• Journal of Environmental Science International
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• v.1 no.1
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• pp.11-17
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• 1992

The treatment performances of anaerobic-aerobic activated sludge Process were investigated under various operation conditions. The treatment system proposed in this study gave a relatively stable performance against hourly change of the flow rate and showed a satisfactory removal efficiency of nitrogen and phosphorus compounds under experimental conditions. The average removal efficiency of total nitrogen gradually decreased as the influent total nitrogen concentration was increased. High C/N ratio of the wastewater was required for the complete removal of nitrogen. Glucose as a carbon source was more efficient than starch and the removal ability for all components become hither with the increase of the fraction of glucose.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.689-696
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• 2007

Kinetic analysis was important to develope the biological nutrient removal process effectively. In this research, anoxic-anaerobic-aerobic system was operated to investigate kinetic behavior on the nutrient removal reaction. Nitrification and denitrification were important microbiological reactions of nitrogen. The kinetics of organic removal and nitrification reaction have been investigated based on a Monod-type expression involving two growth limiting substrates : TKN for nitrification and COD for organic removal reaction. The kinetic constans and yield coefficients were evaluated for both these reactions. Experiments were conducted to determine the biological kinetic coefficients and the removal efficiencies of COD and TKN at five different MLSS concentrations of 5000, 4200, 3300, 2600, and 1900 mg/L for synthetic wastewater. Mathematical equations were presented to permit complete evaluation of the this system. Kinetic behaviors for the organic removal and nitrification reaction were examined by the determined kinetic coefficient and the assumed operation condition and the predicted model formulae using kinetic approach. The conclusions derived from this experimental research were as follows : 1. Biological kinetic coefficients were Y=0.563, $k_d=0.054(day^{-1})$, $K_S=49.16(mg/L)$, $k=2.045(day^{-1})$ for the removal of COD and $Y_N=0.024$, $k_{dN}=0.0063(day^{-1})$, $K_{SN}=3.21(mg/L)$, $k_N=31.4(day^{-1})$ for the removal of TKN respectively. 2. The predicted kinetic model formulae could determine the predicted concentration of the activated sludge and nitrifier, investigate the distribution rate of input carbon and nitrogen in relation to the solid retention time (SRT).

• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.41-41
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• 1993

Recently, the advanced membrane separation technology has even been applied to the post treatment to biological process of wastewater treatment, since the efficiency of biological treatment significantly depends on maintaining a high biomass concentration in the bioreator. Particularly, anaerobic microbes in the biological system have slower growth rates than aerobic microbes and thus it takes a long hydaulic retention time(HRT) to prevent biomass washout in the completely mixed anaerobic digester. The anaerobic sludge also has poor settleability owing to its diffusible and somewhat filamentous nature. Moreover, the residual gasification and consequent sludge rise in the clarifier compartment become a considerable problem, which proves that complete separation of biological solids is difficult.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.906-912
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• 2007

A lab-scale thermophilic aerobic digestion (TAD) system was operated at $64^{\circ}C$ with mixed primary and secondary sludges taken from a large wastewater treatment plant. The semi-continuously operated reactor at HRTs of 1, 3 and 6 days indicated that longer HRT could stabilize sludge organics and solids comparable to anaerobic digestion. It has been found that reduced HRT of 3 and 1 day produced the effluent with highly biodegradable soluble organics, indicating the possibility of energy recovery in TAD. No proof of biological nitrification was observed at thermophilic operating temperature of $64^{\circ}C$, while nitrogen removal seemed due to nitrogen exertion during the aerobic thermophilic cell synthesis as well as ammonia stripping.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.4
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• pp.411-417
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• 2014

The performance of the new aerobic digestion system combined with inorganic sludge separation unit and sludge solubilization unit, CaviTec II, is evaluated. Anaerobic digester effluent sludge is used for feed sludge of CaviTec II system. By addition of CaviTec II, the amount of cake generated is reduced by 27%, and the soluble nitrogen is reduced by 92%.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.97-102
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• 2005

Anaerobic decomposition is one of the most common processes in nature and has been extensively used in waste and wastewater treatment for several centuries. New applications and system modifications continue to be adapted making the process either more effective, less expensive, or suited to the particular waste in question and the operation to which it is to be applied. Animal manure is a highly biodegradable organic material and will naturally undergo anaerobic fermentation, resulting in release of noxious odors, such as in manure storage pits. Depending on the presence or absence of oxygen in the manure, biological treatment process may be either aerobic or anaerobic. Under anaerobic conditions, bacteria carry on fermentative metabolisms to break down the complex organic substances into simpler organic acids and then convert them to ultimately formed methane and carbon dioxide. Anaerobic biological systems for animal manure treatment include anaerobic lagoons and anaerobic digesters. Methane and carbon dioxide are the principal end products of controlled anaerobic digestion. These two gases are collectively called biogas. The biogas contains $60\~70\%$ methane and can be used directly as a fuel for heating or electrical power generation. Trace amounts of ammonia and hydrogen sulfide ($100\~300\;ppm$) are always present in the biogas stream. Anaerobic lagoons have found widespread application in the treatment of animal manure because of their low initial costs, ease of operation and convenience of loading by gravity flow from the animal buildings. The main disadvantage is the release of odors from the open surfaces of the lagoons, especially during the spring warm-up or if the lagoons are overloaded. However, if the lagoons are covered and gases are collected, the odor problems can be solved and the methane collected can be used as a fuel. Anaerobic digesters are air-tight, enclosed vessels and are used to digest manure in a well-controlled environment, thus resulting in higher digestion rates and smaller space requirements than anaerobic lagoons. Anaerobic digesters are usually heated and mixed to maximize treatment efficiency and biogas production. The objective of this work was to review a current anaerobic biological treatment of animal manure for effective new technologies in the future.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.490-495
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• 2005

Since there are very limited numbers of thermophilic anaerobic digesters being operated, it is often difficult to start up a new one using sludge from an existing reactor as a seed. However, for obvious reasons it seems few attempts have been made to compare the start-up performance of thermophilic anaerobic digestion using different sources of seed sludges. The purpose of this study was to evaluate the start-up performance of anaerobic digestion using aerobic Waste Activated Sludge (WAS) from a plant and mesophilic Anaerobic Digested Sludge (ADS) as the seed source at both mesophilic ($35^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures. In this study, two experiments were conducted. First, thermophilic anaerobic reactors were seeded with WAS (VSS = 4,400 mg/L) and ADS (VSS = 14,500 mg/L) to investigate start-up performance with a feed of acetate as well as propionate. The results show that WAS started to produce $CH_4$ soon after acetate feeding without a lag time, while ADS had a lag time of 10 days. When the feed was changed to propionate, WAS removed propionate down to below the detection limit of 10 mg/L, while ADS removed little propionate and produced little $CH_4$. Second, in order to further compare the methanogenic activity of WAS and ADS, both mesophilic and thermophilic reactors were operated. WAS acclimated to anaerobic conditions shortly and after acclimating it produced more $CH_4$ than ADS. WAS at mesophilic temperature biodegraded acetate at the same rate as for thermophilic. However WAS at mesophilic temperature biodegraded propionate at a much faster rate than at thermophilic. WAS as the seed source of anaerobic digestion resulted in much better performance than ADS at both mesophilic and thermophilic temperatures for both acetate and propionate metabolism.

• Resources Recycling
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• v.9 no.4
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• pp.56-62
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• 2000

This study was introduced an amalgamated septic tank system using mineral sintered body was made from non-metallic minerals with a ability being attached or accelerating a vitality of soil microorganism for the effective wastewater treatment. Experimentally, we made an amalgamated septic tank appling anaerobic-aerobic process experimental facilities to two personal houses for handling a residental sewage directly on a small scale from the place of origin. The results are shown as follows; The COD\ulcorner and BOD of effluent were about 10 mg/l after the treatments and T-N removal efficiency was 60-70%. Moreover these results suggested the possibility of denitrification without adding organics and more than 80% of T-P removal also showed the possibility of wastewater treatment biologically.

• Journal of Korean Society on Water Environment
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• v.29 no.6
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• pp.782-789
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• 2013

Enhanced biological phosphorus removal (EBPR) behavior and microbial characteristics in the anaerobic-aerobic SBR (PAO SBR) and the anaerobic-anoxic SBR (DPAO SBR) were examined in this research. For 392 days of operation, both SBRs have exhibited a good EBPR (or denitrifying EBPR) performance. $P_{release}/P_{influent}$ ratio was highest in both reactors after the stabilization, while the efficiency of phosphorus removal was decreased since the sludge granulation has been visually observed within the reactor. The comparative analysis of Pyrosequencing-based microbial population between PAO and DPAO sludges showed indirectly that Dechloromonas spp. could utilize $O_2$ and $NO_3{^-}-N$ as an electron acceptor and Accumulibacter phosphatis use only $O_2$ in EBPR system. Also, we concluded that Thauera spp. as a denitrifier contribute significantly to the anoxic phosphorus removal in the DPAO system.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.3
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• pp.64-73
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• 2013

The application of the Life Cycle Assessment (LCA) methodology to analyze the environmental impact to different swine waste treatment systems was investigated. The first part of LCA is to organize an inventory of parameters and emissions released due to the system under investigation. In the following step of the Life Cycle Impact Assessment, the inventory data were analyzed and aggregated in order to finally get one index representing the total environmental burden. For the Life Cycle Impact Assessment (LCIA) the Eco-indicator 95 method has been chosen because this is well documented and regularly applied impact method. Two different swine waste treatment systems such as aerobic and anaerobic digestion systems were chosen as an example for the life cycle impact analysis. For establishing the parameters to be assessed the agricultural environmental effects to above swine waste treatment systems, it has been observed that there was high at T-P emission in anaerobic digestion system and $CO_2$ emission in aerobic digestion system. For Eco-indicator values per environmental effect for swine waste treatment systems related to one tonne of swine waste, it was shown that there was a negative index for global warm potential and soil acidification in aerobic digestion system, but relatively high positive index for eutrophication in anaerobic digestion system.