A COMPARATIVE-STUDY OF SAND AND NATURAL ZEOLITE AS FILTERING MEDIA INTERTIARY-TREATMENT OF WASTEWATERS FROM TOURIST AREAS

Anaerobic effluents from a fixed bed reactor (FBR) treating sewage wat er from tourist areas were treated by two high rate filters at laborat ory scale one packed with sand and the other with natural zeolite with the aim of obtaining final effluents with quality for irrigation of l and or disposal in tourist zones. During the experiments analysis of t urbidity, GOD, BOD, total solids (TS),total volatile fatty acids (TVFA ), pH, alkalinity, ammonia nitrogen and total coliforms were carried o ut, Besides of these, the changes of pressure losses were determined, The filtering media used were: sand and natural zeolite with particle sizes in the range of 1-3 mm and 0.6-2.5 mm and 1-3 mm, 0.6-2.5 mm for both media and particle sizes of 0.35 - I mm also for the zeolite, It tvas found that turbidity removal was similar for sand and zeolite al though the filter packed with zeolite media had lower pressure losses and better hydraulic behaviour. The evaluation of different particle s ize demonstrated that particle size in the range of 1-3 mm for both me dia was more effective than the rest of particle range studied in the removal of pollutant particles.