The present invention provides a complete-circulation-type bio-toilet system in which adjustment tanks capable of storing water to be treated are arranged before and after a septic tank, thereby enabling stable provision of the system without stopping the system even when the system is in heavy use. In a bio-toilet system 1 that performs microbial treatment on water to be treated containing filth and circulates the water to be treated as washing water, it is provided with: a raw sewage tank 3 into which the water to be treated containing filth discharged from a toilet 2 is fed; a first adjustment tank 4 that stores water to be treated 31 discharged from the raw sewage tank 3 while performing aerobic treatment thereon by aeration and discharges the stored water to be treated 31 by a pump 43; a septic tank 5 that performs microbial treatment on the water to be treated 31 discharged from the first adjustment tank 4; a second adjustment tank 6 that stores the water to be treated 31 discharged from the septic tank 5 while performing anaerobic treatment thereon and discharges the stored water to be treated 31 by a pump 62; a reaction tank 7 that decomposes organic matter in the water to be treated 31 discharged from the second adjustment tank 6; and a washing tank 8 that stores the water to be treated 31 discharged from the reaction tank 7 for use as washing water for a toilet bowl.

A method for efficient separation and enrichment of lithium includes the following steps: pretreatment: diluting and filtering salina aged brine to obtain pretreated brine; separation: separating the pretreated brine via a nanofiltration separation system to obtain nanofiltration permeate and nanofiltration concentrate, wherein the operation pressure of the nanofiltration separation system is 1.0 MPa5.0 MPa; first concentration: carrying out first concentration on the nanofiltration permeate via a reverse osmosis system to obtain reverse osmosis concentrate and reverse osmosis permeate; and second concentration: carrying out second concentration on the reverse osmosis concentrate via an electrodialysis system to obtain electrodialysis concentrate and electrodialysis permeate, wherein the electrodialysis concentrate is a solution enriching lithium ions. The present application couples several different membrane separation technologies and adopts the monovalent ion selective nanofiltration membrane having good separation performance in the process of nanofiltration.

Nitrogen is removed from biogas using a three-stage separation system based on gas separation membranes. The first stage separates a biomethane feed stream into a first permeate gas stream and a first retentate gas stream. The second stage separates the first permeate stream into a biomethane product gas and a first low quality biomethane gas stream. The third stage separates the first retentate into a second low quality biomethane gas stream and a waste gas. A biogas feed stream is pretreated to remove amounts of water, VOCs, and CO.sub.2 to yield a methane-enriched biogas stream. The methane-enriched biogas stream is compressed together with the first and second low quality biomethane gas streams to form the biomethane feed stream.

A concurrent desalination and boron removal (CDBR) process and a system thereof are provided. The system includes: a plurality of single-stage reverse osmosis (SSRO) stages connected in series, and a countercurrent membrane cascade with recycle (CMCR). The process includes the following steps: introducing a retentate from one SSRO stage or a series of SSRO stages optimally as a feed to a CMCR; countercurrent a retentate flow and a permeate flow in the CMCR; permeate recycling to a retentate side in the CMCR; retentate self-recycling in at least one of membrane stages in the CMCR; introducing a permeate from the SSRO stage(s) as a feed to an LPMS; and blending permeate streams from the CMCR and LPMS to achieve concentrations in a water product.

The present invention relates to processes and systems for basic gas, e.g., ammonia, recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

A method of obtaining a compound may include adding a substrate to a medium in a reactor, and reacting the substrate in the reactor to form the compound. A first stream is separated from the reaction liquid through a first membrane. A second stream is separated from the reaction liquid through a second membrane. The first membrane is a filtration membrane and the second membrane is configured for liquid-gas or liquid-liquid extraction The first membrane and the second membrane are at least partially immersed in the medium and are moved relative to the reactor during the separation steps.

An ion-exchange and ultrafiltration filter system having an exterior housing having an inlet and an outlet with an ultrafiltration membrane provided within the housing along a central axis about a central portion of the housing with an ion-exchange membrane provided within the housing between the ultrafiltration membrane and the housing. The ion-exchange and ultrafiltration filter system being capable of being configured so as to provide two-step filtration in a plurality of modes, either ion-exchange to ultrafiltration, or ultrafiltration to ion-exchange.

A process to remove transition metals from waste water. The process includes the steps of passing waste water to a first pH resin bed, monitoring the effluent from the first resin bed, and adjusting pH to greater than 4. The effluent is passed to a first stage liquid tank and to a first brackish water membrane to filter out complex metals. Rejected effluent from the first brackish water membrane is passed to a second stage liquid tank and thereafter to a second brackish water membrane. The permeate from the second brackish water membrane is passed back to the first stage liquid tank. The rejected effluent from the second brackish water membrane is heated and evaporated. The evaporated effluent is condensed so that metal crystals are gathered for disposal. The permeate through the first brackish membrane is passed to an EDTA resin bed to sequester metal ions. The pH of the discharge from the second pH resin bed is adjusted to between 7 and 11.

A single-use filtration device (10) comprises a plurality of single-use filter capsules (12) connected with each other by rigid lines, of which at least a part is firmly mounted in a raster universally specified by a holder (14). The filter capsules (12), in particular as regards the type of filter, type of construction and/or size, and/or the connections of the filter capsules (12), are preconfigured for a desired filtration process.

The invention relates to a process for recovering methane from digester biogas or landfill gas. More specifically, the invention pertains to a method for producing biomethane that removes impurities from a compressed digester biogas with staged membrane modules of at least two different types, to produce a biomethane having at least 94% CH.sub.4, below 3% of CO.sub.2, and below 4 ppm of H.sub.2S.