• Journal of Soil and Groundwater Environment
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• 제19권3호
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• pp.25-32
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• 2014

The amount of TPH contaminated soil treated at off-site remediation facilities is ever increasing. For the recycle of the treated-soil on farmlands, it is necessary to restore biological and physico-chemical soil characteristics and to remove residual TPH in the soil by an economic polishing treatment method such as phytoremediation. In this study, a series of experiments was performed to select suitable plant species and to devise a proper planting method for the phyto-restoration of TPH-treated soil. Rye (Secale cereale) was selected as test species through a germination test, among 5 other plants. Five 7-day-old rye seedlings were planted in a plastic pot, 20 cm in height and 15 cm in diameter. The pot was filled with TPH-treated soil (residual TPH of 1,118 mg/kg) up to 15 cm, and upper 5 cm was filled with horticulture soil to prevent TPH toxic effects and to act as root growth zone. The planted pot was cultivated in a greenhouse for 38 days along with the control that rye planted in a normal soil and the blank with no plants. After 38 days, the above-ground biomass of rye in the TPH-treated soil was 30.6% less than that in the control, however, the photosynthetic activity of the leaf remained equal on both treatments. Soil DHA (dehydrogenase activity) increased 186 times in the rye treatment compared to 10.8 times in the blank. The gross TPH removal (%) in the planted soil and the blank soil was 34.5% and 18.4%, respectively, resulting in 16.1% increase of net TPH removal. Promotion of microbial activity by root exudate, increase in soil permeability and air ventilation as well as direct uptake and degradation by planted rye may have contributed to the higher TPH removal rate. Therefore, planting rye on the TPH-treated soil with the root growth zone method showed both the potential of restoring biological soil properties and the possibility of residual TPH removal that may allow the recycle of the treated soil to farmlands.

• Korean Journal of Microbiology
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• 제47권4호
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• pp.356-363
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• 2011

The accidental releases of total petroleum hydrocarbons (TPH) due to oil spills frequently ended up with soil and ground water pollution. TPH may be degraded through physicochemical and biological processes in the environment but with relatively slow rates. In this study an attempt has been made to develop an integrated chemical and biological treatment technology in order to establish an efficient and environment-friendly restoration technology for the TPH contaminated soils. A Fenton-like reaction was employed as a preceding chemical treatment process and a bioaugmentation process utilizing a diesel fuel degrader consortium was subsequently applied as a biological treatment process. An efficient chemical removal of TPH from soils occurred when the surfactant OP-10S (0.05%) and oxidants ($FeSO_4$ 4%, and $H_2O_2$ 5%) were used. Bioaugmentation of the degrader consortium into the soil slurry led to an increase in their population density at least two orders of magnitude, indicating a good survival of the degradative populations in the contaminated soils ($10^8-10^9$ CFU/g slurry). TPH removal efficiencies for the Fenton-treated soils increased by at least 57% when the soils were subjected to bioaugmentation of the degradative consortium. However, relatively lower TPH treatment efficiencies (79-83%) have been observed in the soils treated with Fenton and the degraders as opposed to the control (95%) that was left with no treatment. This appeared to be due to the presence of free radicals and other oxidative products generated during the Fenton treatment which might inhibit their degradation activity. The findings in this study will contribute to development of efficient bioremediation treatment technologies for TPH-contaminated soils and sediments in the environment.

• Journal of the Korean GEO-environmental Society
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• 제17권11호
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• pp.35-43
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• 2016

In this study, by using a Effective Microorganisms Brewing Cycle, it confirmed the purification effect of pollutants that are adsorbed on the basins stench removal and retarding soil. On the basis of on-site application test, a soil decontamination system will be suggested. Using a Effective Microorganisms Brewing Cycle, the odor concentration is reduced 2.5 times than that of natural purification treatment method. It was measured and found that the quality of the pore water discharged from the soil is improved. In addition, it was found that a composite of copper and lead with the fermentation microorganisms adsorbed on soil particles from the surface of the stirred experiments lagoon mixed soil is reduced to 65% and 66%, respectively, The TPH organic component was confirmed that the reduction effect of 85%. Restoration of reservoir contaminated soils using the effective microorganism brewing cycle needs to be more developed and implemented as a long-term purification system. This study may be a good reference of developing more complete microorganism brewing system which will efficiently reduce the odor and soil contamination based on optimal stirring and mixing ratio of the compound solutions and contaminated soils in reservoir.

• Journal of the Korean Society for Marine Environment & Energy
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• 제11권2호
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• pp.63-69
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• 2008

As a basic study on the creation of artificial tidal flats using dredged sediments, the pilot-scale artificial tidal flats with 4 different mixing ratio of ocean dredged sediment were constructed in Nakdong river estuary. The phragmites australis was transplanted from the adjacent phragmites australis community after construction, and then the survival and growth rate of the planted phragmites australis were measured. Also the changes of soil chemical oxygen demand (COD), ignition loss (IL), and the heterotrophic microbial numbers were monitored. The survival rate of the planted phragmites australis decreased as the mixing ratio of dredged sediment increased but there was little difference of length and diameter of the shoots. 30% of COD and 9% of IL in the tidal flat with 100% dredged sediment decreased after 202 day, however, fluctuations of COD and IL concentrations were also observed possibly due to the open system. It was suggested that the construction of tidal flats using ocean dredged sediment and biological remediation of contaminated ocean dredged sediment can be possible considering the growth rate of transplanted phragmites australis, decrease of organic matter and increased heterotrophic microbial number in the pilot plant with 100% dredged sediment. However, the continuous monitoring on the vegetation and various environmental factors in the artificial tidal flat should be necessary to evaluate the success of creation of artificial flats using dredged sediments.

• Microbiology and Biotechnology Letters
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• 제34권2호
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• pp.83-93
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• 2006

In heavily industrialized areas, soil sites are contaminated with high concentrations of heavy metals. These pollutants are highly accumulated to the human body through the food web and cause serious diseases. To remove heavy metals from the soil, a potential strategy is the environmental friendly and cost effective phytoremediation. For the enhancement of remediation efficiency, the symbiotic interaction between the plant and plant growth-promoting rhizobacteria (PGPR) has been attended. In this review, the interaction of the plant and PGPR in the heavy metal-contaminated soil has been reviewed. The physicochemical and biological characteristics of the rhlzosphere can influence directly or indirectly on the biomass, activity and population structure of the rhizobacteria. The root exudates are offered to the soil microbes as useful carbon sources and growth factors, so the growth and metabolism of rhizobacteria can be promoted. PGPR have many roles to lower the level of growth-inhibiting stress ethylene within the plant, and also to provide iron and phosphorus from the soil to plant, and to produce phytohormone such as indole acetic acid. The plant with PGPR can grow better in the heavy metal contaminated soil. Therefore higher efficiency of the phytoremediation will be expected by the application of the PGPR.

• Korean Journal of Environmental Agriculture
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• 제33권2호
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• pp.78-85
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• 2014

BACKGROUND: Recent studies using various industrial wastes for heavy metal stabilization in soil were conducted in order to find out new alternative amendments. The acid mine drainage sludge(AMDS) contains lots of metal oxides(hydroxides) that may be useful for heavy metal stabilization not only waste water treatment but also soil remediation. The aim of this study was to investigate the applicability of acid mine drainage sludge for heavy metals stabilization in soils METHODS AND RESULTS: Alkali soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine sites nearby. Three different amounts(1%, 3%, 5%) of AMDS were applied into control soil and contaminated soil. For determining the changes in the extractable heavy metals, $CaCl_2$ and Mehlich-3 were applied as chemical assessments for metal stabilization. For biological assessments, lettuce(Lactuca sativa L.) and chinese cabbage(Brassica rapa var. glabra) were cultivated and accumulation of heavy metals on each plant were determined. It was revealed that AMDS reduced heavy metal mobility and bioavailability in soil, which resulted in the decreases in the accumulation of As, Cd, Cu, Pb, and Zn in each plant. CONCLUSION: Though the high level of heavy metal concentrations in AMDS, any considerable increase in the heavy metal availability was not observed with control and contaminated soil. In conclusion, these results indicated that AMDS could be applied to heavy metal contaminated soil as an alternative amendments for reducing heavy metal mobility and bioavailability.

• Microbiology and Biotechnology Letters
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• 제39권3호
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• pp.301-307
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• 2011

Oil pollution was world-wide prevalent treat to the environment, and the physic-chemical remediation technology of the TPH (total petroleum hydrocarbon) contaminated soil had the weakness that its rate was very slow and not economical. Bioremediation of the contaminated soil is a useful method if the concentrations are moderate and non-biological techniques are not economical. The aim of this research is to investigate the influence of additives on TPH degradation in a diesel contaminated soil environment. Six experimental conditions were conduced; (i) diesel contaminated soil, (ii) diesel contaminated soil treated with microbial additives, (iii) diesel contaminated soil treated with microbial additives and the mixture was titrated to the end point of pH 7 with NaOH, (iv) diesel contaminated soil treated with microbial additives and accelerating agents and (v) diesel contaminated soil treated with microbial additives and accelerating agents, and the mixture was titrated to the end point of pH 7 with NaOH. After 10 days, significant TPH degradation (67%) was observed in the DSP-1 soil sample. The removal of TPH in the soil sample where microbial additives were supplemented was 38% higher than the control soil sample during the first ten days. The microbial additives were effective in both the initial removal rate and relative removal efficiency of TPH compared with the control group. However, various environmental factors, such as pH and temperature, also affected the activities of microbes lived in the additives, so the pH calibration of the oil-contaminated soil would help the initial reduction efficiency in the early periods.

• Journal of Soil and Groundwater Environment
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• 제14권2호
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• pp.33-44
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• 2009

The objective of the study was to develop a hybrid technology integrating biological and physicochemical technologies to efficiently remediate arsenic contaminated lands such as abandoned mine area. The tailing soil samples contaminated with As at a high level were obtained from Songchon abandoned mine, and the content of arsenic and heavy metals as well as physicochemical properties and mineral composition were investigated. In addition, two sets of sequential extraction methods were applied to analyze chemical speciations of arsenic and heavy metals to expect their leachability and mobility in geoenvironment. Based on these geochemical data of arsenic and heavy metal contaminants, column-type experiments on the bioleaching of arsenic were undertaken. Subsequently, experiments on the hybrid process incorporating bioleaching and electrokinetics were accomplished and its removal efficiency of arsenic was compared with that of the individual electrokinetic process. With the results, finally, the feasibilty of the hybrid technnology was evaluated. The arsenic removal efficiencies of the individual electrokinetic process (44 days) and the hybrid process incorporating bioleaching (28 days) and electrokinetics (16 dyas) were measured 57.8% and 64.5%, respectively, when both two processes were operated in an identical condition. On the contrary, the arsenic removal efficiency during the bioleaching process (28 days) appeared relatively lower (11.8%), and the result indicates that the bioleaching process enhanced the efficacy of the electrokinetic process as a result of mobilization of arsenic rather than removed arsenic by itself. In particular, the arsenic removal rate of the electrokinetics integrated with bioleaching was observed over than 2 times larger than that obtained by the electrokinetics alone. From the results of the study, if the bioleaching which is considered a relatively economic process is applied sufficiently prior to electrokinetics, the removal efficiency and rate of arsenic can be significantly improved. Consequently, the study proves the feasibility of the hybrid process integrating both technologies.

• Journal of Korean Society of Environmental Engineers
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• 제37권7호
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• pp.432-440
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• 2015

Biochar, a by-product from pyrolysis of biomass, is a promising option to mitigate climate change by increasing soil carbon sequestration. This material is also considered to have potential to remediate a soil with heavy metal pollution by increasing the soil's adsorptive capacity. This study conducted the assessment of two biochars considering the climate change mitigation potential and heavy metal removal capacity at the same time. Two kinds of biochars (BC_Ch, TW_Ch) were prepared by pyrolyzing the biomass of burcucumber (BC_Bm) and tea waste (TW_Bm). The soils polluted with Pb were mixed with biochars or biomass and incubated for 60 d. During the incubation, $CO_2$, $CH_4$, and $N_2O$ were regularly measured and the soil before and after incubation was analyzed for chemical and biological parameters including the acetate extractable Pb. The results showed that only the BC_Ch treatment significantly reduced the amount of Pb after 60 d incubation. During the incubation, the $CO_2$ and $N_2O$ emissions from the BC_Ch and TW_Ch were decreased by 24% and 34% compared to the BC_Bm and TW_Bm, respectively. The $CH_4$ emissions were not significantly affected by biochar treatments. We calculated the GWP considering the production of amendment materials, application to the soils, removal of Pb, and soil carbon storage. The BC_Ch treatment had the most negative value because it had the higher Pb adsorption and soil carbon sequestration. Our results imply that if we apply biochar made from burcucumber, we could expect the pollution reduction and climate change mitigation at the same time.