• Journal of the Korean GEO-environmental Society
• /
• v.13 no.3
• /
• pp.71-76
• /
• 2012

Since sediment in a stable state is disturbed during the process from sediment in a natural state to dredged soil, the turbidity of water is not good. When the dredged soil settles again, the volume change in the sediment occurs. Coagulant and flocculant are added for turbidity mitigation of the water and faster settling process of suspended solid, and the amount of the substances affects the characteristics of the dredged soil. This study is to investigate the characteristics of the dredged soil depending on the amount of three chemical products added to the wet dredged soil and the dry dredged soil through measuring the suspended solids (SS), volume change and sedimentation velocity. The experimental measurements show that the SS decreased, the volume change rate increased, and the sedimentation velocity increased, as the chemical amount increased. In addition, it was found that the dry dredged soil reacted even with little quantity of the chemicals because derelict and microorganism are removed due to the drying process at $100{\pm}5^{\circ}C$.

• Journal of Environmental Science International
• /
• v.19 no.11
• /
• pp.1315-1322
• /
• 2010

A membrane bioreactor (MBR) was designed using polyvinylidene fluoride(PVDF)-type hollow fiber membrane modules with a treatment capacity of 10 ton/day. A pilot plant was installed in a sewage treatment plant and was operated with an intermittent aeration method which avoids any concentration gradient of suspended solids (SS) in the MBR. For continuous operation, the pilot plant was first tested with influent (mixed liquor suspended solid:MLSS of 1000-2000 mg/L) of aeration tanks in the sewage treatment plant. The MBR was pre-treated with washing water, 10% ethanol solution, 5% NaOCl solution and finally washing water, one after another. To demonstrate the effect of the MBR on sewage treatment, compared with conventional activated sludge processes, we investigated the relationships among permeate amount (LMH), change in operation conditions, influent MLSS level and sludge production. It was found that the optimum aeration rate and suction pressure were $0.3\;m^3$/min and 30~31 cmHg, respectively. Under stable conditions in aeration, suction pressure, influent flow rate and drainage, the SS removal efficiency was more than 99.99% even when the MLSS loading rate changes. Compared with conventional activated sludge processes, the MBR was more effective in cost reduction by 27% based on permeate amount and by 51.5% on sludge production.

• Korean Journal of Food Science and Technology
• /
• v.27 no.3
• /
• pp.318-323
• /
• 1995

To improve wastewater treatment in a confectionery factory and to optimize chemical coagulation process, this study was performed. $COD_{Mn}$ and total solid of untreated wastewater were $200{\sim}820ppm\;and\;860{\sim}1350ppm$, respectively. Composition of total solid was sugar 40%, protein 10%, hexane-soluble 20%, and ash 30%. Turbidity at 650 nm and the amount of suspended solid (SS) showed correlation, thus turbidity could be used for the on-line measurement of SS. The most effective combination of coagulants for the removal of $COD_{Mn}$ and SS was that of $Al_2(SO_4)_3\;and\;Ca(OH)_2$. The optimal concentration of $Al_2(SO_4)_3\;and\;Ca(OH)_2$ was 480 ppm and 200 ppm, respectively. Optimal retention time of wastewater for $Al_2(SO_4)_3$ addition $Ca(OH)_2$ addition : flocculation was 2 : 2 : 10 min. Multiple treatment of $Al_2(SO_4)_3:Ca(OH)_2$ overcame coagulation inhibition by gelatin and detergent, and addition of microbial sludge reduced it.

• Journal of Environmental Impact Assessment
• /
• v.26 no.6
• /
• pp.524-537
• /
• 2017

Post-Environmental impact investigation(Post-EII) plays an important role in investigating and reducing the environmental impacts of construction operations in South Korea. To date, it has been estimated that the results for Post-EII showed the low reliability; however, understanding those reliability has rarely been studied. We investigated the effect on water qualities by construction operations of the quarry mine, training center, and golf club in South Korea. In addition, the results of water quality analysis in this study were compared and analyzed with those in Post-EII. Treated wastewater in a quarry mine showed high concentrations of biochemical oxygen demand(BOD), suspended solid(SS), total nitrogen(T-N), and total phosphorus(T-P). Compared with the water quality results between this study and Post-EII, the concentrations of BOD, SS, T-N, and T-P in the treated wastewater were higher than the interquartile range(IQR) as well as the range of the results from minimum to maximum in Post-EII(p<0.05). The concentrations of BOD, SS, T-N, and T-P in treated wastewater were high under constructions in a training center. The concentrations of BOD and SS exceeded the consultation standard for the treated wastewater. These concentrations showed the significant difference with the IQR and the range from minimum to maximum of the water quality results in Post-EII(p<0.05). Therefore, the management and monitoring for water quality should be conducted in the treated wastewater by of construction operations. In addition, the alternative to enhance the reliability for the water quality results should be sought in Post-EII.

• Korean Journal of Agricultural Science
• /
• v.49 no.2
• /
• pp.193-202
• /
• 2022

The recurrent neural network (RNN) algorithm has been widely used in water-related research areas, such as water level predictions and water quality predictions, due to its excellent time series learning capabilities. However, studies on water quality predictions using RNN algorithms are limited because of the scarcity of water quality data. Therefore, most previous studies related to water quality predictions were based on monthly predictions. In this study, the quality of the water in a reservoir in Nonsan, Chungcheongnam-do Republic of Korea was predicted using the RNN-LSTM algorithm. The study was conducted after constructing data that could then be, linearly interpolated as daily data. In this study, we attempt to predict the water quality on the 7th, 15th, 30th, 45th and 60th days instead of making daily predictions of water quality factors. For daily predictions, linear interpolated daily water quality data and daily weather data (rainfall, average temperature, and average wind speed) were used. The results of predicting water quality concentrations (chemical oxygen demand [COD], dissolved oxygen [DO], suspended solid [SS], total nitrogen [T-N], total phosphorus [TP]) through the LSTM algorithm indicated that the predictive value was high on the 7th and 15th days. In the 30th day predictions, the COD and DO items showed R² that exceeded 0.6 at all points, whereas the SS, T-N, and T-P items showed differences depending on the factor being assessed. In the 45th day predictions, it was found that the accuracy of all water quality predictions except for the DO item was sharply lowered.

• Journal of Korean Society on Water Environment
• /
• v.22 no.2
• /
• pp.314-320
• /
• 2006

Diffuse pollution from an urban area contributes to the significant pollution loading to a receiving water body. In this paper, rainfall runoffs from an urban basin with combined sewer systems located in the city of Daejeon were monitored to measure the rainfall runoff discharge rates and pollutant concentrations. Strong first flush effects were observed for all monitored rainfall runoffs. The first flush effects were closely related to rainfall intensity, while suspended solids were closely related to pollutant constituents. The observed averaged Event Mean Concentrations (EMCs) of Combined Sewer Overflows (CSOs) were 536.1 mg SS/L, 467.7 mg CODcr/L, 142.7 mg BOD/L, 16.5 mg TN/L, and 13.5 mg TP/L. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on suspended solid concentration. In this study, retainment of the first flush equivalent to 5mm of precipitation could reduce diffuse pollution loading induced by CSOs to a receiving water body by up to 80% of suspended solid loading.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.8
• /
• pp.25-32
• /
• 2010

Contamination of soil and groundwater by the compounds of hydrocarbon petroleum has been widely accepted as the main cause that harms the environments and health. To remove those pollutants, absorbing clothes, activated carbons, or oil-water separation devices with the gravity method are employed for treatment. However, those materials and devices cannot remove the emulsion pollutants despite of their efficiency for removing free products. Therefore, we investigated the problems which occur during the groundwater treatment for the highly concentrated suspended solid particles, which can be resulted from excavation, and to propose methods to remove TPH(Total Petroleum Hydrocarbon). After coagulation experiment with high molecular polymers, the concentration of SS(Suspended Solids) and COD(Chemical Oxygen Demand) turned to satisfy the groundwater quality criteria within 5 minutes while the concentration of TPH failed to meet the water quality standard of effluent. Consequently, the water quality criteria for effluent could not be met by single DAF(Dissolved Air Flotation) process. However all water quality criteria could be satisfied after 20 minutes when coagulation reactions are carried out simultaneously in the DAF reactor.

• Journal of Korean Society on Water Environment
• /
• v.31 no.4
• /
• pp.392-398
• /
• 2015

The aim of this study was to investigate the bio-adsorption using modified zeolite with Mg (Mg-zeolite) in the dyeing wastewater treatment. Mg-zeolite adsorbed successfully 100% of the color, suspended solid (SS). chemical oxygen demand (COD), biological oxygen demand (BOD), total nitrogen (TN) and total phosphorus (TP) in the dyeing wastewater at the following optimal Mg-zeolite loading: 20 mg/L for colour, SS, TN and TP, 30 mg/L for BOD and COD. These results indicated that the amount of 1 mg/L Mg-zeolite adsorbed 11.6 mg/L for color, 9.5 mg/L for SS, 45.0 mg/L for COD, 12.7 mg/L for BOD, 0.91 mg/L for TP and 2.25 mg/L for TN. The bio-adsorbent, Mg-zeolite, can be a promising adsorption due to its high efficiency and low dose requirements.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.5
• /
• pp.649-653
• /
• 1999

A magnetic fluid separation technology was confirmed to be very effective to remove the suspended solids (SS) from aquacultural recirculating water, In this study, the effects of operating variables on the characteristics of SS removal were investigated through the test runs using magnetite of 2 $\mu$m mean diameter as magnetic powder. Magnetic flocculation here formed by adsorbing fine magnetites on the surface of suspended solid was observed. The strength of magnet was of significance in determining the SS removal efficiency as well as the capacity of the equipment. In addition, the SS removal efficiency decreased with an increase in the superficial liquid velocity, but the effect became negligible when the mass ratio of magnetite to the suspended solids was higher than 1.0.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.703-705
• /
• 2003

A comparison was made between the chlorophyll a and suspended solid (SS) retrievals from OSMI and SeaWiFS sensor to chlorophyll a and SS values determined with the standard method during the NFRDI's research cruises. The percentage of organic and inorganic materials from the SS was calculated to study the contribution of turbid water in the northern part of the East China Sea. The open sea waters in the Kuroshio regions of the East China Sea showed relatively higher concentration of volatile SS. However, towards the northwestern part of the East China Sea, the situation became much more optically different with the non-volatile SS from the Yangtze river and the sea bottom sources in the sea in winter and spring seasons. Furthermore, in order to indirectly detect low salinity water with high turbidity, which related to the Yangtze river using remote sensed data from the satellites, a comparison between the results of the band ratio(nLw 490nm/nLw 555nm) of SeaWiFS (OSMI) and the distribution of low salinity around the Jeju Island was presented.