Abstract
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/(m3 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.
Original language | English |
---|---|
Journal | Journal of Bioscience and Bioengineering |
Volume | 107 |
Issue number | 6 |
Pages (from-to) | 641-645 |
ISSN | 1389-1723 |
DOIs | |
Publication status | Published - 2009 |
Externally published | Yes |