A kind of novel rare-earth wastewater comprehensive treatment system and method
Technical field
The invention belongs to sewage disposal and energy resource circulation and stress technical field, relate to a kind of novel rare-earth wastewater comprehensive treatment system and method.
Background technology
Traditional RE waste water precipitation bicarbonate of ammonia that adopts does precipitation agent more, and its advantage is that the carbonated rare earth deposit seeds obtained is thick, and easily washing, impurity are few.But because the ammonia radical ion in precipitation agent does not utilize, all enter into precipitation waste water, cause the ammonia-nitrogen content in waste water very high.
Ammonia nitrogen has caused the attention of field of Environment Protection and global range to the impact of environment; in order to preserve the ecological environment; alleviate water pollution; unanimously there is strict regulation in country to the ammonia-nitrogen content in waste water; in the waste water that directly discharges of the existing Rare Earth Production enterprise of clear stipulaties, ammonia-nitrogen content is less than or equal to 15mg/L in a standard, and total ammonia is less than or equal to 30mg/L.RE waste water treatment system difficulty up to standard in the past, and the energy resource generated in wastewater treatment process utilizes undesirable.
Therefore, need to seek a kind of RE waste water total system of being more suitable for and method.
Summary of the invention
The object of the invention is to overcome prior art Problems existing and deficiency, provide that a kind of processing efficiency is high, no pollution discharge, simple to operate, novel rare-earth wastewater comprehensive treatment system and the method that simultaneously can realize the energy and resource reclaim.
The present invention solves its technical problem and is achieved through the following technical solutions:
A kind of novel rare-earth wastewater comprehensive treatment system, is characterized in that: it comprises pretreatment unit, sewage enrichment unit and supercritical water oxidation unit; Wherein, described pretreatment unit comprises the screen apparatus, equalizing tank and the air flotation pool that are communicated with successively, and the entrance of described sewage enrichment unit connects the outlet of described pretreatment unit, and the clear water output of sewage enrichment unit connects clean water basin;
Described supercritical water oxidation unit comprises oxygen supply system, starting fluid system, overcritical water oxidization reactor, gas solid separation system, Separate System of Water-jet, wherein, overcritical water oxidization reactor, gas solid separation system, Separate System of Water-jet connect successively, the sewage inlet of described overcritical water oxidization reactor connects the dense water out of described sewage enrichment unit, the oxygen intake of overcritical water oxidization reactor connects described oxygen supply system, and the outlet of described Separate System of Water-jet connects described clean water basin.
Sewage enrichment unit comprises intermediate regulations pond, strainer, the first membrane separation unit, the second membrane separation unit, tertiary membrane tripping device and the 4th membrane separation unit.The entrance of intermediate pool connects described pretreatment unit, the dense water out of tertiary membrane tripping device and the dense water out of the 4th membrane separation unit.The entrance of the first membrane separation unit connects the outlet of strainer, and the dense water out of the first membrane separation unit connects the entrance of the second membrane separation unit, and the product water out of the first membrane separation unit connects the entrance of tertiary membrane tripping device; The product water out of tertiary membrane tripping device connects the entrance of the 4th membrane separation unit, and the product water out of the 4th membrane separation unit connects described clean water basin.The dense water out of the second membrane separation unit connects the sewage inlet of described overcritical water oxidization reactor, and the product water out of described second membrane separation unit connects intermediate pool or the entrance of tertiary membrane tripping device or the entrance of the 4th membrane separation unit.
Described first film filter, second membrane separation unit, tertiary membrane tripping device and the 4th membrane separation unit are dish tubular membrane tripping device, this dish tubular membrane tripping device is by pressure casing, power supply end cap, intake end cover, flow guiding disc, disc-type film bag, battery lead plate and center pull rod are formed, power supply end cap, multiple flow guiding disc and intake end cover stack successively, and adopt center pull rod to install fixing in the middle, pressure casing sealing is installed in outside power supply end cap and intake end cover, former aquaporin is formed between flow guiding disc periphery and pressure casing, notch is shaped with in the middle part of flow guiding disc, to form filtration channel, formed between flow guiding disc Center-to-Center pull bar and produce aquaporin, closed assembly disc-type film bag between adjacent two flow guiding discs, do not contact between disc-type film bag and upper and lower flow guiding disc, form filtration channel, at the inner installing electrodes plate of stacked film bag.
Described screen apparatus is thin grid or screen cloth.
Described overcritical water oxidization reactor comprises cylindrical shell, burner, evaporation wall; Described inner barrel arranges evaporation wall with one heart, the narrow gap closed of the multistage annular along cylindrical shell axial distribution is formed between described evaporation wall and cylindrical shell, each described narrow gap has water inlet on cylindrical shell, the liquid passed into via water inlet can be infiltrated by described evaporation wall, forms moisture film at evaporation wall internal surface; Burner stretches into from cylindrical shell top, and the burner of described burner is positioned at cylindrical shell, and evaporation wall is made of porous materials, described liquid is subcritical water, cylindrical shell top is shaped with sewage inlet and oxygen intake, and burner is shaped with fuel inlet and oxygen intake, and cylinder body bottom is shaped with liquid outlet.
Pneumatic outlet Bonding pressure energy recovery system, oxygen enrichment reclaiming system and the described oxygen supply system successively of described Separate System of Water-jet.
Arrange heat exchange system between described gas solid separation system and Separate System of Water-jet, the vapour outlet of described heat exchange system connects steam utilization equipment.
A kind of novel rare-earth comprehensive treatment method for wastewater, its step comprises:
1) homogeneous: RE waste water removes suspended substance through screen apparatus, then enters equalizing tank, carries out homogeneous and all measures adjustment;
2) dissolved air flotation: enter in air flotation pool through the equalizing tank homogeneous RE waste water all measured after adjustment, remove most of scum silica frost, then enter intermediate regulations pond;
3) filter, concentrate: RE waste water, behind intermediate regulations pond, enters strainer and filters, then the RE waste water after filtering is concentrated, export dense water;
4) supercritical water oxidation: by described dense water input overcritical water oxidization reactor, the fuel that the oxygen of oxygen supply system output simultaneously, starting fluid equipment export enters overcritical water oxidization reactor respectively and carries out oxidizing reaction, remove the organism in described dense water, generate supercutical fluid and inorganic salt;
5) gas solid separation: carry out desalination by cyclonic separator at the reacted supercutical fluid of overcritical water oxidization reactor internal oxidition and inorganic salt;
6) gas-liquid separation: after desalination, enter in Separate System of Water-jet and carry out being separated of gas phase and liquid phase, gas fraction is carbon dioxide and oxygen, and liquid portion is water, and the clear water that gas-liquid separation obtains enters clean water basin.
Described step 3) in concentration process comprise: by RE waste water the concentrating for twice successively through the first membrane separation unit and the second membrane separation unit after filtering, the dense water that the second membrane separation unit exports is carried out supercritical water oxidation; The product water input tertiary membrane tripping device of described first membrane separation unit, the dense water of described tertiary membrane tripping device returns to described intermediate regulations pond, and the product water of described tertiary membrane tripping device enters in described 4th membrane separation unit; The dense water of described 4th membrane separation unit returns to described intermediate regulations pond, the product Water Sproading of described 4th membrane separation unit; The product water of described second membrane separation unit inputs in described intermediate regulations pond or tertiary membrane tripping device or the 4th membrane separation unit.
Described step 6) gas that produces enters pressure energy recovery system, and can reclaim pressure energy, can obtain carbon dioxide and oxygen after being separated, described oxygen can carry out reuse in systems in which.
Advantage of the present invention and beneficial effect are:
The present invention is directed to the situation that RE waste water COD variation range is larger, by film enrichment (MET) and supercritical water oxidation (SCWO) R. concomitans, add film enrichment (MET:Membrane EnrichTreatment) technique to concentrate waste water in the front end of supercritical water oxidation technique, the RE waste water of wider COD value can be enable to carry out supercritical water oxidation process, realize minimizing, resource utilization, innoxious, organic removal rate can reach more than 99 percent, and effluent color dilution can be up to standard; Be designed with Energy resources range site, directly utilize or reclaim the resource produced in RE waste water treating processes, the energy, reduce processing cost, economic benefit is better.
Overcritical water oxidization reactor of the present invention adopts multi-layer cylinder, separate region is formed between each layer cylindrical shell and evaporation wall, what enter this region is subcritical water, subcritical water is under the effect of pressure reduction, flow into evaporation wall internal surface, because evaporation wall adopts multistage installation, each subregion regulates flooding quantity separately, ensure that and form the uniform moisture film of a layer thickness thereon, the inorganic salt produced in supercritical reaction process are dissolved, prevent the fouling of inorganic salt on inwall, prevent corrosives to contact with inner tube wall thus the corrosion caused simultaneously; Reacting fluid after desalination flows out from bottom, improves the security of device, and the use of evaporation wall reduces the selection difficulty to reactor cylinder material; Simultaneously when evaporation wall is broken or block, without the need to changing all evapn wall, the evaporation wall only need changing damage can use.
Accompanying drawing explanation
Fig. 1 is the structural representation of novel rare-earth wastewater comprehensive treatment system;
Fig. 2 is the structural representation of the dish tubular membrane tripping device in the present invention;
Fig. 3 is the structural representation of the battery lead plate in the dish tubular membrane tripping device in the present invention;
Fig. 4 is the structural representation of the overcritical water oxidization reactor in the present invention.
Description of reference numerals:
Fine fack 1, equalizing tank 2, air flotation pool 3, intermediate regulations pond 4, strainer 5, first dish tubular membrane tripping device 6, 3rd dish tubular membrane tripping device 7, 4th dish tubular membrane tripping device 8, clean water basin 9, first medicine system 10, second medicine system 11, second dish tubular membrane tripping device 12, starting fluid system 13, supercritical water oxidation (SCWO) reactor 14, gas solid separation system 15, heat exchange system 16, Separate System of Water-jet 17, pressure energy recovery system 18, oxygen supply system 19, solid salt collecting device 20, steam utilization equipment 21 oxygen enrichment reclaiming system 22, center pull rod 23, power supply end cap 24, pressure casing 25, dense water out 26, produce water out 27, intake end cover 28, original water inlet 29, former aquaporin 30, flow guiding disc 31, disc-type film bag 32, battery lead plate 33, filtration channel 34, produce aquaporin 36, terminal stud dodges hole 37, terminal stud open holes 38, cylindrical shell 39, water inlet 40, narrow gap 41, sewage inlet and oxygen intake 42, fuel inlet and oxygen intake 43, burner 44, evaporation wall 45, liquid outlet 46.
Embodiment
Below by specific embodiment, the invention will be further described, and following examples are descriptive, is not determinate, can not limit protection scope of the present invention with this.
A kind of novel rare-earth wastewater comprehensive treatment system, be made up of pretreatment unit, sewage enrichment unit, supercritical water oxidation unit, pretreatment unit, sewage enrichment unit, supercritical water oxidation unit are communicated with successively.
Pretreatment unit, comprise fine fack 1, equalizing tank 2, air flotation pool 3, first medicine system 10, second medicine system 11, fine fack, equalizing tank, air flotation pool are communicated with successively, and the first medicine system is communicated with equalizing tank, and the second medicine system is communicated with air flotation pool.
The entrance of sewage enrichment unit connects the outlet of described pretreatment unit, and the clear water output of sewage enrichment unit connects clean water basin.Sewage enrichment unit comprises intermediate regulations pond 4, strainer 5, first dish tubular membrane tripping device 6, second dish tubular membrane tripping device the 12, the 3rd dish tubular membrane tripping device 7 and the 4th dish tubular membrane tripping device 8.The entrance of intermediate pool connects pretreatment unit, the dense water out of tertiary membrane tripping device and the dense water out of the 4th membrane separation unit.The entrance of the first dish tubular membrane tripping device connects the outlet of strainer, the dense water out of the first dish tubular membrane tripping device connects the entrance of the second dish tubular membrane tripping device, and the product water out of the first dish tubular membrane tripping device connects the entrance of the 3rd dish tubular membrane tripping device; The product water out of the 3rd dish tubular membrane tripping device connects the entrance of the 4th membrane separation unit, and the product water out of the 4th dish tubular membrane tripping device connects described clean water basin.The dense water out of the second dish tubular membrane tripping device connects the sewage inlet of described overcritical water oxidization reactor, and the product water out of described second dish tubular membrane tripping device connects intermediate pool or the entrance of the 3rd dish tubular membrane tripping device or the entrance of the 4th dish tubular membrane tripping device.
As shown in Figure 2, above-mentioned dish tubular membrane tripping device is by pressure casing 25, power supply end cap 24, intake end cover 28, flow guiding disc 31, disc-type film bag 32, battery lead plate 33 and center pull rod 23 are formed, power supply end cap, multiple flow guiding disc and intake end cover stack successively, and adopt center pull rod to install fixing in the middle.Pressure casing sealing is installed in outside power supply end cap and intake end cover, former aquaporin 30 is formed between flow guiding disc periphery and pressure casing, notch 35 is shaped with in the middle part of flow guiding disc, to form filtration channel 34, formed between flow guiding disc Center-to-Center pull bar and produce aquaporin 36, between adjacent two flow guiding discs, closed assembly disc-type film bag, does not contact between disc-type film bag and upper and lower flow guiding disc, forms filtration channel.At the inner installing electrodes plate of stacked film bag.
As shown in Figure 3, battery lead plate is shaped with terminal stud open holes 38, and side relative to terminal stud open holes is shaped with terminal stud and dodges hole 37, and two battery lead plates forming interdigital electrode are symmetrical placement, and two adjacent electrode plates form interdigital electrode.Intake end cover is shaped with the original water inlet 29 be communicated with former aquaporin, and intake end cover is also shaped with the dense water out 26 be communicated with filtration channel, and the product water out 27 be communicated with product aquaporin.Produce water out and be formed on lower jacket sidewall.
Supercritical water oxidation unit, comprises oxygen supply system 19, starting fluid system 13, supercritical water oxidation (SCWO) reactor 14, gas solid separation system 15, heat exchange system 16, Separate System of Water-jet 17, pressure energy recovery system 18, oxygen enrichment reclaiming system 22.Oxygen supply system is connected with the oxygen intake of overcritical water oxidization reactor, starting fluid system is communicated with the fuel inlet of supercritical water oxidation (SCWO) reactor, supercritical water oxidation (SCWO) reactor, gas solid separation system, heat exchange system, Separate System of Water-jet, pressure energy recovery system, oxygen enrichment reclaiming system are communicated with successively, and the vapour outlet of heat exchange system connects steam utilization equipment 21.The solid outlet of gas solid separation system is connected to solid salt collecting device 20.Separate System of Water-jet is communicated with clean water basin 9 simultaneously.
Overcritical water oxidization reactor comprises cylindrical shell 39, burner 44, evaporation wall 45; Inner barrel arranges evaporation wall with one heart, the narrow gap 41 closed of the multistage annular along cylindrical shell axial distribution is formed between evaporation wall and cylindrical shell, each narrow gap has water inlet 40 on cylindrical shell, and the liquid passed into via water inlet can be infiltrated by described evaporation wall, forms moisture film at evaporation wall internal surface; Burner stretches into from cylindrical shell top, and the burner of burner is positioned at cylindrical shell, and evaporation wall is made of porous materials, liquid is subcritical water, cylindrical shell top is shaped with sewage inlet and oxygen intake 42, and burner is shaped with fuel inlet and oxygen intake 43, and cylinder body bottom is shaped with liquid outlet 46.
A kind of novel rare-earth comprehensive treatment method for wastewater, its step comprises:
In the present embodiment, design influent COD is 14400mg/L, PH is 6.3.
(1) homogeneous: RE waste water removes suspended substance through fine fack, then enters equalizing tank, carries out homogeneous and all measures adjustment, add the medicaments such as PAC, PAM by the first medicine system in equalizing tank, removes most suspended substances and colloidalmaterial.
(2) dissolved air flotation: the RE waste water after equalizing tank homogeneous enters in air flotation pool, adds the medicaments such as PAC, PAM by the second medicine system in this pond, removes most of scum silica frost, then enters intermediate regulations pond.
(3) filter: RE waste water, behind intermediate regulations pond, enters strainer and filters, and then enters the first dish tubular membrane tripping device (DTNF1) and carries out filtering and concentrating.
(4) membrane concentration: be about to the RE waste water after filtering again through three membrane concentration, output clear water, secondary clear water, dense water, clear water is recycled, and secondary clear water filters again, and dense water carries out supercritical water oxidation.Detailed process is: the water outlet in strainer enters the first dish tubular membrane tripping device (DTNF1) and carries out filtering and concentrating, its dense water again enter the second dish tubular membrane tripping device (DTNF2) carry out secondary filtration concentrate, dense water after secondary filtration concentrates enters overcritical water oxidization reactor, and the product water after secondary filtration concentrates enters the 4th dish tubular membrane tripping device (DTNF4) filtering and concentrating again; First dish tubular membrane tripping device (DTNF1) produces mouth of a river water out and enters the 3rd dish tubular membrane tripping device (DTNF3) and carry out filtering and concentrating again, the product water of the 3rd dish tubular membrane tripping device (DTNF3) enters the 4th dish tubular membrane tripping device (DTNF4) filtering and concentrating again, and the product water of the 4th dish tubular membrane tripping device (DTNF4) enters clean water basin reuse; Through the dense water of the 3rd dish tubular membrane tripping device (DTNF3) with get back to intermediate regulations pond through the dense water cycle of the 4th dish tubular membrane tripping device (DTNF4).
(5) supercritical water oxidation (SCWO): be about to the dense water after membrane concentration and carry out oxidizing reaction in overcritical water oxidization reactor, exceeding the stagnation point (T=374.15 DEG C of water, P=22.12MPa) under high-temperature and high-pressure conditions, organism is carried out " burning " oxidation, to remove most of organism with oxygen and other oxygenants.
(6) gas solid separation: be namely separated by gas-solid separating device with inorganic salt at the reacted supercutical fluid of overcritical water oxidization reactor internal oxidition, inorganic salt remove in solid form.
(7) gas-liquid separation: the supercutical fluid after desalination enters heat exchange system multi-stage heat exchanger, thermal power transfer is that steam enters steam utilization equipment and carries out generating electricity or heating etc.; Supercutical fluid after multipole heat exchange, its temperature 100 ~ 200 DEG C, pressure at 22 ~ 35MPa, enter into pressure energy recovery system, relief pressure also enters Separate System of Water-jet after output kinetic energy; Separate System of Water-jet passes through back pressure valve control pressure to 5 ~ 10MPa, carry out gas phase and liquid phase separation, gas fraction is carbonic acid gas and unnecessary oxygen, and liquid portion is water, the clear water that gas-liquid separation obtains directly enters clean water basin and is utilized, and gas fraction enters oxygen enrichment reclaiming system.
(8) oxygen enrichment reuse: obtain carbon dioxide and oxygen after gas-liquid separation, unnecessary oxygen can directly be recycled in the present system.