CN101530793A - Method for preparing attapulgite clay catalyst and method for measuring COD by the catalyst - Google Patents

Method for preparing attapulgite clay catalyst and method for measuring COD by the catalyst Download PDF

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CN101530793A
CN101530793A CN200910025695A CN200910025695A CN101530793A CN 101530793 A CN101530793 A CN 101530793A CN 200910025695 A CN200910025695 A CN 200910025695A CN 200910025695 A CN200910025695 A CN 200910025695A CN 101530793 A CN101530793 A CN 101530793A
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attapulgite
catalyst
recessed
recessed soil
cod
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CN101530793B (en
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尹起范
史昆波
朱玉兰
盛振环
夏敏
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Huaiyin Normal University
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Abstract

The invention discloses a method for preparing an attapulgite clay catalyst and a method for measuring COD by the catalyst. The method for preparing the attapulgite clay catalyst comprises the following steps: (1) attapulgite purification, namely adding the primary attapulgite into water according to a mass ratio of 1:10-15, stirring the mixture for 24 to 48 hours to form attapulgite slurry, keeping the attapulgite slurry standing naturally, taking suspension on the upper layer, and filtering, drying and grinding the suspension to obtain purified attapulgite; and (2) acidification treatment, namely adding the purified attapulgite into mixed acid solution according to a mass ratio of 1:10-15, slightly boiling the mixture for 70 to 90 minutes by continually stirring, filtering the boiled mixture, washing the filter cake to be neutral, and drying and grinding the filter cake to obtain acidified attapulgite, namely the attapulgite catalyst, wherein the mixed acid solution of which volume concentration is 5 percent is formed by mixing sulphuric acid and phosphoric acid. The steps in the COD measuring method are the same as GB11914-1989; when domestic sewage is measured, 20 milliliters of concentrated sulphuric acid and 0.3 gram of attapulgite are added into the domestic sewage and reflowed for 30 minutes; and when industrial sewage is measured, 30 milliliters of concentrated sulphuric acid and 0.3 gram of acidified attapulgite are added into the industrial sewage and reflowed for 30 minutes. By adopting the primary attapulgite to prepare the catalyst, the development and utilization values of the primary attapulgite are promoted; and by adopting the acidified attapulgite to measure COD, the measuring cost is lowered, the measuring time is shortened, and the secondary pollution is reduced.

Description

The preparation method of attapulgite clay catalyst and this catalyst are measured the method for COD
Technical field
The present invention relates to Preparation of catalysts method and using method, be specifically related to the preparation method of attapulgite clay catalyst and the method that this catalyst is measured COD.
Background technology
COD (COD Cr) be meant under strong acid and heating condition the amount of the oxidant that consumes during as the oxidizer treatment sewage sample with potassium bichromate.COD CrThe size of value has reflected the degree that polluted by reducing substances, is one of important indicator of weighing organic matter relative amount in the water.Mensuration (COD in the GB11914-1989 COD Cr) in, be to make catalyst with silver sulfate, the every 20.00mL water sample of conventional determining will add the sulfuric acid solution 28.00mL that contains 1% silver sulfate, and is heated to the backflow 2h that boils.The COD that this method is measured CrThe value scope is at 30-700mg/L.
The length because standard method expends time in uses silver sulfate catalyst cost higher again, and the alternative catalysts of report has MnSO both at home and abroad in recent years 4, Mn (H 2PO 4) 2And Ag 2SO 4-MgSO 4, CuSO 4-KAl (SO 4) 2-Na 2MoO 4Mixtures etc., existing single component catalyst also has multicomponent catalyst.
Recessed soil claims concavo-convex excellent face clay, Concave-convex clay rod, attapulgite etc. again, be to be a kind of clay mineral of main component with attapulgite (Attapulgite), main component is palygorskite (Palygorskite) or sloping thin white silk used in ancient China stone, it is a kind of moisture zeopan clay mineral, be under the jurisdiction of sepiolite group, its typical molecular formula is: Mg 5(Si 8O 20(OH) 2(OH 2) 44H 2O belongs to 2:1 type layer chain crystal structure, is natural nano material.Because microstructure, appearance and charged character that itself is unique, recessed soil has many premium properties, as colloidality, adsorptivity, caking property, catalytic etc., thereby is widely used in fields such as chemical industry, building materials, medicine, agricultural and environmental protection.But do not see the report that utilizes recessed soil to measure COD as catalyst so far.
Summary of the invention
The objective of the invention is to: the preparation method of attapulgite clay catalyst and the method that this catalyst is measured COD are provided, utilize recessed soil preparation catalyst, this catalyst substitutes silver sulfate in COD of sewage is measured, reduce cost of determination, shorten minute, reduce secondary pollution, and improve the value of going deep into development and utilization of recessed soil.
Technical solution of the present invention is: recessed native Preparation of catalysts method may further comprise the steps:
(1) recessed soil is purified, get the former recessed soil of 100-200 order according to mass ratio 1:10-15 add stirred 24-48 hour in the entry recessed soil paste liquid, static naturally, get upper strata suspension, filter, dry, grind the recessed soil of purifying;
(2) acidification adds the recessed soil of purifying in the mixed acid liquid according to mass ratio 1:10-15, and little 70-90min that boils under constantly stirring boils the back and filters and be washed till neutrality, dry, grind the recessed soil of acidifying, promptly recessed native catalyst; Wherein, the mixed acid liquid of volume by volume concentration 5% is made up of sulfuric acid and phosphoric acid mixing.
Recessed native catalyst is measured the method for COD: the same GB11914-1989 of the step in this assay method is characterized in that: when measuring sanitary sewage, add the 20mL concentrated sulfuric acid, the recessed native catalyst of 0.3g, backflow 30min; When measuring trade effluent, add the 30mL concentrated sulfuric acid, the recessed native catalyst of 0.3g, backflow 30min.
The present invention has the following advantages: 1, adopt recessed soil to be prepared into catalyst, this preparation method is easy, has promoted former recessed native development and utilization and has been worth; 2, adopt the recessed soil of acidifying to substitute silver sulfate and measure COD, reduced cost of determination, shortened minute, reduced secondary pollution.
Description of drawings
Fig. 1 is the XRD figure of former recessed soil.
Fig. 2 is the XRD figure of recessed native catalyst,
Fig. 3 is the IR figure of former recessed soil
Fig. 4 is the IR figure of recessed native catalyst.
Fig. 5 is the SEM figure of former recessed soil
Fig. 6 is the SEM figure of recessed native catalyst.
Fig. 7 melts pore size distribution curve figure for recessed native hole, and wherein Y0 is former recessed soil, and Y1 is the recessed soil of purifying, and Y2 is the recessed soil of acidifying
The specific embodiment
Below in conjunction with specific embodiment, the present invention is described in further detail.Should be understood that these embodiment just in order to demonstrate the invention, but not limit the scope of the invention by any way.
Instrument: x-ray diffractometer (XRD) ARL/X ' TRA (Arl Inc., Switzerland), AVATAR-360FT-IR FTIS (NICOLET company, the U.S.), SA3100PLUS specific surface, pore size determination instrument (Beckman Coulter Inc., the U.S.), S-3000N type SEM (HITACHI company, Japan).
Reagent and glass apparatus: it is pure that iron ammonium sulfate, silver sulfate, mercuric sulfate, the concentrated sulfuric acid, phosphoric acid, phenanthroline, ferrous sulfate, potassium bichromate etc., reagent are analysis, ground conical flask (500mL), and spherical condensation tube, acid buret, water are distilled water.
Material: former recessed soil (Xuyi Jiangsu), the recessed soil of acidifying (self-control); Water sample (Huai second sewage treatment plant's sanitary sewage, Chinese holly sewage treatment plant trade effluent).
Reagent preparation and demarcation: all reagent are all prepared and are demarcated by the concentration and the method for GB11914-1989 defined.
Example 1: recessed native Preparation of catalysts:
(1) recessed soil is purified, get the former recessed soil of 100 orders according to mass ratio 1:10 add stirred 24 hours in the entry recessed soil paste liquid, static naturally, get upper strata suspension, filter, dry, grind the recessed soil of purifying;
(2) acidification adds the recessed soil of purifying in the mixed acid liquid according to mass ratio 1:10, and little 70min that boils under constantly stirring boils the back and filters and be washed till neutrality, oven dry grind the recessed soil of acidifying, promptly recessed native catalyst; Wherein, the mixed acid liquid of volume by volume concentration 5% is made up of sulfuric acid and phosphoric acid mixing.
The XRD figure of the recessed soil of acidifying that obtains by example 1 as shown in Figure 2, the XRD of former recessed soil as shown in Figure 1, by the free SiO of the former as can be seen recessed soil of Fig. 1,2 2Exist apparent in viewly, purify and also to handle the free SiO in back 2Exist smallerly, and handle forward and backward structure and do not change.
Example 2: recessed native Preparation of catalysts:
(1) recessed soil is purified, get the former recessed soil of 150 orders according to mass ratio 1:13 add stirred 36 hours in the entry recessed soil paste liquid, static naturally, get upper strata suspension, filter, dry, grind the recessed soil of purifying;
(2) acidification adds the recessed soil of purifying in the mixed acid liquid according to mass ratio 1:13, and little 80min that boils under constantly stirring boils the back and filters and be washed till neutrality, dry, grind the recessed soil of acidifying, promptly recessed native catalyst; Wherein, the mixed acid liquid of volume by volume concentration 5% is 5% to be mixed by sulfuric acid and phosphoric acid and to form.
The IR figure of the recessed soil of acidifying that obtains by example 2 as shown in Figure 4, the IR of former recessed soil can see that from Fig. 3,4 characteristic absorption of recessed soil does not change basically yet before and after handling as shown in Figure 3; High frequency region 4000~3000cm -1Be the stretching vibration (3552.13cm of R-OH -1) and the stretching vibration district of zeolite water; Intermediate frequency zone (1700~800cm -1) middle 1653.99cm -1Absorption of vibrations is the reflection of mineral adsorbed water and intermediary water; 1200~800cm -1Be (Mg Al)-Si-O, the stretching vibration interval of Si-O-Si (Al), Al in the octahedron 3+, Mg 2+, Fe 3+Between isomorphous replacement and Al 3+Displacement tetrahedron Si 4+Quantity all influence number, position and the intensity of absorption band around here, the result that the structure that infrared spectrum reflected and XRD research draws is consistent, wherein 3552.13cm -1, 1653.99cm -1, 1399.38cm -1, 1006.13cm -1, 489.91cm -1The characteristic infrared that is recessed soil absorbs.
Example 3: recessed native Preparation of catalysts:
(1) recessed soil is purified, get the former recessed soil of 200 orders according to mass ratio 1:15 add stirred 48 hours in the entry recessed soil paste liquid, static naturally, get upper strata suspension, filter, dry, grind the recessed soil of purifying;
(2) acidification adds the recessed soil of purifying in the mixed acid liquid according to mass ratio 1:15, and little 90min that boils under constantly stirring boils the back and filters and be washed till neutrality, dry, grind the recessed soil of acidifying, promptly recessed native catalyst; Wherein, the mixed acid liquid of volume by volume concentration 5% is 5% to be mixed by sulfuric acid and phosphoric acid and to form.
The SEM figure of the recessed soil of acidifying that is obtained by example 3 as shown in Figure 6, the SEM of former recessed soil as shown in Figure 5, the crystal shape of recessed soil of being untreated as can be seen from Fig. 5,6 is a needle-like, handle recurve soil crystal shape and the cluster shape partly occurred, illustrate that recessed soil is under the synergy of mixed acid, hole in the layer structure increases, may be relevant with the coordination of the oxidation of sulfuric acid and solvability and phosphoric acid, and the partial impurities of removing in the recessed soil is desirable more; Also may be relevant with the size of exchange ion, particularly octahedral cation Mg 2+, Fe 3+, Fe 2+, Al 3+Deng with H +Exchange; Or crystallization water molecule in the layer structure or dissociating water molecule minimizing, the hole in the layer structure is increased, thereby make specific area by original 140m 2Increase to 400m about/g 2About/g; Measure the pore volume pore size distribution curve drawn as shown in Figure 7 by BET, with the basically identical as a result of SEM figure; Recessed penus is in the porous clay mineral, has the surface-active center, after handling, mixed acid increased its specific area, the activated centre strengthens, from the result that BET measures, the total pore volume before the acidifying is 0.3540mL/g, and the total pore volume after the acidifying is 0.6960mL/g, hole has systematicness, a large amount of H +Replaced partial cation, gone into solid acid, thereby had good catalytic performance, organic molecular dimension is not very big in the sewage simultaneously, so can not influence the catalytic reaction that it carries out in the recessed native hole of acidifying, has produced good catalytic effect thus.
Example 4: former recessed soil is made catalyst and is measured COD:
Draw sanitary sewage water sample 20.00mL in 500mL ground conical flask according to standard method, add the 2mL concentrated sulfuric acid and 0.4g mercuric sulfate, make its reaction dissolving; Add 10.00mL potassium bichromate standard liquid and bead number, slowly add concentrated sulfuric acid 20.00mL more respectively, add the former recessed soil of 0.3g, add hot reflux 30min; Other step is identical with the standard method of GB11914-1989, the consumption V (mL) of the record iron ammonium sulfate standard liquid that consumes; Do blank assay simultaneously, the consumption V of record iron ammonium sulfate standard liquid 0(mL).COD=18.4mg/L as a result, reference value: COD=60.0mg/L does not have catalytic action substantially.
Example 5: recessed native catalyst is measured the selection of the recessed native catalyst amount of acidifying of COD:
Draw water sample 20.00mL respectively in 3 500mL ground conical flasks according to standard method, add the 2mL concentrated sulfuric acid and 0.4g mercuric sulfate respectively, make its reaction dissolving; Each adds 10.00mL potassium bichromate standard liquid and bead number, slowly adds concentrated sulfuric acid 28.00mL (consumption of acid in the standard method) more respectively, adds 0.3g respectively, 0.5g, and the recessed soil of 0.7g acidifying adds hot reflux 30min; The same GB11914-1989 of other step the results are shown in Table 1.
COD value when the different return times of the recessed native consumption of table 1 are identical
Figure A200910025695D00081
As can be seen from Table 1, recessed native catalyst amount also can illustrate thus to almost not influence of result, and this process is not suction-operated but catalytic action; So selecting the recessed native consumption of acidifying under identical situation is 0.3g.
Example 6: recessed native catalyst is measured the selection of the return time of COD:
Draw water sample 20.00mL respectively in 5 500mL ground conical flasks according to standard method, add the 2mL concentrated sulfuric acid and 0.4g mercuric sulfate respectively, make its reaction dissolving; Add 10.00mL potassium bichromate standard liquid and bead number respectively, slowly add concentrated sulfuric acid 28.00mL more respectively, add the recessed soil of 0.3g acidifying respectively, add hot reflux 15min, 30min, 60min, 90min, 120min; The same GB11914-1989 of other step the results are shown in Table 2.
The asynchronous COD value of the identical return time of the recessed native consumption of table 2
Figure A200910025695D00091
As can be found from Table 2, the recessed native consumption of acidifying is 0.3g, and return time is 30min, differs less with reference value.
Example 7: recessed native catalyst is measured the selection of the sulfuric acid consumption of COD:
Draw sewage sample 20.00mL in 500mL ground conical flask according to standard method, add the 2mL concentrated sulfuric acid and 0.4g mercuric sulfate, make its reaction dissolving; Add 10.00mL potassium bichromate standard liquid and bead number, slowly add concentrated sulfuric acid 10.00mL, 20.00mL, 30.00mL more respectively, add the recessed soil of 0.3g acidifying respectively, add hot reflux 30min; The same GB11914-1989 of other step, result see Table 3 respectively, table 4.
The different result of table 3 sulfuric acid consumption compares (sanitary sewage)
Figure A200910025695D00101
The different result of table 4 sulfuric acid consumption compares (trade effluent)
Can find that from table 3, table 4 behind definite return time, recessed native catalyst amount, for sanitary sewage, the recessed native consumption of acidifying is 0.3g, return time is 30min, and the sulfuric acid consumption is 20.00mL, and result and reference value are close substantially, and absolute error only is 0.4; For trade effluent, the recessed native consumption of acidifying is 0.3g, and return time is 30min, and the sulfuric acid consumption is 30.00mL, and result and standard value are close substantially, and absolute error only is-0.6.
Example 8: recessed native catalyst is measured the comparison of COD and standard method mensuration actual water sample:
To Huai second sewage treatment plant (sanitary sewage), the water sample that Chinese holly sewage treatment plant (trade effluent) provides compares experiment, the results are shown in Table 5 respectively
The contrast of two kinds of catalyst of table 5
Figure A200910025695D00103
Example 9: recessed native catalyst is measured the comparison of COD and standard method mensuration COD standard liquid:
Press the GB11914-1989 method, accurately take by weighing Potassium Hydrogen Phthalate 0.2126g, insert in the 250mL beaker, with dissolved in distilled water and accurate constant volume 1000mL, this solution is equivalent to the COD value and is 250.0mg/L; Undertaken 7 times by this bright method and measure, the mean value when the recessed soil of acidifying is made catalyst is 249.6mg/L, and absolute error is-0.40, S=2.91, RSD=1.16%; The mean value of standard method is 245.8mg/L, and absolute error is-4.20, S=3.62, RSD=1.47%; Can reach a conclusion thus, make catalyst with the recessed soil of acidifying, its precision and the degree of accuracy can meet the demands fully, are feasible.

Claims (2)

1. the preparation method of attapulgite clay catalyst is characterized in that recessed native Preparation of catalysts method may further comprise the steps:
(1) recessed soil is purified, and gets the former recessed soil of 100-200 order and adds according to mass ratio 1:10-15 and stir the 24-48 hour recessed soil paste liquid of row in the entry, and is static naturally, gets upper strata suspension, filter, dry, grind the recessed soil of purifying;
(2) acidification adds the recessed soil of purifying in the mixed acid liquid according to mass ratio 1:10-15, and little 70-90min that boils under constantly stirring boils the back and filters and be washed till neutrality, dry, grind the recessed soil of acidifying, promptly recessed native catalyst; Wherein, the mixed acid liquid of volume by volume concentration 5% is made up of sulfuric acid and phosphoric acid mixing.
2. recessed native catalyst is measured the method for COD, it is characterized in that: the same GB11914-1989 of the step in this assay method, its feature in: when measuring sanitary sewage, add the 20mL concentrated sulfuric acid, the recessed soil of 0.3g, backflow 30min; When measuring trade effluent, add the 30mL concentrated sulfuric acid, the recessed soil of 0.3g acidifying, backflow 30min.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102188952A (en) * 2011-05-12 2011-09-21 西北师范大学 Multifunctional palygorskite base adsorbing material
CN102329524A (en) * 2011-06-28 2012-01-25 淮阴工学院 Method for preparing attapulgite supported high weather resistance composite pigment
CN105092775B (en) * 2015-07-27 2016-10-12 青岛果子科技服务平台有限公司 A kind of waste water COD rapid assay methods
CN108855148A (en) * 2018-06-15 2018-11-23 宁夏宝塔化工中心实验室(有限公司) A kind of preparation method of compound soil type acidic catalyst
CN112611832A (en) * 2020-12-25 2021-04-06 河北旋盈环境检测服务有限公司 Method for detecting chemical oxygen demand of water quality

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102188952A (en) * 2011-05-12 2011-09-21 西北师范大学 Multifunctional palygorskite base adsorbing material
CN102329524A (en) * 2011-06-28 2012-01-25 淮阴工学院 Method for preparing attapulgite supported high weather resistance composite pigment
CN105092775B (en) * 2015-07-27 2016-10-12 青岛果子科技服务平台有限公司 A kind of waste water COD rapid assay methods
CN108855148A (en) * 2018-06-15 2018-11-23 宁夏宝塔化工中心实验室(有限公司) A kind of preparation method of compound soil type acidic catalyst
CN112611832A (en) * 2020-12-25 2021-04-06 河北旋盈环境检测服务有限公司 Method for detecting chemical oxygen demand of water quality
CN112611832B (en) * 2020-12-25 2022-06-14 河北旋盈环境检测服务有限公司 Method for detecting chemical oxygen demand of water quality

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