A method for determining the stability of polyacrylamide

Abstract

The application discloses a method for judging the stability of polyacrylamide, which comprises the following steps: evenly distributing a polyacrylamide sample to be detected into at least three polyacrylamide sub-samples; dissolving each polyacrylamide sub-sample in water to obtain a polyacrylamide solution with a mass concentration of 0.1%, adding the polyacrylamide solution into sewage samples, and stirring uniformly; detecting and recording the flocculation settling velocity, the supernatant turbidity, the supernatant COD and the supernatant pH of each sewage sample; judging the product stability of the polyacrylamide sample A through data analysis, and if the relative errors of each data of each sample are all within 5%, the stability of the polyacrylamide sample is determined to be qualified, and if the relative errors of at least one more data are more than 5%, the stability of the polyacrylamide sample is determined to be unqualified. The method can quickly and accurately judge whether the polyacrylamide product is stable.

Description

TECHNICAL FIELD

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

[0002] Polyacrylamide (PAM) is a linear polymer, which is polymerized from acrylamide monomers. It has good water solubility and can be dissolved in water at any ratio, and is widely used in water treatment, oil exploitation, papermaking, textile and other industries. Polyacrylamide is mainly used as flocculant, thickening agent, lubricant, etc., and has excellent flocculation and sedimentation properties, which can effectively improve the water clarity and treatment efficiency.

[0003] Polyacrylamide needs to have good stability, such as thermal stability and chemical stability, to facilitate its product utility. At present, the stability of polyacrylamide product is usually determined by observing the appearance of the product, such as observing whether the color and form of the product are translucent or milky white liquid. However, this method only relies on visual observation and cannot accurately determine the stability of polyacrylamide product and ensure its sewage treatment effect. Therefore, a method for quickly, effectively and accurately detecting the stability of polyacrylamide product is needed. SUMMARY

[0004] The purpose of the present application is to solve the above technical problems, and to provide a method for quickly and accurately determining the stability of polyacrylamide.

[0005] In order to achieve the above purpose of the application, the present application provides a method for determining the stability of polyacrylamide, which comprises the following steps:

[0006] (1) The polyacrylamide sample to be detected is evenly divided into at least three polyacrylamide sub-samples;

[0007] (2) Each polyacrylamide sub-sample is dissolved in water to obtain a polyacrylamide solution with a mass concentration of 0.1%;

[0008] (3) The polyacrylamide solution is added to the sewage sample and stirred uniformly;

[0009] (4) The flocculation settling velocity, supernatant turbidity, supernatant COD and supernatant pH of each sewage sample are detected and recorded;

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

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

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

[0013] According to the method of the present application, preferably, in step (2), the stirring dissolving is performed using a magnetic stirrer.

[0014] According to the method of the present application, 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 application, 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 application, preferably, in step (3), the sewage sample is stirred evenly before the polyacrylamide solution is added. More preferably, the stirring speed of the sewage sample is 600r / min, and the stirring time is 60 seconds.

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

[0018] By the method of the present application, the stability of the polyacrylamide product can be quickly and accurately determined. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A structural schematic diagram of the SX-6L scale selector is shown.

[0020] Figure 2 A front view of the SX-6L scale selector is shown. DETAILED DESCRIPTION

[0021] The present application will be further described in conjunction with specific embodiments. It should be understood that the following embodiments are only used to illustrate the present application, and are not used to limit the scope of the present application.

[0022] The method for determining the stability of polyacrylamide provided by the present application will be described in detail below, but the protection scope of the present application is not limited thereto. The specific polyacrylamide sample type and sample quantity are only illustrative, and the present method can be applied to the determination of the stability of any type and any quantity of polyacrylamide product. The stability of the polyacrylamide product refers to the ability of the polyacrylamide to maintain its original physical and chemical properties, i.e., the property of not being prone to chemical, physical or biological changes. The stability of the polyacrylamide is an important indicator for measuring whether the polyacrylamide can maintain its performance during preparation, storage and use.

[0023] The stability of the polyacrylamide sample is determined according to the following steps:

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

[0025] (2) The 6 parts of the evenly divided polyacrylamide sample were dissolved in distilled water at a mass concentration of 0.1%, and the dissolution time was 60 minutes. Preferably, a magnetic stirrer (400 r / min) was used for stirring and dissolution.

[0026] (3) The wastewater sample Y was evenly placed in the six beakers of the SX-6L scale selector (from Guangdong Shuxin Environmental Protection Material Technology Co., Ltd.). Each beaker contained 1000 mL of wastewater sample. The structure of the SX-6L scale selector is shown in Figure 1 and Figure 2 The selector in the figure has 6 beakers in parallel, labeled as ①, ②, ③, ④, ⑤, and ⑥.

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

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

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

[0030] (7) Simultaneously detect and record the flocculation settling velocity (cm / s), supernatant turbidity (NTU), supernatant COD (chemical oxygen demand, mg / L), and supernatant pH of the wastewater 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 the data of the 6 samples are all within 5%, it is determined that the stability of the polyacrylamide sample is qualified. If the relative errors of at least one or more data exceed 5%, it is determined that the stability of the polyacrylamide sample is unqualified.

[0032] The flocculation settling velocity of the wastewater sample Y was detected using a stopwatch and a camera.

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

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

[0035] The supernatant pH of the sewage sample Y was detected by using an acidimeter.

[0036] The indexes of the sewage sample Y treated by the polyacrylamide sample SAY85 were detected by using the method, and the detection results are shown in the following table.

[0037] Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Floccule settling 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] Through the above detection data, it can be determined that the stability of the polyacrylamide sample SAY85 is qualified.

Claims

1. A method for determining the stability of a polyacrylamide, characterized in that The method comprises the following steps: (1) evenly divide the polyacrylamide sample to be detected into at least three polyacrylamide sub-samples; (2) dissolve each polyacrylamide sub-sample in water to obtain a polyacrylamide solution with a mass concentration of 0.1%; (3) add the polyacrylamide solution into the sewage sample and stir uniformly; (4) detect and record the floc settling velocity, supernatant turbidity, supernatant COD and supernatant pH of each sewage sample; (5) determine the product stability of the polyacrylamide sample A through data analysis; if the relative errors of each data of each sample are all within 5%, it is determined that the stability of the polyacrylamide sample is qualified; if the relative errors of at least one item of data exceed 5%, it is determined that the stability of the polyacrylamide sample is unqualified.

2. The method of claim 1, wherein, In step (2), the water is distilled water.

3. The method of claim 1, wherein, In step (2), the dissolving time is 60 minutes.

4. The method of claim 1, wherein, In step (2), a magnetic stirrer is used for stirring and dissolving.

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

6. The method of claim 1, wherein, In step (1), the polyacrylamide sample to be detected is evenly divided into six polyacrylamide sub-samples.

7. The method of claim 1, wherein, In step (3), the sewage sample is stirred uniformly before the polyacrylamide solution is added.

8. The method of claim 7, wherein, The stirring speed of the sewage sample is 600 r / min, and the stirring time is 60 seconds.

9. The method of claim 1, wherein, In step (3), the stirring time is 120 seconds.

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