• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.115-121
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• 2006

The purpose of this study was to investigate applicability of pretreatment on the existing biological treatment for domestic wastewater reclamation. From Jar Tests, it was found that optimum dosage of coagulant was PAC 0.5mg/L and $FeCl_3$ 180mg/L for urban sewage. In this study, PAC 0.5mg/L was selected considering sludge production and the amount of coagulant required. In a continuous experiment performed with combining chemical coagulation and biological treatment, a considerable removal efficency was obtained in term of BOD, SS, T-N, T-P and ABS. When the raw sewage was supplied into the pre-chamical treatment facility, the removal of BOD and SS was 48.3% and 81.1%. However T-N removal was very low which means T-N consists of $NH_3-N$ mostly. T-P was almost completely recluced by the chemical addition. The effluent BOD & SS was 57~76 and 21~43mg/L, which could reduce the size of biological treatment facility. From the cost estimation pre-chemical treatment could save around half of the area required for biological treatment with post ceagulation.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.67-77
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• 1995

This study was performed for minimization of excessive biofilm effects at the high strength organic wastewater treatment. As a results of biofilm attachment experiment using piggery wastewater, aggravation of water quality due to excessive biofilm showed after 15 days of operating times.4 excessive biofilm phase, the equivalent biofilm thickness and VSS contents per unit aura were observed in the range of 1,100 to $1,200{\mu}m$ and 2.5 to 3.0mg $VSS/cm^{2}$, respectively. In the aerobic fixed biofilm reactor/anoxic fixed biofilm reactor(AFBR/ANFBR) process with endogenous respiration phase, the BOD removal efficiency was obtained more than 90 percentage at the surface loading rate and volumetric loading rate of the AFBR maintained less than 17 g $BOD/m^{2}{\cdot}$day and 1.7kg $BOD/m^{3}{\cdot}$day, respectively. The removal efficiency of TKN and $NH_{3}$-N at the loading rates below 5.60g $NH_{3}-N/m^{2}{\cdot}day$ and 0.56kg $NH_{3}-N/m^{3}{\cdot}$day were above 76 percentage and 82 percentage, respectively. In order to reduced sludge production rate and aggravation of water quality, endogenous respiration phase was accepted at first AFBR reactor. As a results of this operating condition, sludge production was minimized and removal efficiency was maintained stability.

• Journal of Environmental Health Sciences
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• v.35 no.5
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• pp.365-375
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• 2009

Agriculture reservoirs need a systematic approach that can control water purity and water improvement. The area under study, Bunam Lake exceeds the agricultural water standard level due to contamination from the upper stream. When the Taean Enterprise City was planned, the water quality improvement plan was applied to minimize the environmental change. However, in order to continuously maintain the water quality in the Bunam Lake, it was essential to apply the Total Pollution Load Management System (TPLMs). In order to achieve the targeted water quality in the Bunam Lake, standard flow rates and targeted water quality levels were applied to obtain the loading capacity which is as follows : BOD 1,891.2 kg/d, T-N 1,945.7 kg/d, T-P 131.7 kg/d. Also, the regional development load was calculated as, BOD 1,083.6 kg/d, T-N 942.2 kg/d, T-P 61.8 kg/d, which is required to be deceased :- by BOD 378.4 kg/d, T-N 198.9 kg/d, T-P 31.6 kg/d in order to safely achieve the targeted water quality in the Bunam Lake.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.631-636
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• 2009

This study has its intention to investigate the water quality of non-point source which is runoff from roads. We have classified and selected twelve sites as city road, industrial road, national road and mountain road by considering their traffic volume and surroundings. Water quality was analyzed based on BOD, COD, SS, T-N and T-P and the concentrations were measured by sampling after rainfall with the interval of 10 minutes, 20 minutes, and 30 minutes. BOD was the highest in city road with 57.6 mg/L and the lowest in mountain road with 45.0 mg/L. For COD, the highest concentration in industrial road was 146.5 mg/L and the lowest was in mountain road with 98.0 mg/L. The run off concentration of SS was up to maximum 630.0 mg/L (average 280.4 mg/L) which was remarkable compared to other types of road. It showed its lowest concentration in national road with 76.0 mg/L. T-N and T-P were the highest in industrial road and the lowest in mountain road. We found out that the runoff concentration was high with large amount of traffic volume and it seemed to be high in city road and industrial road where they were largely affected by their surroundings. Relatively, national road and mountain road seemed to show low concentration as they have less traffic volume and less affected by their surroundings.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.548-557
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• 2015

This study investigated environmental assessments of leachate containing formaldehyde from medium density fiberboard (MDF) disposed in laboratory-scale simulated landfills. Environmental impact assessment of leachate was conducted by measuring formaldehyde, toxicity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), bacterial enumeration, and pH. Amount of formaldehyde in leachate from MDF in soil decreased to the level of soil only treatment by 28 days, and toxicity decreased as the amount of formaldehyde decreased. BOD and COD levels in leachate from the treatments containing MDF exceeded permissible discharge levels of BOD or COD throughout the experimental period. The pH levels of all treatment were within permissible discharge range except on day 0. Fewer bacteria were observed in leachate from MDF in soil treatment than other treatments (MDF only, cured UF resin in soil, and soil only). Consequently, the leachate from disposal of MDF in soil detrimentally affect on environment. However, soil buffered formaldehyde leaching and pH on leachate in this study. Waste MDF may be required the pre-water soaking treatment for leaching formaldehyde to reclaim on land.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.377-381
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• 2006

A study was carried out to determine a suitable light intensity and inoculum size for the growth of Rhodopseudomonas palustris strain B1. The pollution reduction of sago effluent using free and immobilised R. palustris cells was also evaluated. The growth rate in glutamatemalate medium was highest at 4 klux compared to 2.5 and 3 klux. The optimal inoculum size was 10% (v/v). Both the COD and BOD of the sago effluent were reduced by 67% after three days of treatment. The difference in biomass production or BOD and COD removal with higher inoculum sizes of 15 and 20% was minimal. This could be attributed to limited nutrient availability in the substrate. The use of immobilised cells of R. palustris reduced the pollution load 10% less compared to pollution reduction by free cells. Hence, there was no significant difference in using free or immobilised cells for the treatment of sago effluent.

• Journal of environmental and Sanitary engineering
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• v.23 no.3
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• pp.39-46
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• 2008

In order to study the estimate of $CH_4$ emission factors in the municipal wastewater treatment plants, the active sludge process, 5-stage process, Denipho process, and SBR process were investigated. When active sludge process, 5-stage process, and Denipho process were used in wastewater treatment plant, the $CH_4$ emission factors were 2.88, 1.61, and 0.57 g-$CH_4/kg$-BOD, respectively. On the other hand, in the case of SBR process, it was 4.14 g-$CH_4/kg$-BOD. These results indicate that SBR process was effective for $CH_4$ emission in municipal wastewater treatment plants. Using the above processes, the methane emission factor and amount of waste water sludge were $4.78m^3/t$ and $12,204,506m^3/yr$, respectively. The remove of BOD was a range of $93.91{\sim}98.63%$.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.91-96
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• 2006

Many small scale Sewage Treatment Plants (STPs) are currently being constructed at many rural areas. The STPs in rural area suffer from low concentration and large inflow quantity fluctuation during wet weather mainly due to illicit combined sewer system. Sequencing Batch Reactor (SBR) is a process effectively coping with these obstacles. The main objective of this study was to evaluate SBR with high hydraulic loading and low inflow concentration. The operating conditions tested were: organic loading rate = $0.17-0.42KgBOD/m^3/d$, hydraulic loadings = $12.1-61.5m^3/m^2/d$, average MLSS concentration = 2500 mg/L, F/M ratio = 0.026-0.17 KgBOD/Kg MLSS, HRT = 9-12 hr HRT, and SRT = 5.6-33.6 days. Organic loading rate on SBR did not impact significantly on BOD and SS removal efficiencies. To increase treatment efficiencies, low hydraulic loading rate with low concentration was required. The results suggested that low influent concentration with high inflow rates during wet weather requires extended time for settling.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.73-81
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• 2021

The objective of this study was to analyze the waste nutrient generation loads from hydroponics for three major crops in Gyeongsangnam-do. Study hydroponic farms were selected for the three major crops such as paprika, strawberry, tomato based on the agricultural statistics data and field investigation. The flow amount and water quality for inflow and outflow of study hydroponic farms were monitored and analyzed on a monthly basis. Monitored samples were analyzed in terms of DO, BOD, T-N, T-P, SS, and EC. The generated load of BOD, T-N, and T-P were calculated from the monitored flow and water quality. The monitoring results showed that the drainage ratio for the circular hydroponic farm was lower than the non-circular hydroponic farm because the outflow from the circular hydroponics were much lower than that from the non-circular. The generated load calculation results showed that the BOD tended to have a smaller value than the TMDLs guideline for land, while T-N and T-P showed higher value than that from the TMDLs guideline. In order to effectively manage the pollutant load discharged from the hydroponics farming complex, it is necessary to manage the non-circulating hydroponics farm. To improve water quality, it is necessary to gradually expand the circulating hydroponics farm through policy and economic support.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.301-312
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• 2016

This study has performed comparative analysis on characteristics of contaminated 35 tributaries on seasonal variation/point discharge load/pollutant distribution of water quality factors(8) in order to understand the effect of the watershed in Nakdong River Basin. As a results, the water quality of $BOD_5$(Biochemical Oxygen Demand), Chl-a(Chlorophyll a) and Fecal E. Coli shows II grade at tributaries of more than 50% without COD(Chemical Oxygen Demand), TP(Total Phosphate), TOC(Total Oxygen Carbon) and TN(Total Nitrogen) factors. The specific discharge(Q) were occupied about 54.4% (19 sites) as $0.05m^3/sec/km^2$ value. Among these results, the contaminant level of Dalseocheon, Hyeonjicheon, Seokkyocheon 1, Uriyeongcheon and Dasancheon was also high, which has to consider a discharged pollutant load(kg/day). The 35 major tributaries of Nakdong River were included in 7 mid-watershed, such as Nakdong Waegwan, Geumho River, Nakdong Goryung, Nakdong Changnyung, Nam River, Nakdong Milyang, Nakdong River Hagueon. Especially, the discharged pollutant load of Nam River and Geumho River also was high according to the amount of discharge such as Kachang dam, Gongsan dam and Nam river dam. Seasonal difference of the water quality factors such as $BOD_5$, TN, SS and Q was observed largely, on the other hand the TP and Chl-a was not. This is guessed due to the precipitation effect of site, biological and physicochemical degradation properties of pollutant and etc. The co-relationship between the seasonal difference and water quality factors was observed using a Pearson correlation coefficients. Besides, the Multiple Regression analysis using a Stepwise Regression method was conducted to understand the effect between seasonal difference and water quality factors/regression equations. As a result, the Multiple Regression analysis was adapted in the spring, summer and autumn without the winter, which was observed high at spring, summer and autumn in the order COD/TP, Chl-a/TOC, TOC/COD/$BOD_5$ water quality factors, respectively.