• 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.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_3
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• pp.97-106
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• 2001

To improve the water quality, particularly for sea bathers, the behaviour of wastewater from sewage outfalls in water adjacent to Swansea, UK, was studied using a mathematical model. The water quality in the sewage receiving basin was determined using factors like the outfall diffuser location(distance from land boundary), sewage treatment scheme, discharge time, and bacteria decay rate, etc. With respect to these factors, an optimal strategy for sewage discharge was then investigated to minimize bacteria levels along the bathing beaches. As water quality criteria, predicted faecal coliform levels were monitored along the coast adjacent to the outfall locations. The resultant values were compared with EC Mandatory(<2000, 95 % of 20 samples) and Guideline Standards(< 100, 80 % of 20 samples). For the advective-diffusion equation, the non linear advective terms were represented using the ULTIMATE algorithm and the third-order accurate QUICKEST scheme to avoid numerical diffusion. Details of the simulation results are then presented as an optimal policy for sewage discharge in the region.

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.203-209
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• 2014

This study investigated characteristics of rainfall and water quality in Saemangeum area with attention to temporal and spatial distributions. A high variability in rainfall was noted during July and August. The temporal analysis of water quality data indicated that DO and TN as well as BOD, COD and SS were within national standards except for increased concentrations during spring and summer, unlike TP values that indicated poor water quality. Standard deviation showed a high variability in SS among the seasons most especially during summer. The high dispersion indicated variability in the chemical composition of pollutants where the temporal and spatial variations caused by polluting sources and/or seasonal changes were most evident for BOD and COD during winter and spring. The box plots and bar charts showed steadily low concentrations of BOD, COD, TN and TP except within Iksan and notable significant variations in SS concentrations among the monitoring stations. Thus, high pollution levels requiring intervention were identified in Mangyeong river basin with particular concern for areas represented by Iksan station. It was noted that Iksan received a considerable amount of rainfall which meant high runoff which could explain the significant pollution levels revealed in the water quality spatial distribution. Major pollution contributing pollutants within Saemangeum area were identified as SS, BOD, COD and TN. Therefore the present results could be used as a guideline for the temporal and spatial distributions analysis of both rainfall and water quality in Saemangeum watershed.

• Journal of Korean Society of Rural Planning
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• v.11 no.4 s.29
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• pp.59-65
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• 2005

Proper management of small rural watershed is important since it does affect water quality improvement of larger scale watershed. Therefore, effective small watershed management guideline including participatory program of local people is required to achieve water environment improvement. Feasibility of water quality goal, short and long-term watershed management plan and funding sources were investigated by field monitoring of Hampyungchun watershed which has characteristics of rural stream, and literature review. The relevant parties and their roles fer watershed management were identified and suggested. A hybrid model, that is mixture of government driven model and NGO model, is recommended for watershed management organization in this study.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.151-156
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• 2004

A decision support system, Watershed Analysis Risk Management Framework(WARMF), was applied to the Kyungan Stream watershed, a tributary of Lake Paldang, for calculation of total maximum daily loads(TMDL). The WARMF system was developed by Systech Engineering, USA, and has been successfully used in several watersheds, for TMDL studies. The study area was divided into 14 sub-basins, based on digital elevation model(DEM). The integrated watershed and stream model of WARMF was validated by flow and BOD data measured during the year of 1999. There were reasonable agreements between model results and field data, both in water flow and BOD. The validated Kyungan WARMF was extensively utilized to study the quantitative relationship between waste loads and receiving water quality. Based on TMDL guideline at Paldang Lake and Kyungan Stream, the water quality criterion were set to be 3.0mg/L, 3.5mg/L, and 4.0mg/L at the watershed outlet. The allowable waste loads of BOD, both from point and non-point sources, were determined at each water quality criterion. From this study, it was concluded that the WARMF provided several advantages over the conventional application of watershed and stream models for TMDL study, such as time variable simulations, multiple possible soutions, and reduction loads for goal water quality, etc.

• Journal of Environmental Impact Assessment
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• v.9 no.1
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• pp.13-24
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• 2000

This paper presents a study of water quality model applications in environmental impact statements which were submitted during recent years in Korea. Most of the applications have reported that the development projects would have significant impacts on the water quality, especially, of streams and rivers. The water quality models, however, were hardly used as an impact prediction tool. Even in the cases where models were used, calibration and verification studies were not performed and thus the predicted results would not be reliable. These poor model applications in environmental impact assessment can be attributable to the fact that there were no available model application guidelines as well as no requirements by the review agency. In addition, the expected waste loads were improperly estimated in most cases, especially in non-point sources, and the predicted parameters were not good enough to understand water quality problems expected from the proposed plans. The effects of mitigation measures were not analyzed in most cases. Again, these can be attributed to no formal guidelines available for impact predictions until now. A brief guideline is described in this paper, including model selection, calibration and verification, impact prediction, and analysis of effects of mitigation measures. The results of this study indicate that the model application should be required to overcome the current improper predictions of environmental impacts and the guidelines should be developed in detail and provided.

• Environmental Engineering Research
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• v.15 no.3
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• pp.173-179
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• 2010

Pasig River is an important river in the Metro Manila, Philippines, since it provides food, livelihood and transport to its residents, and connects two major water bodies; Laguna de Bay and Manila Bay. However, it is now considered to be the toilet bowl of Metro Manila due to the large amount of wastes dumped into the river. Even with the efforts of the government to revive the quality of the Pasig River and its tributaries, it continues to deteriorate over time. This paper provides an overview of the current condition of the Pasig River. The existing water management policies were reviewed, and the issues and challenges hindering the improvement of its water quality identified. Moreover, the water qualities of the rivers in Metro Manila were compared to those of the major rivers in South Korea. The current watershed management system practiced by South Korea has been discussed to serve as a guideline for future recovery of the water quality of the rivers in the Philippines.

• Environmental Analysis Health and Toxicology
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• v.6 no.3_4
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• pp.155-161
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• 1991

The water quality in Wonju stream, Seom river in Kangwon province and Bokha, Shindun stream in Kyeonggi province was investigated between the season of irrigation on July, 1990 and of non-irrigation on September in 1989. The results of water quality obtained from this study were as follows; As for water quality of the Wonju stream and the Seom river, the concentration of COD, T-N, SS and Cu, and for the Bokha, Shindun stream, the concentration of T-N, SS and Cu were exceeded standard levels of quality guideline of agricultural water use in the season of irrigation. However, in the water quality of Wonju and Bokha stream, the concentration of T-N , SS and Cu, and in the Seom river, the concentration of T-N, SS, Cu and Zn were exceeded standard levels of agricultural water quality in the season of non-irrigation. And the average water quality of the 4 streams were not suitable for agricultural water use. The comparison of the annual average water quality of the 4 streams for pH, DO, T-N and SS were in statistics significantly different with p values less than 0.01. When the average water quality between the season of irrigation and non-irrigation in each stream was compared, DO and COD in the Wonju stream, COD in the Seom river, pH, DO, T-N, SS and Cu in the Shindun stream showed a significant difference with p<0.01. The average in the sediment were; COD, 5.65∼26.53 ppm; Cu, 0.26∼0.49 ppm and Zn 0.95∼2.97 ppm. The concentration of three contaminants were markedly higher than the water quality. And the concentration of COD, Zn in the sediment showed a significant difference with p<0.01, and Cu showed a considerably significant difference with p<0.05.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.167.2-168
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• 2003

This study was performed to evaluate Quality of spring water in seoul. After the revision the guideline of water Quality control on July 2002, the ratio of non-passed samples of spring water increased evidently(2001, 24.5％$\rightarrow$2002, 37.5％). So Citizens of Seoul have been worried about what makes the difference between two years. To find out the major reason of that rapid increasement, the experimental results of standard plate count and psychrotrophilic bacteria in seoul were used. (omitted)

• Journal of Environmental Impact Assessment
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• v.14 no.5
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• pp.255-262
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• 2005

In summer and early autumn, eutrophication occurs occasionally in many reservoirs. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during water surface is rising after rainy season. This study include examination of pollutant load, species of plant, community structure and productivity of macrophyte in unit area at lakeside. The result of this research will be used as a guideline of water quality management on reservoir through assessing water quality effect of submerged plant. The areal distribution, composition of species and submerged area of macrophyte changes according to rainfall pattern every year, so it is difficult to calculate nutrient load annually from submerged macrophyte. In this study, the nutrient load from submerged macrophyte assess from Daecheong and Juam reservoir in 2001. TN and TP load of submerged macrophyte shows 0.043% and 0.069%, respectively, of annual discharge load on Daecheong watershed. At lake Juam, TN and TP shows 0.64% and 1.28% load, respectively. The reason that nutrient load of lake Juam is greater than that of lake Daecheong is that macrophyte distribution area of lake Juam is 5 times greater than that of lake Daecheong. Total nutrient load of lake Daecheong is 3 times greater than that of lake Juam.