학회소개 한국생물공학회

장호남 한국공학교육학회 1994 Ingenium(人材니움) Vol.1 No.2

교수는 방향만 조언할 뿐, 네 몫이다

장호남 샘터사 1997 월간 샘터 Vol.28 No.3

인공신장을 위한 셀룰로즈 격막의 평가

장호남,서진호 한국화학공학회 1978 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.16 No.3

전하나 흡착능이 거의 없는 셀룰로즈 격막의 물질전달에 관한 특성을 혈액투석기 설계를 위해서 조사하였다. 유니온 셀로판회사(한국)에서 제조한 셀로판 격막의 총괄격막 저항계수를 이중(二重) 폐쇄투석장치에 의해서 구했다. 혈류속도, dialyzate속도 및 분자크기가 총괄저항계수에 미치는 영향도 아울러 살펴 보았다. Ultrafiltration 실험은 Amicon ultrafilter를 사용하여 행하였고 용질 거부계수는 분자량 60에서 44,000까지의 범위에 걸쳐서 구했다. 분자반경(Stokes-Einstein 반경)이 격막의 저항계수를 추정하는데 있어서 분자량 보다 더 합당한 인자임을 알았다. 셀룰로즈 격막에 대한 관계식은 다음과 같다. 격막 1(22μ 두께, 유니온 셀로판, 서울, 한국) log(R_0) =2.224(r_0) +7.745 격막 2(38μ 두께) log(R_0) = 1.326 log(r_0) +0.945 R_0 ; 총괄격막저항계수(min/㎝) r_0 ; Stokes-Einstein 반경 (Å) 격막 2로 만든 혈액투석기를 신부전환자에게 적용시켰다고 했을 때 환자내의 노폐물(요소, 크레아티닌)의 동력학을 two compartment 모델을 사용하여 전산기로 simulation 하였다. The mass transfer characteristics of cellulosic membranes nearly devoid of any charge or adsorption property were investigated in vitro for the design of hemodialyzer. Overall membrane resistance(O.M.R.) of cellophane produced by Union Cellophane(Seoul, Korea) was determined by a dual closed-loop dialysis technique with which the effects of blood flow rate, dialyzate flow rate and molecular size on O.M.R. were examined. Ultrafiltration experiment was performed by making use of Amicon ultrafilter with which solute rejection was determined covering M. W. 60 to 44,000. Solute radius(Stokes-Einstein radius) is found to be more reasonable parameter in estimating membrane resistance than molecular weight. The correlations for cellulosic membranes have the following formula. For membrane 1(22,μ thickness, Union Cellophane, Seoul, Korea) log (R_0) = 2.224 log (r_0)+0.745 For membrane 2(38μ thickness) log (R_0) = 1.326 log (r_0)+0.945 where R_0 : overall membrane resistance(min/㎝) r_0 : Stokes-Einstein radius,(Å). The kinetics of metabolic wastes(urea, creatinine) of the uremic patient treated by hemodialyzer made of membrane 2(37㎛ dry thickness, Union Cellophane, Seoul, Korea) was simulated with computer using a two compartment model.

국산품을 아껴주자

장호남 한국화학공학회 1985 NICE Vol.3 No.2

두 고정화 효소 충전 반응탑에 대한 준 최적화 방법

장호남 한국화학공학회 1978 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.16 No.2

두 개의 고정화 효소를 사용한 충전 반응로에서 때때로 최적 방법으로 충전하는 것보다 준 최적 방법으로 충전하는 것이 실제 유리할 때가 있다. 이런 일은 최적방법이 실험적으로 불가능하고 이론적으로만 가능할 때 흔히 일어난다. 최적 pH가 4.5인 고정화당화효소와 최적 pH가 7.0인 고정화 이성화효소를 두 효소의 안정도와 활성도를 감소시키지 않고서는 한 반응탑에 사용될 수가 없다. 그러나 단속충전방법(bang-bang or bang-bang-bang)을 사용하면 두 효소에 따로 따로 최적조건을 맞춰줄 수 있어 안정성이나 활성도에 지장이 없게되고 수율도 최적조건이 이론적으로 추측한 값에 못미치나 상당히 근사한 값에 이르게 된다. 본 연구에서는 위의 준 최적반응중의 일부를 효소 불활성화를 고려치 않은 조건에서 실험과 이론으로 시험했고, 그 외의 충전방법에 대해서는 이론적으로 효소의 불활성을 고려하여 조사한 결과 과당시럽의 최적생산은 단속충전방법이 최선의 방법중의 하나임을 알아내었다. A properly chosen suboptimal policy for catalyst distribution in a two-enzyme packed bed reactor is sometimes better than optimal policy itself in actual cases. This often occurs when optimal policy is only theoretically possible and experimentally infeasible. Immobilized glucoamylase (=G.A.) with optimum pH 4.5 and immobilized glucose isomerase(G.I.) with optimum pH 7.0 cannot be mixed without sacrificing the activities and the stabilities of two immobilized enzymes. However utilizing suboptimal policies such as bang-bang policy (maximization of product) and bang-bang-bang policy (minimization of reactant) would permit two immobilized enzymes in separate reactors where optimum environments for G.A. and G.I. could be provided. The partial experimental investigation of the above suboptimal policies was conducted using immobilized G.A. and immobilized G.I. at the temperature of 40℃ and pH 6.5 where no appreciable decay in the activities of both emzymes could take place. The simulated results of suboptimal policies in a reactor undergoing decay of enzyme activity showed that the predicted conversions using bang-bang policy were comparable to the theoretical conversions of the optimal bed policy and it should be one of the best policy for the maximum production of fructose syrup in practice.

생물화공에서의 분리기술 ; 생물분리공정

장호남 한국화학공학회 1989 NICE Vol.7 No.2

Modeling of Poly(3-hydroxybutyrate)Production by High Cell Density Fed-batchCulture of Ralstonia eutropha

장호남,김문일,Longan Shang,Dai Di Fan,Jin-dal-rae Choi 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.4

High cell density culturing has been conducted for the production of poly(3-hydroxybutyrate) fed-batch cultures of Ralstonia eutropha with phosphate limitation. It was found that a high glucose concentration inhibited the synthesis of P(3HB) in the high cell density culture of R. eutropha. Although a low glucose concentration can trigger the synthesis of P(3HB) in a manner similar to that of phosphate limitation, it also limited both the P(3HB) synthesis and the cell growth, and led to a low P(3HB) productivity because glucose is the sole carbon source in this reaction. An unstructured model was proposed for predicting the cell growth and P(3HB) synthesis in high cell density cultures of R. eutropha, where the phosphate concentration played a key role in the accumulation of P(3HB) and in cell growth. Good agreements were found between the experimental data and model predictions. The results of simulation showed that the final P(3HB) concentration would decrease more than 25% when the glucose was concentration increased to 40 g/L, and indicated that the optimal glucose concentration for P(3HB) production by high cell density cultures of R. eutropha was around 9 g/L.

High Cell Density Ethanol Fermentation in an Upflow Packed-Bed Cell Recycle Bioreactor

장호남,박중곤,Byoung Jin Kim,Jong Won Kang,Chang Moon Jeong,Nag-Jong Kim 한국생물공학회 2008 Biotechnology and Bioprocess Engineering Vol.13 No.2

An upflow packed-bed cell recycle bioreactor (IUPCRB) is proposed for obtaining a high cell density. The system is comprised of a stirred tank bioreactor in which cells are retained partially by a packed-bed. A 1.3 cm (ID) × 48 cm long packed-bed was installed inside a 2 L bioreactor (working volume 1 L). Continuous ethanol fermentation was carried out using a 100 g/L glucose solution containing Saccharomyces cerevisiae (ATCC 24858). Cell retention characteristics were investigated by varying the void fraction (VF) of the packed bed by packing it with particles of 0.8~2.0 mm sized stone, cut hollow fiber pieces, ceramic, and activated carbon particles. The best results were obtained using an activated carbon bed with a VF of 30~35%. The IUPCRB yielded a maximum cell density of 87 g/L, an ethanol concentration of 42 g/L, and a productivity of 21 g/L/h when a 0.5 h-1 dilution rate was used. A natural bleeding of cells from the filter bed occurred intermittently. This cell loss consisted of an average of 5% of the cell concentration in the bioreactor when a high cell concentration (approximately 80 g/L) was being maintained.

Nitrate Removal in a Packed Bed Reactor Using Volatile Fatty Acids from Anaerobic Acidogenesis of Food Wastes

장호남,김은영,안영희,Seong Jin Lim 한국생물공학회 2006 Biotechnology and Bioprocess Engineering Vol.11 No.6

A packed bed reactor (PBR) was fed with nitrate containing synthetic wastewater or effluent from a sequencing batch reactor used for nitrification. The C source introduced into the PBR consisted of volatile fatty acids (VFAs) produced from anaerobic acidogenesis of food wastes. When nitrate loading rates ranged from 0.50 to 1.01 kg N/m3·d, the PBR exhibited 100~98.8% NO3--N removal efficiencies and nitrite concentrations in the effluent ranged from 0 to 0.6 NO2--N mg/L. When the PBR was further investigated to determine nitrate removal activity along the bed height using a nitrate loading rate less than 1.01 kg N/m3·d, 100% nitrate removal efficiency was observed. Approximately 83.2% nitrate removal efficiency was observed in the lower 50% of the packed-bed height. When reactor performance at a C/N ratio of 4 and a C/N ratio of 5 was compared, the PBR showed better removal efficiency (96.5%) of nitrate and less nitrite concentration in the effluent at the C/N ratio of 5. VFAs were found to be a good alternative to methanol as a carbon source for denitrification of a municipal wastewater containing 40 mg-N/L.

특별강연발표초록 : Biomedical Engineering - 화학공학자의 역할

장호남 한국화학공학회 1976 추계총회초록집 Vol.- No.-