Effects of polyamines on chlorophyll and protein content, and δ-aminolevulinate dehydratase(ALAD) activity were investigated during the greening of mung bean cotyledons. Polyamines stimulated chlorophyll formation in greening cotyledons, and this effect was enhanced by KCl. The changes in protein content were similar to the changes for chlorophyll content. The excision entailed an increase in ALAD activity. Then a decrease appeared after 48 h incubation on water in the dark. It was more precocious in the light, but was accelerated when the cotyledons were illuminated after a dark preincubation. Putrescine had little effect on ALAD activity in the dark. In the light, putrescine prevented the decrease in ALAD activity and enhanced this activity when a dark preincubation preceded illumination. KCl had a slight stimulating effect in the dark, but was uneffective in the light. The combination putrescine+KCl was devoid of stimulating effect. The results obtained suggest that plastid development of mung bean cotyledons during greening was affected by polyamines and light and that polyamines may play a role in the regulation of plastid development.
Optimal biodegradation kinetics models to the initial nonylphenol ethoxylates-30 concentration were investigated and had been fitted by the linear regression. Microorganisms capable of degrading nonylphenol ethoxylates-30 were isolated from sewage near Ulsan plant area by enrichment culture technique. Among them, the strain designated as EL-10K had the highest biodegradability and was identified as Pseudomonas from results of taxonomical studies. The optimal conditions for the biodegradation were 1.0 g/l of nonylphenol ethoxylates-30 and 0.02 g/l of ammonium nitrate at pH 7.0 and 30℃. The highest degradation rate of nonylphenol ethoxylates-30 was about 89% for 30 hours incubation on the optimal condition. Biodegradation date were fit by linear regression to equations for 3 kinetic models. The kinetics of biodegradation of nonylphenol ethoxylates was best described by first order model for 0.1 ㎍/l nonylphenol ethoxylates-30 ; by Monod no growth model and Monod with growth model for 0.5 ㎍/ml and 1.0, 5.0 ㎍/ml, respectively.
Light qualities and three kinds of plant hormones, NAA, GA_3 and BA were treated on maize seedlings to investigate the effect on formation of the chlorophyll-protein complexes. Each three kinds of plant hormones accelerated the chlorophyll proteins formation, particularly LHCP-1 and LHCP-3, but two kinds of hormonal combinations didn`t promote these proteins accumulation under sun light condition. The formation of chlorophyll proteins of LHCP-1, CPA and LHCP-3 associated with PSⅡ was promoted under red light compared to sun light, on the contrary the formation of chlorophyll proteins was not affected by white light. Plant hormones under red light induced chlorophyll proteins formation associated with PSⅡ at early state of chloroplast development and two kinds of hormonal combinations under red light were very effective in accumulation of chlorophyll proteins of PSⅡ in contrast to sun light. The results obtained suggest that light may play an important role compared to plant hormones in the formation of chlorophyll proteins.
The COD values and chloride ion concentrations of the Taewha river flowing through Ulsan area were determined along the main stream and the relationships between CODs and chloride ion concentrations were described. The results showed that the middle-upper stream and downstream of the Taewha river were polluted deeply with municipal sewage and self-purification occured in the middle-downstream of the river. When domestic sewage is a main source of pollutants, and is especially the only source of chloride in the stream water, the ratio of COD/[Cl^-] will be utilizable as a measure of self-purification of the stream.
This study was aimed to evaluate the effects of effluent recycling on the UASB reactor performances at the various organic loading rates and influent substrate concentrations. The organic removal efficiency of the reactors operated with effluent recycle were above 85%. However, the efficiencies of the reactors operated without the recycle were below 40% even though the effort to increase the efficiencies was made by changing the influent substrate concentrations and the organic loading rates, and introducing the effluent recycle at the final stage of the experiment. It was realized that the certain amount of effluent recycling from the start-up stage in UASB reactors seemed to be necessary to provide the effective contact chances between the substrate and granular sludge for better performances of the UASB
Methane production from grain dust was studied using a 3 L laboratory-scale anaerobic plug flow digester. The digester was operated at; temperature of 35, 45, and 55℃ hydraulic retention time(HRT) of 6 and 12 days; and influent concentration(S_0) of 7.8 and 9.0 % total solids(%TS). With ten different operation conditions, this study showed the significant effects of temperature, hydraulic retention time, and influent concentration on methane production, The highest methane-production rate achieved was 1.903 (L methane) /(L digester)(day) at 55℃, 6 days HRT, and S_0 of 7.8 %TS. A total of 3.767 L of biogas per day with a methane content of 50.57% was obtained from this condition. The ultimate methane yield(B_0 was found to be a function of temperature and influent concentration, and was described as : B_0= 0.02907T-0.1263-0.00297(T-10)(%TS), where TS is the total solids in the liquid effluent, and T is temperature(℃). Our results showed that thermophilic condition is better than mesophilic for grain dust stabilization in an anaerobic plug flow digester.
Effluent recycling effect on UASB reactor performances is known as an important operational factor. In the present study, the possibility of intermittent recycle in UASB process for saving the power consumption was examined at different organic loading and various operational modes in recycle time period. The organic removal efficiencies of the reactors operated with the intermittent effluent recycle were considerably higher compared to those without the effluent recycle. In the intermittent recycle mode, the organic removal efficiencies slightly decreased as the non-recycle time period in the operational mode increased. Proper ratio of recycle and non-recycle time period in the mode seemed to be required to prevent the produced biogas from accumulation in the sludge bed, which caused dead zone in the reactor and sludge loss when the gas was escaped from the bed at the certain pressure.
A number of experiments were conducted in order to investigate the organic removal efficiency and biomass characteristics according to the organic shock loading rate in a fluidized bed biofilm reactor. At the operation conditions of HRT, 8.44 hour, superficial upflow velocity, 0.9 ㎝/sec and temperature, 22±1 ℃, the removal efficiency of SCOD was founded to be 96.5, 92 and 90 % with the organic shock loading rate of 3.5, 10.8 and 33 kgCOD/㎥·day, respectively. Within the F/M ratio ranged 0.4 to 2.0 ㎏COD/㎏VSS·day, the SCOD removal efficiency was shown as 90% at F/M ratio of 2.0 ㎏COD/㎏VSS·day, but the TCOD removal efficiency was 72 % at F/M ratio of 1.8 kgCOD/kgVSS·day. The average biomass concentrations were 7800, 14950 and 27532 ㎎/l on the organic shock loading rate of 3.5, 10.8 and 33 ㎏COD/㎥·day, respectively. This result was agreed with the fact that more biomass could be produced at high concentration of substrate, but some biomass was detached at the onset of shock and easily acclimated at the shock condition.
A mathematical model for organic removal efficiency was investigated in a fluidized bed biofilm reactor by changing the feed flow rate, the residence time and the recycle flow rate. In batch experiment, organic removal could be assumed as first order and an intrinsic first order rate constant(kl) was found 6.4 x 10 exp (-6) ㎤/㎎ sec at influent COD range of 3040 - 6620 ㎎/L. In continuous experiment, at the condition of the influent COD, 3040 ㎎/L, the superficial upflow velocity, 0.47 ㎝/sec, the biofilm thickness 336 ㎛ and the biofilm dry density 0.091 g/mL, the calculated COD removal efficiency from the mathematical model gave 60 % which was very close to the observed value of 66 %. As the feed flow rate was increased, the COD removal efficiency was sharply decreased and at constant feed flow rate, the COD removal efficiency was decreased also as the residence time being decreased.
The amount of inorganic ions such as Na^+, K^+, Ca^2+, Mg^2+, NH_4^+, Cl^-, NO_3^-, and SO_4^2- in the precipitation at Chongwon area were analyzed during the period of February 1991 - June 1993. Ammonium ion was analyzed using Nessler and indophenol methods. Cations were determined by atomic absorption spectroscopy, and ion chromatography was used for anions. For the entire period of study, there was no particular ion which has significantly high correlation coefficient with hydrogen ion. The correlation between NO_3^-, and SO_4^2- was 0.6, which suggests that these ions may be from the same source. Most cations have high correlation with each other. In the seasonal analysis, the nitrate and sulfate ions have high correlations with the acidity in the fall and winter. The rain waters of Taeahn area showed usually high concentrations of the ions, even though the pH was much higher than that of Chongwon area. It is considered that the ions came as neutral salt in Taeahn, while NO_x and SO_x contributes largely to the acidity of rains in Chongwon.
The three natural zeolites collected in Yungil-gun, Kyungsangbuk-do, Korea, were analyzed by means of chemical wet methods and X-ray diffraction. The results indicated that the primary species of those zeolites were clinoptilolite mixed with heulandite, feldspar, montmorillonite, and quartz. These zeolites were chemically treated with NaOH, Ca(OH)_2, and HCl solution and their differences were also studied with X-ray diffraction method. The capabilities of removing Cs^+ and Sr^2+ ions with chemically untreated zeolites, chemically treated zeolites, and also with synthetic zeolites were compared. The effect of other cations in removing Sr^2+ ions was also studied. The experimental results showed that Cs+ and Sr^2+ ions could be removed up to 98% and 95% respectively out of 5 ppm with chemically untrearted natural zeolites. The treatment of 0.02N-Ca(OH)_2 and that of 2N-NaOH were most effective in removing Cs^+ and Sr^2+ ions, respectively. It was found that the mountaintop of Sangjung 1-dong natural zeolite treated with 2N-NaOH was most efficient in removing Sr^2+ ions mixed with other cations, compared with any other chemically treated and untreated natural zeolites in this work.
This study was conducted for the efficient utilization of biomaterials such as starch residue, tangerine skin, and green tea residue, which are agricultral by-products discarded in Cheju Province annually, as adsorbents and biomaterials were examined for their removal ability of heavy metal ions in waste water by batch adsorption experiments. The removal efficiency of biomaterials for heavy metal ions was above 80-90% and almost similar to activated carbon and the adsorption ability of those treated with 포르말린 was improved in the green tea residue only for Pb^2+, Cu^2+, and Zn^2+. In the conditions of pH, the removal efficiency of heavy metal ions was high in the range of 5-7. In the solutions which heavy metal ions were mixed, the removal efficiency was similar at Ag^+, Pb^2+ and reduced to about 10% at the other ions, as compared with the solutions they were not mixed. Adsorption isotherms of biomaterials was generally obeyed to Freundlich formular than Langmuir formular and Freundlich constant, 1/n were obtained in the range of 0.1-0.5.
Phytoplankton flora of Chinyang Lake and Hapchun Lake were studied. A total of 161 species(Chinyang Lake, 135 species; Hapchun Lake, 80 species) were identified. The major species of two lakes were Melosira granulate var. angustissima and M. italica. As the bloom causing species, Microcystis aeruginosa, Ceratium hirundinella, and Peridinium sp. were identified. The chlorophyll a concentration of Chinyang Lake was higher than Hapchun Lake.