• Journal of Environmental Science International
• /
• v.9 no.2
• /
• pp.145-149
• /
• 2000

The purpose of this study was to determine whether Vermi Cast could be used effectively to remove $SO_2$ from flue gas, and then to investigate optimum adsorption conditions. The Vermi Cast used as adsorbent was mechanically screened with 8~20 mesh sieve. The adsorption data for $SO_2$ were regressed using the Freundlich isotherm. The fit was generally satisfactory ($R^2$=0.945~0.982). With the temperature changes from 2$0^{\circ}C$ to 4$0^{\circ}C$, the constant k in Freundlich isotherm qe= $kCe^{1/n}$, decreased from 1.409 at 2$0^{\circ}C$to 0.297 at 4$0^{\circ}C$, and the exponent 1/n were decreased from 0.343 to 0.134. With the bed depth changes from 10cm to 30cm, the adsorption capacity expressed as mmol of $SO_2$ adsorbed per g of Vermi Cast increased from 0.247 to 0.381. Moisture content is an important parameter in the $SO_2$ adsorbed were observed over 0.3mmol $SO_2$ /g Vermi Cast. The best adsorption capacity was 0.487mmol $SO_2$ /g Vermi Cast, and it was obtained with moisture content 37%, temperature 2$0^{\circ}C$. From the above results, ti might be concluded that Vermi Cast is effectively as a good adsorbent to remove $SO_2$ from flue gas.

• Journal of Korean Society for Atmospheric Environment
• /
• v.10 no.4
• /
• pp.245-251
• /
• 1994

We considered that characteristics of SO$_2$, concentration level and relations of the meteorological parameters and high pollution concentration from the data measured 7 air quality continuous monitoring stations during 4 years, from 1990 to 1993 in Pusan. The SO$_2$ concentration level showed decreasing trend yearly, it was maximum in Winter, minimum in Summer. The time of SO$_2$ peak concentration lagged from seashore to land because of break-down of the nocturnal inversion layer and seabreeze. Ihe correlations of daily SO$_2$, value between various air quality continuous monitoring stations were highest between Beomcheondong and Meongryundong, lowest between Daeyeondong and Sinpyeongdong because of difference of air Pollution emission sources characteristic. The meteorological parameters affecting SO$_2$ concentration level were minimum temperature, relative humidity, wind speed and air pressure. The SO$_2$ high pollution($\geq$95ppb) occurred almost in Winter, particulaly in such day showing lower wind speed and higher air pressure. Elementary SO$_2$ high Pollution Predictor were high pressure system and stability of lower atmosphere.

• Journal of Nutrition and Health
• /
• v.17 no.1
• /
• pp.60-67
• /
• 1984

Inhibiting action of sulfur dioxide $(SO_{2})$ on enzymatic discoloration was investigated with crude enzyme preparations from homogenized tissues or sliced disks of raw potato tubers. $SO_{2}$ appeared to inhibit the formation of dopachrome in a competitive manner. At insufficient concentrations of $SO_{2}, the formation of dopachrome was reinitiated as time elapsed. The present results suggested that $SO_{2}$ would form an additional compounds with certain intermediate during the course of enzymatic browning and delay the enzymatic discoloration. To inhibit the production of dopachrome in sliced disks of raw potato tubers, much higher concentrations of $SO_{2}$ were required than homogenized tissues.

• Membrane and Water Treatment
• /
• v.3 no.1
• /
• pp.63-76
• /
• 2012

Mother liquid discharged from a salt-manufacturing plant was electrodialyzed at 25 and $40^{\circ}C$ in a continuous process integrated with $SO_4{^{2-}}$ ion low-permeable anion-exchange membranes to remove $Na_2SO_4$ and recover NaCl in the mother liquid. Performance of electrodialysis was evaluated by measuring ion concentration in a concentrated solution, permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions, current efficiency, cell voltage, energy consumption to obtain one ton of NaCl and membrane pair characteristics. The permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions was low enough particularly at $40^{\circ}C$ and $SO_4{^{2-}}$ transport across anion-exchange membranes was prevented successfully. Applying the overall mass transport equation, $Cl^-$ ion and $SO_4{^{2-}}$ ion transport across anion-exchange membranes is evaluated. $SO_4{^{2-}}$ ion transport number is decreased due to the decrease of electro-migration of $SO_4{^{2-}}$ ions across the anion-exchange membranes. $SO_4{^{2-}}$ ion concentration in desalting cells becomes higher than that in concentration cells and $SO_4{^{2-}}$ ion diffusion is accelerated across the anion-exchange membranes from desalting cells toward concentrating cells.

• Resources Recycling
• /
• v.11 no.1
• /
• pp.19-25
• /
• 2002

For $ZnSO_4$-$Na_2$$SO_4$-$H_2$ $SO_4$-$NaOH-H_2$O system, pH of solutions with different electrolyte concentrations was measured at $25^{\circ}C$ and ionic equilibria were analyzed by using K-value method. Activity of water and activity coefficients of solutes were calculated by Pitzer equation. The equilibrium concentration and activity coefficients of solutes were calculated from initial experimental conditions. At high ionic strength of 4m, the pH values calculated were in good agreement with those measured. In the experimental ranges of ionic strength of solution from 3.5 to 4.3 m, the mean activity coefcient of $ZnSO_4$calculated agreed well with those obtained from literature.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.28 no.2
• /
• pp.75-80
• /
• 2008

To investigate the sulfate utilization efficiency that has been examined in rape (Brassica napus L.) cultivars (cv. Akela and Colosse). During 72h of treatment, in two cultivars, ${SO_4}^{2-}$ uptake was significantly higher in complete S condition (2.0 mM ${SO_4}^{2-}$) than that of the S-deficient condition (2.0 mM ${SO_4}^{2-}$). In young leaves, ATP sulfurylase activity increased after S-deficient treatment. However, in old leaves, ATP sulfurylase activity was not significantly changed in Akela. Glutathione concentration in young leaves significantly increased in all cultivars examined under S-deficient condition. The rate of increase in glutathigne concentration caused by S-deficiency treatment was higher in Akela. However, in old leaves, the glutathione concentration in Akela significantly decreased. The results suggest that ${SO_4}^{2-}$ uptake and ATP sulfurylase in rape plants were species specific, and that ${SO_4}^{2-}$ uptake was highly related to its assimilation into S containing compound such as glutathione.

• Journal of Electrochemical Science and Technology
• /
• v.13 no.2
• /
• pp.177-185
• /
• 2022

Electrochemical properties of LiMn₂O₄ cathode were investigated in three types of Zn-containing electrolytes: lithium-zinc sulfate electrolyte (1M ZnSO₄ / 2M Li₂SO₄), zinc sulfate electrolyte (2MZnSO₄) and lithium-zinc-manganese sulfate electrolyte (1MZnSO₄ / 2MLi₂SO₄ / 0.1MMnSO₄). Cyclic voltammetry measurements demonstrated that LiMn₂O₄ is electrochemically inactive in pure ZnSO₄ electrolyte after initial oxidation. The effect of manganese (II) additive in the zinc-manganese sulfate electrolyte on the electrochemical performance was analyzed. The initial capacity of LiMn₂O₄ is higher in presence of MnSO₄ (140 mAh g^-1 in 1 M ZnSO₄ / 2 M Li₂SO₄ / 0.1 M MnSO₄ and 120 mAh g^-1 in 1 M ZnSO₄ / 2MLi₂SO₄). The capacity increase can be explained by the electrodeposition of MnO_x layer on the electrode surface. Structural characterization of postmortem electrodes with use of XRD and EDX analysis confirmed that partially formed in pure ZnSO₄ electrolyte Zn-containing phase leads to fast capacity fading which is probably related to blocked electroactive sites.

• Journal of Energy Engineering
• /
• v.14 no.3 s.43
• /
• pp.203-211
• /
• 2005

To investigate the effects of the number of multiple-cycles and $SO_2$ concentration on $CO_2$ absorption characteristics by means of limestone, $CO_2$ capture capacity has been measured in a bubbling fluidized bed reactor (0.1m 1.D., 1.17m high). Danyang limestone was used as a $CO_2$ sorbent and the number of cycles $(\~10th\;cycle)$ and $SO_2$ concentrations (0, 2000, 4000 ppm) were considered as variables. The measured $CO_2$ capture capacity decreased as the number of cycles increased and it showed $50\%$ or initial value after 10 cycles. Moreover, $CO_2$ rapture capacity decreased with 501 concentrations. For three different $SO_2$ concentrations, the total CaO utilization was almost the same but $SO_2$ capture capacity increased and $CO_2$ capture capacity decreased as $SO_2$ concentration increased. These results suggest that $SO_2$ capture reaction is predominant over $CO_2$ capture reaction in the simultaneous $CO_2/SO_2$ capture conditions.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.2
• /
• pp.95-102
• /
• 2009

To determine $SO_4^{2-}$ uptake and its assimilation in response to the exogenous $SO_4^{2-}$supply level in forage rape (Brassica napus L.), the concentration of this element in plant tissues and the activity of ATP sulfurylasc and APS reductase was measured after 25 hours of treatment (1.0 mM $SO_4^{2-}$, control; 0.1 mM $SO_4^{2-}$, S deficiency; 0 mM $SO_4^{2-}$, S deprivation). $SO_4^{2-}$ uptake and the concentration in the plant tissues significantly decreased in S-deficient and S-deprived condition, while it maintained at nearly same level in the control. The activity of ATP sulfurylase tended to increase with decreasing the exogenous $SO_4^{2-}$ supply, while that of APS reductase to decrease. A significant change in both enzymes responding to S-deprivation treatment was observed only young and middle leaves. The results indicated that $SO_4^{2-}$ assimilation in young leaf tissues would be much more sensitively responded to S-limited nutrition.

• Journal of the Korean Ceramic Society
• /
• v.35 no.9
• /
• pp.933-938
• /
• 1998

The hydration for the system of fluorogypsum and 20wt% blast furnace slag was investigated at liquid/soild ratio of 0.45 for 1, 3, and 7 days by using 3 kinds of accelerators such as K2SO4 Al2(SO4)3 $.$16-18H2O and AlK(SO4)2$.$12H2O After curing the hardened specimen was characterized by the compressive strength the content of combined water XRD, DTA and SEM It was found that the activating effect was increased in the order of K2SO4