• Korean Journal of Microbiology
• /
• v.47 no.4
• /
• pp.356-363
• /
• 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.

• Korean Journal of Microbiology
• /
• v.53 no.3
• /
• pp.233-233
• /
• 2017

• 한국생물공학회:학술대회논문집
• /
• 2004.07a
• /
• pp.107-125
• /
• 2004

A bioremediation of petroleum-contaminated soil in Korea was evaluated for the optimization of enhanced biodegradation and the minimization of effects of seasonal variations, The short-term bioremediation in combination of biopile pretreatment and landfarming was performed by lowering contaminated levels and overcoming the inhibiting factors in the rainy and winter seasons. A microbial density was maintained with indigenous microbial addition for bioaugmentation and with fertilizers for biostimulation. A lesser volatile and biodegradable fraction due to their abiotic removals following the biopile pretreatment was effectively removed by the laterally applied landfarming. The optimal temperature in greenhouse was maintained by buffering of the soil temperature even with slight decreases in removal rates during the winter and extensive leaching of nutrients and contaminants was restricted with adjusting the water contents during the Korean rainy season. Although the tilling process was effective for biodegradation with aeration only, the simultaneous treatment due to apparent mixing of nutrients and microbes more favorably degraded the petroleum than the sequential treatment.

• Progress in Superconductivity and Cryogenics
• /
• v.25 no.3
• /
• pp.7-12
• /
• 2023

Isolation of pollutant-degrading bacteria is important in bioaugmentation, one of the methods for biological degradation of environmental contaminants. We focused on the magnetic activated sludge (MAS) process as a culture method that efficiently concentrates degrading bacteria, and cultured activated sludge with 1,4-dioxane as a model pollutant. After 860 days of operation, MLVSS, which indicates the amount of sludge, increased from 390 mg/L to 10,000 mg/L, and the removal rate of organic matter including 1,4-dioxane, tetrahydrofuran, and glucose in the artificial wastewater reached up to 97%. Based on these results, the MAS process was successfully used to acclimate activated sludge with 1,4-dioxane. Bacterial flora analysis in the MAS showed that bacteria of the genus Pseudonocardia, already reported as 1,4-dioxane degrading bacteria, play an important role in the degradation of this pollutant. The MAS process is a suitable culture method for acclimation of environmental pollutants, and the findings indicate that it can be used as an enrichment unit for pollutant-degrading bacteria.

• Environmental Engineering Research
• /
• v.20 no.4
• /
• pp.356-362
• /
• 2015

Many burial sites were constructed in a short time to prevent the rapid spread of foot and mouth disease in infected livestock carcasses in Korea. More than 4,700 carcass burial sites were constructed in 2011. Approximately seven million poultry and 3.5 million livestock, including cattle and swine, were buried on farmland. Some burial sites were suspected of leachate leakage and were excavated and carcasses redisposed in a bioaugmentation process. This study performed interviews in order to understand the economic issues related to carcass burial and redisposal. The internal data from local government and the assumption data from online sites were analyzed to evaluate the costs; the focus was on burial site construction. The results showed that the local government paid $4.7 and $10.9 per carcass for traditional burial and redisposal. The comparable costs shown online were $4.5. This study found that the standard operating procedures should be carried out to reduce environmental impact and avoid additional costs. We estimated that the cost could be reduced by the advance preparations of materials against the emergency situations such as catastrophe of epidemics. In addition, the innovative technology for the stabilization of carcasses should be established through a future study.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.207-210
• /
• 2004

Effect of electron accepters on anaerobic degradation of petroleum hydrocarbons by an anaerobic sludge taken from a sludge digestion tank in a soil artificially contaminated with 10,000 mg/kg soil of diesel fuel was tested. Treatments of soil with 30 mL of the digestion sludge (2,000 mg/L of vss (volatile suspended solids)) were incubated under several anaerobic conditions including nitrate reducing, sulfate reducing, methanogenic, and mixed electron accepters conditions for 120 days. Treatments with the digested sludge showed significant degradation of diesel fuel under all anaerobic conditions compare to control treatments with an autoclaved sludge and without the sludge. The amount of TPH degradation after 120days incubation was the largest in the treatment with the sludge and mixed electron accepters (75% removal of TPH) followed in order by sulfate reducing, nitrate reducing, methanegenic condition as 67%, 53％, 43%, respectively. However, the rate of TPH degradation in the nitrate- and sulfate reducing condition within 105 days were comparable with that of the mixed electron accepters condition. Microorganisms in each electron acceptor condition were plated on solid mediums containing nitrate or sulfate as sole electron acceptor and several nitrate- and sulfate reducing bacteria showed effective degradation of diesel fuel within 30 days incubations. These results suggest that anaerobic degradation of diesel fuel in soil with digested sludge is effective for practical remediation of soil contaminated with petroleum hydrocarbons.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.1
• /
• pp.79-87
• /
• 2005

세계적으로 가장 널리 사용되는 제초제의 하나인 EPTC(s-ethyl-N,N'- dipropylthiocarbamate)에 대하여, 이를 분해하는 미생물의 토양 내에서의 직접 증식과 이를 함유한 토양(INOCULUM)의 토양내 EPTC 분해촉진을 위한 접종재(inoculant)로서의 효용성을 조사하였다. 한 차례의 EPTC(20mg EPTC/kg 토양)처리에 의해, 순수분리 없이 토양 내에서, EPTC-분해 미생물의 수가 $10^2$ 수준에서 $10^5$ 수준으로 약 $10^3$배 증식되었으며, EPTC 분해속도 또한, 토양으로부터 추출 가능한 EPTC가 초기 EPTC농도(20mg EPTC/kg 토양)의 20%까지 떨어지는데 걸리는 시간을 기준으로 할 때, EPTC처리 전의 20여 일에서 EPTC 처리 후에는 1일 이내로 빨라졌고, 이 토양의 EPTC 분해능력은 토양내의 EPTC 초기농도가 토양 kg당 2,000mg일 때까지도 크게 저해되지 않았다. 이 토양(INOCULUM)을 EPTC로 오염된 토양에 접종(0.05-5%, w/w)하였을 때, 오염된 토양 내에서의 EPTC 분해속도가 크게 향상되었다. 이 토양의 EPTC 분해능력은, 저온($10^{\circ}C$ 이하)의 습한 상태(수분함량 25%)에 보관하였을 때, 최소 6개월간 유지되었다. 본 연구는 EPTC-분해 미생물이 토양 내에서 쉽게 증식됨과, 이를 함유하는 토양(INOCULUM)이 토양내의 EPTC 분해 촉진을 위한 접종재로서 매우 효과적임을 확인하였고, 이 같은 방법은 다른 화합물과 그에 오염된 토양에도 적용될 수 있을 것으로 기대된다.

• Journal of Mushroom
• /
• v.12 no.3
• /
• pp.163-170
• /
• 2014

The potential ability of Button mushroom compost (BMC) to solubilize heavy metals was estimated with metal contaminated soils collected from abandoned mines of Boryeong area in South Korea. The bacterial strains in BMC were isolated for investigating the mobilization of metals in soil or plant by the strains and identified according to 16S rRNA gene sequence analysis. When metal solubilization potential of BMC was assessed in a batch experiment, the BMC was found to be capable of solubilizing metals in the presence of metals (Co, Pb and Zn) and the results showed that inoculation of BMC could increase the concentrations of water soluble Co, Pb and Cd by 35, 25 and 45% respectively, than those of non-inoculated soils. BMC-assisted growth promotion and metal uptake in sunflower (Helianthus annuus) was also evaluated in a pot experiment. In comparison with non-inoculated seedlings, the inoculation led to increase the growth of H. annuus by 27, 25 and 28% respectively in Co, Pb and Zn contaminated soils. Moreover, enhanced accumulation of Co, Pb and Zn in the shoot and root systems was observed in inoculated plants, where metal translocation from root to the above-ground tissues was also found to be enhanced by the BMC. The apparent results suggested that the BMC could effectively be employed in enhancing phytoextraction of Co, Pb and Zn from contaminated soils.

• Journal of Soil and Groundwater Environment
• /
• v.21 no.5
• /
• pp.8-15
• /
• 2016

Bioremediation, which uses microbes to degrade most organic pollutants in soil and groundwater, can be used in solving environmental issues in various polluted sites. In this research, a wind-driven bioventing system is built to degrade about 20,000 mg/kg of high concentration diesel pollutants in soil-pollution mode. The wind-driven bioventing test was proceeded by the bioaugmentation method, and the indigenous microbes used were Bacillus cereus, Achromobacter xylosoxidans, and Pseudomonas putida. The phenomenon of two-stage diesel degradation of different rates was noted in the test. In order to interpret the results of the mode test, three microbes were used to degrade diesel pollutants of same high concentration in separated aerated batch-mixing vessels. The data derived thereof was input into the Haldane equation and calculated by non-linear regression analysis and trial-and-error methods to establish the kinetic parameters of these three microbes in bioventing diesel degradation. The results show that in the derivation of μ_m (maximum specific growth rate) in biodegradation kinetics parameters, K_s (half-saturation constant) for diesel substance affinity, and K_i (inhibition coefficient) for the adaptability of high concentration diesel degradation. The K_s is the lowest in the trend of the first stage degradation of Bacillus cereus in a high diesel concentration, whereas K_i is the highest, denoting that Bacillus cereus has the best adaptability in a high diesel concentration and is the most efficient in diesel substance affinity. All three microbes have a degradation rate of over 50% with regards to Pristane and Phytane, which are branched alkanes and the most important biological markers.

• Journal of Soil and Groundwater Environment
• /
• v.18 no.2
• /
• pp.1-9
• /
• 2013

The landfarming treatment for the remediation of the petroleum contaminated soil at the returned U.S. Military bases was investigated in this study. Specifically, the bioaugmentation performance using various commercially available petroleum-degrading bacteria was evaluated and the directions for enhancing the performance of the landfarming treatment were suggested. The environmental factors of the soils at the returned U.S. Military bases chosen for remediation indicate that the landfarming treatment can be used as the remediation technique; however, the addition of nitrogen or phosphorus is required. The lab-scale landfarming treatment tests using the model soil and the site soil showed that the degradation efficiency was greater with the model soil than the site soil and that the treatment performance was not affected by the number of bacteria present in the soil in the range of $10^6-10^{12}$ CFU/g. These results suggest that the successful landfarming treatment depends on the petroleum degradability of bacteria used and the environmental conditions during the treatment rather than the number of petroleum-degrading bacteria used.