Advances in the precoat filtration process

Precoat filtration with body-feed is widely applied during wine-making. This technique employs filter aids, such as diatomites (silica particles), to form the precoat layer. However, the spent diatomites, which retain organic matter, represent an important source of pollution and land disposal of this type of waste is forbidden. In addition, these spent diatomites are not regenerable. The aim of this study was to evaluate regenerable filter aids which have a high environmental acceptability. Polyamide particles were characterized as filter aids, tested in precoat filtration and compared to diatomites which are the classic filter aids used in wine filtration. Polyamide particles seemed to be efficient filter aids, reducing turbidity by 72% and the fouling index by 56% without affecting wine quality.