Deep bed filtration of anaerobic cattle manure effluents with natural zeolite

Abstract

This study was carried out in a pilot plant for the treatment of anaerobic cattle manure waste. The pilot plant consisted of a semicontinous anaerobic reactor, a settling tank, a filtration process and an ionic exchange column. The study was focused on the filtration process, with natural zeolite as filtering material. In the filtration process different media sizes of natural zeolites packed in columns were tested. The ranges of media size were 0.4 ‐ 1.0, 1.0 ‐ 3.0 and 3.0 ‐ 5.0 mm. Filtration systems operated by gravity flow from 2 to 10 m³m^‐2h^‐1. The process control was done by assays of solids, turbidity, total and soluble COD, ammonium and orthophosphate. The results showed a better behaviour in the filters packed with a media size range between 1.0 and 3.0 mm, operating at 7 m³m^‐2h^‐1, principally when effluent gross particles were previously retained in an Heterogeneous Media Filter, operating at 4 m³m^‐2h^‐1. The head losses diagrams in the filter runs were obtained, at each operational conditions. The hydraulic behaviour of traditional silica sand and natural zeolite beds were compared at the same operational conditions.