A microbial fuel cell contains a negative electrode including a sheet-like first carbon material including a graphene sheet, the negative electrode supporting microorganisms, and a positive electrode opposed to the negative electrode. The negative electrode has an arithmetical mean roughness Ra on the surface thereof set in a range of 4.0 m to 10000 m. A waste liquid treatment system includes the microbial fuel cell, wherein the positive electrode is arranged in contact with gas containing oxygen. The microbial fuel cell can be deformed into a shape so as to have high resistance to water pressure. The microbial fuel cell can also increase in the amount of microorganisms supported on the negative electrode due to the high arithmetical mean roughness Ra, so as to enhance output power of the microbial fuel cell.

The present invention provides a bioelectrochemical system for removing a polyvalent ion present in seawater etc., capable of producing electricity. The bioelectrochemical system according to the present invention comprises: an anode chamber comprising an anode which accommodates an electron produced when treating an organic material in wastewater with a microorganism; a cathode chamber comprising a cathode receiving the electron from the anode, for producing a hydroxide ion by reacting the electron with oxygen and water provided from the outside, and depositing the polyvalent ion inside an electrolyte by using the hydroxide ion; and an anion exchange membrane for blocking the polyvalent ion inside the electrolyte from moving to the anode chamber. Also, the present invention provides the bioelectrochemical system capable of removing the polyvalent ion present in seawater etc., and simultaneously producing hydrogen. The present invention comprises: the anode chamber, provided with the anode to which electrochemically active bacteria are attached, for producing the electron by having organic wastewater, as a substrate, injected thereto; the cathode chamber, provided with the cathode, for removing the polyvalent ion and simultaneously producing a hydrogen gas by having seawater, as an electrolyte, injected thereto; the anion exchange membrane for separating the anode chamber and the cathode chamber and preventing the polyvalent cation in seawater from moving to the anode chamber; and a power source connected between the anode and the cathode.

We provide methods, systems, and apparatus for treatment of high chemical oxygen demand wastewater using anaerobic treatment with ceramic membranes. We also provide post-treatment using microbial fuel cells.

The invention relates to a ternary sewage treatment method integrating microbial fuel cells with anaerobic acidification and forward osmosis membrane, and belongs to the technical field of sewage treatment. The method of the invention comprises the following steps: Sewage is driven into the anaerobic acidification device for mixture with the NaOH solution. The mixed liquid enters into the MFC for converting the enriched organics to bioelectricity and then flows back to the anaerobic acidification device. A part of the mixed liquid passes through the MF membrane module to form effluent and enters into the sedimentation basin for phosphate removal and finally passes through activated carbon adsorption column, another part passes through the FO membrane module to form effluent and obtain high quality recycled water after the RO membrane processing. The method is a new coupled model of FO membrane and MFC and it provide a ternary combined technique integrating MFCs with anaerobic acidification and FO membrane. The change and accumulation of sewage to organic acids are achieved under anaerobic acid production and FO retention, the electricity generation performance of MFC is improved, and the reuse of reclaimed water is realized by separating of FO and RO membranes. Finally, the wastewater reuse and electricity generation are realized synchronously.

The invention presents a urea bio-electrochemical (UBE) system to achieve resource recovery from water recycling systems. A GAC-urease bioreactor was used to recover urea from wastewater stream, and converted to ammonia. Then, the ammonia produced was used to feed an electrochemical cell to gather electrical energy. The invention shows the feasibility of using the UBE system in combination with a forward osmosis subsystem for water reclamation.

An electrode for use in bio-electrochemical systems is described, including: a substantially planar electrode material; a frame comprising a non-conductive substance; and one or more first conductive substances linked or secured to the frame. Bio-electrochemical systems, racks for inserting the electrode, and methods of using the racks are also described.

A technique for wastewater treatment involves ensuring that all paths for wastewater must pass through at least one porous microbial support to go from the inlet to the outlet, and allowing a biofilm to grow on the porous microbial support under microaerobic conditions (concentration of oxygen between 0.05 and 0.35 mg/L). The biofilm formed comprises a population of anaerobic microbes for digesting organics in the wastewater including methanogenic microbes, and an aerobic methanotrophic and heterotrophic population that catabolizes methane from the methanogenic microbes, and oxygen from the injector, to produce heat. The support may be an electrode, and the technique is applied in a microbial electrolysis cell, with substantial COD removal rates.

The present application provides a device for treating a black and odorous water body comprising a pre-treatment unit, a biomimetic intestine tubular purification system which imitates a digestion of small intestine, a microbial fuel cell which imitates a digestion of large intestine, and an inclined tube sedimentation tank which imitates human excretion.

The present application provides a method for treating a black and odorous water body comprising the following steps: pre-treating the black and odorous water body; passing the pre-treated water body through a biomimetic intestine tubular purification system which imitates a digestion of small intestine; passing the tubular purification system-treated water body into a microbial fuel cell which imitates a digestion of large intestine to treat the water body; and pumping the microbial fuel cell-treated water body into an upward flow inclined tube sedimentation tank to treat the water body.

Systems and methods for treating a metal or metalloid ion-contaminated liquid are provided. The method may include (i) feeding the metal or metalloid ion-contaminated liquid into a bioelectrochemical reactor containing a bacteria selected by the cathode to produce extracellular metal or metalloid nanoparticles; and (ii) operating the bioelectrochemical reactor anaerobically to reduce the metal or metalloid ions in the metal or metalloid ion-contaminated liquid to extracellular metal or metalloid nanoparticles. The method may further include separating the metal or metalloid nanoparticles from the bacteria with no energy input. A bioelectrochemical reactor system for production of extracellular metal and metalloid nanoparticles may include a bioelectrochemical reactor, a separation device, and a tangential flow filtration unit.