Combining phosphate species and stainless steel cathode to enhance hydrogen evolution in microbial electrolysis cell (MEC)

Microbial electrolysis cells (MEC) must work around neutral pH because of microbial catalysis at the anode. To develop a hydrogen evolution cathode that can work at neutral pH remains a major challenge in MEC technology. Voltammetry performed at pH 8.0 on rotating disk electrodes showed that the presence of phosphate species straightforwardly multiplied the current density of hydrogen evolution, through the so-called cathodic deprotonation reaction. The mechanism was stable on stainless steel cathodes whereas it rapidly vanished on platinum. The phosphate/stainless steel system implemented in a 25 L MEC with a marine microbial anode led to hydrogen evolution rates of up to 4.9 L/h/m2 under 0.8 V voltage, which were of the same order than the best performance values reported so far. Keywords: Hydrogen; Microbial electrolysis cell (MEC); Stainless steel; Phosphat

Congenital microcephaly: Case definition & guidelines for data collection, analysis, and presentation of safety data after maternal immunisation.

Need for developing case definitions and guidelines for data collection, analysis, and presentation for congenital microcephaly as an adverse event following maternal immunisation Congenital microcephaly, also referred to as primary microcephaly due to its presence in utero or at birth, is a descriptive term for a structural defect in which a fetus or infant’s head (cranium) circumference is smaller than expected when compared to other fetuses or infants of the same gestational age, sex and ethnic background

Microbial fuel cells: From fundamentals to applications. A review

© 2017 The Author(s) In the past 10–15 years, the microbial fuel cell (MFC) technology has captured the attention of the scientific community for the possibility of transforming organic waste directly into electricity through microbially catalyzed anodic, and microbial/enzymatic/abiotic cathodic electrochemical reactions. In this review, several aspects of the technology are considered. Firstly, a brief history of abiotic to biological fuel cells and subsequently, microbial fuel cells is presented. Secondly, the development of the concept of microbial fuel cell into a wider range of derivative technologies, called bioelectrochemical systems, is described introducing briefly microbial electrolysis cells, microbial desalination cells and microbial electrosynthesis cells. The focus is then shifted to electroactive biofilms and electron transfer mechanisms involved with solid electrodes. Carbonaceous and metallic anode materials are then introduced, followed by an explanation of the electro catalysis of the oxygen reduction reaction and its behavior in neutral media, from recent studies. Cathode catalysts based on carbonaceous, platinum-group metal and platinum-group-metal-free materials are presented, along with membrane materials with a view to future directions. Finally, microbial fuel cell practical implementation, through the utilization of energy output for practical applications, is described