The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

A wastewater to chemical fuel conversion device is provided that includes a housing having a first chamber and a second chamber, where the first chamber includes a bio-photoanode, where the second chamber includes a photocathode, where a backside of the bio-photoanode abuts a first side of a planatized fluorine doped tin oxide (FTO) glass, where a backside of the photocathode abuts a second side of the FTO glass, where a proton exchange membrane separates the first chamber from the second chamber, where the first chamber includes a wastewater input and a reclaimed water output, where the second chamber includes a solar light input and a H.sub.2 gas output, where the solar light input is disposed for solar light illumination of the first chamber and the second chamber.

A wastewater to chemical fuel conversion device is provided that includes a housing having a first chamber and a second chamber, where the first chamber includes a bio-photoanode, where the second chamber includes a photocathode, where a backside of the bio-photoanode abuts a first side of a planatized fluorine doped tin oxide (FTO) glass, where a backside of the photocathode abuts a second side of the FTO glass, where a proton exchange membrane separates the first chamber from the second chamber, where the first chamber includes a wastewater input and a reclaimed water output, where the second chamber includes a solar light input and a H.sub.2 gas output, where the solar light input is disposed for solar light illumination of the first chamber and the second chamber.

A biological cathode and biological battery system for converting carbon feedstock into organic chemicals and producing electrical current is described. The method involves a biological battery system comprising of a reaction vessel and biological cathode electrode. The organic chemicals are processed in a space having at least one anode and at least one cathode with cathode electrode having biologically active material adjacent to at least one layer of the cathode electrode. The material can be a gel, liquid, or solid. This system can be carried out to process organic waste in an environmentally friendly manner.

A biological cathode and biological battery system for converting carbon feedstock into organic chemicals and producing electrical current is described. The method involves a biological battery system comprising of a reaction vessel and biological cathode electrode. The organic chemicals are processed in a space having at least one anode and at least one cathode with cathode electrode having biologically active material adjacent to at least one layer of the cathode electrode. The material can be a gel, liquid, or solid. This system can be carried out to process organic waste in an environmentally friendly manner.

A microbial fuel cell (MFC) in which the anode and/or cathode half-cell comprises at least one additional electrode insulated from direct contact with the working electrode and arranged to be coupled to an external voltage or current source, wherein the additional electrode does not comprise an internal redox system, methods of operation of MFCs and methods for measuring, controlling or modulating MFC circuits are described.

A microbial fuel cell (MFC) in which the anode and/or cathode half-cell comprises at least one additional electrode insulated from direct contact with the working electrode and arranged to be coupled to an external voltage or current source, wherein the additional electrode does not comprise an internal redox system, methods of operation of MFCs and methods for measuring, controlling or modulating MFC circuits are described.

A method of preparing an electrode for use in a biophotovoltaic device, comprising the steps of: coating a self-assembled film on a substrate using Langmuir-Blodgett technique; and immersing the coated substrate into an microalgae culture, followed by incubating thereof to grow microalgae thereon hence obtaining a biofilm, characterised in that the self-assembled film is derived from graphene.

A method of preparing an electrode for use in a biophotovoltaic device, comprising the steps of: coating a self-assembled film on a substrate using Langmuir-Blodgett technique; and immersing the coated substrate into an microalgae culture, followed by incubating thereof to grow microalgae thereon hence obtaining a biofilm, characterised in that the self-assembled film is derived from graphene.