Hong-Jae Lee

A Study on the Improvement of Treatment Efficiency for Nitrogen and Phosphorus by Improved Sewage Treatment Process in Constructed Wetland by Natural Purification Method

To effectively treat the domestic sewage that was produced on a small-scale in farming and fishing village in order to encourage an ecologically friendly environment, a small-scale sewage treatment apparatus using natural purification methods that consisted of an aerobic and an anaerobic plots were constructed. The efficiency of sewage treatment according to the sewage loading was investigated to obtain the optimum sewage loading in small-scale sewage treatment apparatus. Removal rate of pollutants according to the sewage loading were in the order of >. Therefore, the optimum sewage loading was 300 L m-2 day-1. Under the optimum sewage loading, removal rate of BOD, , turbidity, T-N and T-P were 99, 94, 99, 49 and 89%, respectively. However, to satisfy the water quality standard in effluent in small-sclae sewage treatment apparatus for domestic sewage treatment, the low removal efficiency of T-N and T-P must be improved. So to improve the removal rate of T-N and T-P, the efficiency of sewage treatment according to the improved sewage treatment process such as, re-treatment at aerobic plot, anaerobic condition of aerobic plot, changing the filter media sizes and the depths in anaerobic plot, and also addition of oyster shells to filter media at anaerobic plot were investigated. In case of 150 cm depth in anaerobic plot with filter medium A (effectivity particle size 1.50 mm) and addition of oyster shells to filter media at anaerobic plot, removal rate of T-N and T-P in both plots were increased by 10 and 3%, and 14 and 7% in comparison with 100 cm depth in anaerobic plot with filter medium B(effectivity particle size 0.95 mm), respectively. The optimum improved sewage treatment process in small-scale sewage treatment apparatus were 150 cm depth in anaerobic plot with filter medium A and addition of oyster shells to filter media at anaerobic plot.

Development of Sewage Treatment Apparatus for Detached House in Agricultural Village by Natural Purification Method

To develop small-scale sewage treatment apparatus for detached house of agricultural village, a small-scale sewage treatment apparatus by natural purification method that consisted of packaged form of aerobic, anoxic and anaerobic bed was constructed. The efficiency of sewage treatment according to the sewage treatment method, sewage loading, and the injection method of sewage were investigated for small-scale sewage treatment apparatus of packaged form of aerobic, anoxic and anaerobic bed. The removal rate of pollutants according to the sewage treatment method for small-scale sewage treatment apparatus was high in the order of aerobic-anoxic-anoxic bed . The removal rate of pollutants according to injection method of sewage in small-scale sewage treatment apparatus was high in the order of continuous injection intermittent injection. When loaded under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P were 99, 95, 99, 83 and 96%, respectively, through this 3-stepped small-scale treatment apparatus arrayed with the order of aerobic, anoxic and anaerobic bed.

Selection of Optimum Pebbles Size in Sewage Treatment Plant by Natural Purification Method

An investigation was carried out to evaluate the effects of pebble size on the small-scale sewage treatment apparatus by natural purification method that consisted of aerobic and anaerobic plot. pH and EC in both plots varied minimally regardless of pebble size. DO in aerobic plot increased as the pebble size decreased. That in the anaerobic plot was slightly less in comparison with that of the aerobic plot but varied minimally, regardless of pebble size. Under all experimental conditions, removals of BOD, COD and turbidity in anaerobic plot were more than 98, 91 and 98, 98% respectively. Removals of T-N and T-P increased as pebble size decreased. Under all experimental conditions, removals of T-N and T-P in anaerobic plot were about and , respectively. Judging from the above results, it should be considered that the optimum pebble size and pebble permeability in both plot was and , respectively.

Treatment Efficiency of Existing Forms of Pollutants in Sewage Treatment Plant by Natural Purification Method

A study was conducted to investigate the behavior of pollutant forms at each area in the sewage treatment plant by natural purification method. The sewage treatment plant by natural purification method that consisted of aerobic and anaerobic area was constructed. The efficiency of sewage treatment depending on the operation time, the loading amount of pollutant season variation were investigated. The removal amount of BOD, COD, TOC and SS in the aerobic area was significantly increased as the treatment proceeded. Decreased BOD, COD, TOC, SS, T-N and T-P depending on the loading amount of pollutants in the aerobic and ananerobic area were mostly insoluble BOD (IBOD), insoluble COD (ICOD), soluble TOC (STOC), volatile SS (VSS), dissolved T-N (DTN) and dissolved T-N (DTP) types, respectively. The removal efficiency of BOD, COD, TOC, SS, T-N and T-P in hot season (summer and autumn) were more than that in cold season (spring and winter). The removal efficiencies of BOD, COD, TOC, SS, T-N and T-P of the effluent were about 92, 89, 73, 95, 46 and 84% in all seasons, respectively.

Behavior and Decomposition Velocity of Pollutants on Various Forms from Domestic Sewage in Small-scale Sewage Treatment Plant by Natural Purification Method

Behavior and decomposition velocity of pollutants on various forms from domestic sewage in sewage treatment plant were investigated in order to obtain the basic data for improving the removal efficiency of pollutants and to reduce the area in constructed wetland by natural purification method. The removal amounts of BODs and CODs in aerobic bed were significantly higher than those of the other beds. In aerobic bed, the removal amounts of IBOD and ICOD were more than those for SBOD and SCOD, respectively, whereas the removal amounts of BODs and CODs in anoxic and anaerobic beds were little different. The removal amounts of SSs in aerobic bed were also higher than those for the other beds, and the removal amounts of VSS in all beds were more than those for FSS. The removal amounts of DTN and DTP in all beds were more than those for STN and STP, respectively. In addition, the decomposition velocities of TBOD, TCOD and TSS in aerobic bed were 30.79, 17.15 and 29.96 . Moreover, the decomposition velocities of BODs, CODs and SSs in aerobic bed were very rapid than those in the other beds. On the other hand, the decomposition velocities of BODs, CODs and SSs in anoxic and anaerobic beds were a little different regardless of the forms of pollutant. The decomposition velocities constants of T-N in aerobic, anoxic and anaerobic beds were 4.78, 0.12 and 0.10 , respectively. Moreover, the decomposition velocities constants of T-P in aerobic, anoxic and anaerobic beds were 13.09, 0.12 and 0.13 respectively. The decomposition velocity of T-Ns and T-Ps in aerobic bed were slightly rapid than those in the other beds, whereas the decomposition velocities of T-Ns and T-Ps in anoxic and anaerobic beds were slightly different regardless of the forms of pollutant.

Optimum Depth and Volume Ratio of Aerobic to Anaerobic Bed for Development of Small-Scale Sewage Treatment Apparatus by Natural Purification Method

To develop small-scale sewage treatment apparatus for detached house of agricultural village, a small-scale sewage treatment apparatus by natural purification method that consisted of aerobic and anaerobic bed was constructed. To reduce the area of a sewage treatment apparatus, four different fitter media were used and each filter medium was coarse sand, broken stone, steel slag, and mixed fitter media (coarse sand : broken stone : steel slag = 1:1:1). The efficiency of sewage treatment according to the depth of aerobic and anaerobic bed and the volume ratio of aerobic to anaerobic bed were investigated in small-scale sewage treatment apparatus. The removal rate of pollutants according to the depth of aerobic and anaerobic bed in small-scale sewage treatment apparatus was high in the order of 50 cm 1:3. Under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P were respectively, in small-scale sewage treatment apparatus.

Germanium Contents of Soil and Crops in Gyeongnam Province

To investigate the germanium content in paddy soil in Gyeongnam province, 310 paddy soil samples were collected at 19 areas in Gyeongnam, Ulsan and Busan. Contents of germanium in paddy soils were analyzed in different topographies, soil types and soil textures. Average content of germanium in Gyeongnam was 0.24 mr/kg, those of Masan, Jinju and Hadong were above 0.30 mg/kg. Germanium content with different topographies were no difference. Germanium contents in different soil types were 0.27 mg/kg in well adapted soil and 0.23 mg/kg in poorly drained soil. Germanium contents in different soil textures were 0.27 mg/kg in silt loam and 0.23 mg/kg in sandy loam. To determine germanium content on agricultural product in the field, content of germanium in cereals, vegetables and fruits were analyzed. Germanium content of agricultural product was high in the order of cereals>vegetables>fruits. In case of vegetables, germanium contents were high in the order of leaf vegetables>root vegetables>fruit vegetables. Germanium contents were high with 62 and in lettuce and young radish, respectively. To analyze the germanium content in medicinal plant, samples were collected from 19 medicinal plants at Hamyang areas. Germanium contents in Angelica keiskei, Ligusticum chuanxiong, Panax ginseng and Atractylodes macrocephala were relatively high with above.

Evaluation of Pollutant Removal Efficiency in Environmentally Friendly Full-scale Constructed Wetlands for Treating Domestic Sewage during Long-term Monitoring

A constructed wetland which was composed of aerobic and anaerobic areas was evaluated for 3 years to effectively treat the sewage produced in farming and fishing communities. For 3 years in a constructed wetland, biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(T-N), and total phosphorus(T-P) in effluent were 0.211.8, 1.041.9, 1.16.5, 460 and 0.023.51 mg/L, respectively. Removal rate of BOD, COD and SS in effluent were 97, 92 and 99%, respectively, in the third year. As time goes by, removal rate of T-N and T-P in treated water in aerobic area and effluent were gradually increased in a constructed wetland. In the third year, removal rate in effluent were 62 and 73%, respectively. By the seasons, removal rate of BOD, COD, SS, T-N and T-P were 9798, 8791, 99, 4361 and 7686%, respectively. Removal rate of BOD, COD, SS and T-P were not affected by the seasons, but that of T-N in winter and spring were decreased than the other seasons.

Screening of the Optimum Filter Media in the Constructed Wetland Systems through Phosphorus Adsorption Capacities

The phosphorus(P) adsorption capacities of various filter media were investigated in relation to the size and types of fitter media to screen the optimum condition. The objective of this study was to evaluate the constructed wetland longevity by improving P adsorption capacity. The maximum P adsorption capacities of filter media A(), B() and C() were 8, 10 and 22 mg/kg, respectively, showing those increased as the filter media size decreased. Among the experimental media, the optimum filter media size was . When the filter Medium was supplemented with organic materials which were piled up and decayed in the constructed wetland, the P adsorption capacity was significantly enhanced Under the conditions of optimum fitter media size, the respective Maximum P adsorption capacities of filter media C when supplemented with Ca, Mg, Al and Fe were higher than that of filter media C. However the addition of Ca, Mg, Al and Fe to constructed wetland were not recommended because of the possibility of their secondary pollution. The maximum P adsorption capacity of filter media C was 22 mg/kg, but this was increased to 36 mg/kg when filter media C was supplemented with 2% oyster shell.

Efficiency of Activated Carbon Treatment Processing on Raw Water Purification for Nakdong River

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using activated carbon process. for raw water, Nakdong river was used. from the activated carbon adsorption experiment the fellowing results were obtained The efficiency of water treatment enhanced with increase in empty bed contact time. Variation of pH was not detected to the bed depth, but DO content gradually decreased with the bed depth. Removal efficiency of consumption, UV254 absorption, DOC and THMFP also were increased by increasing in the bed depth. Transition of adsorption zone from upper parts of the bed to the lower parts were detected as treatment periods increased. Large portion of DOCs were degraded and removed by the microbes growing on the surface of activated carbons. Cell numbers of microbes were estimated over at the depth of 20 cm from the surface 126 days after starting operation. The results shown that the activated carbon Inter was successfully acted as a biofilm filter.