EVALUATION OF TREATMENT EFFICIENCY OF AN AEROBIC BIOGRAPHIC FILTERS MODEL USING RED SCORIA STONE AS A CARRIER IN LIVESTOCK WATER TREATMENT

Abstract

Currently, researching on finding and applying new types of media (carriers) to improve and stabilize the aerobic biological treatment systems of wastewater rich in biodegradable organics and nutrients such as nitrogen, phosphorus in the general wastewater treatment plants and livestock wastewater treatment plants in particular have been increasingly interested. Red Scoria Stone (RSS) is known as a volcanic rock with low weight, high porosity and large specific surface area, so it has the potential to be used as a carrier for attached growth of microorganism in the biological wastewater treatment technology. Therefore, in this study, the red lava rock was used as an attached medium in aerobic biological filtration technology to treat livestock wastewater. Results show that, when using the RSS mediums with size from 1-2 cm with 30% of the media volume in the aerobic biofilter reactor operating continuously at organic loading of 1.0 kgCOD/m3.day, the treament effieciencies of COD reached 92.16±2%, N-NH4 of 89.49±1%, TN of  89.35±1% and P-PO43- of 86.37±1%. A comparative study between using a biological filter tank with the RSS mediums and an aerotank with suspended growth of microorganims when was operated under the same conditions at an organic loading of 1.0 kg COD/m3.day has shown that the biological filter tank with RSS media gave a higher and more stable pollutants treatment efficiency compared with the aerotank model. Specifically, the COD removal efficiency in the biological filter reactor using RSS media was higher than that of aertank by 12%-14%, N-NH4 , TN by 13%-15% and P-PO43- by 15%-17%. The findings obtained from this study have indicated that the applying RSS media in aerobic biological filtration technology has significantly contributed to effectively improve the high biodegradable organics and nutrients concentrations containing-wastewater treatment performance, especially in effectively treating wastewater rich in nitrogen and phosphorus which are very difficult to remove from wastewater.