Abstract
The objective of this investigation was to evaluate applicability of precoat filtration that can be substituted for rapid sand filter of conventional water treatment system(CWTS). Precoat filter used in this experiment are candle filter. Element disk of candle are pore size $10{\mu}m(R),\;20{\mu}m(B)$ And diatomaceous earth are cake pore size $3.5{\mu}m$(Standard Super- Cel; A), $7{\mu}m$(Hyflo Super-Cel; B) and $17{\mu}m$(Celite 545RV; C). $2kg/m^2$ diatomaceous earth is used for precoating, it coated candle in $5{\sim}6mm$ thickness. 1. Al adsorption dosages by diatomaceous earth used in experimental we Hyflo Super-Cel 0.843mg/g, Standard Super-Cel 0.782 mg/g and Celite 545RV 0.766 mg/g. 2. Filtrate of precoat filter during 60min are R-C combination 20.7($m^3/m^2$)>B-C 18.3($m^3/m^2$)>B-B 15.0($m^3/m^2$)> R-B 12.9($m^3/m^2$)> R-A 11,093($l/m^2$). 3. Water quality of precoat filter effluent are thus. $KMnO_4$ consumption are $1.10{\sim}2.20mg/l$, removal rate are $30.9{\sim}65.6\%$. They are R-A 1.10(mg/l)(removal rate $65.6\%$). R-C(2.20 mg/l)(removal rate $30.9\%$). 4. $Al^{3+}$ are not detected with all combination, removal rate $100\%$. 5. Considering water quality and flux, continued running time of R-A combination is 7 hr. Accumulated filtrate are $74.4 m^3/m^2$, average flux is $177.2 l/m^2{\cdot}min$. And filtrate per diatomaceous earth 1g are 37.2 l. 6. R-A effluent's water quality are $KMnO_4$ Consumption 1.10(mg/l), DOC 1.161 mg/1, Al 0.0 mg/1, $UV_{254}$ 0.016/cm, Turbidity 0.1(NTU). R-A combination is suitable to precoat filtration for the settling basin effluent treatment.
