Treatment of wastewater containing heavy metal ions, and providing an efficient bio-electrochemical copper ion removal system. Based on the technology of microbial fuel cell and membrane bioreactor, using sacrificial aluminum anode and externally supplied power from microbial fuel cell, aluminum micro-electrolysis is realized. Aluminum hydrate ion, produced by micro-electrolysis of aluminum under the action of water molecules, is naturally efficient flocculating agent. The flocculating agent of this system is self-generated without any external reagent addition. The process of flocculation is mild, and the flocculation removal efficiency of copper ion is high. Under the filtration and screening effect of bifunctional conductive membrane, the copper ion in the cathode chamber can be completely removed. The concentration of the copper ion in the effluent of the system can fully meet the national first-level discharge standard, and the effluent can be recycled and reused.

Provided is a wastewater treatment process including: (a) circulating wastewater including biodegradable organic material, between an anaerobic digester (AD) and at least one microbial electrolysis cell (MEC), the MEC including an anode and a cathode; (b) applying voltage on said anode and said cathode; and (c) discharging from said AD biogas with a methane fraction of above 70% v/v.

Also provided is a biological wastewater treatment system including wastewater inlet, and (i) an anaerobic digester (AD) comprising biogas outlet, and effluent outlet; and (ii) at least one microbial electrolysis cell (MEC) including an anode and a cathode; said AD and said at least one MEC being in liquid communication through liquid circulation lines configured for at least circulating wastewater between said AD and said at least one MEC.

The present invention relates to a bio-electrochemical system (BES) and a method of in-situ production and removal of H.sub.2O.sub.2 using such a bio-electrochemical system (BES). Further, the invention relates to a method for in-situ control of H .sub.2O.sub.2 content in an aqueous system of advanced oxidation processes (AOPs) involving in-situ generation of hydroxyl radical (OH) by using such a bio-electrochemical system (BES) and to a method for treatment of wastewater and water disinfection. The bio-electrochemical system (BES) according to the invention comprises: an aqueous cathode compartment comprising a first cathode and a second cathode, an aqueous anode compartment comprising an anode at least partly covered in biofilm, wherein the first cathode is connected to a first circuit and the second cathode is connected to a second circuit, wherein the first and the second circuit are connected to the system by an external switch.

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.

Method of desalination and wastewater treatment in a microbial desalination cell reactor is provided, the microbial desalination cell reactor has three compartments, an anodic compartment, a cathodic compartment and a saline compartment, the method is carried out by (a) adding electrically conductive particles or electrically conductive material in the anodic compartment and cathodic compartment, (b) adding bacteria species of the genus Geobacter in the anodic compartment and several solutions in the compartments (c) replacing the solutions in the cathodic compartment and in the saline compartment and (d) oxidizing organic matter present in wastewater by bacteria from the genus Geobacter in the anodic compartment and desalinating the solution in the saline compartment and (e)after 20 to 30 operation cycles, replacing the solution in the saline compartment by a solution of hypochlorite salt

Disclosed are modular microbial fuel cell (MFC) devices, systems and methods for treating wastewater and generating electrical energy through a bioelectrochemical waste-to-energy conversion process. In some aspects, a modular MFC system includes a wastewater pretreatment system to receive and pre-treat raw wastewater for feeding pre-treated wastewater for bioelectrochemical processing; one or more modular MFC devices to bioelectrochemically process the pre-treated wastewater by concurrently generating electrical energy and digesting organic contaminants and particulates in the wastewater to yield treated, cleaner water; and a water collection module to receive the treated water from the one or more modular MFC devices and store the treated water and/or route the treated water from the system.

Disclosed herein are methods, systems, and devices for generating electricity from an effluent source. In the presence of electrogenic bacteria and substrate electrodes, an electroactive biofilm is produced which possesses bioconductive capacity for efficiently producing an electric current while treating an effluent source such as, e.g., wastewater. This disclosure relates generally to the production of electricity from a biological source. In particular, this disclosure relates to microbial fuel cells (MFCs) and other bioelectrochemical systems (BES) that exploit an exogenous fuel source.

Embodiments of the present disclosure provide a device for kitchen waste digestion, including: a first treatment container, provided with a feed pipe and an exhaust pipe at a top, and internally configured with a plurality of pole plate pairs, the pole plate pairs including two pole plates, one of the pole plates being connected to a positive pole of a power source and another being connected to a negative pole of the power source, and a plurality of sieve holes being provided in each of the pole plates; and a second treatment container, a top of the second treatment container connecting to a bottom of the first treatment container, a middle part being configured with a plurality of filler layers spaced apart in a vertical direction, and a bottom being configured with an iron-carbon filler; and a filler in the filler layers including calcium peroxide and magnetite particles.

A system for biological nitrogen removal and negative carbon discharge from wastewater with low carbon-to-nitrogen ratio may include a water intake pump, a carbon capture apparatus, a carbon recovery sedimentation tank, an integrated ammonium apparatus, an autotrophic denitrification apparatus and a denitrification sedimentation tank that are connected in sequence by pipes. The carbon capture apparatus may include an anode chamber communicated with the water intake pump via a water inlet pipe and a cathode chamber communicated with the carbon recovery sedimentation tank via a first water outlet pipe. The anode and cathode chambers may be spaced apart by an ion exchange resin membrane. The anode and cathode chambers may be provided with an anode plate and a cathode plate electrically connected to positive and negative electrodes of a power source, respectively. A bottom of the cathode chamber may be provided with aerators connected to a first air compressor by a pipe.

Methods, systems, and apparatus for treating wastewater and generating electricity. The system includes layers of sediment containing microorganisms for treating the wastewater. The system includes layers of granular activated carbon or granular activated carbon with graphene oxide or sand with graphene oxide disposed on top of the sediment layers for enhancing electron transfer, current generation rate, and wastewater treatment. The system also includes one or more anodes and one or more cathodes located on top of the layers of granular activated carbon or granular activated carbon with graphene oxide or sand with graphene oxide. The one or more anodes and the one or more cathodes are configured to generate electrical voltage. The system also includes a battery connected to the one or more anodes and the one or more cathodes and configured to store the electrical voltage generated by the one or more anodes and the one or more cathodes.