Bioenergy production from chicken feather waste by anaerobic digestion and bioelectrochemical systems.

BACKGROUND: Poultry feather waste has a potential for bioenergy production because of its high protein content. This research explored the use of chicken feather hydrolysate for methane and hydrogen production via anaerobic digestion and bioelectrochemical systems, respectively. Solid state fermentation of chicken waste was conducted using a recombinant strain of Bacillus subtilis DB100 (p5.2). RESULTS: In the anaerobic digestion, feather hydrolysate produced maximally 0.67 Nm3 CH4/kg feathers and 0.85 mmol H2/day.L concomitant to COD removal of 86% and 93%, respectively. The bioelectrochemical systems used were microbial fuel and electrolysis cells. In the first using a microbial fuel cell, feather hydrolysate produced electricity with a maximum cell potential of 375 mV and a current of 0.52 mA. In the microbial electrolysis cell, the hydrolysate enhanced the hydrogen production rate to 7.5 mmol/day.L, with a current density of 11.5 A/m2 and a power density of 9.26 W/m2. CONCLUSIONS: The data indicated that the sustainable utilization of keratin hydrolysate to produce electricity and biohydrogen via bioelectrical chemical systems is feasible. Keratin hydrolysate can produce electricity and biofuels through an integrated aerobic-anaerobic fermentation system.

Comparison between a Conventional Anti-Biofouling Compound and a Novel Modified Low-Fouling Polyethersulfone Ultrafiltration Membrane: Bacterial Anti-Attachment, Water Quality and Productivity.

In this work, the efficiency of a conventional chlorination pretreatment is compared with a novel modified low-fouling polyethersulfone (PES) ultrafiltration (UF) membrane, in terms of bacteria attachment and membrane biofouling reduction. This study highlights the use of membrane modification as an effective strategy to reduce bacterial attachment, which is the initial step of biofilm formation, rather than using antimicrobial agents that can enhance bacterial regrowth. The obtained results revealed that the filtration of pretreated, inoculated seawater using the modified PES UF membrane without the pre-chlorination step maintained the highest initial flux (3.27 ± 0.13 m3·m-2·h-1) in the membrane, as well as having one and a half times higher water productivity than the unmodified membrane. The highest removal of bacterial cells was achieved by the modified membrane without chlorination, in which about 12.07 × 104 and 8.9 × 104 colony-forming unit (CFU) m-2 bacterial cells were retained on the unmodified and modified membrane surfaces, respectively, while 29.4 × 106 and 0.42 × 106 CFU mL-1 reached the filtrate for the unmodified and modified membranes, respectively. The use of chlorine disinfectant resulted in significant bacterial regrowth.

Experience with supracricoid laryngectomy variants.

BACKGROUND: The purpose of this study was to evaluate the outcomes after supracricoid laryngectomy (SCL) as an alternative to total laryngectomy (TL) for treatment of laryngeal cancer. METHODS: This retrospective study involved 333 patients who underwent 4 types of SCL for squamous cell carcinoma of the larynx in an Egyptian hospital between May 1984 and May 2007. Both functional outcomes and oncological outcomes were evaluated. RESULTS: Surgical margins were free from tumor invasion. The overall 5-year survival rate was 74%. Three hundred nine patients (92.8%) were decannulated, whereas 8 patients had permanent stenosis, 6 patients underwent TL, and 10 patients died. Only 7 patients (2.1%) had persistent aspiration; 6 of these patients underwent TL, whereas 1 patient died of pneumonia. The voice intelligibility score ranged from 70% to 100%, with a mean score of 89%. The score was highest when both arytenoids were preserved (mean, 95%). Ten patients died of complications directly related to the surgery. CONCLUSION: Supracricoid laryngectomy is effective for managing laryngeal cancer. Modification of the technique to permit resection of both arytenoids is possible in select patients.