• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.500-507
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• 2020

This study examined the wastewater at a livestock farm, and found that the dairy wastewater from the milking parlor had a lower concentration than the piggery wastewater, and that it was produced at a rate under 1.3 ㎥/day in a single farmhouse. The amount of dairy wastewater was determined based on the performance of the milking machine, the maintenance method of the milking parlor, and the amount of milk production allocated for each farmhouse, not by the area. The results confirmed that both dairy wastewater treatment processes, specifically those using Hanged Bio-Compactor (HBC) and Sequencing Batch Reactor (SBR), can fully satisfy the water quality standards of discharge. The dairy wastewater has a lower amount and concentration than piggery wastewater, meaning it is less valuable as liquid fertilizer, but it can be easily degraded using the conventional activated sludge process in a public sewage treatment plant. Therefore, discharging the dairy wastewater after individual treatment was expected to be a more reasonable method than consigning it to the centralized wastewater treatment plant. The effluent after the SBR process showed a lower degree of color than the HBC effluent, which was attributed to biological adsorption. In the case of the milking parlor in the livestock farm, the concentrations of the effluents obtained after HBC and SBR treatments both satisfied water quality standards for the discharge of public livestock wastewater treatment plants at 99% confidence intervals, and the concentrations of total nitrogen and phosphorous in untreated wastewater were even lower than the water quality standards of discharge. Therefore, we need to discuss strengthening the water quality standards to reduce environmental pollution.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.590-598
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• 2006

In-situ Air sparging (IAS) is a groundwater remediation technique, in which organic contaminants volatilize into air form the saturated to vadose zone. This study was carried out to evaluate the effect of sludge and soil microbial community structure on air sparging of Total Petroleum Hydrocarbons (TPH) contaminated groundwater soils. In the laboratory, diesel (10,000 mg TPH/kg) contaminated saturated soil. The Air was injected in intermittent (Q=1500 mL/min, 10 minute injection and 10 minute idle) modes. For Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis of eubacterial communities in sludge of wastewater treatment plants and soil of experiment site, the 16S rDNA was amplified by Polymerase Chain Reaction (PCR) from the sludge and the soil. The obtained 16S rDNA fragments were digested with Msp I and separated by electrophoresis gel. We found various sequence types for experiment with sludge soil samples that were closely related to Agrococcus, Flavobacterium, Thermoanaerobacter, Flexibacter and Shewanella, etc, in the clone library. The results of the present study suggests that T-RFLP method may be applied as a useful tool for the monitoring in the TPH contaminated soil the fate of microorganisms in natural microbial community.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.85-93
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• 2011

The structural components of microorganism are quite related to the toxin and environmental conditions. The vegetative and dormant cells are quite affected by the physical and chemical environments to survive and they will be dormant when they are in the extreme environment. The mechanism to activate the microorganisms however, is not well defined yet in the area of activation state and sporulation state through the analysis of EPS. Other than that even the main mechanism of prior to acquisition of analysis values is not well understood. Therefore, what kind of specific environment to affect the activation and sporulation will be discussed through the analysis of the extracellular polymeric substances(EPS). EPS are a high molecular weight mixture of polymers presenting both outside of cells and interior of microbial aggregates. They are a major complex materials in microbial aggregation for sustaining them together in a three dimensional matrix. Three commonly used extraction methods were applied to this study their effectiveness and quantification in extracting EPS from several Bacillus microorganisms and activated sludge. Three extraction methods used for this study are regular centrifugation with formaldehyde (RCF), Steaming, and EDTA extraction. The results of EPS contents such as the quantitative proteins, carbohydrates and the ratio of protein versus carbohydrate from the several species with the several specific methods showed in this research. This study aims to get comparable results of the quantitative production of EPS and the effectiveness of sedimentation for Bacillus microorganisms and activated sludge from several wastewater treatment plans. The results revealed that the protein amount extracted was the highest by the Steaming method of three extraction methods before sporulation and the carbohydrate amount extracted was the highest by the RCA method of three extraction methods after sporulation. The higher amount of protein compared with carbohydrate from Bacillus microorganisms affected higher sedimentation efficiency, however it could not be found the relation between the EPS production and sedimentation efficiency for the activated sludge.

• Journal of Korean Society on Water Environment
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• v.39 no.2
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• pp.175-180
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• 2023

The aim of this study was to compare the fouling characteristics of Extracellular polymeric substances (EPS) secreted by Chlorella vulgaris with the case of Bacterial-MBR (BMBR), Microalgal-MBR (MMBR) for advanced wastewater treatment using the Laboratory scale, in order to suggest a method to minimize fouling in MMBR by identifying the effects of amounts and compositions of EPS secreted by C. vulgaris and bacteria in the activated sludge on fouling. Contrary to expectations, fouling occurred relatively severely in the MMBR from the beginning of the operation than in the BMBR. Reasons for such a fouling pattern were considered to be the effect of C-EPS, which accumulates on the membrane surface of MMBR 30 times more than that on the membrane surface of activated sludge (BMBR). In this respect, according to the results of this experiment and a comparative review of several previous studies, it was confirmed that unlike activated sludge, in which the ratio of P-EPS was relatively higher than that of C-EPS, in case of C. vulgaris, the ratio of C-EPS to P-EPS was relatively higher than that in case of activated sludge. This was presumed to be the main cause of the significant fouling phenomenon in MMBR. However, an increase in TMP with increasing C-EPS concentration was not observed.

• Korean Journal of Materials Research
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• v.34 no.5
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• pp.254-260
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• 2024

This study is to manufacture a titanium dioxide (TiO₂) photocatalyst by recycling sludge generated using titanium tetrachloride (TiCl₄) as a coagulant. Compared to general sewage, a TiCl₄ coagulant was applied to dyeing wastewater containing a large amount of non-degradable organic compounds to evaluate its performance. Then the generated sludge was dried and fired to prepare a photocatalyst (TFS). Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and nitrogen oxide reduction experiments were conducted to analyze the surface properties and evaluate the photoactive ability of the prepared TFS. After using titanium tetrachloride (TiCl₄) as a coagulant in the dyeing wastewater, the water quality characteristics were measured at 84 mg/L of chemical oxygen demand (COD), 10 mg/L of T-N, and 0.9 mg/L of T-P to satisfy the discharge water quality standards. The surface properties of the TFS were investigated and the anatase crystal structure was observed. It was confirmed that the ratio of Ti and O, the main components of TiO₂, accounted for more than 90 %. As a result of the nitric oxide (NO) reduction experiment, 1.56 uMol of NO was reduced to confirm a removal rate of 20.60 %. This is judged to be a photocatalytic performance similar to that of the existing P-25. Therefore, by applying TiCl₄ to the dyeing wastewater, it is possible to solve the problems of the existing coagulant and to reduce the amount of carbon dioxide generated, using an eco-friendly sludge treatment method. In addition, it is believed that environmental and economic advantages can be obtained by manufacturing TiO₂ at an eco-friendly and lower cost than before.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.398-404
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• 1984

This study was attempted to investigate variation of the bacterial flora in waste water treatment of fish meat paste plant by batch and continuous culture. The results of the experiment are as follows : 1. The removal rate of BOD in waste water treatment by activated sludge of continuous culture was above $90\%$. 2. In the process of nitric acidification of protein waste water, $NH_4-N\;and\;NO_2-N$ increased untill the lapse of 48 hours from culture, but $NO_3-N$ showed little change. 3. In activated sludge obtained from acclimation by batch culture for 10 days, bacteria good in capacity of nitric acidification were not appeared. 4. Among 120 strains of isolated bacteria, the most predominantly appeared bacterial flora were Enterobacteriaceae ($28\%$) and Pseudomonas spp. ($25\%$), In the latter term of aeration during which ammonia originates in abundance, Pseudomonas spp. was decreased but Enterobarteriaceae was increased. 5. Fifty percent of the isolated strains were able to grow in $0\%,\;3\%$ NaCl and $75\%$ artificial sea water, Therefore, it is suggested that sea water can be used as dilution water instead of tap water during the treatment of waste water.

• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.1-12
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• 2004

This study was conducted to evaluate the variation characteristics of influent and effluent quality from sewage treatment facilities using activated sludge processes and to assess the impact caused by discharge of treated sewage on the receiving water Monthly data of five water quality items (BOD, COD, SS, T-N, T-P) were used to understand the water quality at three sewage treatment plants in Seoul for five years from 1999 to 2003. Concentration differences of water quality parameters were observed between upstream and downstream site at the sewage treatment plant outfall to investigate the impact of discharge in Tan stream and Han river basin. 1. Due to the effect of continuous improvement in sewer system, the concentrations of influent went on increasing generally. 2. Effluent concentrations of BOD, COD and SS showed the trend of a little decreasing, but the trend of increasing in T-N and T-P. 3. In Tan stream basin, the impact of sewage treatment plant discharge was not observed directly, because concentration of discharge was lower than stream water's. But discharges from sewage treatment plants affected water quality at downstream site in Han river, concentration of T-P especially.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.119-125
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• 2015

A concentration meter is widely used at purification plants, sewage treatment plants and waste water treatment plants to sort and transfer high concentration sludge and to control the amount of chemical dosage. When the strange substance is contained in the sludge, however, the attenuation of ultrasonic wave could be increased or not be transmitted to the receiver. At that case, the value of concentration meter is higher than the actual density value or vibrated up and down. It has also been difficult to automate the residuals treatment process according to the problems as sludge attachment or damage of a sensor. Multi-beam ultrasonic concentration meter has been developed to solve these problems, but the failure of the ultrasonic beam of a specific concentration measurement value degrade the performance of the entire system. This paper proposes the method to improve the accuracy of sludge concentration rate by choosing reliable sensor values and learning them by proposed algorithm. The prediction algorithm is chosen as neuro-fuzzy model, which is tested by the various experiments.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.96-100
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• 2014

Recently, the management system of wastewater treatment facility has magnified due to the stringent regulations for the protection of the environment, and a sewage treatment plant efficiency and research of the car development are activated in large facilities or industrial park. however, the existing sewerage disposal system and specific water quality monitoring network reliability for real-time transmission of this building is insufficient. In this paper, we proposed a local wireless network design for sludge multi meter data collection and control for measuring the concentration of the sludge efficiently. Also, the collected data over the local wireless network to transmitted to the central monitoring system and accumulate the data in real time to calculate statistics is possible to monitor the status of the sewage treatment facilities. The proposed system uses a short-range wireless networks of IEEE 802.15.4 and configures an IEEE 802.11 network which can monitor real-time status in central system. Also, we install a sludge multimeter and communication network in sewage treatment facilities and confirm the usefulness of the proposed technique by demonstrating its effectiveness.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.437-442
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• 2010

This work was initiated both to maximize purity of calcium fluoride sludge and to minimize water content in the settled sludge. The sludge was produced in the process of fluoride removal of semiconductor wastewater by the addition of $Ca^{2+}$ ion. Fludized bed reactor(FBR) using calcium fluoride as a seed was adapted. Optimum pH and molar ratio of $Ca^{2+}/F^-$ were determined in lab-scale study. The experimental results showed that fluoride removal was increased as pH and molar ratio of $Ca^{2+}/F^-$ increased, with the best removal of 79.8% in an optimum condition. In the optimum point of fluoride removal, very low ${PO_4}^{3-}$-P removal of 9.3% was observed. It indicates forming $CaF_2$ crystal of high purity, when side reaction of calcium with phosphate was minimized. In addition, water content of settled sludge was 19.3%, which is relatively low compared to other fluoride removal processes. Consequently, the FBR process proposed in this study was very effective in fluoride removal, producing good sludge of high purity and less water content.