Moving and Fixed Biological Biofilm Systems in Wastewater Treatmentwhen dose an Application Makes Sense

Abstract

This study demonstrates the optimization of different Biofilm applications in wastewater treatment for a cost-effective solution. The increase of wastewater treatment cost because of high treatment efficiency requested and energy consumption makes such applications very interested in this field. Therefore, aerated reactors for wastewater treatment units were designed to work as Submerged Fixed Biofilm Bed, on the basis of biofilm-microorganisms attached to monolithic plastic supports to increase the treatment efficiency. This application depends on the aerobic process and achieved by the aeration in BOD reduction and Nitrifications reactors (Oxidation of organic compounds and nitrification). This was implemented by mixing and transport treatment processes within the biofilm attached to the plastic fixed media. The anaerobic reactor in this study was designed also to be simultaneous the de-nitrification stage by the application of a moving bed de-nitrification reactor which was considered as a part of the wastewater treatment process to achieve high treatment efficiency for the study pilot plant. The one-year-scientific evaluation was conducted onsite for the municipal wastewater pilot plant includes a test series with well-defined treatment parameters (soft mixing of the suspending the moving bed carriers; intermediate solids removal unit prior to the nitrification reactors; the mechanism for preventing the carriers to move with the flow into the subsequent reactor) such as waste-water-flow, quality, temperature, salinity, organic and hydraulic load and extensive sampling). The above application of the compact-container-system is considered as a typical field of application, for the following reasons: Need of quality improvements discharged into water body, which is often in the vicinity of bathing beaches; Need for Nutrient-Removal-Systems to avoid algae growth going into water bodies and; Space limitations in a resort and saving the implementation capital cost). The comparison between the application of the biofilm concept and the activated sludge system saved more than 40% tank size; 85% space/area; and up to 30% construction cost.