• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.609-614
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• 2010

The effluent from anaerobic digestion contains organic nitrogen and phosphorus, which are both required for growth of Spirulina platensis. Effluent (20%) from the upflow anaerobic sludge blanket (UASB) from a pig farm, supplemented with 4.5 g/l sodium bicarbonate ($NaHCO_3$) and 0.2 g/l urea fertilizer (46:0:0, N:P:K), was found to be not only a suitable medium for the growth of Spirulina platensis but also a low-cost alternative. Cost calculation showed that this medium is 4.4 times cheaper than modifized Zarrouk's medium. The average productivities of a semi-continuous culture grown under outdoor conditions in a 6-1 scale and a 100-1 pilot scale were 19.9 $g/m^2/d$ and 12 $g/m^2/d$, respectively. In addition, the biomass of organisms grown in UASB effluent contained approximately 57.9% protein, 1.12% $\gamma$-linolenic acid, and 19.5% phycocyanin. The average rates of bicarbonate, total nitrogen, and phosphorus removal were 380 mg/l/d, 34 mg/l/d, and 4 mg/l/d, respectively.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1513-1520
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• 2013

Novel chitosan (CS) based membrane networks were developed by solution casting and followed by crosslinking with different crosslinkers such as glutaraldehyde, urea-formaldehyde, and thiourea-formaldehyde. The developed membrane networks were designated as CS-GA, CS-UF and CS-TF. Crosslinking reaction of CS membranes was confirmed by Fourier transform infrared spectroscopy. Membrane rigidity and compactness were studied by the differential scanning calorimetry. The surface morphology of CS membranes was characterized by scanning electron microscopy. The sorption behaviour with respect to contact time, initial pH and initial metal ion concentration were investigated. The maximum adsorption capacity of CS-GA, CS-UF and CS-TF sorbents was found to be 1.03, 1.2 and 1.18 mM/g for $Cu^{2+}$ and 1.48, 1.55 and 2.18 mM/g for $Ni^{2+}$ respectively. Swelling experiments have been performed on the membrane networks at $30^{\circ}C$. Desorption studies were performed in acid media and EDTA and it was found that the membranes are reusable for the metal ion removal for three cycles. The developed membranes could be successfully used for the separation of $Cu^{2+}$ and $Ni^{2+}$ metal ions from aqueous solutions.

• 대한화학회지
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• 제55권2호
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• pp.208-217
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• 2011

Maghnia montmorillonite clay를 이용하여, 두 가지 염료(neutral red; NR과 malachite green oxalates; MG)에 대한 pH 및 온도 효과를 측정하였다. 수용액 속에서 MG는 pH 3-9에서 흡수가 나타나는 반면에, 양이온 NR은 pH 3-5에서 red shift 흡수피크가 나타났으며, 중성 NR은 pH 8-12에서 흡수피크가 얻어졌다. NR에 대해서는 465.13 mg/g, MG에 대해서는 459.89 mg/g의 최대 흡수 피크가 각각 298와 318 K에서 얻어졌으며, 자유에너지 Ea 값은 각각 4.472-5.559 kJ/mol과 2.000-2.886 kJ/mol로 얻어졌다. 도한, as ${\Delta}H^{\circ}$, ${\Delta}S^{\circ}$, ${\Delta}G^{\circ}$ and Ea과 같은 다양한 열역학적인 변수들을 계산했으며, 전체적인 반응의 흡수과정은 자발적이고, 흡열반응으로 진행됨을 알 수 있었다.

• 한국환경과학회지
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• 제16권2호
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• pp.227-232
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• 2007

Water pollution in enclosed water bodies such as lake and river has become a serious problem over the world. Domestic wastewater is responsible for more than 60 % pollution load in public water area in Korea. Effluent of the treated domestic wastewater at low removal level is abundantly fed rivers and lakes and thus be an serious cause of lake pollution. Therefore, effective implement of domestic wastewater treatment in basin of lake and river must be prepared. The septic tank is one of the effective domestic wastewater treatment equipment and used in individual treatment for a unit of household, The purpose of septic tank as biological treatment system is simultaneously to remove BOD, T-N, T-P and reduce turbidity from influent. Accordingly, the appropriate control of functional microorganisms is important subject for the establishment of stability and economy of the biological treatment method. Especially, microanimals as a high-ranked microorganisms of food-chain are important, because microanimals control the other microorganisms especially various bacteria and effect on function of treatment. Therefore, it is necessary that functional predator like rotifers are attached in wastewater treatment process. In this study, the methods for attachment high density the rotifer to and improvement of transparency in the effluence by a dense rotifer was examined using laboratory scale biological treatment reactor simulated septic tank and real one.

• 한국농공학회논문집
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• 제55권2호
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• pp.77-85
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• 2013

The aim of this study is to investigate strength and water purification characteristics of effective microorganism-applied volcanic ash block using flexural strength test and water quality analysis. The specimens were prepared with volcanic ash from Mt. Baekdusan and Mt. Hallasan, and cement as the ratios of 3.5:1, 4.0:1, 4.5:1, 5.0:1 with and without metakaolin. Flexural strength degraded with increasing of the amount of volcanic ash, and increased with addition of metakaolin as a binder. Based on these results, the optimal ratio for fabricating volcanic ash-cement mixture block is determined as 3.5:1 with metakaolin. Furthermore, from water quality analysis on contaminated water, removal ability of effective microorganism-applied volcanic ash-cement mixture block and caged volcanic ash block against T-N, T-P and SS was highly evaluated because of adsorption due to the large specific surface area of volcanic ash. Hence, volcanic ash-cement mixture block and caged volcanic ash block possibly contribute to water purification.

• 대한의생명과학회지
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• 제9권4호
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• pp.241-248
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• 2003

Sodium salicylate, a plant stress hormone that plays an important role(s) in defenses against pathogenic microbial and herbivore attack, has been shown to induce a variety of cell responses such as anti-inflammation, cell cycle arrest and apoptosis in animal cells. p38MAPK plays a critical role(s) in the cell regulation by sodium salicylate. However, the signal pathway for sodium salicylate-induced p38MAPK activation is yet unclear. In this study, we show that although sodium salicylate enhances reactive oxygen species (ROS) production, N-acetyl-L-cysteine, a general ROS scavenger, did not prevent sodium salicylate-induced p38MAPK, indicating ROS-independent activation of p38MAPK by sodium salicylate. Sodium salicylate-activated p38MAPK appeared to be very rapidly down-regulated 2 min after removal of sodium salicylate. Interestingly, sodium salicylate-pretreated cells remained fully responsive to re-induction of p38MAPK activity by a second sodium salicylate stimulation or by other stresses, $H_2O$$_2$ and methyl jasmonate (MeJA), thereby indicating that sodium salicylate does not exhibit both homologous and heterologous desensitization. In contrast, pre-exposure to MeJA, $H_2O$$_2$, heat shock, or hyperosmotic stress reduced the responsiveness to subsequent homologous stimulation. Sodium salicylate was able to activate p38MAPK in cells desensitized by other heterologous p38MAPK activators. These results indicate that there is a sensing mechanism highly specific to sodium salicylate for activation of p38MAPK, distinct trom pathways used by other stressors such as MeJA, $H_2O$$_2$ heat shock, and hyperosmotic stress.

• 대한환경공학회지
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• 제35권1호
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• pp.57-63
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• 2013

고농도 질소를 함유한 하 폐수를 아질산염 축적 경로를 통하여 처리하고자 생물막공정과 연속혼합반응조의 탈질공정을 결합하여 운전하였다. 생물막 반응조의 폴리에틸렌 담체 표면에 아질산염 산화균에 비해서 암모늄 산화균의 성장을 촉진하여 아질산염을 선택적으로 축적하고자 반응조 온도를 $35^{\circ}C$로 유지하면서 석달 이상 장기간 운전하였음에도 불구하고 유입수 암모늄(500 mg-N/L)의 일부만 아질산염(240 mg-N/L)으로 전환되었다. 하지만 pH를 7.5에서 8.0으로 증가시켰을 때, 아질산염 산화균들이 높은 암모니아 농도에 성장 저해를 받아 생물막 공정에서 아질산염 축적을 성공적으로 이끌어낼 수 있었다. 생물막 공정의 수리학적 체류시간을 12시간으로 운전하였을 때, 반응조의 성능이 급격하게 저하되어 유입수의 암모늄이 완전히 산화되지 않았다. 하수슬러지의 생분해성을 높이기 위해서 다양한 가용화 기술을 적용한 결과, 알칼리와 초음파 처리를 순차적으로 병합하였을 때, 가장 높은 가용화율(58%)을 얻을 수 있었으며, 이를 탈질반응조의 외부탄소으로 사용하였다. FISH 분석결과로부터 담체표면에 암모늄 산화균인 Nitrosomonas와 Nitrospirar계열의 미생물들이 우점종이었으며 일부 아질산염 산화균인 Nitrobacter 계열의 미생물도 소량이지만 관찰되었다.

• 산업기술연구
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• 제20권A호
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• pp.57-62
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• 2000

This experiment was done to investigate the leaching and adsorption properties of heavy metals on porphyry. The comparison with respect to the leachability of heavy metals from porphyry between the Korea Standard Leaching Test (KSLT) and the Toxicity Characteristic Leaching Procedure (TCLP) was carried out. The fractional composition of leachate and the total concentration of heavy metal of porphyry were studied through Sequential Extraction Procedure (SEP) and EPA Method 3050. Adsorption experiment of porphyry has pointed out that the optimum dosage of porphyry for 50ppm Pb was over 10g/L, the effective particle size for absorption was below 200 mesh and the optimum pH was about 7. From the Freundlich' adsorption equation, 1/n was 1.0722, and k was 0.0041. After adsorption, the fractional composition of Pb was changed. The exchangeable, carbonate, reducible fractions were increased, and the organic fraction was not changed, and the residual fraction was decreased.

• 한국환경과학회지
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• 제16권6호
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• pp.699-706
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• 2007

Many lakes or irrigative reservoirs in Korea are rapidly contaminated due to the ever increasing pollutants. Although lots of treatment processes have been recommended and practiced, economical and technical improvement is currently needed. In this study, contaminated irrigation reservoir was treated using the proposed process which is consisted of fine air bubbles, coagulation and flotation. Fine bubbles, approximate diameter of 3 to $10{\mu}m$, were generated using cavitation in the pressurized tank and polyaluminum chloride was used as coagulants. This fine bubbles, coagulation and flotation effectively controlled the low density algae, for example, Chlorophyll-a was removed more than 97 %. Removal efficiency of COD, SS, T-N and T-P were 80.7%, 94.3%, 64.1 % and 92.4%, respectively. Pollutants released from the sediments was removed more than 80% of organics and 60-70 % of nutrients. Consequently, fine bubbles coagulation and flotation process could be effectively used as an alternative treatment method for the purpose of control of lake water quality.

• 한국환경과학회지
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• 제13권2호
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• pp.161-165
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• 2004

This study has been conducted to develop a new recycling technology of sewage sludge using a carbonization process. The carbonizing yield, the calorific value and EC(electric conductivity) of carbonized sewage sludge had a tendency to be decreased with increase of the carbonizing temperature and time, but pH and the C/N were increased with increase the carbonizing temperature and time. The whole pore volume of carbonized sludge processed in the carbonizing furnace was /g, which was smaller than that in the electric furnace. But, the rates of mesopore and macropore were found to account for 100% therein. Rate of color and organic materials removal for dyeing wastewater were determined 70~97%, 78~83% on cotton yarn, 88~96%, 69~80% on wool wastewater and 77~89%, 77~87% on towel compared with powder activated carbon. Effect of carbonized sludge on chrysanthemum growth was investigated. Plant height and number of leaves was better mixture of carbonized sludge than comparison.