• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.1-12
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• 2005

Treatment level and pond reactions of a pond system were examined from May to October 2002. The system was constructed in July 2000 for purifying water of Sinyang stream that flows into Koheung Estuarine Lake located in the southern part of the Korean Peninsula. The system was composed of a primary and a secondary pond in series and established on the rice field near the lake. Water pumped from the stream was funneled into the primary pond, whose effluent was discharged into the secondary pond by gravity flow. Effluent from the secondary pond was funneled into wetlands. About 130 $m^3$/day of water was pumped into the primary pond and detention time of the primary and secondary pond was about 2 days. DO from the surface to the 1.0 m depth of the primary and secondary pond was in the rage of 5.2 to 11.0 mg/L and 4.3 to 0.7 mg/L, respectively. DO at the bottom layer of the primary pond was 0 mg/L and that of the secondary pond ranged 3.0~4.7 mg/L. The primary pond functioned as a facultative pond and the secondary as an aerobic one. The temperature difference between the surface and bottom layers of the ponds in August was about $2.5^{\circ}C$ and that in May and October was about $1.0^{\circ}C$. Thermocline was observed in the primary pond during the high ambient temperature of August. The sludge depth of the primary pond in May, August, and October was 2.4, 1.9, and 2.2 cm, respectively. That of the secondary pond was 1.2, 1.0, and 1.1 cm, respectively. SS, $BOD_5$, T-N, and T-P concentrations in influent averaged 16.64, 6.71, 6.21, and 0.23 mg/L and those in effluent from the primary pond averaged 11.48, 4.97, 4.81, and 0.17 mg/L, respectively. The removal rates of the primary pond for SS, $BOD_5$, T-N and T-P were 31%, 26%, 22%, and 24%, respectively. Average concentrations of SS, $BOD_5$, T-N, and T-P in effluent from the secondary pond were 9.81, 4.07, 4.03, and 0.14 mg/L, respectively and the abatement rates of the secondary pond for SS, $BOD_5$, T-N and T-P were 20%, 12%, 13%, and 15%, respectively. SS, $BOD_5$, T-N and T-P concentrations in effluent from the primary pond were significantly low(p=0.001) when compared with those from the secondary one.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.323-329
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• 2005

In this paper, performance of a hybrid sequential aerobic-anaerobic natural system was investigated. Continuous aerobic and anoxic conditions were created by alternatively placing waste stabilization pond (WSP) and wale. hyacinth pond (WHP). Two pilot-scale treatment lines were built and operated; The first consists of WSP integrated with WHP and the second of WSP connected with Dark Pond(DP), namely control system ponds which were used to examine the effects of water hyacinth on nitrification and de-nitrification. The overall performance in nitrogen was 86% reduction in WSP-WHP and 36% in WSP-control pond system. Nitrogen was mostly removed by nitrification and de-nitrification which simultaneously occurred in the same water hyacinth ponds. For the de-nitrification, benthic layer was found out to be adequate support as a carbon source. In addition, WSP-WHP system was very effective in reducing phosphorus. Overall P removal efficiency in WSP-WHP is 81%, while it is only 16% in WSP-control. difference in phosphorus reduction between those two systems is thought to be caused by the plants and probably their roots producing extra-cellular materials, but these aspects need to be further studied.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.214-220
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• 2004

The microcosm type wetland systems were constructed in order to treat wastewater contaminated with parathion. The microcosm reactor consisted of marsh and pond type. The experiment was carried out using batch (marsh or pond) and continuous (marsh-pond and pond-marsh type) systems. In the batch reactor, marsh-type wetland completely removed parathion in water within 8 days, while pond reactor removed 97% of parathion during the same period. During parathion degradation, the amount of 4-nitrophenol production, one of the metabolites from parathion degradation, was higher in marsh-type batch reactor. In the continuous systems, both marsh-pond and pond-marsh combination systems effectively removed parathion from water, and the production of 4-nitrophenol was also minimal. In the extraction experiment, the parathion and its metabolite were not found in the wetland soil and the plant. In order to achieve both aerobic and anaerobic conditions, the continuous wetland system combining marsh and pond type can be the alternative for the non-point source pollutants such as parathion pesticide.

• Journal of environmental and Sanitary engineering
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• v.11 no.1
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• pp.83-91
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• 1996

It is not too much to say that the territorial inhabitants' concerns are wholly c concentrated on the environmental preservation-problem and development-problem in Korea given effect to the local self-government system. At a time like this I was studied the effect on nutrients removal through lighting period in aerobic high rate pond and we know that waste stabilization pond method is the most economical and energy saving wastewater treatment technology than others. At the results which was studied through operating the reactor-l artifically main-tained at a temperature, $25^{\circ}C$, a light intensity, 3000lux, and a lighting period, 24hrs and the reactor-2 artifically maintained at a tern야rature, $25^{\circ}C$ and a light intensity 3000lux, and a lighting period period, 12hrs, It has appeared for 24hrs.-lighting period -reactor-1 to be prior to the reactor-2. The attained results are that 1. reactor-1 is prior to reactor-2 on oxygen-generation 2. reactor-1 is prior to reactor-2 on algal production 3. COD removal efficiency, 90.76%, T-N removal efficiency, 80%, T-P removal e efficiency, 74.47 % in reactor-2, in reactor-1 COD removal efficiency, 94.85 %, T-N removal efficiency, 98.07%, T-P removal efficiency, 72.13% are, so the treatment efficiency of reactor-1 is more excellent than things of reactor-2 4. it appeared that the detention time is 8, 9days.

• Environmental Engineering Research
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• v.20 no.4
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• pp.377-382
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• 2015

The high concentration of nitrogen and phosphorus in wastewater incorporated with the ability to use carbon dioxide as the carbon source make the microalgae become more attractive in wastewater treatment process. This study evaluates the optimal conditions for the digestion of settelable solids from the recirculating aquaculture system to produce the biomass of the green microalga Scenedesmus sp. After solids separation, aerobic digestion of settleable solids under disperse condition produced nitrate as the final product of consequently ammonification and nitrification processes. With the optimal digestion procedure, nitrate concentration during aerobic digestion in 2000 mL vessel increased from $9.63{\pm}0.65mg\;N/L$ to $58.66{\pm}0.06mg\;N/L$ in 10 days. Thereafter, cultivation of Scenedesmus sp. was performed in 1000 mL Duran bottle with air bubbling. The highest Scenedesmus sp. specific growth rate of $0.321{\pm}0.01/d$ was obtained in treatment using liquid fraction after aerobic digestion as the whole culture medium for Scenedesmus sp. cultivation. With this study, digestion of $8,800{\pm}128.12mg\;dry\;weight/L$ of settleable solids from fish pond finally produced $1,235{\pm}21mg\;dry\;weight/L$ of Scenedesmus sp. biomass.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.141-152
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• 1997

The pilot plant had been made so as to be an association system from the various items managed to have degrees of efficiency and It have been done to consider the experimental result with irradiance period and pH influence of all major things to treatment function of Waste Stabilization Pond. The results are as following. The attained results for continuous & cyclic irradiance 1. 24L.-reactor was prior to 12L.-12D.-reactor on oxygen generation & algal production ability. 2. 24L.-reactor was prior to 12L.-12D.-reactor on nutrients removal efficiency. 3. In 24L.-reactor it maintained 5mg/L∼6mg/L, DO concent enough to a fish's survival. The attained results for pH condition 1. Oxygen generation ^ algal production in pH 4-reactor were higher than those in pH 10-reactor. 2. The acidic condition at pH 4 and alkalic condition at pH 10 did not so much affect an algal growth and nutrients removal. The attained results for whole 1. In view of the results appeared as [(NH3-N)+(NO3-N)] removal efficiency, 89.1%∼93.9% and PO4-P removal efficiency, 34.3%∼83.7% & COD removal efficiency, 88.5%∼93.9%. It is possible to treat the wastewater with starch and pH which have been known as thedifficult problem. 2. At the point of non using methanol to nitrificate NO3-N, the nutrients removal method by using an algal growth is the most economical method in the whole nutrients removal methods. 3. The nutrients removal method by using an algal growth contributes to natural ecosystem. 4. The nutrients removal method by using an algal growth is excellant in the prevention against the eutrophication.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1386-1392
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• 2010

A bacterial strain designated GR5$^T$, previously isolated from a freshwater culture pond in Taiwan while screening for bacteria for antimicrobial compounds, was characterized using a polyphasic taxonomic approach. Strain GR5$^T$ was found to be Gram-negative, aerobic, greenish-yellow colored, rod-shaped, and motile by means of a single polar flagellum. Growth occurred at $10-40^{\circ}C$ (optimum, $35^{\circ}C$), pH 7.0-8.0 (optimum pH 8.0), and with 0-2.0% NaCl (optimum, 0.5-1.0%). The major fatty acids were $C_{16:1}{\omega}7c$(36.3%), $C_{16:0}$(16.6%), $C_{12:0}$ 3-OH (12.5%), and $C_{18:1}{\omega}7c$(9.1%). The major respiratory quinone was Q-8, and the DNA G+C content of the genomic DNA was 51.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GR5$^T$ belongs to the genus Rheinheimera, where its most closely related neighbors are Rheinheimera texasensis A62-14B$^T$ and Rheinheimera tangshanensis JA3-B52$^T$ with sequence similarities of 98.1% and 97.5%, respectively, and the sequence similarities to any other recognized species within Gammaproteobacteria are less than 96.5%. The mean level of DNA-DNA relatedness between strain GR5$^T$ and R. texasensis A62-14B$^T$, the strain most closely related to the isolate, was $26.5{\pm}7.6%$. Therefore, based on the phylogenetic and phenotypic data, strain GR5$^T$ should be classified as a novel species, for which the name Rheinheimera aquatica sp. nov. is proposed. The type strain is GR5$^T$ (=BCRC 80081$^T$=LMG 25379$^T$).

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.192-199
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• 2012

Microalgal biotechnology has gained prominence because of the ability of microalgae to produce value-added products including biodiesel through photosynthesis. However, carbon and nutrient source is often a limiting factor for microalgal growth leading to higher input costs for sufficient biomass production. Use of municipal wastewater as a low cost alternative to grow microalgae as well as to treat the same has been demonstrated in this study using mini raceway open ponds. Municipal wastewater was collected after primary treatment and microalgae indigenous in the wastewater were encouraged to grow in open raceways under optimum conditions. The mean removal efficiencies of TN, TP, COD-$_{Mn}$, $NH_3$-N after 6 days of retention time was 80.18%, 63.56%, 76.34%, and 96.74% respectively. The 18S rRNA gene analysis of the community revealed the presence of Chlorella vulgaris and Scenedesmus obliquus as the dominant microalgae. In addition, 16S rRNA gene analysis demonstrated that Rhodobacter, Luteimonas, Porphyrobacter, Agrobacterium, and Thauera were present along with the microalgae. From these results, it is concluded that microalgae could be used to effectively treat municipal wastewater without aerobic treatment, which incurs additional energy costs. In addition, municipal wastewater shall also serve as an excellent carbon and nitrogen source for microalgal growth. Moreover, the microalgal biomass shall be utilized for commercial purposes.

• Environmental Engineering Research
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• v.25 no.2
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• pp.212-221
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• 2020

This work discusses the palm oil mill processing carried out at Jugra Palm Oil Mill Sdn Bhd, situated at Selangor, Malaysia with the capacity of 45-t fresh fruit bunch (FFB)/h. Typically, oil palm residues and palm oil mill effluent (POME) from FFB are generated while processing. Prior to discharge, POME should be treated to remove pollutants in the effluent. As such, the performances of anaerobic and aerobic ponds were assessed in this study to determine temperature, pH, biological oxygen demand (BOD), sludge volume index (SVI), and dissolved oxygen (DO). From the experiments, mesophilic temperature due to better process stability was applied in anaerobic ponds. The pH results displayed a fluctuating trend between lower control limit and upper control limit, and, the pH value increased from one pond to another. The final discharge BOD and SVI appeared to be lower than 100 mg/L and 10 mL/L indicating low degree of pollution and good settling ability for biomass/solid. DO was close to normal, mostly below 2 mg/L. The experimental outcomes revealed the effective treatability of POME in adherence to the standard regulation, which is the priority for environmental sustainability within this industry domain.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.504-510
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• 2003

This study has been carried out to evaluate the passive treatment systems for acid mine drainage in Korea and to suggest, if possible, the method for the improvement. 35 passive treatment systems in 27 mines have been constructed since 1996. SAPS, being the main process, was combined with more than one of processes such as anaerobic wetland, aerobic wetland, and oxidation pond for the construction of passive treatment system. Problems observed during the operation include the poor sulfate removal ratio, overflow, leakage, unusabless of the whole system, and inefficiency. The reasons of the poor sulfate removal ratio are believed that the low temperature during the winter prohibits the SRB activity and HRT for bacterial sulfate reduction is insufficient. An alternative method In Adit Sulfate Reducing System which enables to keep the temperature constant at about $15^{\circ}C$ was suggested. IASRS is the methods of placing the SAPS inside the adit, which enables the temperature around the system constant can be maintained. The experiments using the laboratory scaled model systems made up of four sections showed high efficiencies in pH control and metal removal ratios, but showed still low sulfate removal ratio of about $23\%$ also with high COD at the beginning of the operation.