|
The main purpose of this study was to present the application of biological fixed bed reactor in the tannery wastewater treating. Raw tannery sewages are characterized by a great concentration of ammonia nitrogen, total suspended solids (TSS), total dissolved solids (TDS) and the presence of sulphide and chromium. The chemical pretreatment does not solve the problem because it removes only part of the biological oxygen demand (BOD) and the chemical oxygen demand (COD) (65 - 85%), suspended solids, sulphide and chromium. Due to the insufficient effectiveness of the mechanical and chemical methods, a biological method has been developed. Therefore the fixed bed reactor with Terrapol®-type filling packs was used. Its operational volume of 537 m3 was divided into the denitrification chamber, nitrification chamber with the fixed bed and the multi-streams secondary settling chamber. The experimentation comprised 2 stages. The first one was carried out in the full scale during the technological starting-up of the Szczakowa tannery wastewater plant (Jaworzno, Poland), while the other one concerned some improvements of the method. With the additional use of active carbon and polyelectrolyte, the proposed biological treatment has proved its effectiveness and suitability for tannery wastewater purification.
|
