• Membrane and Water Treatment
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• v.3 no.3
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• pp.181-200
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• 2012

At present water crisis is not an issue of scarcity, but of access. There is a growing recognition of the need for increased access to clean water (drinkable, agricultural, industrial use). An encouraging number of innovative technologies, systems, components, processes are emerging for water-treatment, including new filtration and disinfectant technologies, and removal of organics from water. In the past decade many methods have been developed. The most important membrane-based water technologies include reverse osmosis (RO), ultrafiltration (UF), microfiltration (MF), and nanofiltration. Beside membrane based water-treatment processes, other techniques such as advanced oxidation process (AOP) have also been developed. Some unconventional water treatment technology such as magnetic treatment is also being developed.

• Elastomers and Composites
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• v.32 no.5
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• pp.325-329
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• 1997

Microbial treatment of the powdered waste tire was studied to recycle the waste tires. Chemoautotrophic acidophilic, iron-oxidizing bacterium was employed to unvulcanize the powdered tires. Biotreated rubber powder was compared to a untreated and a chemically treated powder. The results showed sulfur content of rubber powder(1.33%) were decreased to 1.22% by chemical treatment and 1.12% by microbial treatment for 20 days, 0.88%, for 30 days. One of the problems of the powdered utilization of the waste tires is that rubber powder leads to decrease mechanical properties when it is compounded with other virgin polymers. When tee biotreated powder was compounded with natural rubber, the mechanical properties were less decreased when untreated or chemically treated powder. Therefore, the microbial treatment can be one of useful methods to recycle the waste tire.

• Textile Coloration and Finishing
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• v.19 no.1 s.92
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• pp.45-52
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• 2007

Polyacrylonitrile(PAN) fiber was treated with low-temperature plasmas of argon and oxygen for surface modification, and its surface chemical structure and morphology were examined by a field emission scanning electron microscope(FESEM) and a Fourier-transform infrared microspectroscopy(IMS). The argon-plasma treatment caused the only mechanical effect by sputtering of ion bombardment, whereas the oxygen plasma brought about a chemical effect on the PAN fiber surface. The experimental evidences strongly suggested that cyclization of nitrile group and crosslinking were likely to occur in the oxygen-plasma treatment. On the other hand, with the argon-plasma treatment, numerous my pits resulted in ranging from several tens to hundreds nanometers in radius. The plasma sensitivity of functional groups such as C-H, $C{\equiv}N$, and O-C=O groups in the PAN fiber was dependent on their chemical nature of bonding in the oxygen-plasma, in which the ester group was the most sensitive to the plasma. Vacuum-ultraviolet(VUV) radiation emitted during plasma treatment played no substantial role to alter the surface morphology.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.83-89
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• 1996

Multivariate statistical procedures were used to analyse data on the chemical composition and in vitro digestibility of four varienties of rice straw after treatment with 4% NaOH solution, 4% urea solution or distilled water (control) for 48 hours. For each treatment, stepwise discriminant analysis identified the variables which maximized differences between varieties and the eigenvectors from principal component analysis quantified the contribution of these criterion variables to varietal differences. The overall response of varieties to chemical treatment was demonstrated qualitatively, by cluster analysis, and quantitatively, from the magnitude of the principal component scores. The analysis revealed that the urea and control treatments elicited the same response whereas NaOH had the greatest effect on the poorest straw variety. Similar analyses conducted on the botanical fractions of the varieties showed that the relative response of the inflorescence, stem, leaf blade and leaf sheath fractions was not altered by chemical treatment.

• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.532-537
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• 2022

The need for obtaining treated wastewater that meets high quality standards for discharge or reuse necessitates the use of highly efficient wastewater treatment techniques. In the present study, experiments have been carried out to reduce the concentration level of biological oxygen demand (BOD), chemical oxygen demand (COD), and total dissolved solids (TDS) from the wastewater sample. Treatment of sample of a real municipal wastewater collected from a sewage treatment plant (STP) was carried out in an electrochemical membrane bioreactor (EMBR). The EMBR was operated continuously for five days, and readings were taken at regular intervals. This paper has experimental results conducted in EMBR that indicate reduction of BOD, COD, and TDS levels of up to 32.25%, 29.25%, and 31.93%, respectively. Further, it was observed that a current of magnitude of 0.00752 mA was generated due to the metabolic activities of bacteria present in municipal wastewater, which gradually decreased day by day due to the decay of bacteria.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.348-353
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• 1996

Mutation tachniques inducing more useful mutations and reducing somatic effects need to be improved for crop breeding. Seeds of barley varieties ; Dema, Grosso were treated with two types of mutagens ; 1) chemical treatment: single treatment or double treatment of two mutagens (N-nitroso-N-methylurea ; MNH, Sodium Azide; NaN$_3$) 2) gamma ray irradiation treatment. After treatment, half of seeds were used for germination test and half of seeds were sown to the field. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher rate of growth reduction rate was in M$_1$ seedling. In chemical treatment, germination rate of seeds, growth rate of coleoptile and root in double treatment of chemical mutagens were better than single treatments, especially in same dose. Growth inhibition rate of plant in double treatment of 1.0mM MNH(0.5mM MNH + 0.5mM MNH), for example, were less than one of plants of single treatment of 1.0mM MNH in pot and petri dish test. Growth reduction rate of culm and fertility rate in M$_1$ plants double treated in same dose of single treatment were also less than single one. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher frequency of chlorophyll mutants was in M$_2$ seedling. The rate of chlorophyll mutants in double treatment of chemical mutagens were higher than single treatment. Double treatment methods can be a improved method for induction of new good mutants, which were induced more useful mutations and reduced harmful somatic effects.

• KSBB Journal
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• v.19 no.5
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• pp.399-405
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• 2004

A reticulated PU-g-PAAc foam was modified through the surface treatment of PU foam by one atmospheric pressure plasma. The synthesized PU-g-PAAc foam was prepared for the purpose of immobilizing microbial organisms. We also attempted different plasma treatment methods including simple plasma treatment, plasma induced grafting and plasma induced grafting followed by plasma re-treatment. The effect of grafting on equilibrium water content (EWC) of PU forms was examined by swelling measurements. Adhesion test was performed to investigate the effect of different plasma treatment methods on the improvement of microbial immobilization. Two foams modified by plasma induced grafting and plasma re-treatment after grafting showed 2.7 and 3.0 fold higher microbial immobilization than unmodified one, respectively. Meanwhile, simple plasma treatment showed a little enhancement. FT-IR analysis of each sample verified the contribution of surface functional groups on the enhancement of microbial immobilization. SEM observation confirmed microbial adherence.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.269-276
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• 1995

An experimental research was conducted in order to study the treatability of municipal landfill leachate using a combined physio-chemical and biological treatment. The leachate was obtained from Nanjido landfill site in Seoul. Several sets of bench-scale sequencing batch reactor(SBR) and physic-chemical reactors were used as experimental apparatus. This experiment lasted for about 2 years. The results are as follows: 1. The characteristics of Nanjido landfill leachate were pH 7.4~8.2, BOD 79~450mg/L, COD 998~1460mg/L, $NH_3-N$ 1380~3412mg/L, 7-P 2.6~7.0mg/L, color 890~1992 unit, and heavy metals are a very small amount. 2. Either physio-chemical or biological treatment of Landfill leachate alone did not work well. So for the adequate treatment of leachate, it was necessary to deal with the physio-chemical pretreatment before biological treatment. And it was found that both electrolysis and ozone treatment are better pretreatments of leachate than others. 3. In this study, landfill leachate was effectively processed by two step : first by electrolysis pretreatment, and secondly by SBR treatment. Thus, the study showed considerable substrate removal of raw leachate, even though the rate of COD removal depended on HRT.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.117-117
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• 1995

An experimental research was conducted in order to study the treatability of municipal landfill leachate using a combined physio-chemical and biological treatment. The leachate was obtained from Nanjido landfill site in Seoul. Several sets of bench-scale sequencing batch reactor(SBR) and physic-chemical reactors were used as experimental apparatus. This experiment lasted for about 2 years. The results are as follows: 1. The characteristics of Nanjido landfill leachate were pH 7.4~8.2, BOD 79~450mg/L, COD 998~1460mg/L, $NH_3-N$ 1380~3412mg/L, 7-P 2.6~7.0mg/L, color 890~1992 unit, and heavy metals are a very small amount. 2. Either physio-chemical or biological treatment of Landfill leachate alone did not work well. So for the adequate treatment of leachate, it was necessary to deal with the physio-chemical pretreatment before biological treatment. And it was found that both electrolysis and ozone treatment are better pretreatments of leachate than others. 3. In this study, landfill leachate was effectively processed by two step : first by electrolysis pretreatment, and secondly by SBR treatment. Thus, the study showed considerable substrate removal of raw leachate, even though the rate of COD removal depended on HRT.

• Carbon letters
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• v.6 no.3
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• pp.166-172
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• 2005

The objective of this study was to investigate the possibility of application for water treatment using the zeocarbon. The zeocarbon was mixture of zeolite and activated carbon. In general, the application of commercial zeocarbon to water treatment is difficult because of weak strength in water and the high pH value of effluents after water treatment. Therefore, we have modified the surface of zeocarbon. For the surface modification, we used the acid treatment to make surface functional group. As a result of modification, was created functional group on zeocarbon surface and was formed mesopore in zeocarbon. The surface modified zeocarbon was applied to removal of nitrogen. In removal experiments of nitrogen, removal efficiency was very high. And, strength of zeocarbon after water treatment and pH of effluents were stabilized. This indicates that the surface modified zeocarbon was easy to recover and reuse. Consequently, our results were shown the possibility of application for water treatment using the surface modified zeocarbon.