• Analytical Science and Technology
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• v.14 no.2
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• pp.167-172
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• 2001

The technique that could collect efficiently the hanji fibrous sludge from wastewater using surfactants was developed. When fibrous sludge of which concentration was about 80mg/L, was floated and collected, the optimum concentration of sodium oleate, the pore size of glass filter and the air flow rate were 10mg/L, $5-10{\mu}m$ and 200mL/min., respectively. The behavior of sodium oleate might be interfered by polyvalent cations such as $Ca^{2+}$. But when the concentration of $Ca^{2+}$ was less than 100mg/L, the interference effect did not appear. And when a typical cationic surfactant, cetyltrimethylammonium bromide(CTAB), was used, the collecting yield was less than that of sodium oleate, and the amount of foam was higher than sodium oleate. When 1mg/L of CTAB was added to the hanji sludge sample contained 1mg/L of $PAMID^{(R)}$, a dispersant, fibrous sludge was effectively coagulated, the flotation time was very short and the collecting yield was above 95%. But in the case, sodium oleate was inefficient.

• Analytical Science and Technology
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• v.15 no.2
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• pp.157-162
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• 2002

A technique which could collect the traditional and the industrial hanji fibrous sludge efficiently from wastewater using a cationic surfactant cetyltrimethylammonium chloride (CTAC) was developed. When the concentration of CTAC was $1{\mu}g/mL$ in wastewater that the amount of the traditional hanji fibrous sludge was about 0.08 g/L, the collecting yield was more than 95% and the collecting time was less than 30 sec. When only CTAC was used to collect the industrial hanji fibrous sludge, about 90% of collecting yield was obtained at more than $15{\mu}g/mL$ CTAC. But the sludge layer at the surface of solution was not stabilized and the flotation time was relatively longer. And, when $5{\mu}g/mL$ CTAC and various amount of PAMID$^{(R)}$ was added to the industrial hanji sludge, the collecting yield was increased and sludge layer also was more stabilized. But the collecting yield was higher in the traditional hanji sludge than in the industrial hanji sludge.