Kim S M, Kim S H, Choi H C, Kim I S
Bio-Environmental Engineering Lab, Dept of Environmental Science and Engineering, Kwangju Institute of Science and Technology, Buk-gu, Gwangju 500-712, Korea.
Water Sci Technol. 2004;50(6):157-62.
In order to enhance the solid-liquid separation properties and nitrogen removal efficiency of SBR, the aerobic floc-like granules were cultivated under temporal alternating aerobic and anoxic conditions without the presence of carrier material in a SBR having 15 H/D (height/diameter) ratio. Two different effluent port positions were applied to the SBR for different selection of minimum settling velocities (over 0.6 and 0.7 m/h) of granules retained in the SBR during aerobic floc-like granule formation. The effect of different minimum settling velocities as an operational parameter on the size and solid-liquid separation properties of floc-like granules and also the COD and nitrogen removal of SBR were evaluated. The reactor was operated 6 hours per cycle (aerobic 4.75 hours, anoxic 1.25 hours) under chemical oxygen demand (COD) loading rate of 2.5 kg/m3 x d (1.3 kg acetate-COD and 1.2 kg glucose-COD). When increasing the minimum settling velocity by 0.1 m/h, the following results were observed at steady state. The nitrification efficiency was not changed at about 97% but the denitrification efficiency was improved from 78 to 97%. The COD removal efficiency was improved from 82 to 97% and the concentration of biomass in the reactor was retained at lower level at about 3,000 mg MLSS/L. The average sludge volume index (SVI) value of granules was decreased about 85 to 50 mL/g and the granule sizes were increased 0.1-0.5 mm to 1.0-2.0 mm. The required time to form granules and reach steady state was significantly shortened. Based on the results, the selection of the minimum settling velocity had a significant effect on both the physical properties of granules and the SBR performance, so it is suggested to use the minimum settling velocity as an operational parameter.
为了提高序批式反应器（SBR）的固液分离性能和脱氮效率，在高度与直径比为15的SBR中，在无载体材料的情况下，通过好氧和缺氧交替的条件培养好氧絮状颗粒。在好氧絮状颗粒形成过程中，将SBR的两个不同出水端口位置用于选择SBR中保留的颗粒的不同最小沉降速度（超过0.6和0.7 m/h）。评估了不同最小沉降速度作为操作参数对絮状颗粒的尺寸和固液分离性能以及SBR的化学需氧量（COD）和氮去除的影响。反应器在化学需氧量（COD）负荷率为2.5 kg/m³·d（1.3 kg乙酸盐-COD和1.2 kg葡萄糖-COD）的条件下，每个周期运行6小时（好氧4.75小时，缺氧1.25小时）。当最小沉降速度每小时增加0.1 m时，在稳态下观察到以下结果。硝化效率保持在约97%不变，但反硝化效率从78%提高到97%。COD去除效率从82%提高到97%，反应器中生物量的浓度保持在较低水平，约为3000 mg MLSS/L。颗粒的平均污泥体积指数（SVI）值从约85 mL/g降至50 mL/g，颗粒尺寸从0.1 - 0.5 mm增加到1.0 - 2.0 mm。形成颗粒并达到稳态所需的时间显著缩短。基于这些结果，最小沉降速度的选择对颗粒的物理性质和SBR性能都有显著影响，因此建议将最小沉降速度作为操作参数。
