Method for judging stability of polyacrylamide

Abstract

The invention discloses a method for judging the stability of polyacrylamide. The method comprises the following steps: averagely distributing a polyacrylamide sample to be detected into at least three parts of polyacrylamide sub-samples; dissolving each polyacrylamide sub-sample with water to obtain a polyacrylamide solution with the mass concentration of 0.1%, adding the polyacrylamide solution into the sewage sample, and uniformly stirring; detecting and recording the floc settling velocity, the supernatant turbidity, the supernatant COD and the supernatant pH of each sewage sample; the product stability of the polyacrylamide sample A is judged through data analysis, if the relative error of all data of all the samples is within 5%, it is judged that the stability of the polyacrylamide sample is qualified, and if the relative error of at least one or more data exceeds 5%, it is judged that the stability of the polyacrylamide sample is unqualified. The method disclosed by the invention can be used for rapidly and accurately judging whether the polyacrylamide product is stable or not.

Description

Technical Field

[0001] The present invention belongs to the field of chemical detection, and particularly relates to a method for determining the stability of polyacrylamide. Background Art

[0002] Polyacrylamide (PAM) is a linear high molecular polymer formed by polymerization of acrylamide monomers. It has good water solubility and can dissolve in water in any proportion, and is widely used in industries such as water treatment, oil extraction, papermaking, and textile. Polyacrylamide is mainly used as a flocculant, thickener, lubricant, etc., and has excellent flocculation and sedimentation properties, which can effectively improve the clarity of water quality and treatment efficiency.

[0003] Polyacrylamide needs to have good stability, such as thermal stability and chemical stability, to facilitate the exertion of its product efficacy. At present, the stability of polyacrylamide products is usually determined by observing the appearance of the products, such as observing whether the color and form of the products are semi-transparent or milky white liquids. However, this method relies only on visual observation and cannot accurately determine the stability of polyacrylamide products and ensure their sewage treatment effects. Therefore, a method for quickly, effectively and accurately detecting the stability of polyacrylamide products is needed. Summary of the Invention

[0004] The object of the present invention is to provide a method for quickly and accurately determining the stability of polyacrylamide in view of the above technical problems to be solved.

[0005] To achieve the above invention object, the present invention provides a method for determining the stability of polyacrylamide, which comprises the following steps:

[0006] (1) Evenly divide the polyacrylamide sample to be detected into at least three polyacrylamide sub-samples;

[0007] (2) Dissolve each polyacrylamide sub-sample in water to a polyacrylamide solution with a mass concentration of 0.1%;

[0008] (3) Add the polyacrylamide solution to the sewage sample and stir evenly;

[0009] (4) Detect and record the floc sedimentation rate, supernatant turbidity, supernatant COD, and supernatant pH of each sewage sample;

[0010] (5) Determine the product stability of polyacrylamide sample A through data analysis. If the relative error of each item of data of each sample is within 5%, it is judged that the stability of the polyacrylamide sample is qualified. If the relative error of at least one item of data exceeds 5%, it is determined that the stability of the polyacrylamide sample is unqualified.

[0011] According to the method of the present invention, preferably, in step (2), the water is distilled water.

[0012] According to the method of the present invention, preferably, in step (2), the dissolution time is 60 minutes.

[0013] According to the method of the present invention, preferably, in step (2), magnetic stirrer is used for stirring and dissolving.

[0014] According to the method of the present invention, preferably, in step (3), the volume ratio of the polyacrylamide solution to the sewage sample is 3.6:1000.

[0015] According to the method of the present invention, preferably, in step (1), the polyacrylamide sample to be detected is evenly divided into six polyacrylamide sub-samples.

[0016] According to the method of the present invention, preferably, in step (3), before adding the polyacrylamide solution, the sewage sample is stirred evenly. More preferably, the stirring speed of the sewage sample is 600 r / min and the stirring time is 60 seconds.

[0017] According to the method of the present invention, preferably, in step (3), the stirring time is 120 seconds.

[0018] Through the method of the present invention, the stability of the polyacrylamide product can be determined quickly and accurately. Brief Description of the Drawings

[0019] Figure 1 Shows the structural schematic diagram of the SX-6L large-scale selector.

[0020] Figure 2 Shows the front view of the SX-6L large-scale selector. Detailed Description of the Invention

[0021] The following will further illustrate the present invention in conjunction with specific embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the scope of the present invention.

[0022] The method for determining the stability of polyacrylamide provided by the present invention will be described in detail below, but the protection scope of the present invention is not limited thereto. The specific polyacrylamide sample model and the number of samples are only for illustrative purposes, and this method can be applied to the determination of the stability of any type and any number of polyacrylamide products. The stability of polyacrylamide product refers to the ability of polyacrylamide to maintain its original physical and chemical properties, that is, the property of not easily undergoing chemical changes, physical changes or biological changes. The stability of polyacrylamide is an important index to measure whether polyacrylamide can maintain its performance during the preparation, storage and use processes.

[0023] Determine the stability of the polyacrylamide sample according to the following steps:

[0024] (1) The polyacrylamide sample SAY85 to be detected (this product is a cationic polyacrylamide with an ionic degree of 6.8% and a molecular weight of 6.18 million, a commercially available product from Guangdong Shouxin Environmental Protection Materials Technology Co., Ltd.) is evenly divided into 6 parts, labeled as sample 1, sample 2, sample 3, sample 4, sample 5, and sample 6 respectively.

[0025] (2) The 6 evenly divided polyacrylamide samples are dissolved in distilled water at a mass concentration of 0.1%. The dissolution time is 60 minutes. It is preferred to use a magnetic stirrer (rotation speed 400 r / min) for stirring and dissolution.

[0026] (3) The sewage sample Y is evenly placed into six beakers in the SX-6L large-scale selector (from Guangdong Shouxin Environmental Protection Materials Technology Co., Ltd.). The amount of sewage sample added to each beaker is 1000 mL. The structural schematic diagram of the SX-6L large-scale selector is as Figure 1 and Figure 2 shown. The selector in the figure has 6 parallel beakers, labeled as ①, ②, ③, ④, ⑤, and ⑥ in sequence.

[0027] (4) The six dissolved polyacrylamide solutions with a mass concentration of 0.1% are added to the dosing device (located inside the selector, not shown in the figure) in the SX-6L large-scale selector in the same dosage of 3.6 mL.

[0028] (5) Start the SX-6L large-scale selector. Stir the sewage sample Y evenly at a rotation speed of 600 r / min for 60 seconds.

[0029] (6) Start the dosing device of the SX-6L large-scale selector and evenly add 3.6 mL of polyacrylamide solution to the six beakers containing the sewage sample Y. Stir the polyacrylamide sample and the sewage sample evenly for 120 seconds.

[0030] (7) Simultaneously detect and record the floc settlement velocity (cm / s), supernatant turbidity (NTU), supernatant COD (chemical oxygen demand, mg / L), supernatant pH and other indicators of the sewage sample Y in the 6 beakers.

[0031] (8) Determine the product stability of the polyacrylamide sample A through data analysis. If the relative errors of all data of the 6 samples are within 5%, it is judged that the stability of the polyacrylamide sample is qualified. If the relative error of at least one item of data exceeds 5%, it is determined that the stability of the polyacrylamide sample is unqualified.

[0032] The instrument used to detect the floc settlement velocity of the sewage sample Y is a stopwatch and a camera.

[0033] The turbidity of the supernatant of sewage sample Y was detected using a turbidimeter.

[0034] The COD of the supernatant of sewage sample Y was detected using a German Hach COD detector.

[0035] The pH of the supernatant of sewage sample Y was detected using a pH meter.

[0036] The various indicators of sewage sample Y treated with polyacrylamide sample SAY85 were detected by this method, and the test results are shown in the following table.

[0037] Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Floc sedimentation velocity (cm / s) 0.65 0.64 0.65 0.66 0.64 0.65 Supernatant turbidity (NTU) 28.2 28.0 28.1 28.1 28.2 28.0 Supernatant COD (mg / L) 56.7 57.2 57.3 56.9 56.5 57.8 Supernatant pH 7.18 7.15 7.16 7.13 7.15 7.19

[0038] Based on the above test data, it can be determined that the stability of the polyacrylamide sample SAY85 is qualified.

Claims

1. A method for determining the stability of polyacrylamide, characterized in that The following steps are involved: (1) dividing the polyacrylamide sample to be tested into at least three polyacrylamide subsamples; (2) dissolving each polyacrylamide subsample in water to a polyacrylamide solution with a mass concentration of 0.1%; (3) Add the polyacrylamide solution to the sewage sample and stir evenly; (4) Detect and record the floc settling rate, supernatant turbidity, supernatant COD, and supernatant pH of each sewage sample; (5) The product stability of polyacrylamide sample A is determined by data analysis. If the relative error of each data of each sample is within 5%, the stability of the polyacrylamide sample is judged to be qualified. If the relative error of at least one data exceeds 5%, the stability of the polyacrylamide sample is judged to be unqualified.

2. The method according to claim 1, characterized in that In step (2), the water is distilled water.

3. The method according to claim 1, characterized in that In step (2), the dissolution time is 60 minutes.

4. The method according to claim 1, characterized in that: In step (2), a magnetic stirrer is used for stirring and dissolving.

5. The method according to claim 1, characterized in that In step (3), the volume ratio of the polyacrylamide solution to the sewage sample is 3.6:1000.

6. The method according to claim 1, characterized in that In step (1), the polyacrylamide sample to be tested is evenly divided into six polyacrylamide sub-samples.

7. The method according to claim 1, characterized in that In step (3), the sewage sample is stirred evenly before adding the polyacrylamide solution.

8. The method according to claim 7, characterized in that The sewage sample stirring speed is 600r / min and the stirring time is 60 seconds.

9. The method according to claim 1, characterized in that: In step (3), the stirring time is 120 seconds.

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