Banca de DEFESA: FLAVIO JOSE GARCIA MARQUES

DEVELOPMENT OF FILTERS WITH LITHOTHAMINIUM CALCAREUM BED IN PILOT SCALE

 FOR TERTIARY TREATMENT OF SANITARY SEWAGE AIMING PHOSPHORUS REMOVAL

Bioclastic granulate; wastewater treatment; wastewater

The presence of nutrients (nitrogen and phosphorus) in post-treatment effluents is a problem that is still difficult to solve in terms of available technologies for their removal in treatment stations, although these same nutrients are of relevant importance as an agricultural input. The main objective of this research was to study the performance of Lithothamnium calcareum filters, in pilot scales for phosphorus removal as a tertiary step after effluent treatment stations. Theoretical development and tests were carried out for the assembly of the filtering bed with Lithothamnium calcareum, and subsequent hydraulic sizing of the equipment on a pilot scale, with its respective prototype construction. This prototype was installed and all its operation and sampling was carried out in a sewage treatment station in the BAYSIDE shopping mall, located at Avenida das Américas, 3120 - Barra da Tijuca, Rio de Janeiro. 03 filter prototypes were built, F1 (30cm of bed), F2 (40 cm of bed) and F3 (with 50cm of bed) with granulometry from 1.00mm to 4.7mm of bed, these filters were submitted for a period of 4 days at an average flow of 1.90l*min-1 determined by laboratory tests and the mass ratio of the fixed bed of the filter with average height. Phosphorus input and output concentrations were measured using a spectrophotometer, bed bulk density, porosity and interstitial velocity were also determined. The system efficiency was evaluated in terms of total phosphorus. The results obtained indicated that the F3 filter had the best efficiency values in relation to the other two, indicating a Ptotal removal of up to 62.50% and a minimum output concentration of 1.47mg*l-1. These results demonstrate the viability of building commercial models of filters with low-cost Lithothamnium calcareum beds for the removal of phosphorus present in sanitary, agricultural and industrial effluents, and the possibility of potential agricultural use of the saturated filter medium can also be evaluated.