Luo Gang, Xie Li, Zhou Qi
State Key Laboratory of Pollution Control and Resource Reuse (Tongji University), Siping Road no. 1239, Shanghai 200092, PR China.
J Biosci Bioeng. 2009 Jun;107(6):641-5. doi: 10.1016/j.jbiosc.2009.01.015.
Cassava stillage is a high strength organic wastewater with high suspended solids (SS) content. The efficiency of cassava stillage treatment using an anaerobic sequencing batch reactor (ASBR) was significantly enhanced by discharging settled sludge to maintain a lower sludge concentration (about 30 g/L) in the reactor. Three hydraulic retention times (HRTs), namely 10 d, 7.5 d, 5 d, were evaluated at this condition. The study demonstrated that at an HRT of 5 d and an organic loading rate (OLR) of 11.3 kg COD/(m(3) d), the total chemical oxygen demand (TCOD) and soluble COD (SCOD) removal efficiency can still be maintained at above 80%. The settleability of digested cassava stillage was improved significantly, and thus only a small amount of settled sludge needed to be discharged to maintain the sludge concentration in the reactor. Furthermore, the performance of ASBR operated at low and high sludge concentration (about 79.5 g/L without sludge discharged) was evaluated at an HRT of 5 d. The TCOD removal efficiency and SS in the effluent were 61% and 21.9 g/L respectively at high sludge concentration, while the values were 85.1% and 2.4 g/L at low sludge concentration. Therefore, low sludge concentration is recommended for ASBR treating cassava stillage at an HRT 5 d due to lower TCOD and SS in the effluent, which could facilitate post-treatment.
木薯酒糟是一种高浓度有机废水，悬浮固体（SS）含量高。通过排放沉淀污泥以维持反应器中较低的污泥浓度（约30 g/L），使用厌氧序批式反应器（ASBR）处理木薯酒糟的效率得到显著提高。在此条件下评估了三种水力停留时间（HRT），即10天、7.5天、5天。研究表明，在HRT为5天、有机负荷率（OLR）为11.3 kg COD/(m³·d)时，总化学需氧量（TCOD）和可溶性COD（SCOD）的去除效率仍可保持在80%以上。消化后的木薯酒糟的沉降性能显著改善，因此只需排放少量沉淀污泥即可维持反应器中的污泥浓度。此外，在HRT为5天时，评估了ASBR在低污泥浓度和高污泥浓度（不排放污泥时约79.5 g/L）下的运行性能。高污泥浓度时，TCOD去除效率和出水SS分别为61%和21.9 g/L，而低污泥浓度时分别为85.1%和2.4 g/L。因此，对于ASBR在HRT为5天时处理木薯酒糟，建议采用低污泥浓度，因为出水的TCOD和SS较低，这有利于后续处理。
