Process for the purification of waste waters contaminated by light materials, in particular saponifiable oils or fats

摘要

A novel process is described for purifying waste waters (effluents) contaminated by light materials, in particular saponifiable oils and fats (greases). In order to decrease the residual contamination, it is proposed to pass the waste water through a filter made of reticulated polyurethane foam. The dispersed or emulsified particles of light material are retained on this filter. During backwashing of the filter, which can be assisted by air, heat is used for liquefying the particles. If a web-like filter is used, this can be endlessly wound round a bottom and top reversing roll and can be moved upwards for cleaning by squeezing. During the purification, waste water, filter and squeezing roll can be heated. The filter and/or purification operation itself can be assisted by flotation.