• Ocean and Polar Research
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• v.25 no.3
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• pp.277-286
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• 2003

Nitrification performance of fixed film biofilters using coarse sand, loess bead, or styrofoam beads in biofilter columns 1 meter high and 30cm in diameter were studied at different hydraulic and organic matter loading rates. Synthetic wastewater was supplied to the culture tank in order to maintain desired TAN concentrations in inlet water to biofilters. All the biofilters were conditioned 5 months before start of sampling. TAN and $NO_2-N$ conversion rates increased with an increase in the hydraulic loading rate (HLR). However, the improvement in biofilter performance was not linearly correlated to HLR in styrofoam bead filters. This is mainly due to the characteristics of the styrofoam beads used. TAN conversion rates of sand filters increased with the increase of HLR up to $200m^3/m^2$. per day. No increase in the TAN conversion rate was observed at the highest HLR since flooding on the media surface took place. HLR had a significant impact on the TAN conversion rates in loess bead filter up to the highest HLR tested (P<0.05). TAN conversion rates were much less at organic matter loading rates of 9 and 18kg $O_2/m^3$ per day than those without the addition of organic matter in styrofoam bead filters. The addition of glucose resulted in a reduction of the TAN conversion rate from 540 to 284g $TAN/m^3$ per day. No significant difference of TAN conversion rates between the two organic matter loading rates was found (p<0.05). This indicates that the impact of organic matter on nitrification becomes less and less sensitive with an increase in the COD/TAN ratio. At an organic matter loading rate of 9kg $O_2/m^3$. per day, a great reduction of TAN conversion rates was observed in sand filters and loess bead filters. Clearly, organic matter can be one of the most Important Impacting factors on nitrification. $NO_2-N$ conversion rates showed a similar trend for TAN. Based on the TAN and nitrite conversion rates, styrofoam beads showed the best performance among the three filter media tested. Also, the low gravity and price of styrofoam beads make the handling easier and more cost-effective for commercial application. The results obtained at the highest organic matter loading rates can be used in the biofilter design in recirculating aquaculture system.

• Journal of Environmental Health Sciences
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• v.30 no.1
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• pp.50-58
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• 2004

The present study was designed to evaluate primary production organic matter in basin of lake around by execution of total maximum daily loading. BOD influent loading of Uiam lake was 2,819 kg/day, which was less then 28.3 percent, total effuluent loading as 3,619 kg/day, in comparision with BOD, total nitrogen influent loading was 4,681 kg/day, which was less then 10.0 percent, total effuluent loading as 5,150 kg/day. But in case of total phosphors influent loading was 73.3 kg/day, which was more then 34.2 percent, total run off loading as 48.3 kg/day. The result of survey reduction plan of primary production organic matter in basin of lake around which objectives of abstract is as follows. First plan was reduction of primary production organic matter by moving the outlet of municipal wastewater treatment center from present place to lake downstream. Secondary plan was improvement by diffusion type of outlet municipal wastewater treatment center. The third plan was reduction of environmental impact by passing and storing of municipal wastewater. Finally plan was decline water surface level which was present hydrouric retention time was reduction from 7.6 day to 6.0 day per meter.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.676-681
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• 1999

The organic matter flow in rural watershed in Chongwon-gun , Chungbuk, was evaluated, The study watershed is about 67$\textrm{km}^2$ in area and its population was 7,000 in 1996. The amount of inflow in the study area exceeds the amount of outflow by 534kg/ha , and the livestock feed account for 90 percent of the amount of inflow. The loading of organic matter by livestock waste amounts to 51 percent of total loading to agricultural land and the enviornment. The increase in recycling of livestock waste is essential for the management of orgainc matter in the rural watershed.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.433-437
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• 2011

The study is conducted to evaluate loading of organic matter as seasonal changes during non-storm period into Lake Paldang which is used to a major drinking water source. Samples were taken in Lake Paldang intake during non-storm period and were analyzed loading of organic matter. From the results of the survey, improving of the water quality showed remarkable tendency depending on the changing periods from summer to fall and from fall to winter. Dilution effect from the increase of base run-off caused by the concentrated rainfall in rainy season, the characteristics of Korea's climate seems to have to be the reason. On the other hand, deteriorating of the water quality showed tendency depending on the changing periods from winter to spring and from spring to summer. Increase of Cyanobacteria etc. is explained by seasonal effects which are a small amount of the rainfall in winter and spring and gradational increase of water temperature.

• Membrane and Water Treatment
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• v.9 no.4
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• pp.263-271
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• 2018

The objective of this work was to analyze organic matter removal, nitrification, biomass growth and membrane fouling in a submerged flat-sheet membrane bioreactor, fed with synthetic wastewater, of similar composition to the effluents generated in a fish meal industry. After biomass acclimatization with saline conditions of 12 gNaCl/L and COD/N ratio of 15 in the bioreactor, results showed that the organic matter removal was higher than 90%, for all organic loading rates (0.8, 1, 1.33 and $2gCOD/L{\cdot}d$) and nitrogen loading rates (0.053, 0.067, 0.089 and $0.133gN/L{\cdot}d$) tested during the study. However, nitrification was only carried out with the lowest OLR ($0.8gCOD/L{\cdot}d$) and NLR ($0.053gN/L{\cdot}d$). An excessive concentration of organic matter in the wastewater appears as a limiting factor to this process' operating conditions, where nitrification values of 65% were reached, including nitrogen assimilation to produce biomass. The analysis of membrane fouling showed that the bio-cake formation at the membrane surface is the most impacting mechanism responsible of this phenomenon and it was demonstrated that organic and nitrogen loading rates variations affected membrane fouling rate.

• Journal of Korean Society on Water Environment
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• v.27 no.3
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• pp.306-313
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• 2011

In this paper, runoff characteristics of South-Han river watershed in terms of refractory organic matters were investigated. The concentrations of DOC, POC, R-DOC, R-POC in runoff and flow rates were determined by monitoring 27 times in dry season and 4 times in rainy season. The concentrations of the dissolved refractory organic matter, R-DOC was the lowest in fall and similar in the other dry seasons. The particulate refractory organic matter, R-POC showed less fluctuation than R-DOC. In summer, mass loading was the highest than other dry seasons. The concentrations of R-DOC, R-POC were showed to be affected by runoff volume. The mass loading grows higher as runoff volume gets higher.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.4
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• pp.43-53
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• 1997

In this research, the synthetic livestock wastewater was prepared to study the characteristics of organic matter removal, the change of VFA production, and the amount of gas production with respect to the change of ammonium nitrogen concentration in the waste using anaerobic fixed bed process, which is an anaerobic biofilm process. The HRT and operation temperature were 1 day and $35{\pm}1^{\circ}C$, respectively. Also, the characteristics of organic matter removal and the inhibitory effect on microorganism in the anaerobic process were studied on the organic loading and ammonium nitrogen concentration. The results obtained were as follows: For COD loading of $10kg/m^3$-day and five levels of ammonium nitrogen concentration ranging from 1,000 to 5,000 mg/L, organic removal efficiencies were about 81, 74, 67, 58, and 51%, and gas productions were 3,860, 3,520, 3,240, 3,020, and 2,790 ml/l-day, respectively. Average methane contents in the gas produced on COD loading of $10kg/m^3$-day was about 76%. Throughout the whole period of experiment, remaining VFA (as COD base) in the effluent was over 90% of remaining COD. This result indicated the inhibitory effect of high concentration of ammonium nitrogen through the facts that accumulated VFA was almost COD and organic removal efficiency decreased also with the increase of ammonium nitrogen. Especially, that implys which high concentration of ammonium nitrogen not only inhibits methane forming bacteria, but also acid forming bacteria.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.166-174
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• 2001

The autochthonous and allochthonous organic carbon loading were measured in Lake Soyang, to estimate the amount of carbon loading into the lake and the contribution of their sources to tile lake's carbon loading. Autochthonous carbon loading was estimated from phytoplankton primary production with the extracellular organic carbon (EOC). Allochthonous loading was determined by measuring dissolved organic carbon (DOC) and particulate organic carbon (POC) concentration in the main inflowing Soyang River. Both autochthonous and allochthonous organic carbon loading were high during the svmmer, from July to September, and accounted for 43.2% and 71.7% of the annual loading, respectively. Primary productivity was elevated up to $1,000\;mgC\;m^{-2}\;d^{-1}$ during summer and lowest in winter. EOC production from phytoplankton was also large in summer, resulting in a high DOC concentration in the lake water. Primary production of phytoplankton and allochthonous organic matter loading from the watershed contributed to 53.6% and 46.4% of total loading, respectively. The EOC production accounted far $4.4{\sim}21.2%$ of POC primary production, implying that EOC production of phytolankton must be considered in estimation of primary production.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.591-598
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• 1998

This study was conducted to evaluate water quality in the Keum River estuary using principal component analysis. The results was summarized as follow; Water quality in the Keum River estuary could be explained up to 70.40% by three factors which were included in the inffluent loading by the Keum River and Kyungpo cheon(38.99%), seasonal variation and organic matter pollution(19.05%), sediment resuspension and internal metabolism(12.35%). For spatial variation of factor score, artificial pollutant loading is highest at st.1, below Keum River barrage, and decreases toward the outer sea. For annual variation of factor score, factor 1 was highly related to artificial pollutant leading, and it was gently increased in 1994. Also, organic matter pollution, sediment resuspension and internal metabolism were increased to every year. It is necessary to control the nutrient leading by Keum river and Kyongpo cheon for Water quality management of estuary.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.353-358
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• 2017

As a drinking water source of 26 millions people of Seoul metropolitan region, Han river is one of the most important basin. Managing the Non-point source pollution which is regarded as the main cause of water pollution including refractory organic matter is important thing. This research investigates the runoff characteristics of organic matters from main 3 rivers (South Han, North Han, Kyungan). Water quality measurement items include not only carbon-based TOC (Total Organic Carbon), DOC (Dissolved Organic Carbon), POC (Particulate Organic Carbon) but also R-TOC (Refractory Total Organic Carbon), R-DOC (Refractory Dissolved Organic Carbon), R-POC (Refractory Particulate Organic Carbon) is researched. The research shows that R-TOC takes approximately 61~83% of TOC. Most of the R-TOC is consist of R-DOC (72~77%). Refractory organic matter have a stable runoff characteristics compared to other organic matter. The organic matter concentrations of South Han river and Kyungan river are the highest in spring time and show a gradual decline. The concentrations of Kyunan river is the highest. Kyungan river's small area and the high city land use ratio seem to be the reason. Loading of organic matter in summer time takes the most loading (62~84%). TOC loadings per unit area of each river is Kyungan river ($1.22ton/km^2$), South Han river ($1.01ton/km^2$), North Han river ($0.91ton/km^2$).