No abstract

New insights are reported on the degradation of organics in urine, changes in the anodic bacterial community and MFC performance on urine.

h i g h l i g h t s Only the variable Mg:P molar ratio had a significant influence on P recovery. 99% of P was recovered with MgO as Mg 2+ source, 2:1 molar ratio and 30 rpm. Struvite crystals with 50-100 lm size were obtained. XRD patterns were coherent with the standard model for struvite crystals. Only the variable stirring speed had a significant effect on crystal size.

This work was conducted to examine the composition and electrochemical activity of the bacterial community inhabiting lake Furnas sediments (Azores). Fingerprinting analysis of the bacterial 16S rRNA gene fragment was done by denaturing gradient gel electrophoresis. The sequences retrieved from lake Furnas sediments were affiliated to Bacteroidetes/Chlorobi group, Chloroflexi, Alfa-, Delta-, and Gamma-subclasses of Proteobacteria, Cyanobacteria, and Gemmatimonadetes. A cyclic voltammetric study was carried out with an enriched sediment bacterial suspension in a standard two chamber electrochemical cell using a carbon paper anode. Cyclic voltammograms (scan rate of 50 mV/s) showed the occurrence of oxidation-reduction reactions at the carbon anode surface. The benthic microbial fuel cell operated with lake Furnas sediments presented a low power density (1 mW/m(2)) indicating that further work is required to optimise its power generation. These results suggested that sediment bacteria, probably from the Delta- and Gamma-subclasses of Proteobacteria, were electroactive under tested conditions.