• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.7 no.1
• /
• pp.97-109
• /
• 2004

The disposal of stormwater is one of the major problems in urban water management. One method of reducing peak runoff rates and other detrimental impacts of stormwater is detention storage. Detention ponds as a water quality control alternatives have been investigated by a number of researchers. Recognizing multiple roles such as flood peak attenuation, pollution removal and aesthetic enhancement, the design and management of detentions ponds deserve more research. The purpose of this research is to establish design criteria wet detention ponds to improve water quality. Water quality in detention pond discharge might be improve with physical, chemical and biological alterations. Physical alteration was focused in this study. There are several methods for estimating the suspended solid control capability of wet detention ponds. Existing models of suspended solids removal are based on sedimentation and gravity settling theory. The pollutant trap efficiency of pond is a function of several interrelating factors. Detention time is the most important factor, because it determine gravity settling quantities of pollutants. Desirable modification of physical factors for improvement of water quality in wet detention ponds are volume ratio, area ratio, length to width ratio, depth, out let location, bottom soil type. In order to apply design procedure in actual site, Namak new town development area was selected.

• Journal of environmental and Sanitary engineering
• /
• v.10 no.3
• /
• pp.56-66
• /
• 1995

To investigate environmental impacts of inland fish- farms on the water quality of a stream, environmental parameters including physical, chemical and biological factorswere estimated at trount- farm in 1994. Influences( F-1) were polluted as passing through fish tank( F-2) and settle pond( F-3), so organic and inorganic nutrient concentrations became very high in effluents( F-4). BOD$_{5}$, Chl. a, Nitrite and heterotrophic bacterial numbers in the junction site(5-2) of F-4 and S-1( upstream) were highest among the stream sites. BOD$_{5}$ was proved to a good parameter of organic pollution, and nitrite of Inorganic nutrients in the fishery and it's affected stream, The high concentration of BOD$_{5}$ and Chl. a in S-2 were decreased in downstream(5-3, 5-4). It seems that this results are due to dilution or sedimentation effect. This supposition requires further testing about the sediment of stream. The results of this paper demonstrate that fish farming can deteriorate water quality of a stream by changing environmental factors.

• Economic and Environmental Geology
• /
• v.30 no.2
• /
• pp.143-151
• /
• 1997

The history of the Palgongsan Fault comprises the growth-fault, the dormant and the strike-slip phases. Dissecting the Palgongsan Granite, the Palgongsan Strike-slip Fault, which is the product of the final phase, sinistrally offset about 5.5 km as shown in the dislocation of the Hasandong Formation. Faulting, sedimentation and igneous activity were inter-related in the early phases of the Palgongsan Fault. Some other faults such as the Dansan Pond Fault and the Hayang Fault have also been discovered, and their some stratigraphic implications and the ages of faulting are discussed. The anomalous development of the Jindong Formation in the study area and the related stratigraphic problems are discussed. It has been confirmed that the Konchonri Formation deposited over the Chaeyaksan Volcanic Formation in spite of the recent doubts on their such stratigraphic relation. The chronological sequence of the volcanisms of the Kyongsang Basin has been summarized.

• Environmental Engineering Research
• /
• v.20 no.2
• /
• pp.175-180
• /
• 2015

This research focused on the solid and nitrate removal efficiency in a solid digestion-denitrification column. The 20 L up-flow column consisted of 18 L acrylic column with 2 L down-comer inlet tube located in the middle. In the first part, the wastewater with high suspended solids from the Tilapia fish tank was applied into the sedimentation unit at 5 variable flow rates i.e., 11.25, 25.71, 60, 105.88 and 360 L/h. The results indicated that the flow rate of 11.25 L/h (0.57 m/h) gave the highest solid removal efficiency of $72.72%{\pm}8.24%$. However, the total suspended solids removal was highest at 360 L/h (18.13 m/h). In the second part, methanol was added as an external organic carbon source for denitrification process in a hybrid column containing settled solids. The COD:N ratios of 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1 and 6:1 were investigated and compared with control without methanol addition. This experiment was operated at the HRT of 1 h with 450 L wastewater from recirculating aquaculture pond containing 100 mg-N/L sodium nitrate. The results indicated that the COD:N ratio of 3:1 gave the highest nitrate removal efficiency of $33.32%{\pm}21.18%$ with the denitrification rate of 5,102.88 mg-N/day.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.10
• /
• pp.45-54
• /
• 2011

In this study, the consolidation characteristics are investigated on the artificial soil mixture of kaolinite, fine soils representing dredged soils and reclaimed coal ash from the ash ponds. A large sedimentation chamber was designed and manufactured to produce the artificial soil mixture with uniform stress history. In order to examine the consolidation characteristics in lateral and vertical directions, standard consolidation and Rowe Cell tests were performed. From the results of standard consolidation tests, the artificial soil mixture with coal ash showed lower compressibility and the larger consolidation coefficients enough to aid in early stabilization of the reclaimed sites compared with the kaolinite only. Also, in order to examine the consolidation characteristics when applying vertical drains, the drainage material was installed and tested in the Rowe Cell. The Rowe Cell test results show that the artificial soil mixture yields higher coefficient of consolidation. Thus, the application of artificial soil mixture on the reclaimed sites can shorten the consolidation time.

• Journal of Environmental Health Sciences
• /
• v.24 no.1
• /
• pp.62-69
• /
• 1998

It has been studied that the measurement of odor component emission at confectionery manufacture. The objects of this study were to investigate reduction of offensive odor. The survey effects of odorous materials are presented as follows. The countermeasure of operating process is to minimize sludge sediment in each unit facility. Especially, in summer, we have to clean the sludge frequently, because anaerobic decomposing is likely to occur easily. The sludge or scum from sedimentation tank pond, and floating tank should be treated quickly. We should avoid overloading operation. In the case of overloading, dissolved oxygen should be increased, the quality of wastewater input should be decreased. When dried cakes from condense tank or floating tank are left in treatment plant, we should cover, to prevent diffusion of smell with masking materials. The seasonal condition of operating should be fixed and the kind of coagulants should be changed because the wastewater in each season have different loading rates and organic materials. Odorous materials are very sensitive to the seasonal temperature variation. Especially, when the amount of rainfall is small and the high temperature of maintenance in long periods, air diffusion rate is large, so odorous materials can make great effect on surroundings comparision with other periods. To reduce odorous gas, as short term method, we had better take ceramic addition method. Especially, in summer we should take ceramic addition method. Also, as long term method, the size of wastewater treatment facility is the most important in the normal operating of wastewater treatment facility. But wastewater treatment facilities in this factory are too old, treatment process is old fashion, and the size is too small. So, large wastewater quantity to treat in summer. As results, the expansion of wastewater treatment facility and the process of improvement are required. Restriction level of odor was exceed. As it is overloaded in summer, the basis cause of odor is that the size of wastewater treatment facility is small. The prediction of air quality equilibrium density variation show that the odorous materials from working place are Amine materials whose smell strength is about 2.5(a little strong degree). We can suppose that in summer is sensitive to temperature variation, smell strength is larger as to reduce the origin of odor. We must expand wastewater treatment facility and improve the process A.S.A.P.

• Analytical Science and Technology
• /
• v.18 no.3
• /
• pp.216-223
• /
• 2005

In this study, several kinds of volatile amines in ambiant air were collected and their concentrations were expected from the calibration curves prepared by standard solutions of 7 amines by the official measuring method prescribed in Japanese Offensive Odor Law. The obtained calibration curves showed a good linearity and the detection limit of trimethyl amine was found to be about 0.033 ppb (0.040 ng) in case of 50 liters air. It means that trimethyl amine could be detected with the concentration of lower than its permitting level at the border line of companies. As typical examples of measuring amines in air, results of investigation of two sewage works and one rendering plant around the capital area indicated that 4 kinds of amines, i.e. methyl amine, dimethyl amine, trimethyl amine and isopropyl amine were detectable and concentrations of trimethyl amine at the primary sedimentation pond and sludge dewatering building of the sewage plant A showed 9.07 ppb and 7.79 ppb respectively, being over the concentration of odor strength 2.5, And the aeration tank, excrement input facility and indoor of maintenance room of excrement process building in the sewage plant B showed 70.0 ppb of dimethyl amine and 2.44 ppb of trimethyl amine.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.14 no.5
• /
• pp.81-101
• /
• 2011

This study was conducted to understand the environmental and ecological function of habitat through evaluation of water environment, soil environment, vegetation characteristics, macro-invertebrate characteristics, and visual habits environment evaluation (SVAP) in Hongdong stream located in Hongseong-Gun, Chungnam Province, and hereafter to utilize the results for the habits reconstruction and improvement project. As the results of water quality analysis, BOD, COD, T-P was almost below the standard quality from upper stream to down stream. The construction of small reservoir, wetland and water purification facility, and the management of non-point pollution are proposed to improve these problems. The soil texture was sandy soil, which is unfitted with vegetation development. The construction of shallows and bogs, and induction of soil sedimentation and biotope formation are proposed to improve these problems. In the plant flora, total 90 kinds were observed with 81 species and nine varieties in total 36 families and 85 genera, and the naturalization rate was higher at down area than upper area. As the results of macro-invertebrate fauna survey, total 26 species and 297 individuals in 20 families and 22 genera were collected. Peltodytes sinensis, Chironomidae sp., and Culicidae sp., which are observed at polluted environment, were collected as dominant species. An appropriate vegetation management party idea is necessary, and it is done an idea in consideration of the soil and a physical characteristic. Visual habits environment evaluation (SVAP) result was mostly determined with below normal (Fair) grade. Pollution source interception, purification pond establishment, and various bog establishment are proposed to improve these problems. With the above results, the ecological environment was determined with bad condition, and the improvement of biotope was urgently needed through sustainable monitoring and management of streams habitat in rural area.

• Journal of Environmental Science International
• /
• v.29 no.11
• /
• pp.1055-1064
• /
• 2020

In this research, heavy metals and T-P removal characteristics of plated wastewater are derived using BPC(Break Point Chlorination) process. AA sedimentation pond outflow(Influence) was evaluated for the removal efficiency of heavy metal(Ni) and T-P at a reaction time of 25 minutes by NaOCl input volume(9, 11, 13 and 15 mL). In the case, the higher the NaOCl input volumes, the higher the ORP values were maintained and the higher the removal efficiency tended to be. On the other hand, T-P was judged to have a low relationship between the ORP value and the removal efficiency. In addition, the efficiency of removal heavy metals and T-P in the plated wastewater by injecting 10 mL, 15 mL, 20 mL and 25 mL NaOCl, increased as the amount of NaOCl injected increased, the amount of NaOH input for pH increased. It was found that suspended solid in effluence also increased. It was also observed that the color of the plating wastewater changed from yellowish green to green to charcoal gray to black as the amount of NaOCl injected increased. Treatment characteristics of the reaction time, the longer the reaction time with the substance to be treated after the input of NaOCl, the more the heavy metal removal efficiency tended to increase. Through XRF analysis of the sludge, the constituents in the sludge such as NaCNO, CNCl, Na₃PO₄, CrO₄, 2Na₂CrO₄ and 2NaNO₃ will be analyzed in detail, and the mechanisms of the reaction between the plated wastewater and the complex compound will be elucidated.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.10
• /
• pp.756-762
• /
• 2013

The economical feasibility was conducted to find the adequate method to treat the dredged sediments from agricultural reservoirs in a pilot project that had been operated to improve the quality of water and benthic environments by dredging of contaminated sediments. For benefit/cost (B/C) analysis, the net expenses were considered as the costs of project, and the benefits were calculated from the saving of waste-treatment cost through reuse of dredged sediment, the saving of construction cost of settling pond, and the values of retained water by dredging. Although the economic feasibility depended on the sites of operation, the average B/C value of the pilot project was estimated as 1.32, indicating this project is economically feasible. Depending on the treatment methods, the B/C values were in the order of the methods of coagulating sedimentation, machinery dewatering, stabilization through exothermic reaction, and soil improvement and stabilization. The machinery dewatering method is estimated as the most adequate one to treat the dredged sediments because of the minimum riskiness of secondary pollution, the recyclability, and its economic feasibility.