• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.49-55
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• 1999

The treatment of petroleum contaminated soil requires various physico-chemical remediation technologies which are efficient in time and can reduce the possibility of secondary contamination by themselves In this study, an innovated soil washing process was proposed to treat the diesel-contaminated soil. Micro-bubbles, which were generated by hydrogen peroxide, deserted and floated the contaminants. Soils less than #60(0.25mm) were artificially contaminated by 6,500mg TPH/kg dry soil initially. The process was examined for pH, the soil to water mixing ratio, concentration of $H_2O$$_2$, and contacting times. In the case of less than #60 soil, maximum removal efficiency(60%) was obtained at pH 12. 1.0% hydrogen peroxide, and 1 : 5 soil to water mixing ratio for 1 hour.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.229-233
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• 2011

BACKGROUND: Soil acidification, which is known to be one of the reasons of forest decline, is associated with decreases in exchangeable Ca and increases in Al concentration, leading to low Ca/Al ratio in soil solution. As tree rings are datable archives of environmental changes, Ca/Al ratios of annual growth ring may show decreasing pattern in accordance with the progress of soil acidification. This study was conducted to investigate Ca/Al pattern of Pinus densiflora tree ring in an attempt to test its usefulness as an indicator of historical soil acidification. METHODS AND RESULTS: Three P. densiflora tree disks were collected from P. densiflora forests in Jeonnam province, and soil samples (0-10, 10-20, and 20-30 cm in depth) were also collected from the tree locations. Soils were analyzed for pH and exchangeable Ca and Al concentrations, and Ca/Al was calculated. Annual growth rings formed between 1969 and 2007 were separated and analyzed for Ca/Al. Soil Ca/Al was positively (P<0.01) correlated with soil pH, suggesting that soil acidification decreased Ca while increasing Al availability, lowering Ca/Al in soil solution. The Ca/Al of tree rings also showed a decreasing pattern from 18.2 to 5.5 during the period, and this seemed to reflect historical acidification of the soils. CONCLUSION(s): The relationship between soil pH and Ca/Al and the decreasing pattern of Ca/Al of tree ring suggest that Ca/Al of tree ring needs to be considered as a proxy of the progress of soil acidification in P. densiflora forest in southern Korea.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.1
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• pp.1-9
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• 2005

This study was conducted to establish a management plan for the Sangrim Woodlands restoration by analyzing the site characteristics of the Sangrim Woodlands Natural Monument(Natural Monument 154) in Hamyang-Gun, Gyoungsangnam-Do, Korea. Site preparation to enhance soil aeration should be applied because soil bulk density in all study sites was higher than soil compaction of natural forest soil area. Herbaceous plants could be introduced to hard soil strength for restoration of areas compacted by visitors. Also, visitors around forest areas should be restricted to enhance natural soil restoration. Soil pH in the Sangrim Woodlands was between 4.18 and 4.90. The values were lower than pH 5.34 of Korean forest soil originated from metamorphic parent materials. Lime fertilizer could be applied to reduce soil acidification in the woodlands. Short and long-term management plans such as periodical fertilizations to improve plant growth should be established to restore the Sangrim Woodlands which have high soil compaction, low soil pH and organic matter content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.262-266
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• 2003

The present study was carried out to investigate the relationships among intertillage and muddying by free-ranging ducks (Chinese native ducks) and pH, dissolved oxygen of irrigation water, and physicochemical properties of soil. Two paddy fields comprised of the muddying (muddy water without physical stimulation to a rice plant by the ducks) and the control plots (no ducks) were used for this study. As a muddying plot, 50 hills were randomly selected and each hill was fenced with a wire net in order to prevent from stimulating physically by the ducks. The variation in irrigation pH was smaller in the muddying plot than the control plot, and the pH was around 7.4. Dissolved oxygen was significantly higher (P＜0.01) in the muddying plot than the control plot during the first half period after the ducks were introduced. Then it decreased rapidly as the rice plants grew in all plots. The contents of the suspended soil and turbidity in irrigation water were not changed over the free-ranging period, but $\textrm{NH}_3\textrm{-N}$ and $\textrm{P}_2\textrm{O}_5$ were decreased by intertillage and muddying by the ducks. There were no differences in both the soil physics and chemistry between the muddying plot and the control plot during and after finishing of the free-ranging period. These results indicate that intertillage and muddying by the ducks resulted in a small variation in stagnant water pH, and reduced the dissolved oxygen and $\textrm{P}_2\textrm{O}_5$, although the physiochemical properties of soil were not changed.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.422-430
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• 2000

Three-year-old Pinus koraiensis seedlings, transplanted in brown forest soils originating from granite were treated with simulated acid rain of pH concentrations 5.6(control), 4.0, 3.0, 2.5 and 2.0 for 210 days from April 21 to November 17, 1999. Visible injury of the seedlings were observed at the pH 2.0 and pH 2.5 treatments. The total dry weight of the seedlings decreased at pH 2.0 treatment compared with that of the control, and T/R ratio increased at pH 2.0 treatment compared with others. The elements in each part of the seedlings, concentrations of Ca, P and content of chlorophyll in needles increased at the pH 2.0 treatment compared with the control. The concentration of N in the needles of the seedlings increased as the soil pH decreased. As the treated pH was lowered, soil pH has decreased, and concentrations of Ca, Mg, Al, and Mn increased, especially at pH 4.4. In addition, there was a strong correlation(r=0.90, p<0.05 ; r=-0.94, p<0.01) between the dry weight of the seedlings and the pH and Al concentration of the soils. Therefore, the pH and Al concentration in the soil may be useful indicator for assessing the effect of acid rain on the growth of woody plants.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.31-39
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• 1998

A total of 112 soil samples collected from polluted and unpolluted areas in Korea were investigated for physical properities (such as soil moisture, organic matter and soil pH) and biological properties (such as microbial numbers). The results of organic matter and soil pH showed a great variation(p=0.01) in the four areas, whereas soil moisture and organic matter were similar among three plant vegetations. There was a significant relationship(p=0.01 or 0.05) between soil pH and microbial number These results imply some variations in soil environment and may lead to unfavorable changes of plant vegetation in soil. Presumably, the above results appear to be resulted from soil acidification caused by an acidic rain.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.744-750
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• 2015

The objectives of this study were to investigate soil chemical characteristics for forest rehabilitation and suggest management in abandoned coal mine areas in Boryeong City, Chungcheongnam-do. Total study sites were seven sites, and soil properties analyzed were soil pH, total organic carbon (TOC), total-N, C/N ratio, and available $P_2O_5$ (A.v. P). Average soil pH (range) was 5.9 (4.5~7.0). Three study sites (Samgwang, Shinsung1, and Shimwon1) showed lower soil pH than standard (pH 5.6~7.3) of Korea Industrial Standards (KS) for abandoned coal mine forest rehabilitation. Average contents of TOC, and total-N were 1.5% (0.1~4.7%), and 0.10% (0.03~0.23%), respectively. Five study sites where the collapsed time was less than 10 years (Wangjashingang, Wonpoong, Samgwang, Shinsung1, and Shinsung2) showed lower TOC level than standard of KS (more than 1.2%). Wangjashingang, Wonpoong, Samgwang, and Shinsung1 showed lower level of total-N than standard of KS (more than 0.09%). C/N ratio of six study sites except Shimwon1 was out of proper range (15:1~30:1). Average A.v. P (range) was $20.7mgkg^{-1}$ (4.8~63.1), less than other abandoned coal mine fores rehabilitation areas in Mungyong City, and Hwasun-gun. TOC, total N and A.v. P increased with elapsed time from forest rehabilitation, while other soil properties did not show distinct pattern. Betula platyphylla was planted in Samkwang and Sinsung where soil pH was less than KS standard. Because the growth of Betula platyphylla can be limited in acid soil, it is necessary to neutralize soil pH to proper level with some soil amendment such as lime or shell of oyster. Furthermore, TOC, total-N and A.v. P in early stage of forest rehabilitation showed lower level than proper to vegetation growth. Therefore it needs continuous monitoring of soil characteristics and fertilization for vegetation growth and influx from surrounding forest in early stage of rehabilitation.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.15-20
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• 1990

A laboratory experiment was conducted to investigate the relationship between the composition of phosphorus forms and soil chemical properties. The soil samples were collected from the farms of the 149 locations where vegetables were intensively cultivated with heavy application of phosphorus. The composition percentages of Ca-P and Saloid-P to the total phosphorus were increased as increasing soil pH while those of Fe-P and Al-P were decreased, The composition percentage of Fe-P were increased up to pH 5.0-6.0 and decreased as increasing pH above 6.0. respectively. The pH dependency of Al-P and Fe-P composition percentage was more remarkable for the soils with high available phosphorus (>500ppm) than with low available phosphorus (<500ppm). Composition percentages were in order of Fe-P>Al-P>Ca-P>Saloid-P for the soils with available phosphorus below 500ppm, while those were in order of Al-P>Fe-P>Ca-P>Saloid-P for the soils with high available phosphorus above 1,000ppm. Composition percentages of Al-P and Fe-P were increased as increasing active Al content, and Fe-P was increased as increasing of active Fe and P sorbed but saloid-P, Al-P and Ca-P were decreased.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.641-646
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• 2003

In this study, a series of electrokinetic(EK) remediation experiments are carried out under the different degree of saturation for contaminated soil with lead. for constant electrical potential, the final current of all the sample represents the similarity to steady-state value of 5∼7mA. Under conditions of all the degree of saturation the anode reservoir becomes acidic(pH as low as 3) while the cathode reservoir is basic(pH as high as 12). But pH changes in the sample is a little and decontamination efficiency is the low.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.69-74
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• 1999

Soil properties which affect the retention of Pb(I) were investigated in the laboratory. It was determined, through selective removal, that organic matter and Fe-oxides are of lesser importance in influencing Pb retention than are soil clay minerals. The following trend : clays ＞ organic matter ＞ Fe-oxides represents the relative importance of each constituent in the adsorption of Pb by soils. The consistently greater Pb uptake by surface over subsurface samples was apparently due to differences in organic matter content, inasmuch as organic matter removal from both resulted in similar adsorption characteristics. All five soils stooled exhibited a pH-dependent trend of adsorption. The extent of Pb adsorption was least at low pH values(4~5), was maximum in the neutral pH range, and leveled off or diminished under more alkaline conditions. There was no strong correlation between Pb uptake and soil cation exchange capacity as routinely measured by the NH$_4$OAc method. A knowledge of clay mineralogy in conjunction with soil pH is suggested as being the most reliable guide to predicting Pb retention by soils.