인산석고의 중금속 용출 특성

정종배,조현종,진선재 한국환경농학회 2002 한국환경농학회지 Vol.21 No.3

서울시 주요 도로변의 토양오염 조사 : I . 중랑구 망우로 주변 토양 I . Manguro in Chungnanggu

정종배,김계훈,김권래,류형주 한국농화학회 2001 Applied Biological Chemistry (Appl Biol Chem) Vol.44 No.2

The objectives of this study were to investigate the contamination of the soils around the major roadsides in Seoul and to accumulate base-line data. Fifty topsoils (0∼5 ㎝) and 48 subsoils (20∼50 ㎝) were collected from 50 sampling sites near Manguro in Chungnanggu. The samples were air-dried, passed through 2-㎜ sieves, and analyzed to detemune the physicochemical properties and the contents of heavy metals (Cd, Cu, Pb, Zn) and anions (Cl, NO₃, SO₄). Soil textures of top- and subsoils were mainly loamy sand and sandy loam, respectively. Average pH of top- and subsoil was approximately 7.5, much higher than that of the forest soils in Seoul. Average heavy metal contents were lower than the levels allowed by the Soil Environment Conservation Act of Korea, whereas much higher than those of the forest soils. Contents of some heavy metals were higher than the maximum allowed levels. Anion concentrations were also much higher than those of the forest soils. A careful management to prevent the aggravation of the present contamination level and the diffusion of contaminants is recommended.

Nitrate에 의해 조절되는 논토양의 산화환원현상과 벼 유묘의 생장

정종배 한국토양비료학회 2010 한국토양비료학회 학술발표회 초록집 Vol.2010 No.10

Ca 엽면시비가 토마토의 수량 및 품질에 미치는 영향

정종배,사동민 선문대학교 ·중소기업기술지원연구소 1999 선문공대 연구/기술 논문집 Vol.4 No.1

칼슘의 엽면시비가 토마토의 수량 및 품질에 미치는 영향을 살펴보고저 칼슘비료를 0, 2 및 3회 처리한 후 수량 병해발생률, 칼슘함량 및 과육의 파괴강도를 측정하였다 칼슘의 엽면시비는 과실의 생체량 및 과실 개당 무게에는 유의성 있는 차이를 나타내지 않았으나 병해발생률 감소 및 칼슘농도 증가는 유의성 있는 차이를 나타내었다 이는 칼슘의 엽면시비가 수량에는 영향을 미치지 못하나 토마토 과육에 칼슘함량을 높여 파괴강도를 증가시키고 병해발생률을 감소시키는 것으로 생각된다. The objective of this study was to examine the effect of Ca foliar application on yield, disease occurrence, Ca content and texture of tomato after growing with Ca-foliar application (0, 2 and 3 times). The yield of tomato was not affected by Ca-foliar application but Ca-foliar application decreased the occurrence of disease and increased Ca-concentration of tomato significantly. These results showed that Ca-foliar application had no significant effect of yield but enhanced the quality (disease occurrence, texture) by increasing Ca concentration in tomato.

Comparison of Soil Physical Properties in Conventional and Organic Farming Apple Orchards

정종배 한국환경농학회 2007 한국환경농학회지 Vol.26 No.4

Soil physical properties in organic farming apple orchard were evaluated in relation to conventional farming to better understand the effects of organic farming system on soil quality. Two adjacent apple orchards, matched by soil type, were chosen to ensure the same pedological conditions except management system. Soil samples were collected from middle of two adjacent trees along the tree line at two depths of 5-20 and 20-35 cm in September 2006. Contents of organic matter in organic farming soil were twice as much as those found in soil of conventional farming. The higher level of organic matter in organic farming soil was reflected through a consequent trend in improved soil physical properties. Organic farming produced greater aggregation in >2 mm size and increased aggregate stability. Bulk density was lower by 13% and hence porosity was higher in soils of organic farming as compared with conventional farming. Water holding capacity was significantly greater with organic farming by >17% over conventional farming. The capacity of organic farming to improve soil physical properties can be contributed to the regular application of relatively large amount of organic materials and the sustainable ground-cover managements, mulching with compost and cover crop cultivation.

그린벨트 백서 ( 개발제한구역제도 관련 자료집 ) / 그린벨트 문제해결을 위한 제안

정종배 한국토지행정학회 1997 그린벨트 백서 Vol.- No.-

Chromium Speciation in Cr(III) Oxidation by Mn-Oxides: Relation to the Oxidation Mechanism

정종배,Chung, Jong-Bae 한국응용생명화학회 1998 Applied Biological Chemistry (Appl Biol Chem) Vol.41 No.1

크롬의 산화는 자연계에 존재하는 여러 가지의 Mn-oxide에 의해 일어나며 산화과정에 존재하는 크롬 화학종들은 반응계 내에서 흡착, 침전 현상을 유발할 수 있고 결과적으로 산화반응을 조절할 수 있을 것이다. 본 연구에서는 birnessite와 pyrolusite에 의한 크롬의 산화에서 크롬 화학종이 반응에 미치는 영향을 조사하였다 Mn-oxide는 그 종류에 따라 크롬 산화력에서 큰 차이를 보였으며 용액의 pH와 초기 3가 크롬 첨가량도 산화반응에 큰 영향을 미쳤다. 동일 표면적당의 산화력을 비교하면 pyrolusite의 산화력은 birnessite의 5% 정도에 불과하였다. 이는 pyrolusite 의 결정도에 크게 기인하며 또한 양으로 하전된 표면 특성 때문에 반응물인 3가 크롬의 접근이 어렵고 반응산물인 6가 크롬의 흡착 등에 기인하는 것으로 보인다. Birnessite에 의한 산화반응에서 pH 3에서는 oxide의 표면에서의 크롬 화학종들의 흡착이나 침전 현상은 발견되지 않았으며 pyrolusite의 경우 일부 6가 크롬의 흡착이 나타났으나 침전현상은 발견되지 않았다. 따라서 pH 3의 경우 산화반응은 Mn-oxide의 특성에 따라 결정된다. Mn-oxide에 의한 크롬의 산화는 열역학적으로 용액의 pH가 높아질수록 더 진행되어야 한다. Birnessite의 경우 pH 5에서 오히려 산화반응이 현저히 저해되었는데 이는 birnessite의 표면에 형성되는 3가 크롬의 침전이 반응표면을 감소시킴으로써 나타나는 현상으로 판단된다. Pyrolusite의 경우 pH 3보다 pH 5에서 크롬의 산화는 더 일어나나 초기 3가 크롬의 첨가량이 많아지면서 반응이 억제된다. 일부 3가와 6가 크롬의 흡착이 일어나나 이 경우도 역시 pyrolusite의 표면에 형성되는 3가 크롬의 침전이 반응을 조절하는 주 요인으로 생각된다. Mn-oxide의 표면에 형성되는 3가 크롬의 침전은 산화가 일어날 수 있는 반응표면을 감소시키고 또한 반응물의 농도를 낮춤으로써 용액의 pH가 높고 3가 크롬의 첨가량이 많아질 때 크롬의 산화반응을 억제하는 주 요인이 되는 것으로 판단된다. Various Mn-oxides can oxidize Cr(III) to Cr(VI). Behaviors of chromium species in the oxidation system, especially on the oxide surface, are expected to control the reaction. During Cr(III) oxidation by birnessite and pyrolusite, Cr species in the reaction system were determined to elucidate their effects on the oxidation. Capacities of Cr oxidation of the two Mn-oxides were quite different. Solution pH and initial Cr(III) concentration also had significant effects on the Cr(III) oxidation by Mn-oxides. Chromium oxidation by pyrolusite was less than 5% of the oxidation by birnessite. The high crystallinity of pyrolusite could be one of the reasons and the difficulty of Cr (III) diffusion to the positive pyrolusite surface and Cr(VI) and Cr(III) adsorption seems to be other controlling factors. At pH 3, adsorption or precipitation of Cr species on the surface of birnessite were not found. Small amount of Cr(VI) adsorption was found on the surface of pyrolusite, but arty Cr precipitation on the oxide surface was not found. Therefore Cr(III) oxidation at pH 3 seems to be controlled mainly by the characteristics of Mn-oxides. Chromiun oxidation by Mn-oxides is thermodynamically more favorable at higher solution pH. However as solution pH increased Cr oxidation by birnessite was significantly inhibited. For Cr oxidation by pyrolusite, as pH increased the oxidation increased, but as Cr(III) addition increased the reaction was inhibited. Under these conditions some unidentified fraction of Cr species was found and this fraction is considered to be Cr(III) precipitation an the oxide surface. Chromium(III) precipitation on the oxide surface seems to play an important role in limiting Cr(III) oxidation by armoring the reaction surface on Mn-oxides as well as lowering Cr(III) concentration available for the oxidation reaction.

Nitrate에 의해 조절되는 논토양의 산화환원현상과 벼 유묘의 생장

정종배 한국토양비료학회 2010 한국토양비료학회 학술발표회 Vol.2010 No.1

Application of Exchange Equations for NH₄-K NH₄-Ca Equilibria

정종배,사동민,Chung, Jong-Bae,Sa, Tong-Min 한국토양비료학회 1995 한국토양비료학회지 Vol.28 No.3

복숭아 묘목으로 부터 채취한 근권 및 그 주변 토양을 이용하여 $NH_4-K$와 $NH_4-Ca$ 치환 현상을 조사하였으며 이 결과를 토양중 암모니움 등 양이온의 이동과 분포의 모델화에 적용할 수 있는 치환식을 찾고자 했다. 토양시료를 $NH_4Cl$, KCl과 $CaCl_2$ 용액으로 평형에 도달시킨 후 $Sr(NO_3)_2$ 용액으로 추출하여 평형상태에서의 치환태 양이온 조성을 구하였다. Vanselow, Gapon 그리고 kerr의 식은 $NH_4-K$와 $NH_4-Ca$ 치환 현상을 적절히 기술할 수 없었으나 치환태 양이온 농도에 임의의 지수를 갖는 다음과 같은 경험식이 매우 적절한 것으로 나타났다. ${\frac{\alpha_i^m}{a_j^n}}=K{\frac{(iX)^{mPi}}{(jX)^{nPj}}}$ 이 식에서 ${\alpha}i$와 ${\alpha}j$는 원자가가 m과 n인 양이온 i 및 j의 용액 중 activity이며(iX)와 (jX)는 치환태양이온 i와 j의 농도이다. 치환태 양이온의 농도 단위로는 몰 분율 또는 당량 분율을 사용할 수 있다. 임의상수 $P_i$와 $P_j$ 그리고 분배상수 K는 이 식의 대수형을 이용하여 다중 회귀 방법으로 구할 수 있다. Ion exchange equilibria in bulk and rhizosphere soil collected from peach seedlings were studied to find exchange equations that could be used in chromatographic models dealing with movement and distribution of fertilizer ammonium and exchangeable cations in soil profiles. Soil samples were equilibrated with mixtures of $NH_4Cl$, KCI, and $CaCl_2$ solutions and then extracted with $Sr(NO_3)_2$ solution to determine exchangeable cation compositions at equilibrium. Exchange data were fitted to Vanselow's, Gapon's, and Kerr's equations, but those formulations did not adequately describe the equilibria. An empirical equation of the form : ${\frac{\alpha_i^m}{a_j^n}}=K{\frac{(iX)^{mPi}}{(jX)^{nPj}}}$ which has an exponent on each of the exchangeable cation concentrations could describe the equilibria very well over the range of treatments. In this equation ${\alpha}^i$ and ${\alpha}^j$ are activities of cation i and j with valences m and n respectively. (iX) and (jX) are concentrations of exchangeable cations. Mole or equivalent fractions can be considered as the exchangeable ion concentration unit. Arbitrary constants $P_i$ and $P_j$, and distribution coefficient K can be found with multiple regression for the logarithmic form of the equation.

두 단계 중화적정에 의한 산성 광산 유출수 중의 중금속 제거

정종배,정병룡 한국농화학회 1999 Applied Biological Chemistry (Appl Biol Chem) Vol.42 No.1

Acid mine drainage (AMD) results from sulfuric acid produced by the oxidation of pyrite, and contains large amounts of toxic elements. In the neutralization of AMD, iron and aluminum hydroxides are the major precipitates and those two can be separated with two-phase neutralization. In this study, removal of toxic elements by the two phases of neutralization was investigated using an AMD collected from the abandoned antimony mine in Gachang, Taegu. Contents of As, Cd, Cu, Mn, Pb and Zn in the AMD were higher than the criteria of river water quality or permissible waste water discharge. In the first phase, the AMD was neutralized to several % (25, 50, 75, 100, and 125) of Fe(OH), equivalence point with solid Ca(OH)₂. In the second phase, the supernatant of the first phase neutralization was titrated to pH 7.5. After neutralization of the AMD to 100% of the Fe(OH), equivalence point, most of Fe and Pb were removed but levels of As, Cd, Cu, Ni, Mn, and Zn were not reduced in the supernatant solution. In the second phase neutralization, levels of those toxic elements in the supernatants dropped below the wastewater discharge or river water quality criteria. This result suggests that the precipitate formed in the first phase of the neutralization process may be disposed without any special cares. Thus the two-phase neutralization scheme can reduce the cost of disposing precipitates containing toxic metals in comparison with the monophase neutralization scheme.