A method for assessing the self-purification capacity of rivers and lakes based on silk strips

Abstract

This invention relates to the fields of environmental science and engineering, materials science, and water quality monitoring. Specifically, it discloses a method for assessing the self-purification capacity of rivers and lakes based on silk strips, comprising: S1, selecting experimental materials and preparing silk strips; S2, placing the silk strips in situ in river or lake water; S3, recovering the silk strips and determining their DOM (degradation by microorganisms) degradation capacity. The silk strips are cultured in the river or lake for 4 weeks before being recovered, and the recovered silk strips are divided into three parts for weight loss, tensile strength, and respiration rate measurements; S4, laboratory testing and analysis of DOM degradation capacity. The technical solution proposed in this invention can accurately reflect the self-purification capacity of rivers and lakes under complex natural environments. The silk strips used are easily decomposed by microorganisms and light, making it more environmentally friendly. The method is simple, low-cost, and widely applicable.

Description

Technical Field

[0001] This invention relates to the fields of environmental science and engineering, materials science and water quality monitoring technology, specifically a method for assessing the self-purification capacity of rivers and lakes based on silk strips. Background Technology

[0002] The self-purification capacity of rivers and lakes is crucial to their material cycle and energy flow. Many scholars have assessed this capacity, mostly using ex-situ laboratory cultivation methods. This involves culturing collected water samples under controlled experimental conditions for a set period before evaluating the self-purification capacity. However, ex-situ cultivation has the drawback of failing to replicate the original, complex ecological environment of lakes and reservoirs, potentially leading to biased experimental results. Currently, long-term in-situ monitoring of lakes and reservoirs is limited, hindering an accurate and realistic understanding of the degradation capacity and changing patterns of DOM (degradable organic matter) in complex environments.

[0003] The in-situ monitoring method using cotton strips, invented in recent years, relies on cotton strips whose main component is cellulose, which is not easily decomposed. Therefore, there is an urgent need for a material that can be easily decomposed by microorganisms to comprehensively assess the self-purification capacity of rivers and lakes. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides a method for assessing the self-purification capacity of rivers and lakes based on silk strips. This method can accurately and realistically reflect the self-purification capacity of rivers and lakes under complex natural environments, and is more environmentally friendly, lower in cost, and improves assessment efficiency.

[0005] To achieve the above objectives, this invention proposes a method for assessing the self-purification capacity of rivers and lakes based on silk strips, comprising the following steps:

[0006] S1. Select experimental materials and make silk strips;

[0007] S2. Lay out the silk strips and place them in the river or lake water in their original positions;

[0008] S3. Recycled silk strips and DOM degradation capacity determination: The silk strips were cultured in rivers and lakes for 4 weeks and then recycled. The recycled silk strips were divided into three parts and their weight loss, tensile strength and respiration rate were measured respectively.

[0009] S4. Laboratory testing and analysis of DOM degradation ability.

[0010] Preferably, in S1, the selected experimental materials include silk, plastic cable ties, nylon rope, wooden stakes, scissors, rulers, brushes, ethanol, a dynamometer, a drying oven, and a desiccator.

[0011] Preferably, in S1, the silk strip is made by cutting the silk into strips with a length and width of 8 cm and 2.5 cm respectively, making a 3 mm wide welt around the silk strip, and threading a plastic cable tie through one end at a distance of 7 mm.

[0012] Preferably, in step S2, the step of laying the silk strips includes:

[0013] S21. Use nylon rope to string together the prepared silk strips and fix them to one end of a wooden stake or steel bar 40-50cm away. Hammer the wooden stake or steel bar into the bottom of the river or lake so that the silk strips are positioned above the bottom of the river or lake and in contact with the bottom.

[0014] S22. Place 5 wooden stakes or steel bars at each sample point, fix 8 silk strips to each wooden stake or steel bar, and number each silk strip.

[0015] Preferably, the specific operation for determining weight loss is as follows: the silk strips to be divided into portions for weight loss determination are placed in pure water and gently cleaned with a brush. After drying at 40°C in the laboratory, they are stored in a desiccator, the weight is measured, and compared with the weight of the silk strips before cultivation to calculate the weight loss.

[0016] Preferably, the specific operation for measuring tensile strength is to place the silk strips, which are divided into portions for measuring tensile strength, in pure water, gently clean them with a brush, dry them in a laboratory at 40°C, store them in a desiccator, and measure their tensile strength using a tensile tester.

[0017] Preferably, the specific procedure for measuring respiratory rate is as follows:

[0018] S31. Gently wash the silk strips used for measuring the respiratory rate with water and insert them into 50mL breathing chambers; the breathing chambers are 50mL flat-bottomed plastic centrifuge tubes.

[0019] S32. Immerse each breathing chamber in the river or lake water sample with the tube opening facing upwards, filling the tube with the river or lake water sample, and tighten the lid while immersing.

[0020] S33. Set up 3 controls, each containing only river and lake water samples, and use the average value of the 3 control respiration chambers to estimate the respiration rate of the lake water;

[0021] S34. Incubate the sample in the dark for 2 hours at the in-situ ambient temperature. After removing the cap and removing the silk strip with tweezers, immediately place the DO probe into the breathing chamber and measure the DO consumption.

[0022] Preferably, the formula for calculating weight loss is:

[0023] Weight loss =1-Weight 培养前 / Weight 培养后 .

[0024] Preferably, the standard for tensile strength testing is to use daily tensile strength loss to reflect the degree of decomposition of the silk strip, and the calculation formula is:

[0025]

[0026] In the formula, Tensile Strength treatment strips The maximum tensile strength of each silk in the treatment group; reference strips The average tensile strength of 10 silk strips that were not cultured in river or lake water samples but were washed with ethanol and stored in a desiccator; Incubation Time is the culture time in days.

[0027] Preferably, when measuring the respiration rate, the respiration effect of river and lake water is used to compensate for differences in the weight of the silk strands and differences in the duration of respiration in the respiration chamber. The calculation formula is as follows:

[0028]

[0029] In the formula, R strip The figure represents the DO consumption of the silk strips and is expressed as the difference in DO concentration before and after incubation; DO is the DO concentration of the river / lake water sample at the beginning of the 2-hour incubation period; DO strip post This refers to the DO concentration in the silk strip chamber after the incubation period; DO controlpost The DO concentration in the control room after the culture period, i.e., the control room containing river and lake water samples but without silk strips; The volume of water in the breathing chamber; m strip The dry weight of the silk strip is given; t is the time; DO concentration is expressed in mg O2 / L; strip mass is expressed in g; and time is expressed in hours.

[0030] Therefore, this invention proposes a method for assessing the self-purification capacity of rivers and lakes based on silk strips, with the following beneficial effects:

[0031] (1) This invention is an in-situ monitoring method that can accurately and truly reflect the self-purification capacity of rivers and lakes under complex natural environments.

[0032] (2) The silk of the present invention is mainly composed of protein, and contains a small amount of fat, sugar, amino acids and inorganic salts. It is easily decomposed by microorganisms and light, and is a very good experimental material that can reflect the self-purification ability of rivers and lakes.

[0033] (3) The method of the present invention is simple, inexpensive and highly efficient in evaluation.

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall process of a method for assessing the self-purification capacity of rivers and lakes based on silk strips according to the present invention.

[0036] Figure 2 This is a diagram illustrating the field monitoring implementation of a method for assessing the self-purification capacity of rivers and lakes based on silk strips, as described in this invention.

[0037] Figure 3 This is an implementation diagram of the method for assessing the self-purification capacity of rivers and lakes based on silk strips, using tensile strength and respiration rate measurements in the laboratory. Detailed Implementation

[0038] To make the technical solutions, advantages, and objectives of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of this application.

[0039] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0040] like Figures 1-3 As shown in the figure, the implementation diagram of the method for assessing the self-purification capacity of rivers and lakes based on silk strips according to an embodiment of the present invention includes the following steps: (The diagram shows the deployment of silk strips for field monitoring and the measurement of tensile strength and respiration rate in the laboratory.)

[0041] S1. Select experimental materials and make silk strips;

[0042] The selected experimental materials included silk, plastic cable ties, nylon rope, wooden stakes, scissors, rulers, brushes, ethanol, a dynamometer, a drying oven, and a desiccator.

[0043] The process of making silk strips involves cutting silk into strips with a length and width of 8cm and 2.5cm respectively, making a 3mm wide welt around the edges of the silk strips, and threading a plastic cable tie through one end 7mm from the other.

[0044] S2. Lay out the silk strips and place them in the river or lake water in their original positions;

[0045] The steps for laying silk strips include:

[0046] S21. Use a 3mm diameter nylon rope to string together the prepared silk strips and fix them to one end of a wooden stake or steel bar 40-50cm away. Hammer the wooden stake or steel bar into the bottom of the river or lake so that the silk strips are positioned above the bottom of the river or lake and in contact with the bottom.

[0047] S22. Place 5 wooden stakes or steel bars at each sample point, fix 8 silk strips to each wooden stake or steel bar, and number each silk strip.

[0048] S3. Recycled silk strips and DOM degradation capacity determination: The silk strips were cultured in rivers and lakes for 4 weeks and then recycled. The recycled silk strips were divided into three parts and their weight loss, tensile strength and respiration rate were measured respectively.

[0049] The specific procedure for determining weight loss is as follows: the silk strips to be divided for weight loss determination are placed in pure water and gently cleaned with a brush. After drying at 40°C in the laboratory, they are stored in a desiccator, the weight is measured, and compared with the weight of the silk strips before cultivation to calculate the weight loss.

[0050] The formula for calculating weight loss is as follows:

[0051] Weight loss =1-Weight 培养前 / Weight 培养后 .

[0052] The specific procedure for tensile strength testing is as follows: the silk strips to be tested are placed in pure water and gently cleaned with a brush. After drying at 40°C in the laboratory, they are stored in a desiccator and their tensile strength is measured using a tensile tester.

[0053] The standard for tensile strength testing is to use daily tensile strength loss to reflect the degree of decomposition of the silk strip, and the calculation formula is:

[0054]

[0055] In the formula, Tensile Strength treatment strips The maximum tensile strength of each silk in the treatment group; reference strips The average tensile strength of 10 silk strips that were not cultured in river or lake water samples but were washed with ethanol and stored in a desiccator; Incubation Time is the culture time in days.

[0056] The specific procedure for measuring respiratory rate is as follows:

[0057] S31. Gently wash the silk strips used for measuring the respiratory rate with water and insert them into 50mL breathing chambers, which are 50mL flat-bottomed plastic centrifuge tubes.

[0058] S32. Immerse each breathing chamber in the river or lake water sample with the tube opening facing upwards, filling the tube with the river or lake water sample, and tighten the lid while immersing.

[0059] S33. Set up 3 controls, each containing only river and lake water samples, and use the average value of the 3 control respiration chambers to estimate the respiration rate of the lake water;

[0060] S34. Incubate the sample in the dark for 2 hours at the in-situ ambient temperature. After removing the cap and removing the silk strip with tweezers, immediately place the DO probe into the breathing chamber and measure the DO consumption.

[0061] When measuring respiration rate, the respiration effect of river and lake water is considered, and compensation and correction are applied to compensate for differences in silk yarn weight and respiration duration within the respiration chamber. The calculation formula is as follows:

[0062]

[0063] In the formula, R strip The figure represents the DO consumption of the silk strips and is expressed as the difference in DO concentration before and after incubation; DO is the DO concentration of the river / lake water sample at the beginning of the 2-hour incubation period; DO strip post This refers to the DO concentration in the silk strip chamber after the incubation period; DO controlpost The DO concentration in the control room after the culture period, i.e., the control room containing river and lake water samples but without silk strips; The volume of water in the breathing chamber; m strip The dry weight of the silk strip is given; t is the time; DO concentration is expressed in mg O2 / L; strip mass is expressed in g; and time is expressed in hours.

[0064] S4. Laboratory testing and analysis of DOM degradation ability.

[0065] Therefore, this invention provides a method for assessing the self-purification capacity of rivers and lakes based on silk strips, which can accurately and truly reflect the self-purification capacity of rivers and lakes under complex natural environments. The silk strips used are easily decomposed by microorganisms and light, making them more environmentally friendly. The method is simple, low-cost, and has wider applicability, reducing implementation costs and improving monitoring efficiency.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for evaluating the self-purification capacity of rivers and lakes based on silk strips, characterized in that, The method comprises the following steps: S1, selecting experimental materials and making silk strips: the selected experimental materials include silk, plastic ribbon, nylon rope, wooden stakes, scissors, ruler, brush, ethanol, tensile tester, drying oven, and desiccator; the silk strips are made by cutting the silk into strips with a length of 8 cm and a width of 2.5 cm, and grinding 3 mm wide around the silk strips, and threading a plastic ribbon at one end of the silk strip at a position of 7 mm; S2, laying the silk strips in the river and lake water body: the steps of laying the silk strips include: S21, connecting the prepared silk strips with the nylon rope and fixing them at a position of 40-50 cm from one end of the wooden stakes or steel bars, hammering the wooden stakes or steel bars into the river and lake bottom, and making the position of the silk strips above the river and lake bottom and in contact with the bottom; S22, placing 5 wooden stakes or steel bars at each sample point, fixing 8 silk strips on each wooden stake or steel bar, and numbering each silk strip; S3, recovering the silk strips and determining the DOM degradation capacity: the recovered silk strips are divided into three parts, and the weight loss, tensile strength, and respiration rate are determined; S4, determining the DOM degradation capacity in the laboratory.

2. The method for evaluating the self-purification capacity of rivers and lakes based on silk strips according to claim 1, characterized in that, The specific operation of determining the weight loss is that the silk strips for determining the weight loss are placed in pure water, cleaned with a brush, dried in the laboratory at 40 DEG C, and stored in a desiccator, and the weight is measured and compared with the weight of the silk strips before cultivation, and the weight loss is calculated.

3. The method for evaluating the self-purification capacity of rivers and lakes based on silk strips according to claim 1, characterized in that, The specific operation of determining the tensile strength is that the silk strips for determining the tensile strength are placed in pure water, cleaned with a brush, dried in the laboratory at 40 DEG C, and stored in a desiccator, and the tensile strength is measured with a tensile tester.

4. The method for evaluating the self-purification capacity of rivers and lakes based on silk strips according to claim 1, characterized in that, The specific operation of determining the respiration rate is: S31, the silk strips for determining the respiration rate are gently washed with water, and are inserted into 50 mL of a respiration chamber respectively; the respiration chamber is a 50 mL flat-bottomed plastic centrifuge tube; S32, each respiration chamber is immersed in the river and lake water sample with the tube opening upward, so that the tube is filled with the river and lake water sample, and the lid is tightly covered when immersed; S33, three controls are set, only containing the river and lake water sample, and the average value of the three control respiration chambers is used to estimate the respiration amount of the lake water; S34, the samples are cultured in the dark at the in-situ environmental temperature for 2 hours, after the lid is removed and the silk strips are removed with tweezers, a DO probe is immediately inserted into the respiration chamber, and the DO consumption is measured.

5. The method for evaluating the self-purification capacity of rivers and lakes based on silk strips according to claim 1, characterized in that, The weight loss calculation formula is: Weight loss =1-Weight 培养前 / Weight 培养后 .

6. The method for evaluating the self-purification capacity of rivers and lakes based on silk strips according to claim 1, characterized in that, The standard for determining the tensile strength is that the daily tensile strength loss reflects the decomposition degree of the silk strips, and the calculation formula is: ； wherein Tensile Strength treatment strips is the average tensile strength of the silk fabric for the treatment group; Tensile Strength reference strips is the average tensile strength of 10 silk strips that were not incubated in a river or lake water sample, but were cleaned with ethanol and stored in a desiccator; Incubation Time is the incubation time, in days.

7. The method for evaluating the self-purification capacity of rivers and lakes based on silk strips according to claim 1, characterized in that, When determining the respiration rate, the difference in the dry mass of the silk strips and the difference in the respiration duration in the respiration chamber are compensated and corrected based on the respiration effect of the river and lake water, and the calculation formula is: ； where R strip is the DO consumption of the silk strip and is expressed as the difference between the DO concentration before and after incubation; DO is the DO concentration of the river / lake water sample at the beginning of the 2-hour incubation period; DO strip post is the DO concentration in the incubation chamber at the end of the incubation period; DO control post is the DO concentration in the control chamber, i.e. the control chamber containing the river / lake water sample but without the silk strip, at the end of the incubation period; is the water volume in the respiration chamber; m strip is the dry weight of the silk strip; t is time; DO concentration is expressed in mg O2 / L, strip mass is expressed in g, and time is expressed in hours.

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