Enhanced performance and degradation of wastewater in microbial fuel cells using titanium dioxide nanowire photocathodes

Active Red 30 was effectively removed in the cathode chamber of the microbial fuel cell.

Electrochemical Synthesis of Hydroxyapatite Nanosheet-Assembled Porous Structures with Bipolar Membrane

The porous nanostructured hydroxyapatite (HA) has the high specific surface area and loading capacity that is useful for enhancing bioactivity, sinterability, densification, and the capacity for loading the drug, protein, heavy metals, etc. For the first time, the bipolar membrane in electrochemical method was developed for the synthesis of hydroxyapatite nanosheet-assembled porous structures. The bipolar membrane was installed in the electrolysis cell to separate the cell into two chambers. The bipolar membrane prevented the OH- ions to move away from the cathode chamber and the H+ ions to go to the cathode chamber. In this condition, HA was formed in the cathode chamber while the other calcium phosphate was formed in the anode chamber. The pH increase of solution rapidly leads to more effective the formation of the nanostructured HA. The higher the electrolysis time and the current density the greater the tendency of nanostructured HA formation. The mechanism of HA hydroxyapatite nanosheet-assembled porous structures formation includes the agglomeration formation of the spherical-like particles, the formation of agglomeration nanosheet structures, and the formation of HA hydroxyapatite nanosheet-assembled porous structures.

Photosynthetic Microbial Desalination Cell to Treat Oily Wastewater Using Microalgae Chlorella Vulgaris

Microbial desalination cell (MDC) offers a new and sustainable approach to desalinate saltwater by directly utilizing the electrical power generated by bacteria during organic matter oxidation. In this study, we used microalgae Chlorella Vulgaris in the cathode chamber to produce oxygen as an electron accepter by photosynthesis process for generate bioelectricity power and treat oil refinery wastewater by microorganisms in both anode and cathode.The power density generated by this Photosynthetic Microbial Desalination Cell (PMDC) with 1KΩ external resistance at the first 4th hr. of operation period was 0.678 W/m3 of anode volume and 0.63 W/m3 of cathode volume. It increased after one day to a peak value of (4.32 W/m3 of anode volume and 4.013 W/m3 of cathode volume). The microalgae growth in the biocathode chamber followed in terms of optical density. The optical density increased from 0.546 at the beginning of the system operation to 1.71 after 24 days of operation period. The percentage removal of chemical oxygen demand (COD) of oil refinery wastewater was 97.33% and 79.22% in anode and cathode chamber, respectively. The microalgae in the biocathode were able to remove volatile compounds causing odor from the influent wastewater. TDS removal rate 159.722 ppm/h with initial TDS in desalination chamber of 35000 ppm.