment was used to the combined process. With the feed sludge pre-treatment and internal recirculation, the experimental results indicated that the volatile suspended solid (VSS) removal was drastically increased from phases 1 to 4. Also, the methane production rate with the thermal-alkaline pre-treatment and internal recirculation was significantly improved, showing an increment to 285 mL/L/day in phase 2. Meanwhile, the VSS removal and methane production in phase 5 were greatly decreased when the raw sludge without any pre-treatment was applied to the combined process. Considering all together, it was concluded that the combined process with the thickened sludge recirculation and thermal-alkaline pre-treatment can be successfully employed for the highly efficient sewage sludge reduction and methane gas production.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.607-628
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• 1999

The swine waste industry is growing rapidly along with the world human population. The trend is toward more concentrated piggeries with numbers of herds in the thousands. Associated with these increased herds are large quantities of wastes, including organic matter, inorganic nutrients, and gaseous emissions. The trend in swine waste management is toward treatment of these wastes to minimize negative impact on the health and comfort of workers and animals and the atmosphere, water, and soil environments. Treatment of these wastes has traditionally involved land application, lagoons, oxidation ditches, and conventional batch and continuously stirred reactor designs. More sophisticated treatment systems are being implemented, involving advanced anaerobic digester designs, integrated with solids separation, aerobic polishing of digester effluents, and biological nutrient removal. This review discusses the present and future role of anaerobic processes in piggery waste treatment with emphasis on reactor design, operating and performance parameters, and effluent processing.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.136-139
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• 2004

The dyeing effluent is a highly colored stream containing unfixed dyes along with salts and auxiliary chemicals such as emulsifying agents. Moreover, Textile dying is a chemically intensive process and consumes large quantities of water. Difficulties in the effluent treatment arise from its non-degradable property by aerobic digestion.(omitted)

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.297-297
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• 1987

A $C_{1}$ enriched cellulase fraction was separated from culture filtrate of anaerobic Clostridium thermocellum by hydroxyapatite column chromatography. The separated fraction showed strong synergistic action with $C_{x}$ component (endo-$\beta$-1, 4-glucanase) in digestion of crystalline cellulose, similar to the other aerobic cellulolytic microorganisms. Unlike the $C_{x}$ component the $C_{1}$ enriched fraction was rapidly inactivated by oxidation at the atmospheric condition. The enzyme activity was significantly enhanced by the addition of reducing agents, especially $\beta$-mercaptoethanol, which indicates that a $C_{1}$ component has a lot of sulfhydryl groups essential for the enzyme activity. The effect of metal ions on $C_{1}$ activity was also investigated. The $C_{1}$ fraction was found to be thermally stable compare to endo-$\beta$-1,4-glucanase. Optimal temperature and pH were found to be 60.deg.C and 6.0, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.783-789
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• 2011

Recently, auto-thermal thermophilic aerobic digestion (ATAD) has a great attention for destruction of wasted sludge biomass in wastewater treatment plant. Reduction of sludge concentration has been successfully achieved with pilot scale ATAD and ceramic filtration process in field condition. However, high concentration of COD, total nitrogen (TN) and total phosphorus (TP) was observed in filtrate, which should be treated before recirculation of filtrate to biological wastewater treatment plant. This study was focused on removal of nitrogen and phosphorus contained in the filtrate of ATAD, using struvite crystallization method. The effect of operational and environmental parameters (such as, N, P and Mg ion concentration and molar ratio, pH, reaction time, agitation strength, seed dosage, and reaction temperature) on the treatment of TN and TP with struvite crystallization were evaluated. Magnesium (as $MgCl_26H_2O$) and phosphorus (as $K_2HPO_4$) ions were, if necessary, added to increase nitrogen removal efficiency by the crystal formation. Average concentration of $NH_4^+-N$ and $PO_4^{3-}-P$ of the filtrate were 1716.5 mg/L and 325.5 mg/L, respectively. Relationship between removal efficiencies of nitrogen and phosphorus and molar ratios of $Mg^{2+}$ and $PO_4^{3-}-P$ to $NH_4^+-N$ was examined. Crystal formation and nitrogen removal efficiencies were significantly increased as increasing molar ratios of magnesium and phosphorus to nitrogen. As molar ratio of $Mg^{2+}:PO_4^{3-}-P:NH_4^+-N$ were maintained to 2 : 1 : 1 and 2 : 2 : 1, removal efficiencies of nitrogen and phosphorus were 71.6% and 99.9%, and 93.8% and 98.6%, respectively. However, the effect of reaction time, mixing intensity, seed dose and temperature on the struvite crystallization reaction was not significant, comparing to those of molar ratios. Settled sludge volume after struvite crystallization was observed to be reduced with increase of seed dose and to be increased at high temperature.