No abstract

Syngas biomethanation is a potent bio-conversion route, utilizing microorganisms to assimilate intermediate gases to produce methane. However, since methanogens have a long doubling time, the reactor works best at a low dilution rate; otherwise, the cells can be washed out during the continuous fermentation process. In this study, the performance of a practical reverse membrane bioreactor (RMBR) with high cell density for rapid syngas biomethanation as well as a co-substrate of syngas and organic substances was examined in a long-term fermentation process of 154 days and compared with the reactors of the free cells (FCBR). The RMBR reached maximum capacities of H 2 , CO, and CO 2 conversion of 7.0, 15.2, and 4.0 mmol/L reactor .day, respectively, at the organic loading rate of 3.40 gCOD/L.day. The highest methane production rate from the RMBR was 186.0 mL/L reactor .day on the 147th day, compared to the highest rate in the FCBR, 106.3 mL/L reactor .day, on the 58th day. The RMBR had the ability to maintain a high methanation capacity by retaining the microbial cells, which were at a high risk for cell wash out. Consequently, the system was able to convert more syngas simultaneously with the organic compounds into methane compared to the FCBR.

Please cite this article as: Youngsukkasem, S., Chandolias, K., Taherzadeh, M.J., Rapid bio-methanation of syngas in a reverse membrane bioreactor: Membrane encased microorganisms, Bioresource Technology (2014), doi: http:// dx.doi.org/10. 1016/j.biortech.2014.07.071 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The performance of a novel reverse membrane bioreactor (RMBR) with encased microorganisms for syngas bio-methanation as well as a co-digestion process of syngas and organic substances was examined. The sachets were placed in the reactors and examined in repeated batch mode. Different temperatures and short retention time were studied. The digesting sludge encased in the PVDF membranes was able to convert syngas into methane at a retention time of one day and displayed a similar performance as the free cells in batch fermentation. The co-digestion of syngas and organic substances by the RMBR (the encased cells) showed a good performance without any observed negative effects. At thermophilic conditions, there was a higher conversion of pure syngas and co-digestion using the encased cells compared to at mesophilic conditions. Rapid Bio-methanation of Syngas in a Reverse

No abstract

The low gas-to-liquid mass transfer rate is one of the main challenges in syngas biomethanation. In this work, a new concept of the floating membrane system with high gas hold-up was introduced in order to enhance the mass transfer rate of the process. In addition, the effect of the inoculum-to-syngas ratio was investigated. The experiments were conducted at 55 °C with an anaerobic mixed culture in both batch and continuous modes. According to the results from the continuous experiments, the H2 and CO conversion rates in the floating membrane bioreactor were approximately 38% and 28% higher in comparison to the free (suspended) cell bioreactors. The doubling of the thickness of the membrane bed resulted in an increase of the conversion rates of H2 and CO by approximately 6% and 12%, respectively. The highest H2 and CO consumption rates and CH4 production rate recorded were approximately 22 mmol/(L·d), 50 mmol/(L·d), and 34.41 mmol/(L·d), respectively, obtained at the highest inoculum-to-syngas ratio of 0.2 g/mL. To conclude, the use of the floating membrane system enhanced the syngas biomethanation rates, while a thicker membrane bed resulted in even higher syngas conversion rates. Moreover, the increase of the inoculum-to-syngas ratio of up to 0.2 g/mL favored the syngas conversion.

Hydrolyzed wheat straw was converted into carboxylic acids and biohydrogen using digesting bacteria. The fermentations were carried out using both free and membrane-encased thermophilic bacteria (55°C) at various OLRs (4.42-17.95g COD/L.d), in semi-continuous conditions using one or two bioreactors in a series. The highest production of biohydrogen and acetic acid was achieved at an OLR of 4.42g COD/L.d, whilst the highest lactic acid production occurred at an OLR of 9.33g COD/L.d. Furthermore, the bioreactor with both free and membrane-encased cells produced 60% more lactic acid compared to the conventional, free-cell bioreactor. In addition, an increase of 121% and 100% in the production of acetic and isobutyric acid, respectively, was achieved in the 2nd-stage bioreactor compared to the 1st-stage bioreactor.

Introduction: The main symptoms of juvenile idiopathic arthritis (JIA) include swelling of the affected joints, sensitivity, painful movement restriction, and walking disorders. A wealth of findings and research is available on the benefits of various physiotherapy interventions. Instead, there are a small number of studies that examine the benefits of more alternative forms of physiotherapy such as hydrotherapy and more specifically the Halliwick therapy. In the hydrotherapy studies so far, the results are equivalent to classical physiotherapy and sometimes better. Aim: This study attempts to record and highlight the effect of the Halliwick hydrotherapy in children with JIA in a 2-month intervention program. In particular, it focuses on (1) balance and (2) plantar pressure distribution before and after the intervention. Methodology: The methodology we used to collect our data was quantitative research, and the research tools used were the Berg balance scale and a modular platform system to measure plantar pressure. The sample consisted of 16 children with JIA who took measurements before and after the intervention. The duration of this intervention was 2 months. Data analysis was performed using the SPSS v21 statistical program. Results: Some remarkable results were obtained: (1) all subjects had no significant change in the already good balance; and (2) all subjects had a significant improvement in the uniform distribution of plantar pressure following the Halliwick treatment sessions. Conclusions: The philosophy of the Halliwick hydrotherapy is a more alternative form of physical therapy that has been shown to contribute to improving the distribution of weight and plantar pressure in children suffering from JIA.

Psychological harassment in the workplace is a silent epidemic nowadays and verbal abuse is the most common form of harassment in the health professions. The apparentdeeper causes of the phenomenon vary, making it difficult to investigate but at the same time necessary because of its serious impact on the individual, the organization and society. Given the characteristics of pediatric physiotherapy, as a specialized profession requiring interdisciplinary collaboration and direct contact with the pain and dysfunction of the delicate group of pediatric patients and their families, we can assume the existence of verbal abuse in this job. In this case, there are negative consequences for the dynamics of the treatment team and the quality of medical care. Purpose: This study aims to investigate the verbal abuse against physiotherapists in pediatrics, in Greece