Simultaneous removal of organic material, nitrogen and phosphorus in a reactor in batches of mobile bed biofilm sequencing by the anaerobic-anoxic-oxic process

ABSTRACT In this study, the performance of a reactor in sequential batch with mobile bed biofilm operated by the anaerobic-anoxic-oxic (A2O) process, applied to the simultaneous removal of organic material, nitrogen and phosphorus from sanitary sewage was evaluated. Two reactors with a useful volume of 36 liters each were used, one of them receiving Kaldnes® type mobile plastic rings, with a specific surface area estimated at 310 m2/m3, which occupied 50% of the reactor’s useful volume (MBSBBR). The study was conducted with 12-day solid retention time (SRT), 6 hour hydraulic retention time (HRT), food/microorganism (F/M) ratio of 0.4 to 0.5 gCOD/VSS.d, dissolved oxygen (DO) in the range of 0.3-0.8 mgO2/L and application rates of organic load, nitrogen and phosphorus of 47.2 gCOD/L.d, 5.4 gTNK/L.d and 0.4 gP/L.d, respectively. The efficiency of chemical oxygen demand (COD), N-NH3 and Phosphorus removal was of 91.1%, 90.5% and 85.4% for the MBSBBR reactor and 89.5%, 91.6% and 84.4% for the RBS reactor, respectively. The results of the statistical ANOVA test were applied to the main variables studied and the values converged to values of f observed < f critical . In this way, it is considered that there was a similarity of performance between the MBSBBR and RBS reactors. It is concluded that the introduction of the support medium did not bring benefits to the treatment in terms of nutrient removal. However, the study showed that it is possible to obtain high nitrogen removal at low concentrations of DO, which is advantageous for the sewage treatment with high nitrogen concentration.

摘要：本研究针对采用厌氧-缺氧-好氧（Anaerobic-Anoxic-Oxic, A²O）工艺的移动床生物膜序批式反应器，在生活污水同步去除有机物、氮、磷中的处理性能开展评价。
实验采用两座有效容积均为36升的反应器，其中一座装填比表面积约为310 m²/m³的卡尔内斯（Kaldnes®）型移动塑料填料环，填料占反应器有效容积的50%，记为移动床生物膜序批式反应器（MBSBBR）。
本实验运行参数设置如下：固体停留时间（solid retention time, SRT）为12天，水力停留时间（hydraulic retention time, HRT）为6小时，食微比（food/microorganism, F/M）为0.4~0.5 gCOD/VSS·d，溶解氧（dissolved oxygen, DO）浓度范围为0.3~0.8 mgO₂/L，有机负荷、氮负荷和磷负荷分别为47.2 gCOD/(L·d)、5.4 gTNK/(L·d)和0.4 gP/(L·d)。
移动床生物膜序批式反应器对化学需氧量（chemical oxygen demand, COD）、氨氮（N-NH₃）和磷的去除率分别为91.1%、90.5%和85.4%，另一座RBS反应器的对应去除率则为89.5%、91.6%和84.4%。
对实验所研究的主要变量进行方差分析（analysis of variance, ANOVA）后，结果显示观测F值小于临界F值，由此可认为两座反应器的处理性能无显著差异。
研究结论表明，添加悬浮填料并未提升营养物的去除效果。但本实验证实，在低溶解氧浓度下可实现高效脱氮，这对于高氮负荷生活污水的处理具有实际应用优势。