C.M.C, gelatine, polyacrylamide 등을 표면흡착시킨 국산 규조토 여과조제를 vacuum leaf-filter에precoating 시켜 희박한 ink 및 coffee 현탁액을 여과하여 그 결과를 비교하였다.
실험결과, 규조토에 대한 polyelectrolyte륭듸 농도비가 증가함에 따라 흡착량은 증가하였고 흡착평형농도와 흡착량의 관계는 Freundlich식에 잘 일치하였다.
Polyelectrolyte를 흡착시키지 않은 규조토를 precoating하여 여과하였을 경우는 여과분리가 불가능했던 미세한 입자까지도 polyelectrolyte를 흡착시킨 규조토로 precoting하여 여과함으로써 미세입자를 제거할 수 있다.
Polyeletrolyte의 흡착량이 증가함에 따라 여액의 현탁도는 그만큼 더 개선되었고 polyelectrolyt를 흡착시킨 규조토를 precoating하여 여과에 사용한 경우, 여과속도는 감소하였다.

Diatomite filter-aids coated with polyeletrolytes such as C.M.C, gelatine and polyacrylamide is adsorb-ed, were used in the vacuum precoat filtration of dilute ink and coffee slurries. The amount of adsorbed polyeletrolytes increased proportionally with the ratio of polyelectrolyte/deatomite, and the relation of adsorption equilibrium concentration and adsorption amount is well fitted with Freundlich equation. The polyelectrolyte adsorption on diatomite enabled to filler out ultrafine particulate matter which would otherwise call for much finer grdes of diatomite. The turbidity of filtrate was improved with increasing amount of polyelectrolyte adsorbed. The polyelectrolyte adsorption on diatomite decreased the filtration rate.