Tay J H, Pan S, Tay S T L, Ivanov V, Liu Y
EERC, CEE, NTU, Blk N1, 50 Nanyang Avenue, Singapore 639798.
Water Sci Technol. 2003;47(11):235-40.
The effect of organic loading rate (OLR) on aerobic granulation was studied by adopting three column-shaped, sequential aerobic sludge blanket reactors (SASBR). The reactors had been fed with laboratory prepared, synthetic dextrose-nutrient broth substrate. Experimental results showed clearly that the formation, characteristics and stability of aerobic granules had a close relationship with the strength of OLR applied. Aerobic granules appeared firstly under the OLR of 4 kg COD x (m3 x day)(-1). The system stabilization was demonstrated by its little-changed amount and morphology of granules. The characteristics of the stabilized granules were: 5.4 mm in mean diameter, 1.29 in roundness, 118 mg O2 x (mg VSS x hr)(-1) in SPOUR. The respective biomass SVI was 50 mL x (g MLVSS)(-1) and the averaged COD removal rate was 95%. Under the OLR of 8 kg COD x (m3 x day)(-1), granules appeared two days later than those for 4 kg COD x (m3 x day)(-1) and they always coexisted with flocs. The formed granule bed was not as compact as that under 4 kg COD x (m3 x day)(-1). There were no granules formed under the OLR of 1 kg COD x (m3 x day)(-1). Instead, flocs with rather loose structure dominated reactor mixed-liquor. The respective SVI's were 65 and 138 mL x (g MLVSS)(-1) under OLR of 8 and 1 kg COD x (m3 x day)(-1). It was proposed that the growth and maintenance of aerobic granules follow the shear force balance theory. Under the OLR of 4 kg COD x (m3 x day)(-1), a balance was reached between the aeration shear force and organic loading rate. Under this favored condition aerobic granules formed quickly and, became stabilized with the experimental parameters remained unchanged.
采用三个柱状序批式好氧污泥床反应器（SASBR）研究了有机负荷率（OLR）对好氧颗粒化的影响。反应器采用实验室配制的合成葡萄糖 - 营养肉汤底物进料。实验结果清楚地表明，好氧颗粒的形成、特性和稳定性与所施加的OLR强度密切相关。在4 kg COD×(m³×天)⁻¹的OLR下首先出现好氧颗粒。系统稳定性通过颗粒数量和形态变化不大得以证明。稳定颗粒的特性为：平均直径5.4 mm，圆度1.29，特定氧摄取率（SPOUR）为118 mg O₂×(mg VSS×小时)⁻¹。各自的污泥体积指数（SVI）为50 mL×(g MLVSS)⁻¹，平均化学需氧量（COD）去除率为95%。在8 kg COD×(m³×天)⁻¹的OLR下，颗粒比在4 kg COD×(m³×天)⁻¹时晚两天出现，并且它们总是与絮体共存。形成的颗粒床不如在4 kg COD×(m³×天)⁻¹时紧密。在1 kg COD×(m³×天)⁻¹的OLR下未形成颗粒。相反，结构相当松散的絮体主导了反应器混合液。在8和1 kg COD×(m³×天)⁻¹的OLR下，各自的SVI分别为65和138 mL×(g MLVSS)⁻¹。有人提出，好氧颗粒的生长和维持遵循剪切力平衡理论。在4 kg COD×(m³×天)⁻¹的OLR下，曝气剪切力和有机负荷率之间达到平衡。在这种有利条件下，好氧颗粒迅速形成，并在实验参数保持不变的情况下变得稳定。
