Assessment of Biogas use as an Energy Source from Anaerobic Digestion of Brewery Wastewater

Energy recovery from a crossflow ultrafiltration (UF) membraneunit employed in order to improve the performance of an anaerobic contact digester for the treatment of brewery wastewater was assessed. The performance of the pilot-scale anaerobic UF membrane system was studied for over 15 months. At steady-state conditions, an organic loading rate of 28.5 kg COD m^-3 d^-1, a hydraulic retention time of 4.2 days and overall COD and BOD removal efficiencies of 99% and almost 100% were achieved, respectively. Percent methane in biogas was found to be in a range of 67–79% with the corresponding methane yield of 0.28–0.35 m³ CH₄ kg^-1 COD_removed. The potential energy recovery from the system treating brewery wastewater at an OLR of 28.5 kg COD m^-3 d^-1 was 87 MJ d^-1 which would enable to maintain all energy requirements of the feed pump, mixing and heating of the reactor contents. In addition to this, 71% of the energy requirement for recirculating the reactor content through the membranes would also be recovered.     

New method for estimating the volume and volume fractions of the nasal structures in the goose (Anser anser domesticus) using computed tomography images

1. The conchae within the nasal cavity of poultry are important for water and energy conservation, but have not been experimentally evaluated. The aim of the present study was to determine the accuracy of volume and volume fraction estimates of the conchae, nasal septum and nasal cavity.

2. The nasal cavities of 7 adult goose heads were scanned using computed tomography (CT), with images sampled randomly at a 1/5 sampling fraction. Physical sections were obtained from the same samples, using an electric saw that had an adjustable section range, and provided 14 to 15 sections with a thickness of 2.5 mm. The section surface areas of the nasal cavity, nasal septum and conchae were estimated using the Cavalieri principle. Results obtained using the CT and physical section images were compared. Volumes and volume fractions obtained from the physical sections were accepted as the gold standard and differences in the CT images were determined.

3. Multiplication of the data obtained on the CT images with the deviation percentage of the physical sections produced normalised values. No differences were observed between the gold standard data and the CT images. While it was possible to normalise the obtained data using the gold standard values, the raw data could also be used for comparative studies because the deviations from normal would be similar for all groups.

4. Our study showed that the nasal structures could be estimated in vivo using CT images.     

Three-dimensional modelling of computed tomography images of limb bones in gazelles (Gazella subgutturosa)

The objective of the present study was to model in 3D the detailed morphometric features of the thoracic and pelvic limb bones of the gazelle (Gazella subgutturosa), whose natural habitat is only in the Sanliurfa province, by using multidetector computerized tomography (MDCT) images. Materials from 14 (7 male and 7 female) dead gazelles were collected from the Harran University Veterinary Medicine Faculty clinics during or after treatment. MDCT images of the gazelles were taken and saved as DICOM (Digital Imaging and Communications in Medicine) files. MIMICS 20.1 software was used to generate a 3D reconstruction of the data, and morphological and morphometrical evaluation was performed. In respect of morphological features, the combined metacarpus (Mc) III and metacarpus Mc IV were the main weight-bearing metacarpal bone, while Mc II and Mc V were rudimentary. On the femur, the lateral condyle was bigger than the medial condyle at the caudodistal end and the medial wing of the trochlea femoris was larger than the lateral. As with the thoracic limb, the combined metatarsus (Mt) III and metatarsus Mt IV were the main weight-bearing metacarpal bone and they displayed a synostosis structure. There was no secondary metatarsus in the gazelles’ pelvic limb. Based on digital measurements, the tibia was the longest bone of the gazelles’ skeletal system, and there was a statistically significant sexual dimorphism throughout the skeleton at the levels of p < .05, p < .01 and p < .001. As a result, the present study's findings are useful as reference data for further studies on anatomy, surgery and archaezoology, while also being useful for classifying species and for forensic sciences.     

Changes in Acetoclastic Methanogenic Activity and Microbial Composition in an Upflow Anaerobic Filter

Changes in the acetoclastic methanogenic activity in the effluentfrom an upflow anaerobic filter (UFAF) were studied throughout a 36 week operating period. The UFAF formed the second phase of a two-phase laboratory-scale anaerobic treatment system. TheSpecific Methanogenic Activity (SMA) test was used to measurethe acetoclastic methanogenic activity of the biomass washed outfrom the UFAF. Throughout the operating period, the SMA testswere carried out at different organic loading rates (OLR) up to6.7 kg COD m^-3 d^-1 and upflow velocities (UV), 5 m d^-1 and 15 m d^-1. The results showed that thebiomass washed out from the UFAF consisted of up to 55%(considered as a draft value) acetoclastic methanogens producing550 mI CH₄ g^-1 VSS d^-1. This high acetoclasticmethanogenic activity measured in the effluent might have beendue to the existence of Methanosaeta (formerly Methanothrix) species. Towards the end of operation,Epifluorescence Microscopic examinations in the effluent revealedthat Methanococcus species were the most dominant groupfollowed by medium rods and short rods, filaments and long rodsand the least dominant Methanosarcina species. Theperformance of the UFAF was not adversely affected by the loss ofthe active biomass and changes in their composition. The UFAFsystem achieved over 85% COD removal efficiency at thehighest OLR of 6.7 kg COD m^-3 d^-1 and UV of 15 m d^-1. Throughout most of the operation, methane yield rangedfrom 0.28–035 m³ CH₄ kg^-1 COD_removed.     

Volatilization of organic chemicals from water

Liquid-phase transfer coefficients of ten selected organic pollutants were measured simultaneously with the O₂ reaeration coefficient in a 2L reactor. The contents of the reactor were stirred in the laboratory by a 0.15 m diameter propeller attached to a constant speed motor. The ratio of the mass transfer coefficient of the chemical to that of O₂ is found to vary between 0.43 and 0.60 for eight of the chemicals tested. This result is in good agreement with the literature concerning high volatility chemicals. The value of this ratio for the other two chemicals was found to be 0.10 for nitrobenzene and 0.01 for phenol, confirming the predominance of gas phase resistances in the transport process for these two compounds.     

In vitro degradation of grass fructan by equid gastrointestinal digesta

Laminitis is a debilitating disease of the equid foot and appears to result from altered metabolism due to insulin resistance (IR) or hindgut acidosis. These disorders may be elicited by high intakes of simple sugars or fructans in pasture grasses. The aim was to determine in vitro (i) whether grass fructan is degraded in the equid foregut and (ii) the fermentation kinetics and organic acid production in cultures containing grasses differing in fructan content incubated with an equid hindgut microbial inoculum. When grass fructan was incubated with equid gastric and small intestinal digesta, polymeric fructan was partially degraded to oligo‐fructan. When incubated with small intestinal digesta, but not gastric digesta, there was limited net loss of total fructan (oligomeric + polymeric fructan). When Lolium perenne of elevated (PRGH) or moderate (PRGL) fructan content was incubated with an equine hindgut microbial inoculum, the rate of fermentation and accumulation of lactate 6 and 9 h post‐inoculation were significantly greater for PRGH than for PRGL (P < 0·05). This may suggest that grass fructan ingested by grazing horses is incompletely digested in the foregut and passes into the hindgut, resulting in elevated production of lactate, which may indirectly lead to metabolic disorders such as laminitis.