• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.141-150
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• 2006

To develop the microbial agents for the environmentally-friendly treatment and recycling of food waste, useful microorganisms, which showed higher degradation activities to various organic compounds and possessed flocculating activities, were isolated from the earthworm. One of the isolated strains, named JS-01, was further selected due to its higher flocculating activity against 0.5% Kaolin clay. JS-01 was identified as Bacillus pumilus sp. by 16s rDNA analysis. The optimal temperature and pH for the growth of JS-01 to express the flocculating activity was found to be at $37^{\circ}C$ in pH 7.0 of EPS broth medium. JS-01 also expressed good degrading activity against cellulose, which is one of the representative organic materials in food waste. We propose that JS-01 will be a good candidate for the efficient treatment of food waste and leachate due to the property to degrade cellulose and flocculating activity.

• Journal of Life Science
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• v.27 no.8
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• pp.930-936
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• 2017

The flocculating properties of bioflocculant Biopol32 produced by Pseudomonas sp. GP32 were investigated for application in industrial wastewater treatment. The major flocculating substance of bioflocculant Biopol32 was identified as polysaccharide. Many anionic flocculants need a counter ion to induce higher flocculating activity. The flocculating activity of bioflocculant Biopol32 was markedly increased by the addition of cationic ions ($Ca^{2+}$, $Al^{3+}$). The flocculating activity of bioflocculant Biopol32 was the most effective when 7.0 mM $CaCl_2{\cdot}2H_2O$ as coflocculant was added. The flocculating activity on the effect of pH and the temperature of the bioflocculant Biopol32 was compared with anionic commercial flocculant (polyacrylamide) and bioflocculant (zooglan from Zoogloea ramigera). In kaolin suspension, the highest flocculating activity was obtained at the bioflocculant Biopol32 concentration of 1.5 mg/l. A high flocculating activity was observed in the pH range of 5.0 to 8.0. The flocculating activity of bioflocculant Biopol32 was sustained up to $60^{\circ}C$, but decreased rapidly at over $70^{\circ}C$. In the batch culture, the charge density of bioflocculant Biopol32 was compared with flocculating activity. The larger the anionic charge density and apparent viscosity of bioflocculant Biopol32, the higher the flocculating activity. Therefore, we confirmed that the flocculating activity and apparent viscosity of bioflocculant Biopol32 was closely related to the charge density of bioflocculant Biopol32.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.237-245
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• 1997

A DEAE-chitin was prepared with DEAE HCl in an aqueous alkali-chitin solution. The resulting DEAE-chitin exhibited a highly improved affinity to water and organic solvents, It was N-deacetylated by heating in aqueous 10% sodium hydroxide containing sodium borohydride for 9h at $80^{\circ}C$ to produce DEAE-chitosan. These conditions were milder than those for the N-deacetylation of chitin. In order to increase its cationic character, the DEAE-chitin was treated with ethyl halide to give TEAE-chitin. The structural changes in the chitin derivatives were confirmed by using both FT-IR and $^1H$ NMR, and their flocculating behavior, in kaoline suspension showed the optimum property at a weak alkaline pH and 8 ppm concentration of resin conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.340-344
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• 2014

Compost and gypsum can be used to ameliorate soil physicochemical properties in reclaimed tidal lands as an organic and inorganic amendment, respectively. To evaluate effects of compost and gypsum on soil water movement and retention as a soil physical property, we measured the soil's saturated hydraulic conductivity and field capacity after treating the soil collected in a reclaimed tidal land with compost and gypsum. Saturated hydraulic conductivity of soil increased when compost was applied at the conventional application rate of $30Mg\;ha^{-1}$. However, the further application of compost insignificantly (P > 0.05) increased saturated hydraulic conductivity. On the other hand, additional gypsum application significantly increased soil saturated hydraulic conductivity while it decreased soil field capacity, implying the possible effect of gypsum on flocculating soil colloidal particles. The results in this study suggested that compost and gypsum can be used to improve hydrological properties of reclaimed tidal lands through increasing soil water retention and movement, respectively.