CN106669593A - Framework modified sepiolite as well as preparation method and application thereof - Google Patents
Framework modified sepiolite as well as preparation method and application thereof Download PDFInfo
- Publication number
- CN106669593A CN106669593A CN201611233954.2A CN201611233954A CN106669593A CN 106669593 A CN106669593 A CN 106669593A CN 201611233954 A CN201611233954 A CN 201611233954A CN 106669593 A CN106669593 A CN 106669593A
- Authority
- CN
- China
- Prior art keywords
- meerschaum
- modification
- preparation
- framework modification
- framework
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
- B01J20/12—Naturally occurring clays or bleaching earth
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- Water Supply & Treatment (AREA)
- Environmental & Geological Engineering (AREA)
- Engineering & Computer Science (AREA)
- Hydrology & Water Resources (AREA)
- Dispersion Chemistry (AREA)
- Geochemistry & Mineralogy (AREA)
- Analytical Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Water Treatment By Sorption (AREA)
Abstract
The invention discloses framework modified sepiolite as well as a preparation method and an application thereof. The method comprises steps as follows: single-fiber sepiolite is obtained after sepiolite is subjected to acidification treatment and dissociation with an inorganic acid solution, and then subjected to hydrothermal modification with trivalent inorganic salt or oxyacid salt; filtration, separation and drying are performed after treatment, and framework modified sepiolite is obtained. The modified sepiolite regulates surface activity sites and pore canal ion exchange characteristics by regulating the stoichiometric ratio of framework doping atoms and counterions as well as the type of the doping atoms and the counterions to improve the absorption performance. The modified sepolite can efficiently adsorb organic pollutants in paper wastewater, sepiolite with the organic pollutants adsorbed can enter a paper pulp system after being separated from water, the utilization rates of pigments and adsorbent materials are increased, and efficient recycling of resources is formed.
Description
Technical field
The invention belongs to meerschaum is modified and its applied technical field, and in particular to a kind of framework modification meerschaum and its system
Preparation Method and the application on organic dye waste water is processed.
Background technology
Meerschaum is a kind of natural porous mineral fiber, and various environmental protection treatments can be obtained after ion-exchanged
Agent, for the absorption decolourized with heavy metal ion, but ion-exchanged is served only for the replacement of meerschaum duct inner equilibrium ion,
It is not related to the change of meerschaum silica structure chain.The present invention adopts natural sepiolite (Mg8Si12O30(OH)4(H2O)2) it is original
Material, is inserted into silicon framing structure and substitutes ion balance simultaneously by object trivalent ion, forms hydridization framing structure, framework modification
After obtain modified meerschaum structural formula for Mg(8-1.5x)MxSi(12-0.75y)NyO30(OH)4(H2O)2, (M=Fe in formula, Al, Bi etc. three
Valency cation, is exchangeable ion modifying moieties；The trivalent ions such as N=Fe, Al, Bi, B, Sb, P, are silicon framework modification ion),
The stoichiometric number x and y of M and N can be adjusted, and modified meerschaum is counted by adjusting the chemistry of skeleton foreign atom and ion balance
The species of amount ratio and foreign atom and ion balance adjusts surface activity site and duct ion exchange property, improves adsorptivity
Energy.
Paper industry organic dye waste water is one of universally acknowledged key industry polluter, usually having containing difficult degradation
Malicious organic pollution, greatly harm is caused to ecological environment and drinking water.Such as：Poly aromatic rings molecular structure of dye is answered
It is miscellaneous, with characteristics such as higher light, heat stability and resistances to oxidation, it is difficult degraded under water environment and illumination condition and removes, greatly
Amount waste water enters colourity after water body and rises, and water body light transmittance declines, and affects the growth of water plant, destroys water ecosystem.
Simultaneously many polyaromatic hydrocarbons are the very strong Organic substances of carcinogenic Teratogenesis toxicity.The method for processing at present is chemical oxidization method, physical absorption
The methods such as method, microbial degradation, photocatalytic degradation.These methods have deficiency, and such as chemical oxidization method processes organic wastewater oxidation
Not exclusively, water body remaining is exceeded；The precipitate that the adsorption-flocculation technique that physisorphtion is adopted is produced has the risk of secondary pollution；
Microbial degradation speed is slow, and organic pigment waste water treatment effeciency is low；Photocatalytic degradation is because of the restriction tool of catalyst activity itself
There is the shortcomings of degraded is incomplete, and catalyst reclaims difficult.Using the present invention through modified meerschaum can with efficient absorption such
Organic pollution, at the same adsorb organic pigment after meerschaum from water body separation after, can enter pulping system, improve pigment and
The utilization rate of adsorbing material, forms resource high-efficiency circulation.
The content of the invention
It is an object of the invention to provide a kind of framework modification meerschaum and preparation method thereof and process organic dye waste water
On application.
The preparation method of the framework modification meerschaum of the present invention, comprises the following steps：Meerschaum is by inorganic acid solution acid
Change to process and obtain ultimate fibre meerschaum after dissociation, then with trivalent inorganic salt or oxysalt hydrothermal modification；Mistake after the completion of process
Filter separates drying, obtains framework modification meerschaum.
The structural formula of described framework modification meerschaum is Mg(8-1.5x)MxSi(12-0.75y)NyO30(OH)4(H2O)2, M in formula
One or more of=Fe, Al, Bi Tricationic；One or more in N=Fe, Al, Bi, B, Sb, P trivalent ion, x takes
Value is less than 6 less than 5, y values.The stoichiometric proportion of M and N can carry out modulation by the addition of trivalent ion salt, change
Become x, the value and balance ionic speciess of y can adjust modified meerschaum surface electrokinetic potential and activated adoption site.
Meerschaum of the present invention obtains ultimate fibre Hai Pao after the inorganic acid solution acidification dissociation of pH value 3.0-5.0
Stone, fibre diameter is 10~30nm, and fibre length is less than 10 μm.
The preparation method of described framework modification meerschaum, described trivalent inorganic salt is preferably villaumite.Trivalent inorganic salt
Including aluminium salt, iron salt, bismuth salt, antimonic salt, borate and phosphate etc..
The preparation method of described framework modification meerschaum, trivalent ion salt or oxysalt addition are accounted for during hydrothermal modification
The 0.1~30% of meerschaum quality, preferably 5~25%.
The preparation method of described framework modification meerschaum, 100 DEG C~200 DEG C of hydrothermal temperature, preferably 120~160
℃。
The preparation method of described framework modification meerschaum, hydrothermal modification adjustment pH to 6.0~10.0, response time：1~
24h, preferred pH to 6.0~9.0, preferred reaction time：3~6h.
The preparation method of described framework modification meerschaum, hydrothermal modification solid-liquid mass volume ratio：1:1~1:20g/mL,
Mixing speed：100rpm~1000rpm, preferred solid-liquid mass volume ratio 1:5~1:10g/mL, preferred mixing speed 300~
600rpm。
A kind of framework modification meerschaum, is prepared by above-mentioned method.
Described framework modification meerschaum is used to process organic dye waste water.Specifically by described framework modification meerschaum
Mix with the waste water containing organic dyestuff, stir, stand, after layering, the supernatant becomes colorless, and lower sediment thing is changed into having engine dyeing
The solid of material color, after being separated by filtration, filtering residue returns paper pulp operation application.The process conditions of absorption are pH value 6.0~9.0, often
Temperature stirring stands 0.5~4h, and modified meerschaum addition quality is 0.1%~5%.
The present invention by from suitable trivalent inorganic salt (particularly preferred villaumite) and hydro-thermal reaction, using natural sea
Afrodite (Mg8Si12O30(OH)4(H2O)2) be raw material, object trivalent ion is inserted into silicon framing structure simultaneously and substitute balance from
Son, forms hydridization framing structure, and modified meerschaum structural formula is obtained after framework modification for Mg(8-1.5x)MxSi(12-0.75y)NyO30
(OH)4(H2O)2, (Tricationic such as M=Fe in formula, Al, Bi is exchangeable ion modifying moieties；N=Fe, Al, Bi, B,
The trivalent ions such as Sb, P, are silicon framework modification ion), the stoichiometric number x and y of M and N can be adjusted, and modified meerschaum passes through
Adjust skeleton foreign atom and the stoichiometric proportion and foreign atom of ion balance and the species of ion balance adjusts surface and lives
Property site and duct ion exchange property, improve absorption property, hence it is evident that better than carrying out non-skeleton ion exchange under normal temperature condition
Modified meerschaum.The framework modification meerschaum ultimate fibre powder body of acquisition in pH9.0, surface -30~-48mv of electrokinetic potential,
Can be with the organic pollution in efficient absorption paper effluent, while absorption through modified meerschaum using the present invention
Meerschaum after organic pigment can enter pulping system from after water body separation, improve the utilization rate of pigment and adsorbing material, shape
Into resource high-efficiency circulation.
Description of the drawings
Fig. 1：Aluminum modified meerschaum filamentary electrons stereoscan photograph (a) and electronic transmission prepared by the embodiment of the present invention 1
Electromicroscopic photograph (b)；
Fig. 2：Al modified meerschaums prepared by the embodiment of the present invention 127AlNMR nuclear magnetic spectrograms；
Label 1 is commutative Al ions in figure, and label 2 is skeleton Al ions；
Fig. 3：Al modified meerschaum the adsorption effect figures prepared by the embodiment of the present invention 1；
1- waste water in figure, the waste water after the aluminum framework modification meerschaum process of 2- embodiments 1,3- conventional aluminium ion is exchanged
Modified meerschaum processed waste water；
Fig. 4：Ferrum modified meerschaum TEM figures (a) and high-resolution TEM prepared by the embodiment of the present invention 2 schemes (b)；
Fig. 5：Ferrum modified meerschaum prepared by the embodiment of the present invention 229Si nmr spectrums；
No. 1 peak is the framework silicon atom of skeleton iron connection in figure, and No. 2 peaks are that skeleton to replace and become Q after silicon2Structure silicon；
Fig. 6：Modified meerschaum absorption paper waste design sketch prepared by the embodiment of the present invention 2；
1- waste water in figure, the iron ion of 2- embodiments 2 exchanges the waste water after modified meerschaum is processed, 3- conventional iron skeleton
Waste water after modified meerschaum process.
Specific embodiment
It is intended to further illustrate the present invention with reference to embodiments, and the unrestricted present invention.
Embodiment 1:By the meerschaum ultimate fibre powder body 10g after inorganic acid dissociation and 100ml deionized water mixed pulps, press
Meerschaum：Aluminium oxide is 100:10 mass ratio adds AlCl3, to 8.0, reaction system is transferred to autoclave pressure to adjustment pH value,
400rpm is stirred, 140 DEG C of reaction 2h, and separating, washing is dried to obtain aluminum modified meerschaum powder body after cooling, and its molecular formula is
(Mg6.75Al0.83)(Si10.82Al1.57)O30(OH)4(H2O)2, scanning electron microscope and transmission electron microscope picture such as Fig. 1 institutes of its powder body material
Show, the Al in modified meerschaum contains tetrahedron and octahedra two kinds of structures,27AlNMR nuclear-magnetisms spectrum is as shown in Figure 2.What is prepared changes
Property meerschaum powder body surface potential -30mV in pH9.0, the powder body and conventional ion are exchanged into each 0.5g difference of modified powder
It is added in red waste water of the 100ml containing organic pigment (such as poly aromatic rings dye molecule) and vibrates 60min, after standing 1h, liquid
Body is layered, and lower floor is pink solid precipitation, and upper strata is colorless clear liquid, and the organic pigment absworption peak of 552nm disappears, uv absorption
Spectrum is as shown in curve 2 in Fig. 3；With reference to the ultraviolet absorption spectrum that sample is the meerschaum process waste water after conventional aluminium ion-exchanged such as
In Fig. 3 shown in curve 3, the organic pigment absorption peak strength of 552nm is basically unchanged, and conventional aluminium ion-exchanged is to paper waste
Decolourize to no effect.
Embodiment 2：By the meerschaum ultimate fibre powder body 10g after inorganic acid dissociation and 80ml deionized water mixed pulps, press
Meerschaum：Ferrum oxide is 100:15 mass ratio adds FeCl3, to 6.0, reaction system is transferred to autoclave pressure to adjustment pH value,
400rpm is stirred, 140 DEG C of reaction 4h, and separating, washing is dried to obtain ferrum modified meerschaum powder body after cooling, and its structural formula is
(Mg7.15Fe0.56)(Si10.35Fe3.3)O30(OH)4(H2O)2, the transmission electron microscope of ferrum modified powder is as shown in figure 4, the modified Hai Pao of ferrum
Stone29SiNMR spectrums show that ferrum enters framing structure and instead of part silicon atom, and substituted silicon atom is fine in meerschaum
The edge of dimension becomes Q2Structure, as shown in Figure 5.Ferrum modified meerschaum surface potential -48mV in pH9.0.By the powder body and often
The each 1.0g of warm ion-exchanged powder body is added separately to redness of the 100ml containing organic pigment (such as poly aromatic rings dye molecule)
30min is vibrated in waste water, after standing 2h, liquid layered, lower floor is red solid precipitation, and upper strata is colorless clear liquid, and 552nm's has
Machine pigments absorbalight peak disappears, in ultraviolet absorption spectrum such as Fig. 6 shown in curve 2；Exchange at modified meerschaum with reference to the common iron ion of sample
As shown in the curve 3 in Fig. 6, the organic pigment absorption peak strength of 552nm is reduced the ultraviolet absorption spectrum of reason paper waste, common ferrum
The decolorizing effect of ion exchange absorption modified meerschaum is poor.
Claims (10)
1. a kind of preparation method of framework modification meerschaum, it is characterised in that comprise the following steps：Meerschaum is molten by mineral acid
Ultimate fibre meerschaum is obtained after the dissociation of liquid acidification, then with trivalent inorganic salt or oxysalt hydrothermal modification；Process is completed
After be separated by filtration drying, obtain framework modification meerschaum.
2. the preparation method of framework modification meerschaum according to claim 1, it is characterised in that described framework modification sea
The structural formula of afrodite is Mg(8-1.5x)MxSi(12-0.75y)NyO30(OH)4(H2O)2, the one of M=Fe in formula, Al, Bi Tricationic
Plant or several；One or more in N=Fe, Al, Bi, B, Sb, P trivalent ion, x values are less than 6 less than 5, y values.
3. the preparation method of framework modification meerschaum according to claim 1, it is characterised in that trivalent inorganic salt is chlorine
Salt.
4. the preparation method of framework modification meerschaum according to claim 1, it is characterised in that during hydrothermal modification trivalent from
Alite or oxysalt addition account for the 0.1~30% of meerschaum quality, preferably 5~25%.
5. the preparation method of framework modification meerschaum according to claim 1, it is characterised in that hydrothermal temperature 100
DEG C~200 DEG C, preferably 120~160 DEG C.
6. the preparation method of framework modification meerschaum according to claim 1, it is characterised in that hydrothermal modification adjustment pH is extremely
6.0~10.0, the response time：1~24h, preferred pH to 6.0~9.0, preferred reaction time：3~6h.
7. the preparation method of framework modification meerschaum according to claim 1, it is characterised in that hydrothermal modification solid-liquid quality
Volume ratio：1:1~1:20g/mL, mixing speed：100rpm~1000rpm, preferred solid-liquid mass volume ratio 1:5~1:10g/
ML, preferred 300~600rpm of mixing speed.
8. a kind of framework modification meerschaum, it is characterised in that be that method by described in any one of claim 1-7 is prepared
's.
9. the framework modification meerschaum described in claim 8 is used to process organic dye waste water.
10. application according to claim 9, it is characterised in that by described framework modification meerschaum and containing organic dyestuff
Waste water mixing, stirring, stand, after layering, the supernatant becomes colorless, and lower sediment thing is changed into consolidating for organic dyestuff color
Body, after being separated by filtration, filtering residue returns paper pulp operation application.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611233954.2A CN106669593B (en) | 2016-12-28 | 2016-12-28 | A kind of framework modification sepiolite and its preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611233954.2A CN106669593B (en) | 2016-12-28 | 2016-12-28 | A kind of framework modification sepiolite and its preparation method and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106669593A true CN106669593A (en) | 2017-05-17 |
| CN106669593B CN106669593B (en) | 2019-09-27 |
Family
ID=58872011
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611233954.2A Expired - Fee Related CN106669593B (en) | 2016-12-28 | 2016-12-28 | A kind of framework modification sepiolite and its preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106669593B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107646750A (en) * | 2017-11-06 | 2018-02-02 | 长沙理工大学 | A kind of coral culture apparatus for promoting coral growth by reducing seawater acidity |
| CN109985600A (en) * | 2019-04-25 | 2019-07-09 | 湖南工程学院 | A kind of modified meerschaum and its application in the treatment of waste water |
| CN112044393A (en) * | 2019-06-06 | 2020-12-08 | 中南大学 | Two-dimensional clay-based composite phosphorus removal agent and preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1669926A (en) * | 2004-03-19 | 2005-09-21 | 中南大学 | Method for preparing mesoporous molecular sieve by sepiolite |
| CN105617981A (en) * | 2016-01-30 | 2016-06-01 | 湘潭大学 | Sepiolite modification method and application of modified sepiolite to wastewater treatment |
-
2016
- 2016-12-28 CN CN201611233954.2A patent/CN106669593B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1669926A (en) * | 2004-03-19 | 2005-09-21 | 中南大学 | Method for preparing mesoporous molecular sieve by sepiolite |
| CN105617981A (en) * | 2016-01-30 | 2016-06-01 | 湘潭大学 | Sepiolite modification method and application of modified sepiolite to wastewater treatment |
Non-Patent Citations (1)
| Title |
|---|
| 李松均，等: "海泡石的改性研究", 《江西科学》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107646750A (en) * | 2017-11-06 | 2018-02-02 | 长沙理工大学 | A kind of coral culture apparatus for promoting coral growth by reducing seawater acidity |
| CN109985600A (en) * | 2019-04-25 | 2019-07-09 | 湖南工程学院 | A kind of modified meerschaum and its application in the treatment of waste water |
| CN112044393A (en) * | 2019-06-06 | 2020-12-08 | 中南大学 | Two-dimensional clay-based composite phosphorus removal agent and preparation method and application thereof |
| CN112044393B (en) * | 2019-06-06 | 2021-05-04 | 中南大学 | Two-dimensional clay-based composite phosphorus removal agent and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106669593B (en) | 2019-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ahmad et al. | Neodymium embedded ordered mesoporous carbon (OMC) for enhanced adsorption of sunset yellow: Characterizations, adsorption study and adsorption mechanism | |
| Tony | Zeolite-based adsorbent from alum sludge residue for textile wastewater treatment | |
| Wawrzkiewicz et al. | Mixed silica-alumina oxide as sorbent for dyes and metal ions removal from aqueous solutions and wastewaters | |
| Rubeena et al. | Iron impregnated biochars as heterogeneous Fenton catalyst for the degradation of acid red 1 dye | |
| Faraji et al. | Cetyltrimethylammonium bromide-coated magnetite nanoparticles as highly efficient adsorbent for rapid removal of reactive dyes from the textile companies’ wastewaters | |
| Unuabonah et al. | Equilibrium, kinetic and sorber design studies on the adsorption of Aniline blue dye by sodium tetraborate-modified Kaolinite clay adsorbent | |
| Fosso-Kankeu et al. | Coagulation/flocculation potential of polyaluminium chloride and bentonite clay tested in the removal of methyl red and crystal violet | |
| Baskaralingam et al. | Adsorption of acid dye onto organobentonite | |
| Gerçel et al. | Removal of disperse dye from aqueous solution by novel adsorbent prepared from biomass plant material | |
| CN106669593A (en) | Framework modified sepiolite as well as preparation method and application thereof | |
| CN112408402B (en) | Preparation method and application of La activated functionalized dendritic mesoporous silica nanosphere | |
| Wu et al. | Adsorption properties of dodecylsulfate-intercalated layered double hydroxide for various dyes in water | |
| Bouberka et al. | Removal of Supranol Yellow 4GL by adsorption onto Cr-intercalated montmorillonite | |
| Nadeem et al. | Polishing of biologically treated textile wastewater through AOPs and recycling for wet processing | |
| Ahrouch et al. | Adding value to natural clays as low-cost adsorbents of methylene blue in polluted water through honeycomb monoliths manufacture | |
| Medjdoubi et al. | Adsorption behavior of Janus Green B dye on Algerian diatomite | |
| CN107262044A (en) | It is a kind of to Congo red magnetic coupling functional material with efficient clearance and preparation method thereof in water | |
| Bożęcka et al. | Methods of dyes removal from aqueous environment | |
| Liu et al. | Removal of triphenylmethane dyes by calcium carbonate–lentinan hierarchical mesoporous hybrid materials | |
| Al-Amrani et al. | A comprehensive review of anionic azo dyes adsorption on surface-functionalised silicas | |
| Mirzaie et al. | Optimized removal of acid blue 62 from textile waste water by SBA-15/PAMAM dendrimer hybrid using response surface methodology | |
| dos Santos et al. | Adsorption of synthetic orange dye wastewater in organoclay | |
| Cai et al. | Application of cetyltrimethylammonium bromide bentonite–titanium dioxide photocatalysis technology for pretreatment of aging leachate | |
| Cheng et al. | The adsorption of Rhodamine B in water by modified zeolites | |
| CN106943995A (en) | A kind of modified clinoptilolite and preparation method and remove waste water in Pb ions application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190927 Termination date: 20201228 |