CN112897643A - Reverse osmosis seawater desalination device based on graphene oxide separation membrane and desalination method thereof - Google Patents

本发明公开了一种基于氧化石墨烯分离膜的反渗透海水淡化装置及其淡化方法，分离膜水处理领域。本发明的基于氧化石墨烯分离膜的反渗透海水淡化装置及其淡化方法，内管采用外方结构，氧化石墨烯分离膜膜安装时不需要弯曲而能够直接平铺在外表面，避免了膜弯曲引起机械强度下降和膜结构破坏，可保证反渗透膜的承压能力和使用寿命；同时，内管上布置的渗透小孔数量多，使单位体积内可渗透的膜面积增加，保证该装置的高产水量。

The invention discloses a reverse osmosis seawater desalination device based on a graphene oxide separation membrane and a desalination method thereof, and the field of separation membrane water treatment. In the reverse osmosis seawater desalination device and desalination method based on graphene oxide separation membrane of the present invention, the inner tube adopts an outer structure, and the graphene oxide separation membrane does not need to be bent during installation and can be directly tiled on the outer surface, thereby avoiding membrane bending The mechanical strength is reduced and the membrane structure is damaged, which can ensure the pressure bearing capacity and service life of the reverse osmosis membrane. High water yield.

Reverse osmosis seawater desalination device based on graphene oxide separation membrane and desalination method thereof

Technical Field

The invention belongs to the field of separation membrane water treatment, and particularly relates to a reverse osmosis seawater desalination device based on a graphene oxide separation membrane and a desalination method thereof.

Background

The separation membrane plays a key role in the membrane-assisted water treatment process and determines the economic benefit of the technology. Separation membrane technology is currently considered to be the most dominant membrane assisted desalination technology and process, and significant progress is constantly being made due to its effective desalination efficiency and reasonable energy consumption. Reverse osmosis represents the mainstream development direction of desalination technology in the future due to the advantages of low investment cost and low energy consumption of water production, and the technical progress of reverse osmosis depends on the development of membrane separation technology. The development of the separation membrane which has high specific surface area, high permeability, high selectivity, high chemical stability, good anti-pollution performance, low cost and large-area preparation inevitably brings huge economic benefits and has profound significance.

The graphene oxide separation membrane has high water permeability and high ion rejection rate, but is difficult to realize large-area and difficult to curl, so a reverse osmosis seawater desalination device is required to realize large-scale application.

Disclosure of Invention

The invention aims to overcome the defect that a graphene oxide membrane is not suitable for the conventional reverse osmosis seawater desalination device due to the fact that the graphene oxide membrane is not easy to curl, and provides a reverse osmosis seawater desalination device based on a graphene oxide separation membrane and a desalination method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a reverse osmosis seawater desalination device based on a graphene oxide separation membrane comprises an outer tube, an inner tube and end covers positioned at two ends of the outer tube;

the outer part of the inner tube is in a polygon prism shape, a plurality of small permeation holes communicated with the inner part are formed in the inner tube, and a graphene oxide separation membrane is arranged on the periphery of the inner tube;

one end cover is provided with a water inlet, the water inlet corresponds to the space between the inner pipe and the outer pipe, the other end cover is provided with a purified water outlet and a wastewater outlet, the purified water outlet corresponds to the inner pipe, and the wastewater outlet corresponds to the space between the inner pipe and the outer pipe.

Further, the graphene oxide separation membrane is prepared by the following preparation method:

the GO-PCTE composite film is prepared by using graphene oxide dispersion liquid as a raw material and a polycarbonate film as a substrate filter film through a vacuum filtration method and is used as a graphene oxide separation film.

Further, the thickness of the graphene oxide separation membrane is 8-14 μm.

Furthermore, the end cover and the outer pipe are connected through threads.

Further, rubber is used for sealing between the end cover and the outer pipe.

Further, the cross section of the inner flow passage of the inner pipe is circular.

The desalination method of the reverse osmosis seawater desalination device comprises the following steps:

when the feed liquid flows in from the water inlet of the end cover, a part of the feed liquid flows through the surface of the graphene oxide separation membrane along the direction parallel to the inner pipe and flows out from the wastewater outlet to form trapped concentrated liquid;

and a part of feed liquid flows into the inner pipe from the periphery of the inner pipe through the graphene oxide separation membrane and flows out from the purified water outlet.

Compared with the prior art, the invention has the following beneficial effects:

according to the reverse osmosis seawater desalination device based on the graphene oxide separation membrane and the desalination method thereof, the inner tube is of the outer square structure, the graphene oxide separation membrane can be directly paved on the outer surface without being bent when being installed, the mechanical strength reduction and the membrane structure damage caused by membrane bending are avoided, and the pressure bearing capacity and the service life of the reverse osmosis membrane can be ensured; meanwhile, the number of the small permeation holes 4 arranged on the inner pipe is large, so that the permeable membrane area in unit volume is increased, and the high yield of the device is ensured.

Furthermore, the thickness of the GO-PCTE composite film is 8-14 mu m, the permeability is correspondingly increased due to the great reduction of the film thickness, the thickness can be 3-5 orders of magnitude higher than that of a commercial film to the maximum extent, the total energy consumption of the device and the total number of the film components can be greatly reduced, the initial investment and the operation cost can be saved, and the economic benefit is remarkable.

Drawings

FIG. 1 is a schematic structural diagram of a seawater desalination plant according to the present invention;

FIG. 2 is a schematic structural view of a cross-sectional view of the present invention;

FIG. 3 is a schematic diagram of the working system of the seawater desalination apparatus of the present invention.

Wherein: 1-an outer tube; 2-inner tube; 3-end cover; 4-infiltrating pores; 5-a water inlet; 6-a purified water outlet; 7-wastewater outlet.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The graphene oxide separation membrane which is newly developed but is still in a laboratory test stage is applied to a small-sized seawater desalination device, and the practical application of the graphene oxide membrane in the field of seawater desalination is promoted. The graphene oxide separation membrane has high water permeability and high ion rejection rate, but is difficult to realize large-area and difficult to curl, so a special reverse osmosis seawater desalination device is needed to realize large-scale application. The invention mainly aims to design a reverse osmosis seawater desalination device based on a graphene oxide film separation membrane, the reverse osmosis seawater desalination device is designed based on the principle of a spiral-wound membrane module, and the reverse osmosis treatment is carried out after seawater is pressurized by a high-pressure pump. The invention has the innovation points that the prepared reverse osmosis membrane and the independently designed device structure are adopted; the reverse osmosis membrane is a graphene oxide film or a porous graphene oxide film based on graphene oxide; the membrane module adopts a roll type, the structure is compact, the outer side and the inner side of the inner tube are square, the membrane is prevented from being bent, the number of the supporting holes is large, the water yield is large, and the recovery rate is high. The invention has important promotion effect on developing high-efficiency compact seawater desalination reverse osmosis technology.

The invention is described in further detail below with reference to the accompanying drawings:

The inner pipe 2 is of an outer square and inner round structure, as shown in figure 2, the inner pipe is directly paved on the outer surface without bending when a membrane is installed, so that the mechanical strength reduction and the membrane structure damage caused by membrane bending are avoided, and the bearing capacity and the service life of the reverse osmosis membrane can be ensured; meanwhile, the number of the small permeation holes 4 arranged on the inner pipe 2 is large, so that the permeable membrane area in unit volume is increased, and the high water yield of the device is ensured.

A reverse osmosis membrane of a core component adopts a vacuum filtration method, GO dispersion liquid with gradient concentration is used, a polycarbonate membrane (PCTE) is used as a substrate filter membrane, GO-PCTE composite membranes with different thicknesses are prepared, and the thickness is between 8 and 14 mu m. The membrane thickness is greatly reduced, the permeability is correspondingly increased, the membrane thickness can be 3-5 orders of magnitude higher than that of a commercial membrane to the maximum extent, the total energy consumption of the device and the total quantity of membrane components can be greatly reduced, the initial investment and the operation cost are saved, and the economic benefit is remarkable.

During the use, will tailor suitable oxidation graphite alkene separation membrane and fully wet earlier and be fixed in foraminiferous square inner tube 2 outer wall on, then pass through threaded connection with inner tube 2 and outer tube 1, use the rubber circle sealed.

In use, care needs to be taken in the case of reverse osmosis graphene oxide membranes. Under the good condition of membrane state, the device can normally operate, when the membrane produces the damage because of pressure and velocity of flow, need in time to cut off the confession liquid, the liquid in the exhaust device, the separation inside and outside pipe 1 clears away damaged membrane, changes the new membrane.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.