Evaluation of different types of anaerobic seed sludge for the high rate anaerobic digestion of pig slurry in UASB reactors

Abstract

Three different types of anaerobic sludge (granular, thickened digestate and anaerobic sewage) were evaluated as seed inoculum sources for the high rate anaerobic digestion of pig slurry in UASB reactors. Granular sludge performance was optimal, allowing a high efficiency process yielding a volumetric methane production rate of 4.1LCHLd at 1.5days HRT (0.248LCHgCOD) at an organic loading rate of 16.4gCODLd. The thickened digestate sludge experimented flotation problems, thus resulting inappropriate for the UASB process. The anaerobic sewage sludge reactor experimented biomass wash-out, but allowed high process efficiency operation at 3days HRT, yielding a volumetric methane production rate of 1.7LCHLd (0.236LCHgCOD) at an organic loading rate of 7.2gCODLd. To guarantee the success of the UASB process, the settleable solids of the slurry must be previously removed.

Removal of solids and chemical oxygen demand in poultry litter anaerobic digestion with different inocula

“…It is known that the presence of inoculum influences the methanogenic activity and can present significant differences for different inoculum sources (Vrieze et al, 2015;Rico et al, 2017). In this study, it is observed that different types of inoculum may also influence the removal of COD and solids.…”

“…It is worthy to note that different inocula lead to different biogas production, with significant effect of the inoculum on the Biochemical Methane Potential (BMP) (Vrieze et al, 2015). Another paper (Rico et al, 2017) shows the influences of inocula on the anaerobic digestion of pig slurry in UASB reactor.…”

Anaerobic / aerobic treatability of livestock wastewater

“…Rico ve diğ. [12], tarafından yapılan domuz çiftliği atıksularının UASB reaktörde arıtılmasında, uçucu yağ asidi konsantrasyonları 1300-1800 mg/l arasında değişmiştir. Bu değerler bu çalışmada ölçülen VFA konsantrasyonları ile uyumludur.…”

“…Amuda [11], tarafından büyükbaş hayvan çiftliğinden kaynaklanan atıksu karakterizasyonunu belirleme amaçlı yapılan çalışmada KOİ, askıda katı madde (AKM), biyolojik oksijen ihtiyacı (BOİ), TP, toplam kjeldahl azotu (TKN), yağ ve pH parametreleri sırasıyla; 14350 mg/l, 19945 mg/l, 14370 mg/l, 720 mg/l, 280 mg/l, 47 mg/l, 6.7 olarak bulunmuştur. Farklı bir çalışmada ise domuz çiftliği atıksuyunun 3 farklı tür aşı çamuru kullanılarak UASB reaktörlerde arıtımı çalışılmıştır [12]. Kullanılan aşı çamurlarından; biyoetanol üreten tesisin atıksularını arıtan UASB reaktörden alınan granüler aşı çamuru metan oluşum oranı açısından en iyi sonucu vermiştir.…”

Anaerobic Process

“…Rico et al (2017) investigated the effect on granular, thickened digestate and anaerobic sewage which were three types of anaerobic sludge to improve the performance by AD of pig slurry in UASB reactors. The results showed that granular sludge had the best performance which can increase the methane generation rate to 4.1 L CH4 /L · d at 1.5 d HRT and OLR of 16.4 g COD /L ·d.…”