Abstract

Eco-innovative technologies in wastewater treatment should provide not only stringent standards for the quality of treated wastewater but also ensure maximum recovery of energy and raw materials from wastewater. One of the ways to improve the removal efficiency of nitrogen and phosphorus compounds in existing conventional wastewater treatment plants is pretreatment of reject water generated during the mechanical dewatering of the digested sewage sludge. The aim of this research was to select the technological parameters of processes to ensure effective removal of nutrient elements (N, P) from RW treated in a SBR reactor in the nitritation/anammox process. The first stage was carried out to optimize nitrogen compounds removal in the effluent from ANAMMOX process used to treat reject water after centrifugation. The installation consists of single vertical subsurface flow (VSSF) beds located in stainless steel containers working parallel marked as BED control “0”, “I”, “II”. Samples have been taken for analysis to determine the changes of NH4-N, NO3-N and NO2-N in the effluent of each filter. In bed “0” the removal of nitrogen compounds was caused only by sorption at last until its capacity was reached. In bed “I” and “II” the NH4-N concentration in effluent and production of NO2-N with simultaneous changes of NO3-N indicated that nitrification was occurring. The investigation has shown different pattern of processes responsible for nitrogen compounds transformation and removal efficiency, depending on the bed substrate and vegetation. In the second stage the optimization of phosphates removal was carried out. The investigation was conducted in steady conditions. Each batch reactor of synthetic wastewater with given concentration of phosphates (15 mg/dm3) was subjected to mixing. Samples for analyzing were taken from each beaker after assumed time of sedimentation. Studies were conducted to determine the optimal dose of Phoslock® with known concentration of phosphate anions PO43- in model solution, time of mixing and time of sedimentation. Samples were analyzed with following parameters: pH, total suspended solids, conductivity, turbidity, color and phosphate concentration. The carried out investigations confirmed high efficiency of phosphate anions PO43- removal (over 95%).

Authors (5)