활성화 수피를 이용한 중금속 흡착제 개발

박창진,양재의,유경열,장용선,김원일 한국환경농학회 2004 한국환경농학회지 Vol.23 No.4

The objective of this research was to develop the adsorbent for heavy metals by activating the bark sample. Barks from pine tree with diameters of 2~4 mm were activated in the muffle furnace under a high relative humidity condition at temperatures of 600~900℃. The removal efficiency of the activated bark (ACTBARK) for Cu and Cd was temperature dependent showing the order of 900℃ > 800℃ > 700℃ > 600℃. The critical temperature was considered to be 900℃ to become an efficient adsorbent for Cu and Cd. The bark samples activated at temperatures lower than 700℃ showed a less removal efficiency than the crude bark The ACTBARK activated at 900℃ removed more Cu and Cd from solution than the commercial activated carbon and charcoal. The ACTBARK (activated at 900℃) adsorbed all of the Cu and Cd in solution with concentrations less than 150 mg/L. The selectivity of the ACTBARK was in the order of Cu>Zn>Ni>Pb>Fe>Cd>Mn.

레이저유도붕괴분광법을 활용한 토양의 정량분석

장용선(Yong-Seon Zhang),이계준(Gye-Jun Lee),이정태(Jeong-Tae Lee),황선웅(Seon-Woong Hwang),진용익(Yong-Ik Jin),박찬원(Chan-Won Park),문용희(Yong-Hee Moon) 한국토양비료학회 2009 한국토양비료학회지 Vol.42 No.5

레이저 유도붕괴 분광법(LIBS)은 물질상태(고체, 액체, 기체)에 상관없이 신체 접촉시 오염 우려 및 미량 시료도 전처리 없이 동시에 많은 종류의 원소 분석으로 분석과정이 단순하고 신속하게 분석이 가능하며, 소형화된 레이저의 개발로 시료의 직접적인 채취가 어려운 조건의 현장분석에도 적합하다. 농산물 안정성 평가나 친환경 농업 및 정밀농업을 위한 조사 등에 활용될 수 있는 비파괴 실시간 정량분석기술로서 LIBS 분석법의 토양분석 가능성을 평가하고자 표준광물, 미국의 표준기술연구소의 표준토양, 미국 테네시주 초지 및 밭토양을 대상으로 토양 구성성분의 정성ㆍ정량적 분석에 필요한 측정조건을 조사하고 이를 토대로 LIBS에 의한 농도값과 기존의 화학분석법을 통해 측정한 결과를 비교하였다. LIBS 측정은 펄스형 Nd:YAG 레이저(Minilite Ⅱ, Continuum, Santa Clara, CA)에서 나오는 1064 ㎚ 에너지 파장의 광원을 시편의 플라즈마를 생성시키는데 사용하였고, 25 mJ/pulse 여기 에너지 빔을 펄스폭 35 ns, 펄스 반복 주기 10 ㎐, 노출시간 10 s 동안 시료의 표면에 조사하였다. LIBS 분광은 0.03 ㎚의 해상력으로 200 ㎚에서 600 ㎚의 영역에서 50 m 이하로 분쇄하여 원형 펠렛 형태로 압축시킨 시료를 10 rpm의 속도로 회전시키면서 상온 상압의 실험실 조건에서 수행되었다. LIBS를 이용한 토양 중 주요한 원소의 적정 파장(㎚)은 Al(I) 309.2 ㎚, Ca(I) 422.6 ㎚, Fe(I) 406.4 ㎚, Mg(I) 285.2 ㎚, Na(I) 589.2 ㎚, Si(I) 288.2 ㎚, Ti(I) 398.9 ㎚ 이었다. LIBS의 피크강도가 물질 중 원소의 농도가 증가됨에 따라 각 원소의 특정 파장대에서 일정하게 증가되는 것으로 나타나고 있으나 표준물질의 LIBS의 신호비와 원소비를 통해 측정된 검량곡선의 상관계수(r2)는 0.863에서 0.977의 범위로 원소별로 상이할 뿐만 아니라 0.98에 미치지 못하였다. 또한, 토양중 분석대상원소에 대하여 기존 ICP-AES에 의한 표준방법으로 분석된 시료의 측정값과 비교하여 상대적인 오차는 대략적으로 (-)40%에서 80%이상이며, 평균오차는 32.2%로 표준척도 20% 이상을 초과하였다. LIBS에 의한 토양분석은 토양의 조성과 입자의 크기에 따른 매질효과(matrix effect)로 표준물질의 검량곡선에서 결정계수가 낮고, 원소별 함량도 기준의 표준방법과 비교할 때 오차가 컸다. 따라서 LIBS에 의한 토양분석은 정성적인 분석 수준의 정밀도를 보였으며, 토양 매질의 영향을 최소화하기 위하여 기존의 분쇄ㆍ펠렛형 시료조제 및 회전측정 이외의 다양한 토양매질의 표준물질(standard reference material)의 확보, 새로운 전처리 방법 및 측정상 방법개선 등 신뢰성 있는 정량 분석을 위한 노력이 필요할 것으로 사료된다. Laser induced breakdown spectroscopy(LIBS) is an simple analysis method for directly quantifying many kinds of soil micro-elements on site using a small size of laser without pre-treatment at any property of materials(solid, liquid and gas). The purpose of this study were to find an optimum condition of the LIBS measurement including wavelengths for quantifying soil elements, to relate spectral properties to the concentration of soil elements using LIBS as a simultaneous un-breakdown quantitative analysis technology, which can be applied for the safety assessment of agricultural products and precision agriculture, and to compare the results with a standardized chemical analysis method. Soil samples classified as fine-silty, mixed, thermic Typic Hapludalf(Memphis series) from grassland and uplands in Tennessee, USA were collected, crushed, and prepared for further analysis or LIBS measurement. The samples were measured using LIBS ranged from 200 to 600 ㎚(0.03 ㎚ interval) with a Nd:YAG laser at 532 ㎚, with a beam energy of 25 mJ per pulse, a pulse width of 5 ns, and a repetition rate of 10 ㎐. The optimum wavelength(λ㎚) of LIBS for estimating soil and plant elements were 308.2 ㎚ for Al, 428.3 ㎚ for Ca , 247.8 ㎚ for T-C, 438.3 ㎚ for Fe, 766.5 ㎚ for K , 85.2 ㎚ for Mg, 330.2 ㎚ for Na, 213.6 ㎚ for P, 180.7 ㎚ for S, 288.2 ㎚ for Si, and 351.9 ㎚ for Ti, respectively. Coefficients of determination(r²) of calibration curve using standard reference soil samples for each element from LIBS measurement were ranged from 0.863 to 0.977. In comparison with ICP-AES(Inductively coupled plasma atomic emission spectroscopy) measurement, measurement error in terms of relative standard error were calculated. Silicon dioxide(SiO2) concentration estimated from two methods showed good agreement with -3.5% of relative standard error. The relative standard errors for the other elements were high. It implies that the prediction accuracy is low which might be caused by matrix effect such as particle size and constituent of soils. It is necessary to enhance the measurement and prediction accuracy of LIBS by improving pretreatment process, standard reference soil samples, and measurement method for a reliable quantification method.

The Acid Buffer Capacity of a Horizons in Young Residual Entisols in Korea

Zhang, Yong-Seon,Sonn, Yeon-Kyu,Lee, Gye-Jun,Han, Kyung-Hwa,Cho, Hee-Rae 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.6

pH buffer capacities (pHBC, $cmol_c\;kg^{-1}\;pH^{-1}$) of 6 residual Entisols derived from granite, granite-gneiss, limestone, sandstone, shale, and basalt in Korea were studied. Soil acidity may become a problem if the soil pH is reduced to critical levels when nutrient cycles are unbalanced (especially N, C and S). The relation between the pHBC and the physico-chemical properties of the 6 soils was also studied. In the A horizons of all the soils except Euiseong series developed from sandstone, the contents of clay, organic matter and cation exchange capacity (CEC) were higher than those of C horizon, but bulk density and pH were lower than C horizon. Clay content of Euiseong series decreased with soil depth, which might be caused by the elluviation. The soils developed from granite, granite-gneiss and sandstone have a higher $SiO_2$ content than those developed from basalt and limestone. The contents of $Fe_2O_3$ and MgO were high in the soils from developed from basalt, limestone and shale comparing with the soils from granite, granite-gneiss and sandstone. The soils from basalt and limestone showed higher values of ignition loss than those from the other parent rocks. The pHBC of the soils was ranged from 1.8 to 3.2 $cmol_c\;kg^{-1}\;pH^{-1}$ showing as follows : basalt, limestone > shale, granite-gneiss > granite sandstone.

The Acid Buffer Capacity of a Horizons in Young Residual Entisols in Korea

Yong-Seon Zhang,Yeon-Kyu Sonn,Gye-Jun Lee,Kyung-Hwa Han,Hee-Rae Cho 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.6

pH buffer capacities (pHBC, cmolc kg<SUP>-</SUP>1 pH<SUP>-1</SUP>) of 6 residual Entisols derived from granite, granite-gneiss, limestone, sandstone, shale, and basalt in Korea were studied. Soil acidity may become a problem if the soil pH is reduced to critical levels when nutrient cycles are unbalanced (especially N, C and S). The relation between the pHBC and the physico-chemical properties of the 6 soils was also studied. In the A horizons of all the soils except Euiseong series developed from sandstone, the contents of clay, organic matter and cation exchange capacity (CEC) were higher than those of C horizon, but bulk density and pH were lower than C horizon. Clay content of Euiseong series decreased with soil depth, which might be caused by the elluviation. The soils developed from granite, granite-gneiss and sandstone have a higher SiO₂content than those developed from basalt and limestone. The contents of Fe₂O₃ and MgO were high in the soils from developed from basalt, limestone and shale comparing with the soils from granite, granite-gneiss and sandstone. The soils from basalt and limestone showed higher values of ignition loss than those from the other parent rocks. The pHBC of the soils was ranged from 1.8 to 3.2 cmolc kg<SUP>-1</SUP> pH<SUP>-1</SUP> showing as follows : basalt, limestone > shale, granite-gneiss > granite sandstone.

Decomposition of Livestock Manure in Soils Cultivated with Chinese Cabbage along an Altitude Gradient

Zhang, Yong-Seon,Lee, Gye-Jun,Lee, Jeong-Tae,Sonn, Yeon-Kyu,Yun, Hong-Bae,Kim, Myung-Sook 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.3

This study was conducted to investigate decomposition of livestock manure in soils cultivated with Chinese cabbage along an alitude gradient. The experiments were conducted in Kangreung (17 m above sea level), Bongpyeong (430 m above sea level), and Daekwanryeong (800 m above the sea level) in order to assess the decomposition rate and accumulations of livestock manures depending on different altitudes. During chinese cabbage cultivation, the decomposition ratios of organic matter derived form livestock manure expressed as % of the initial organic matter content were 42~48% for Kangreung, 26~29% for Bongpyeong and 10~14% for Daekwanryeong. Changes in air temperature with altitude might be a main factor affecting manure decomposition rates.

The buffer capacity of A horizons in Young Residual Entisols in Korea

yong-Seon Zhang,Yeon-Kyu Sonn,Gye-Jun Lee,Jung-Du Shin 한국토양비료학회 2005 한국토양비료학회 학술발표회 초록집 Vol.2005 No.9

Estimating Soil Properties and Rice Plant Growth in Liquefaction Paddy Land as Affected by Earthquake in Pohang City of Korea

Yong-Seon Zhang,Dong-Jin Kim,Jun-Hong Park,Se-Yeong Choi,Myung-Sook Kim,Hyub-Sung Lee 한국토양비료학회 2019 한국토양비료학회지 Vol.52 No.2

On 15th November 2017, an earthquake (magnitude 5.5) occurred at 36.10N and 129.37E on Pohang city in Korea. Due to the earthquake, liquefaction occurred in some agricultural lands of Yongcheon-ri, Heunghae-eup, Buk-gu, Pohang-si, Korea. This study investigated the physical and chemical properties of soil and liquefied sand and crop growth in the liquefaction site as affected by earthquake. The scale of liquefaction site in the experimental paddy was 30 - 50 cm ellipse, and most of the sand mixed with 14 - 22% of the gravel was piled up. The liquefaction scale was less than 0.01% of the area in each paddy land. The pH of the liquefied sand was a suitable property for rice cultivation, and heavy metal contents were lower than the concern level of soil environmental conservation act. As a result of comparing the liquefaction point (LP) and the around point 30 cm (AP) away from the LP, the partial cracked line was verified in the profile of LP. However, the soil structure maintained with the soil penetration resistance of 3 MPa or more. As the scale of sand liquefaction was small and the soil structure maintained, it considered that there was no problem in water and nutrient movement of soil and farming work. The effects of liquefaction on the growth and yield of rice were estimated to be insignificant because there was no statistically significant difference in plant height, stem height, panicle length, panicle number per fill, grain-filling rate, and yield of rice plants in the liquefaction site and control site.

Effects of Vegetative Buffers on Reducing Soil Erosion and Nutrient Loss of Highland Field in Korea

Yong-Ik Jin(진용익),Jeong-Tae Lee(이정태),Gye-Jun Lee(이계준),Seon-Woong Hwang(황선웅),Yong-Seon Zhang(장용선),Chang-Young Park(박창영),Myung-Chul Seo(서명철),Jong-Soo Ryu(류종수),Jin-Cheol Jeong(정진철),Ill-Min Chung(정일민) 한국토양비료학회 2009 한국토양비료학회지 Vol.42 No.4

본 연구는 고랭지 경사밭에서 발생하는 유거수량, 토양유실, 영양물질 유출량을 감소시키는 완충식생대의 효과를 연구하기 위하여 수행하였다. 시험에 사용된 포장의 토양은 운교통이고, 가로 2.5m, 세로 20m인 무저 lysimeter에서 시험하였다. 연구포장은 경사율 17%를 가진 경사밭이며, 배추를 재배하였다. 완충식생대로 이용된 초종은 Rye(Secale cereale L.), Tallfescue(Festuca arundinacea Schreb) Orchardgrass(Dactylis glomerata L.)이다. 이들은 경사밭 아래 부분에 조성되었다. 호밀 식생대의 폭은 1m, 2m, 4m를 두었고, Orchard grass와 Tall fescue는 2m로 설정하였다. 완충식생대를 조성하기 위해 각 초종을 2005년 9월에 파종하였고, 배추는 2006년 6월에 정식하였다. 토양유실량, 유거수량, 영양물질 유출량의 측정은 2006년 6월부터 8월까지 수행하였다. 유거수량, 토양유실량 및 영양물질 유실량은 강우가 집중된 7월에 가장 높았다. 유거수를 감소시키는 완충식생대의 효과를 대조구와 비교해 볼 때, 2m로 폭이 같은 완충식생대에서 호밀은 3%, Orchard grass는 1%, Tall fescue는 2% 저감 효과가 있었다. 폭이 다른 호밀 완충식생대간의 비교에서, 1m는 1%, Rye 2m는 3%, Rye 4m는 13%의 저감효과가 나타나 Rye 4m의 효과가 가장 좋았다. 토양유실저감측면에서 대조구와 비교할 때, 2m 완충식생대 중 호밀식생대는 59%, Orchard grass 46%, Tall fescue 28% 토양유실을 줄이는 것으로 나타나 같은 폭에서 호밀식생대의 효과가 가장 좋았다. 폭이 다른 호밀 식생대의 비교에서 1m는 62%, 2m는 60%, 4m는 88%의 토 양유실 저감 효과가 나타나, 4m의 효과가 토양유실을 저감하는데 가장 좋은 효과를 보였다. 한편, 유거수와 토양에서 발생한 N, P, K 유출 저감에서는 호밀 2m완충식생대에서 각각 54%, 16%, 11%, Orchard grass는 각각 22%, 24%, 22%를, Tall fescue는 10%, 7%, 12% 영양물질유출을 줄였다. 호밀완충식생 중에서 폭이 큰 4m에서 영양물질 유출저감효과가 가장 좋았다. 이 연구의 결과, 유거수량, 토양유실 저감효과는 호밀완충식생대가 다른 초종의 식생대보다 좋아서 유거수, 토양유실 그리고 영양물질 유출 저감을 위해 폭이 큰 호밀완충식생대의 설치가 효과적이라 생각된다. This study was carried out to investigate the effect of vegetative buffer to reduce runoff and soil and nutrient loss at highland agricultural area. The soil of experimental field was classified as Ungyo series (Fine, Humic Hapludults). An area of each field with lysimeter was 50m<SUP>2</SUP>(width 2.5m× length 20m) and was a gradient of 17%. Chinese cabbage (Brassica campestris L.) was cultivated by general management in each field. For establishing vegetative buffer, rye (Secalecereale L.), tall fescue (Festucaarundinacea Schreb) and orchard grass (Dactylis glomerata L.) were planted at the edge of field. Rye buffers were 1m, 2m and 4m wide. Both orchard grass and tall fescue buffers were 2m wide. Vegetative buffers were set up in September 2005 and chinese cabbage was planted in June 2006. Soil loss, runoff and nutrient loss were measured from June to August in 2006. Since the precipitation amount was heavy in July, amounts of runoff, soil erosion and nutrient loss were the highest in July during this study period. In comparison with control, vegetative buffers of rye 2m, orchard grass 2m and tall fescue 2m reduced runoff by 3%, 1% and 2%, respectively. In comparison among width of rye buffer, rye 1m, rye 2m, and rye 4m reduced by 1%, 4% and 13%, respectively. Vegetative buffers of rye 2m, orchard grass 2m and tall fescue 2m showed the reducing of soil loss by 59%, 46% and 28%, respectively. In comparison among width of rye buffer, the highest reducing effect of 88% was observed in 4m treatment. Additionally, vegetative buffer reduced N, P and K losses in runoff and eroded soil which were 10 to 54%, 7 to 24% and 11 to 21%, respectively. In different widths, wider vegetative buffer showed lower loss of N, P and K in runoff and eroded soil. As a result of this study, the vegetative buffer of rye was most effective for reducing runoff and soil loss in comparisons with other plants. In addition, wider range of buffers recommended for reducing runoff and soil loss, if possible.

Effect of Subsoil Breaking on Improvement of Soil Physical Properties in Agricultural Land

Yong-Seon Zhang,Dong-Jin Kim,Kang-Ho Jung,Hee-Rae Cho,Kyung-Hwa Han,Hyub-Sung Lee 한국토양비료학회 2019 한국토양비료학회지 Vol.52 No.2

When the hardpan is formed in the soil, crop productivity reduces due to inhibition of crop root growth, water permeability, and capillary rise, for that reason, improvement of soil physical properties is needed. Therefore, this study investigated the soil physical properties after application of various subsoil breaking method to agricultural lands to establish the effect of improving soil physical properties by subsoil breaking. The penetration resistance of the soils treated with spading (in Wanju), aeration (in Sancheong), and deep plowing (in Namwon) was lower than that of the control soil treated with conventional plowing. However, the penetration resistance of the soils treated with excavation (in Andong) and towing (in Chungju) was higher than that of the control soil. The effect of improving the soil physical properties such as increasing effective soil depth, decreasing bulk density, and increasing permeability observed in the soil subjected to spading, aeration, and deep plowing. Although, in soil treated with excavation and towing methods, it was found that the physical properties such as increasing bulk density and decreasing permeability were deteriorated due to re-compaction such as the formation of a platy structure on the topsoil by using unsuitable agricultural machinery after subsoil breaking. Therefore, the subsoil breaking cycle should be decided depending on the presence or absence of the soil hardpan in consideration of soil management histories, such as the soil moisture condition and the type and use period of agricultural machinery after subsoil breaking.

The Vertical Movement of Water and Nutrient in the Different Paddy and Upland Soils Using the Undisturbed Gravimetric Lysimeter

Yong-seon Zhang,Kyung-hwa Han,Hee-rae Cho,Jung-hun Ok,Seon-ah Hwang,Dong-Jin Kim 한국토양비료학회 2019 한국토양비료학회 학술발표회 초록집 Vol.2019 No.8