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.

A renewable energy microgeneration apparatus is disclosed that includes a mixing tank that mixes waste with a liquid, a buffer tank that receives and pre-warms the mixed waste, a pasteurization tank that pasteurizes on the pre-warmed mixed waste, a digestion tank that performs anaerobic digestion on the pasteurized waste, a de-watering device that separates liquid digestate and removes salt from the liquid, sensors that measure salinity and biogas quality, and a controller. The controller causes the transfer of digestate from the digestion tank to the pasteurization tank to the dewatering device, causes the de-watering device to separate the liquid and remove the salt from the liquid, monitors the salinity of the liquid and the quality of biogas using the sensors, and causes the mixing of the liquid with the waste and adjusts the feed rate of the waste to reduce the salinity of the waste and increase methane production.

Disclosed herein are methods that include producing oil and natural gas from a subterranean formation; separating the oil and the natural gas; dissolving at least a portion of the natural gas in water; exposing microorganisms that consume hydrocarbons to the water having the natural gas dissolved therein; and allowing higher-level organisms to consume the microorganisms.

A system for storing biological feedstock includes receiving tanks, storage tanks, and at least one slop tank. The biological feedstock is supplied to the receiving tanks from sources external to the system. Fat separated from the biological feedstock is transferred from the receiving tanks to the storage tanks, and sludge deposited on a bottom portion of each receiving tank and on a bottom portion of each storage tank is transferred to the slop tank. Fat separated from the sludge is transferred from the slop tank to the receiving tanks. Biological material is blended from biological feedstocks. The tanks act in different roles to improve the removal of sludge, and increases the yield of desired biological material.

A system comprising method and apparatus for separating biologically-digestible materials from an influent sewage stream. The system may comprise a primary clarification tank to capture sixty percent or more of the total solids from an influent stream; a sludge classifying press (SCP) to isolate and concentrate biologically digestible materials from sludge formed in the primary clarification tank, releasing valuable organics, such as are found in corn kernels, by fracturing the protective casings; a grit capture mechanism in a chamber within the primary clarification tank and isolated from the bulk of the sludge containing biologically-degradable materials; a grit trap to remove grit from the sludge prior to classifying the sludge with the SCP; apparatus for adding thickener to the sludge after classification and prior to digestion; and automation of one or more elements of the process for separating and digesting the biologically digestible materials in an influent stream.