Performance evaluation of an anaerobic hybrid digester treating palm oil mill effluent

Palm Oil Mill Effluent Treatment Process Evaluation and Fate of Priority Components in an Open and Closed Digestion System

“…The relationship between influent COD contents and their removal efficiencies (Fig. 2) is consistent with the findings of other researchers 22,37 , who observed that COD and VFA removal efficiencies were directly proportional to influent concentrations. Fig.…”

Kinetic evaluation of palm oil mill effluent digestion in a high rate up-flow anaerobic sludge fixed film bioreactor

“…A comparison of the results obtained with the UASFF reactor in the present study with those obtained from other modern anaerobic techniques, i.e. a UASB reactor [13], an anaerobic hybrid reactor [14], a modified anaerobic baffled (MAB) reactor [22] and a membrane anaerobic system (MAS) [15] treating POME is presented in Table 3. About 90% COD removal was achieved with the UASFF reactor at short HRT (1.5 days) and high OLR (23.15 g COD/l day).…”

“…However, reactor instability was observed after 15 days of operation. Performance of an anaerobic hybrid digester was evaluated by Borja et al [14]. At a hydraulic retention time (HRT) of 3.5 days and OLR of 16.2 g COD/l day, COD removal and methane yield obtained were 92.3% and 0.335 l CH 4 /g COD removed , respectively.…”

Pollution control technologies for the treatment of palm oil mill effluent (POME) through end-of-pipe processes

“…For example, the granulation of anaerobic sludge, which usually requires a longer time (Schmidt and Ahring, 1996), was observed within the limited operational period in the UASFF reactor since the internal recirculation of dispersed bacteria and the resultant high interaction among bacterial consortium could assist in their faster agglomeration to form biogranules (Najafpour et al, 2006). The UASFF reactor has been successfully used for treating various wastewaters such as swine (Lo et al, 1994), POME (Borja et al, 1996a;Najafpour et al, 2006;Zinatizadeh et al, 2006aZinatizadeh et al, ,b, 2007a and slaughterhouse wastewater (Borja et al, 1998).…”

“…The best option to achieve high solid retention time while maintaining HRT at low levels is biomass immobilization, which is applied in the UASFF reactor in the form of granular sludge and biofilm attached on the packing (Zinatizadeh et al, 2007b). Borja et al (1996a) used an anaerobic hybrid digester, in which the bottom two-thirds were occupied by a sludge blanket and the upper one-third by submerged PVC rings, to treat POME under mesophilic conditions. A high COD removal could be achieved at an HRT of 3.5 days, however, a decreasing digester efficiency was observed along with accumulation of propionic acid.…”