RESUMEN
The goal of this study was to investigate what kind of impact the removal of particulate organic matter with 33µm rotating belt filter (RBF) (as a primary treatment) will have on the membrane bioreactor (MBR) performance. Two small MBR pilot plants were operated in parallel, where one train treated 2mm screened municipal wastewater (Train A) and the other train treated wastewater that had passed through a RBF with a 33µm filter cloth (Train B). The RBF was operated without a filter mat on the belt. About one third of the organic matter was removed by the fine mesh filter. The assessment of the overall performance showed that the two pilot plants achieved approximately the same removal efficiencies with regard to total suspended solids (TSS), chemical oxygen demand (COD), total phosphorus and total nitrogen. It was also observed that the system with 33µm RBF as a primary treatment produced more sludge, which could be used for biogas production, and required about 30% less aeration downstream. Transmembrane pressure was significantly lower for the train receiving 33µm primary treated wastewater compared to the control receiving 2mm screened wastewater.
Asunto(s)
Reactores Biológicos , Membranas Artificiales , Nitrógeno/análisis , Eliminación de Residuos Líquidos/métodos , Contaminantes del Agua/análisis , Desnitrificación , Aguas ResidualesRESUMEN
The purpose of this project was to investigate the effect of selective particle removal during primary treatment on nitrogen removal in moving bed biofilm reactors (MBBRs). Two small MBBR pilot plants were operated in parallel, where one train treated 2 mm screened municipal wastewater and the other train treated wastewater that had passed through a Salsnes Filter SF1000 rotating belt sieve (RBS) with a 33 µs sieve cloth. The SF1000 was operated without a filter mat on the belt. The tests confirmed that, for the wastewater characteristics at the test plant, Salsnes Filter primary treatment with a 33 µs RBS and no filter mat produced a primary effluent that was close to optimum. Removal of organic matter with the 33 µs sieve had no negative effect on the denitrification process. Nitrification rates improved by 10-15% in the train with 33 µs RBS primary treatment. Mass balance calculations showed that without RBS primary treatment, the oxygen demand in the biological system was 36% higher. Other studies have shown that the sludge produced by RBS primary treatment is beneficial for biogas production and will also significantly improve sludge dewatering of the combined primary and biological sludge.
Asunto(s)
Reactores Biológicos , Filtración , Nitrógeno/aislamiento & purificación , Purificación del Agua/métodos , Biopelículas , Desnitrificación , Nitrificación , Aguas del Alcantarillado , Aguas ResidualesRESUMEN
The purpose of this project was to investigate the effect of selective particle removal during primary treatment on downstream biological nutrient removal processes. Bench-scale Salsnes Filter fine mesh sieves were used as a primary treatment to obtain different organic fractions to test the effect on denitrification. Activated sludge and moving bed biofilm reactor anoxic tests were performed on municipal wastewater collected from two full-scale wastewater treatment plants located around the Oslo region (Norway). About 43% of the suspended solids in the wastewater was less than 18 µm, and 14% was between 18 and 150 µm. The effect of particulate chemical oxygen demand (COD) removal on denitrification rates was very minor.