• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.4 s.107
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• pp.16-24
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• 2004

The reduction of paper machine water usage is precursor to the water system closure of any mills. This reduction in water consumption reduces the loss of solids; especially fine particulates and their surface adsorbed chemical additives, from mills, which causes an inevitable increase of fine materials in papermaking systems. Also the reduction of paper machine water usage causes substantial increase of organic and inorganic substances in process water. The deterioration of the papermaking process water quality accompanying the reduction of papermaking system closure can be a prime source of the aggravation of paper quality and process efficiency. It is of great importance for paper mills to investigate the influence of the level of papermaking system closure on the paper properties and process runnabililty before implementing process closure. To predict the changes in paper properties at different levels of system closure, highly cotaminated white water was prepared using reverse osmosis technology and used to prepare handsheets from fine paper and newsprint stocks. Results showed that the quality of process water affects the strength. Preparation of highly contaminated process water and handsheet forming with headbox stocks provided important criteria to determine the relationship between the qualities of process water and paper products.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.283-295
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• 2014

Groundwater monitoring wells are important to maintain their performance for long term monitoring. The monitoring wells with extensive internal incrustation by clay adsorption were selected for this study. The performance of these monitoring wells was improved by pump washing, tube replacements for dedicated samplers, and well surging. After each improvement, the Mg, Mn, and Zn concentrations were increased. The results show that under these conditions, the monitoring wells must be carefully inspected at least once a year. Even in the case of no abnormal phenomenon like as internal incrustation, the monitoring wells need to be serviced at least once every four to five years to guarantee that they are effectively monitoring groundwater quality.

• Journal of the Korean Chemical Society
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• v.41 no.5
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• pp.256-265
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• 1997

A rapid and sequential method was studied, which can determine nitrite, nitrate and ammonium ion in soil or water samples with flow injection analysis. Geometric factors including injection volume, length of the reaction coil and flow rate of carrier solution were investigated prior to sample measurement. Nitrite was determined at 540 nm by Griess reaction producing azo dye between N-(1-naphthylethylenediamine dihydrochloride) and sulfanilamide. Nitrate was also measured under the help of reduction mechanism toward nitrite with hydrazine. Ammonium was analyzed at 440 nm with Nessler's reagent. At the optimum condition, the detection limit(S/N=3) has been shown 0.1 ㎍/mL N(NO2-), 0.4 ㎍/mL N(NO3-) and 0.3 ㎍/mL N(NH4+) respectively. The results measured by colorimetry, ion chromatography and FIA were compared showing 80%-125% reasonable match each other. Injection throughput rate could be performed better than 30 times per hour.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.598-607
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• 2004

In this study, the effects of two pre-treatment processes were observed prior to membrane filtration: pre-coagulation and pre-ozonation. To compare the effect of two above-mentioned pre-treatments, we adopted the four schemes: first one is direct membrane filtration of river surface water, second one is membrane filtration after pre-coagulation, third one is membrane filtration after pre-ozonation and fourth one is membrane filtration after pre-coagulation and pre-ozonation. There are two exceptional characteristics in applied processes. One is the usage of the MF membrane which has high ozone resisting characteristic. Therefore, ozone resides in membrane module during filtration. The other is adoption of Jet Mixed Separator (JMS) as coagulation-sedimentation process. The change in transmembrane pressure and permeate water quality were also examined. As a result, considering the filtration performance efficiency and permeate water quality, the process composed of filtration with combination of both pre-coagulation and pre-ozonation was proved most effective. The improved efficiency was due to the reduction of loading rate of fouling inducing materials to membrane module by coagulation process as well as variable reactions, such as degradation, particle destabilization and coagulation, occurred by residual ozone in membrane module. The additional effect of pre-coagulation before pre-ozonation is suppression of AOC, one of the by-products induced by ozonation. Therefore, combination of pre-coagulation and pre-ozonation is the effective process to overcome the major de-merit of ozonation i.e. by-products formation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.316-321
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• 2016

This study developed an eco-block for grass growth using the expanded vermiculites that absorb bacteria selected considering for the high pH and dry environments and plant growth. For the developed eco-block, a fundamental properties including compressive strength gain and water absorption and ecology characteristics were tested. The selected bacteria was Bacillus alcalophilus a nd Rhodoblastus acidophilus and had high concentration of $10^9cell/mL$. The expanded vermiculite that was used for shelter of bacteria was added by 7.5% and 10% replacement of the natural aggregates by volume. The developed eco-block achieved the minimum requirements specified in SPS provision and significantly effective in reducing chemical Chemical Oxygen Demand(COD) concentration and enhancing the growth of fish and plant.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.183-189
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• 2017

Sodium hypochlorite used in water disinfection processes is generally in the production of chlorine to 0.8％. As the dose of chlorine increases, disinfection by-products (Chlorate) also increase simultaneously and exceed water quality standards. In this study, the electrolytic cell of a sodium hypochlorite generator (12％ chlorine) was adjusted to control the production of the disinfection by-products. As a result, it was possible to reduce Chlorate concentrations by more than 95％ by adjusting the pH of the electrolytic cell from 1.53 to 4.2 (normal pH of the electrolytic cell). As a low current is required to obtain these results, a 15％ improvement in the efficiency of the positive electrode is also observed. For the development of High Sodium Hypochlorite Generation can be used in a safe sodium hypochlorite solution, which is expected to contribute to improvement in the safety of the disinfection process.

• Journal of Environmental Impact Assessment
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• v.23 no.6
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• pp.517-526
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• 2014

This paper performed studies on a guide for an environmental assessment necessary to select railroad route optimally, and presented techniques for an environmental friendly route selection using AHP(Analytical Hierarchy Process) as an objective method. The AHP is an approach to decision making that involves multiple choice criteria into a hierarchy and assessing the relative importance of each criterion, and determining an overall ranking of the alternatives. For the purpose of this study, we established the weight and the order of major environmental assessment items based on the survey of experts. The results of the weight by AHP were in order of Fauna & Flora, Topography & Geology, Nature Environmental Assets, Noise & Vibration, Water Quality, Landscape and Air Quality indicating natural environment should be in priority. To develop the more efficient environmental friendly route selection systems, it is necessary to consider economical, technical, and social aspects in addition to environmental consideration.

• Archives of design research
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• v.13 no.4
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• pp.33-41
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• 2000

More recently, the ecocide like an environmental shocks of acid rain, oil spills and now the ozone layer have driven home the fact that we're all responsible for looking after our natural environment and threaten the our right to live. At such a situation enterprises has been to develop techniques of enhancing environment friendly design. However it is difficult to producing environment friendly product - especially at electronic product like a high accumulated thing and produced with a small amount - while they know the importance of environment. Because of a direct and actual disadvantage of enterprise and customer. Moreover it is rare and negative for physical point that an adaptation case of recycled material or natural one for designing. Therefore it is important to positive consideration and action of design process for the nature. In this paper the focus of interest is find out the active and real environmental friendly design practice scheme as a designer and understanding of basic of the environmental friendly design for a coexistence of the enterprise, customer, and environment.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.40-49
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• 2007

For effective watershed management, we must understand the complex and dynamic relationships of land uses and water quality. Despite numerous studies investigated the relationships between water quality and land use, there are increasing concerns on the geographical variation and lack of spatial integrations in previous studies. We investigated the relationships between land use and water quality characteristics in the Hwa-Sung estuarine reservoir watershed in Korea, which has spatially integrated land uses. The spatial variations of these relationships were also examined using zonal analysis. Water quality parameter were correlated positively with residential and forest and negatively with paddy and upland especially during base flow in the near buffer zone. During storm flow, correlation between land use and water quality was less apparent. Population and livestock density was correlated well to water quality parameter than just number of population and livestock. Relationships across zones, distinguished by distances from streams, were inconsistent and erratic, suggesting that the relationships between remote land uses and water quality may be affected more significantly by sub-basin characteristics than by the land use itself. The watersheds studied are mainly non-urban and their land uses are similar to typical watershed of other estuarine reservoirs, therefore, the correlation developed in this study might be helpful to manage other watersheds of estuarine reservoir. This methodology could be applied to other areas where the watershed characteristics are not significantly different from the study area.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.665-675
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• 2011

Dam as a Wetland can provide functions of ecological conservation, water quality improvement, landscape, and so on as well as. Dam's own various functions. Here we tried to assess function and value of Yongdam dam as a wetland by Hydrogeomorphic(HGM) Method which was developed by U.S. Army Corps of Engineers. In this study, the Upo wetland and Boryeong dam were selected as reference wetlands to assess the functional index of the Yongdam dam. As the results, we obtained the functional index values over 0.6 for total index of the Yongdam dam. It describes that Yong dam dam-wetland is providing over 60% functions of the Upo wetland and Boryung dam-wetland. This result suggests that dam-wetland can provide good wetland functions efficiently if we conserve and manage well.