• Resources Recycling
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• v.9 no.1
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• pp.36-43
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• 2000

This study was carried out for treatment and reuse of inorganic sludge from Fenton process at B dyeing wastewater treatment plant. The parameters for pilot-scale treatment system were derived from the results of this study. It was found that $COD_{cl}$ of the treated effluent became lower than 100 mg/l approximately on the optimal reaction condition. 2nd sludge which was generated after redissolving sludge was analyzed, and it showed that reduction ratio of ash in 2nd sludge and total dry sludge weight in comparison with current sludge were 85% and 65%. Also Fe salt in sludge was redissolved about 90~95% of initial Fe by weight. It was estimated almost ￦350,000,000 for sludge reuse process. It was estimated saving of about ￦1,300,000 per day (￦420,000,000 per year) in operating cost based on 30,000 $m^3$/d treatment, which these were about ￦430,000 per day in chemical, ￦1,100,000 per day in sludge transportation and ￦200,000 per day in equipment maintenance. Payback period with interest charge for investment cost was estimated about 10.5 months. Also, net present value (NPV) was ￦792,000,000 and internal rat of return (IRR) was about 110%.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.253-263
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• 2002

To test for the effect of applied fertilizer and nutrients on uptake and transport for paddy rice, two paddy field trials were conducted with Dongjinbyeo in degenerated salt paddy field of Jeonbuk series from 1999 to 2000. After experiment, soil acidity, content of organic matter phosphate, silicate, potassium, calcium, and total nitrogen was increased by application of fresh cattle manure(FCM). Content of Nitrogen in soil layer leached inorganic nitrogen $NO_3$ was higher that that of $NH_4$ and was high in treatment of FCM. Content of $PO_4$ was higher in FCM than other treatments. But content of potassium was in high control. During the growth of rice plant, the amount of water consumption was 477mm. The amount of supplied nitrogen was high in treatment of no nitrogen(NN), 20% reduced application of LCU(LCU-20%), and no fertilizer. In case of phosphate, the supplied amount was more than the consumed amount with the exception of treatment "no phosphate(NP) and no fertilizer(NF)". In case of potassium, the consumed amount was more than the supplied amount in all treatments. The amount of applied nitrogen in the nutrient infiltrated water was high in treatment soil test(ST), C+FCM+Si(Silicate) and the ratio of recovered nitrogen was high in 20% reduced application of LCU. The amount of applied phosphate in the nutrient infiltrated water was high in FCM and that of applied potassium was high in 20% reduced application of LCU. Nitrogen use efficiency of paddy rice was high in 20% reduced application of LCU and use efficiency of phosphate and potassium was high in C+Si(Silicate). Grain yield of rice was high in order of 20% reduced application of LCU>C+Si=C+FCM+Si>C+FCM.

• Membrane Journal
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• v.4 no.3
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• pp.163-170
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• 1994

The separation of inorganic salt from amino acid solution using was performed electrodialysis. In order to review the availability of electrodialysis using isoelectric point of amino acid as a bio-separation technique, electrodialysis stacks were designed using ion exchange membrane. Separation of NaCl from amino acid solution was performed in the condition similar to amino acid fermentation process. To obtain otimum conditions of separation, leakage of amino acid depending of pH and limiting current density were measured. On the basis of optimum condition, removal of NaCl and leakage of amino acid were investigated quantitatively in batch and continuous process, and current efficiencies were also obtained. As a result of batch experiment for 11 hours each amino acid solution, removal efficiencies of NaCl were in the ranges of 96.1~96.2%. Amino acid leakage rate of glycine, methionine, alanine were 2.5, 1.7, 2.0% respectively. Current efficiencies were in the ranges of 44.5~44.6%. As a result of continuous experiment in various flow rate of each amino acid solution, it took 120 ~ 150 min to reach to steady state. Removal efficiency of NaCl was increased as the flow rate was decreased, but current efficiency was decreased. At the steady states, there were no leakage of amino acid.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.330-339
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• 2008

Effect of additives such as NP series nonionic surfactant and cosurfactant on AgCl nanoparticles was investigated where nanoparticles were prepared using two different types of water-in-oil (W/O) microemulsions containing silver nitrate and sodium chloride, respectively. Phase behavior experiments showed that the region of one phase W/O microemulsion was found to be broadened with an increase in the ethylene oxide length of a nonionic surfactant mainly due to an increase in hydrophilic nature of a surfactant. Photomicrographs obtained by transmission electron microscopy indicated that an increase in ethylene oxide length of a nonionic surfactant results in both increases in particle size and size distribution. Phase behavior experiments for the systems containing AOT surfactant, isooctane and aqueous solution of an inorganic salt showed that addition of a cosurfactant caused a shrinkage in phase region of one phase W/O microemulsion, especially water contents contained in W/O microemulsion with an increase in the chain length or the concentration of a cosurfactant used. Photomicrographs obtained by transmission electron microscopy indicated that characteristics of AgCl nanoparticles produced were dependent both on the radius of spontaneous curvature and film rigidity of a microemulsion.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.519-533
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• 2010

Activity oefficients and solubilities of L-Alanine in aqueous solutions containing each of four electrolytes(NaCl, KCl, $NaNO_3$ and $KNO_3$) were measured at 298.15 K. The measurements of activity coefficients were carried out in the electrochemical cell coupled with two ion-selective electrodes(cation and anion), and the solubilities were measured by the gravimetric analysis of saturated solutions in equilibrium with the solid phase of L-alanine. To model the activity coefficients and solubilities of amino acid in the amino acid/electrolyte aqueous solutions, thermodynamic relations of the residual Helmholtz free energy in the amino acid/electrolyte aqueous solutions were developed based on the perturbed-chain statistical associating fluid theory(PC-SAFT) combined with the primitive mean spherical approximation(primitive-MSA). In the present model, it is assumed that the zwitterions of L-alanine are associated with each other and cross-associated with water molecules, and also cross-associated with the cation and anion dissociated from an electrolyte(inorganic salt). The activity coefficients and solubilities of L-Alanine calculated from the theoretical model proposed in this work are found to be well agreeable with experimental data.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.80-88
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• 1995

This survey has been conducted, mostly in inorganic ions, to get some basic data for the culture solution composition, analyzing water quality of some hydroponic farms. pH range was shown from 5.95 to 7.61 and the average of 6.75. Relatively wide range of EC, from 0.07 to 0.97 mS/cm and the average of 0.35 mS/cm were obtained. 19.5 percent of farms investigated showed over 0.5 mS/cm of EC, which means more careful culture solution composition and its management are needed in these farms. Na concentration ranged from 5.0 to 41.4 ppm and Cl concentration ranged from 10 to 99 ppm were shown and their average were 20.38 ppm and 35.16 ppm, respectively. Higher Na concentration compared to standard of 11.5 ppm was shown in 75% of farms and Higher Cl concentration compared to standard of 35.5 ppm was shown in 33.3% of farms. These concentration were considered rather high, which can cause salt accumulation in substrate mats. Ca and Mg concentrations were ranged from 1.60 to 131 ppm and 0.96 to 34.1 ppm, respectively. Average concentrations were 26.11 ppm in Ca and 8.10 ppm in Mg. In case of HCO$_3$, 24 to 295 ppm of concentration range and average of 63.13 ppm were obtained. Fe range was 0.01 to 0.87 ppm and its average was 0.14 ppm. This results showed that Fe elimination was necessary in well water.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.4
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• pp.196-203
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• 2004

To understand the geochemical processes in the Han River Estuary, distributions and behaviors of nutrients, dissolved organic matters, and uranium were investigated and analyzed during estuarine tidal mixing in June 2000 and February 2001. The distribution of inorganic nutrients showed very dynamic distributional patterns implying an apparent nitrification process and a concave non-conservative mixing along the salinity gradient. Dissolved organic carbon was high in the upstream region and decreased sharply in the low salinity region of around 5 psu. The 3-D fluorescence characteristic of dissolved organic matter showed two distinct fluorophores in the study area. Biomacromolecules originated mainly from the indigenous biochemical processes and geomacromolecules from terrestrial humic materials. In the study area, the distribution of geomacromolecule showed a concave non-conservative property along the salinity gradient presumably due to the flocculation and removal processes in the estuary. Meanwhile, distribution of the dissolved uranium, mainly in the form of stable uranium carbonate complex, also showed a concave non-conservative property along the salinity gradient in the Han River Estuary. From this study, the removal rate of dissolved uranium in the Han River Estuary was estimated to be about 7.1 ton per year.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.257-260
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• 2012

Sundried salt was recently registered in food category in Korea in 2008, and food hygiene regulation only applied to several heavy metals and a few inorganic ions. In this report, we investigated the residual amounts of tricyclazole, a highly concerned contaminant from agricultural activity, and estimated their daily intake and hazard index. All 60 sundried salts were collected by region, and qualitatively and quantitatively were analyzed with GC-NPD. In this investigation, only three samples were confirmed the residual tricyclazole in sundried salts. Their maximum residue was $1.7{\mu}g/kg$, and their estimated average daily intake was $2.40{\times}10^{-8}{\sim}6.22{\times}10^{-8}mg/kg-day$. From these results, HI of tricyclazole for sundried salts was $7.53{\times}10^{-7}{\sim}2.07{\times}10^{-6}$ for Koreans, and the values were not considered as serious risk issues currently.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.160-163
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• 1998

In this study, the compostable household wastes from a house were composted in a home composter without adding any bulking agent and microorganisms. Every day wastes of 1kg were added to the composter during the experimental period. The following results were obtained : 1. Each component of the compostable household wastes generated every day showed very difference. 2. While composting proceeded at room temperature by suppling 1,1322 l air per hour, the composting material maintained the water content of 74.36 ${\sim}$ 85.14%, whereas while composting proceeded at $45^{\circ}C$ by suppling 427 l air per hour, the compost had optimal water content. The electric power of 132kwh a month was required by operating the composting unit at $45^{\circ}C$. 3. During 20 day, decomposition of 28% at room temperature and 44% at $45^{\circ}C$ were obtained respectively. 4. The accumulation of inorganic compound contents were not shown during the composting period, However, the content of salt and Cd was very high. Therefore, using the compost for agriculture has to be careful. 5. The biofilter removed the odorous substants efficiently at the room temperature due to increasing surface loading.

• Applied Biological Chemistry
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• v.43 no.3
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• pp.163-168
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• 2000

To remove phosphate accumulated in the soil and water, Acinetobacter lwoffi PO8 possessing a high ability to accumulate phosphate was isolated from a active sludge. Bacterium was cultured in the liquid medium containing $150\;{\mu}g/mL$ of phosphate at $30^{\circ}C$ in different culture conditions to examine intracellular phosphate uptake. The initial pH in the range of $7.5{\sim}8.5$ was effective on the growth and phosphate uptake of the strain. Glycerol and arabinose used as a carbon sources showed 93 and 91% the phsphate uptake, respectively. Among the nitrogen sources, ammonium salt such as $NH_4NO_3$ and $(NH_4)_2SO_4$ was effectively utilized on the phosphate uptake compared with amino compounds. The rate of phosphate uptake of $NH_4NO_3$, and $(NH_4)_2SO_4$, was 95 and 96%, respectively The growth and Phosphate uptake ability in the strain were significantly promoted when metal ions were added in the medium; $Co^{2+}$, however, was not utilized by the strain. The capacity of phosphate uptake was enhanced to $10{\sim}20%$ when arginine, methionine, or lysine was added. Using $^{32}P$ to examine the uptake Pattern of intracellular phosphate, experiment result showed that polyphosphate was largely found in the fraction of intracellular inorganic phosphate of Acinetobacter lwoffi PO8.