Review On the Detection Methods of Anti-seepage Geomembrane Defects

Abstract: In view of the inevitable high quality aquaculture geomembrane defects in geomembrane anti-seepage engineering, on the basis of reading and collating relevant literature at home and abroad, the methods of high quality textured geomembrane defect detection (including quality inspection and leakage monitoring) applicable to different stages are introduced. Focus on the advantages and disadvantages of various types of electrical detection methods and the scope of application. Finally, the applicability of various defect detection methods is summarized and some technical suggestions for textured geomembrane for sale defect treatment are proposed. The conclusions show that compared with other detection methods, the electrical method has the advantages of strong applicability and high precision, and is the mainstream method for low price aquaculture geomembrane defect detection in the future. The electrical method can form an effective set if combined with defect processing technology. LDPE geomembrane factory price defect prevention and treatment measures to improve the integrity of the aquaculture geomembrane manufacturers anti-seepage system.

Keywords: anti-seepage material; geomembrane; defect detection; quality inspection; leakage monitoring; review

Geomembrane is a new type of flexible anti-seepage material. It has been widely used in dikes, storage trays, reservoirs, channels, dams, and dams because of its advantages of good anti-seepage effect, strong deformation ability, low cost, and convenient construction. Anti-seepage projects such as shovel and landfills. At present, the thickness of common aquaculture geomembrane factory price is generally 0.5 ~ 2mm, so it is easy to cause various degrees of damage to form macro defects in the production, construction and engineering operation process of textured geomembrane for sale. Nosko et al. analyzed the quality inspection data of about 3.25 million m2 high quality aquaculture geomembrane in more than 300 sites in 16 countries and found that 24% of the damage in high quality LDPE geomembrane defects occurred in the laying stage, and 73% of the damage occurred in the protective layer laying on the film. At the stage, 3% of the damage occurred at other stages such as the operation period. Once a defect occurs in the high quality environmental geomembrane, a concentrated leak will form at the defect after the project is run. For landfills, seepage of seepage will contaminate soil and groundwater sources; for water storage projects, leakage will not only cause water loss (such as reservoirs, channels, etc.) but may also affect membranes. The osmotic stability of the post-filled materials will endanger the safety of the project (such as dikes, cofferdams, earth-rock dams, etc.). Therefore, in order to ensure the integrity of the low price aquaculture geomembrane barrier as much as possible, in addition to improving the quality standards of LDPE geomembrane manufacturers production and construction, the preventive measures that can be taken are timely and effective defect detection and repair of the environmental geomembrane for sale at each stage.

On the basis of reading and collating relevant literature at home and abroad, the author expands the meaning of high quality textured geomembrane defect detection, and generalizes it as the general term for low cost textured geomembrane quality inspection, defect leakage monitoring and narrow low price aquaculture geomembrane defect detection. At the same time, the method for detecting the generalized defects of textured geomembrane for sale is classified according to the construction period and operation period of the anti-seepage project. On this basis, some common methods for detecting LDPE geomembrane factory price defects at different stages of each period are introduced in detail, and corresponding comparative evaluations are carried out. Among them, the electrical detection method has the advantages of clear principle, simple operation, accurate positioning, etc. It is suitable for the construction period and operation period of high quality aquaculture geomembrane anti-seepage engineering. Therefore, it is important to carry out the advantages and disadvantages and applicability of various sub-methods included in it. Detailed explanation and evaluation. Finally, various types of detection methods are summarized, and some aquaculture geomembrane manufacturers defect repair techniques are given for reference selection when repairing environmental geomembrane for sale during construction and operation.

1. Geomembrane defect detection during the construction period

According to the survey statistics of Darilek et al. and Line et al., during the construction period, especially in the laying and welding of LDPE geomembrane factory price, including the bonding, the same as the laying of the protective layer on the film, the probability of damage of the high quality aquaculture geomembrane is large and easy to produce. Macro defects. Nosko et al. pointed out that the occurrence of high quality environmental geomembrane defects during the construction period is closely related to the objective factors such as climatic conditions, application range and site conditions, and subjective factors such as the skills, attitudes and equipment use of construction workers. Therefore, in addition to the strict control of each detail of each construction link and the improvement of the quality of textured geomembrane for sale construction during the construction period, it is necessary to supplement the necessary defect detection (detection) technology to ensure the integrity of the low price aquaculture geomembrane anti-seepage system and reduce Engineering leakage problems.

1.1 Geomembrane laying and welding stage
In the geomembrane laying and welding stage, the geomembrane defects mainly include two parts, one is the defects caused by the welding quality of the aquaculture geomembrane factory price in the welding area, and the other is the non-welding aquaculture geomembrane manufacturers exposed to the site before the uncovered protection. Defects caused by various disturbances. The detection (detection) methods of the two types of low cost textured geomembrane defects are also different due to the differences in the causes, size, and distribution of defects.

During the laying and welding process of the environmental geomembrane manufacturers, the welding personnel’s operating procedures and instrument setting parameters may lead to welding quality problems, such as virtual welding, desoldering and leakage welding, resulting in “seam-like” defects at the weld. Foreign countries have conducted quality inspections on 28 200,000 m2 textured geomembrane factory price put into operation. The results show that there are about 26 leak holes per 10,000 m2, of which 69% appear at the weld. Therefore, the LDPE geomembrane factory price must be tested for weld quality after splicing and welding. Commonly used testing methods include visual inspection, weld destructive testing and non-destructive testing of welds. Visual inspection is a visual evaluation of the quality of high quality textured geomembrane welds. It is a relatively rough evaluation method. The destructive test tests the strength of the high quality aquaculture geomembrane samples in the weld zone by shearing and/or tensile test. The test results can be fed back. Guide the setting of relevant welding forms and parameters; non-destructive testing includes a vacuum box test method and air pressure test method, which can effectively detect the welding quality of environmental geomembrane for sale under double weld conditions. The engineering practice shows that the above several high quality environmental geomembrane defect detection (detection) methods can effectively detect the quality of high quality LDPE geomembrane welding, but the detection speed, accuracy, efficiency, and automation are low, and it is not suitable for the detection of large-scale and small defects.

For existing projects that do not have a low price aquaculture geomembrane defect leakage monitoring system, the dipole method in the electrical detection method can be used for defect detection. According to the model research and numerical simulation results of electric detection methods by domestic and foreign scholars, the thickness and conductivity of the coating material on the film affect the potential distribution on the surface of the coating. The thicker the coating on the film, the weaker the surface potential distribution and the lower the detection sensitivity.

The above several electrical detection methods are suitable for the detection of micro-defects of environmental geomembrane manufacturers in large-area non-welding areas, and the detection accuracy and sensitivity are high. In actual engineering applications, the EDM method and the water gun method also have certain restrictions. For example, the EDM method is only applicable to conductive textured geomembrane for sale with a relatively high cost; the water gun method uses low voltage, and its detection accuracy is relatively low, which is not suitable for the detection of small defects in high humidity environments. In addition, the water gun method should not detect the defects of the high quality environmental geomembrane laid on the steep slope, because the water flow down the slope may not pass through the defects, and the surface tension generated will “cover” the tiny holes, and the detection sensitivity of the water gun method will be Significantly reduced. In contrast, the advantage of the arc method is that the defect detection does not rely on the conventional signal transmission medium (conductive geomembrane or water), is suitable for ordinary non-conductive aquaculture geomembrane factory price, has high detection accuracy, and therefore is laid in LDPE geomembrane factory price welding. It is recommended when exposed.

1.2 Membrane protective layer laying stage
After the environmental geomembrane for sale is laid and welded, it is generally required to lay sand, gravel, and other earth and stone materials as the protective layer on the film. According to the statistics of Nosko et al., in the process of laying and compacting the earth and stone protective layer, the probability of damage or defects of the geomembrane is much greater than that of the welding stage, which is caused by the puncture of the covering material and the heavy mechanical rolling during the construction process. The low price aquaculture geomembrane was damaged. After covering the protective layer, the defects of the high quality LDPE geomembrane are difficult to be directly observed by the naked eye, and the electrical method is usually used to detect the defects of the textured geomembrane factory price at this stage.

Different from the detection of bare film defects in the absence of the upper protective layer, for the high quality environmental geomembrane with the upper protective layer, the defect detection can be performed by the two-electrode method and the dipole method in the electrical detection method. The two-electrode method was proposed by LeakLocationServices [28] in the United States in 1985. Its working principle is to arrange the power supply electrodes on the high quality aquaculture geomembrane and the underlying layer respectively and connect the positive and negative electrodes of high-voltage direct current. If the high quality textured geomembrane is intact, the geotechnical The high-resistance characteristics of the film, a current loop cannot be formed between the two electrodes; and when the environmental geomembrane for sale is defective, the defect will provide a path for the current to change the current meter index in the loop. The two-electrode method judges the existence of defects only by generating a current loop between the power supply electrodes and cannot determine the position and number of defects, and many conductive factors in the field may interfere with the detection results. To this end, the conventional two-electrode method is improved to form a dipole method (also known as an electrode-dipole method or an improved two-electrode method), and its working principle is to use a pair of spacings after forming a current loop by the two-electrode method. A fixed probe electrode (ie, a dipole) is detected on the surface of a medium (aled material or water, etc.) on the LDPE geomembrane factory price. When the aquaculture geomembrane manufacturers are intact, there is no current in the medium on the membrane, and the dipole does not detect the signal; when the low cost textured geomembrane is defective, a potential field is formed in the medium on the membrane. At this time, if the dipole is detected on the route There is a defect in the film. As the complete area of ​​the aquaculture geomembrane factory price approaches the defect position, the potential difference between the dipoles will gradually increase. When the front end electrode of the dipole is located at the defect, the potential difference between the two detection electrodes reaches the maximum value. When the two detecting electrodes are in the symmetric position of the defect center, the potential difference between the two electrodes is zero; if the forward-moving is continued, the potential difference will increase in the reverse direction until the rear detecting electrode reaches the maximum value at the defect; the detecting electrode continues to advance. When the potential difference will gradually decrease. During the movement of the detecting electrode, the potential (difference) change process can be continuously recorded, and the potential (difference) curve along the detecting direction is drawn, wherein a peak and a trough appear in the potential difference distribution curve, and the midpoint of the two is the location of the defect. Parra first conducted an in-depth study of the electrode dipole method and determined its engineering practical value. By the end of the 1990s, hundreds of landfills had been tested for defect leakage using the electrode-dipole method. Hansen et al. used the dipole method to detect defects in two landfills in different protective layers, and successfully detected defects with a diameter less than 5 mm under a 0.6 m thick overlay. Gao Kang and others used the dipole method to successfully detect the defects in a landfill in Shanghai and summarized the causes of the defects in low price aquaculture geomembrane. In practical engineering, the thickness of the protective layer on the film is generally relatively thin. Under the condition that the protective layer material has certain conductivity, the dipole method has high detection sensitivity, and the protective layer can cover the millimeter-level LDPE geomembrane manufacturers. Accurate positioning of defects is an effective method for the fine detection of defects.

2. Geomembrane leakage monitoring and defect detection during operation

When the low cost textured geomembrane is completed and enters the operation period, the uneven settlement of the foundation, the water pressure on the membrane, and the destruction of the animal and plant may cause damage and damage, and the high quality aquaculture geomembrane dissolves in the upper cover layer (soil or water) or the filtrate. Under long-term effects, stress cracking or environmental stress cracking may occur. Unlike the direct damage caused by strong external interference during the construction period, the environmental geomembrane manufacturers defects during the operation period are caused by the long-term cumulative effects of external loads, internal stresses and environmental factors. The statistics of Nosko et al. confirmed the defects of the high quality LDPE geomembrane during the operation period. The probability is relatively small. Therefore, the main means to evaluate the integrity of high quality environmental geomembrane anti-seepage system during the operation period of the project is to carry out effective monitoring and analysis of defect leakage, especially for projects such as landfills that may cause environmental pollution. The effective monitoring of defect leakage is particularly effective. important.

2.1 Defect leakage monitoring and arranging of construction in progress
For the construction in progress, if you want to monitor the integrity of the aquaculture geomembrane manufacturers during the operation period of the project, it is generally necessary to arrange the corresponding monitoring equipment in the sub-membrane layer before the LDPE geomembrane for sale is laid. According to different working principles, the existing operation The monitoring method of defect leakage can be divided into two types: conventional monitoring method and electrical monitoring method.

Conventional monitoring methods include groundwater testing, diffusion hose testing, and chemical reagent tracking. (a) The groundwater test method requires the collection of water collection wells around the site to determine whether the site has leaked by monitoring changes in certain components or concentrations in the groundwater in the collection well. This method is mainly applicable to underground anti-seepage projects with high groundwater level. (b) The diffusion hose method needs to pre-bury the gas-permeable pipe grid in the soil under the aquaculture geomembrane factory price and judge whether the site leaks by the gas composition and concentration change that penetrates into the hose. This method is mainly applicable to the field where it is easy to vaporize the leakage liquid. (c) The chemical reagent tracking method requires the collection of probes around the site to determine whether the site is leaking by monitoring the reaction of the collection probe with a volatile chemical tracer in the injection site. This method is mainly applicable to landfill projects. In practical applications, the groundwater detection method and the chemical reagent tracking method can only judge whether the high quality environmental geomembrane has defects, and the specific position and number of defects cannot be determined. Although the diffusion hose method can determine the position and number of defects, the actual detection accuracy and the number of hoses arranged is closely related. The above-mentioned high quality textured geomembrane defect leakage monitoring method is mainly used for landfill engineering, and is not suitable for water conservancy engineering, especially for chemical reagent tracking method. If the dosage of chemical reagent is too small, it is easy to be diluted by the reservoir water to reduce the detection sensitivity, and the dosage is too much. It will pollute the reservoir water. Hix has classified and compared the commonly used methods for detecting environmental geomembrane for sale defects in the market. It is pointed out that the diffusion hose method and the chemical reagent tracking method are not widely used in practical engineering because of their high technical level and high cost.

Conventional monitoring methods are often based on the inherent characteristics of a certain type of engineering, thus limiting its widespread application. In contrast, the electrical monitoring method uses the insulation of the high quality aquaculture geomembrane and the change of the electrical index of the soil permittivity and resistivity before and after the leakage of the defect to carry out the corresponding defect leakage monitoring, which has wider applicability. For example, sand is used as the underlayer material, and the dry sand resistivity is about 105 Ω·m. When the LDPE geomembrane manufacturers are defective, the underlying soil layer will be gradually saturated by the leakage effect, and the resistivity of the saturated sand will be About 10 Ω·m, the LDPE geomembrane for sale defects are located by the difference in sand resistivity near the defect. Therefore, the electrical monitoring method can be applied to the leakage monitoring of various high quality textured geomembrane anti-seepage projects. In addition, the degree of automation and detection accuracy of electrical monitoring methods are superior to conventional monitoring methods, and its application and promotion have become the development trend of environmental geomembrane manufacturers integrity monitoring in modern engineering operation period.

The electrical monitoring methods include a capacitive sensor method, an electrochemical sensing cable method, a resistivity method, and an electrode grid method. (a) The capacitive sensor method is to embed the capacitive sensor in the field before the laying of the high quality LDPE geomembrane and determine whether the aquaculture geomembrane manufacturers have defects by changing the dielectric constant of the soil near the defect caused by the leakage liquid. The method requires a large number of capacitive sensors to be embedded in advance, and the cost is high. Groundwater and other factors in the site may also cause local soil dielectric constant changes, which may interfere with the detection results. (b) The chemical sensing cable method pre-embeds the electrochemical sensing cable in the soil of the field area and determines whether the LDPE geomembrane for sale is defective according to whether certain components in the leakage liquid can cause a physical or chemical reaction of the sensing cable. Rumer et al. analyzed and evaluated various engineering anti-seepage system control technologies from the perspective of environmental protection, pointing out that the suitability of the electrochemical sensing cable method is greatly limited due to the different leakage liquid components produced by different sites. (c) The law of resistivity is to pre-buried the probe electrode under the textured geomembrane for sale and to determine whether the high quality environmental geomembrane is defective by using the property of reducing the soil resistivity near the loophole after the occurrence of the leak. Phaneuf et al. conducted a survey of various landfills in New York State that used resistivity to detect defects, demonstrating that the resistivity method plays a key role in ensuring the integrity of the seepage system during project operation, but the disadvantage is that After the repair of the low price aquaculture geomembrane defects, the resistivity of the soil under the membrane cannot be completely recovered, which will interfere with the detection results of the late defects. (d) Electrode grid method: The detection electrode is pre-buried in the soil under the environmental geomembrane manufacturers in the form of a grid, and the site is electrically tested periodically, and the number of high quality textured geomembrane defects is determined according to the potential contour map of the soil under the membrane and position. Oh, et al. proposed a grid conductivity measurement system based on the electrode grid method, and carried out model tests to estimate the sensitivity of the monitoring system by changing the soil moisture content and electrode spacing. The test proved that the system can accurately identify the location of defects. It is also possible to qualitatively assess whether the leaking liquid is landfill leachate or pure water. Ben and other large parallel circuits using cables and electronic lights replace the traditional electronic sensor grids, which greatly reduces the cost of the monitoring system and is suitable for basic monitoring of engineering defect leakage. All the above methods can accurately determine the location of the defects of the environmental geomembrane for sale, and the degree of automation is high. After being put into use, the defects of the LDPE geomembrane manufacturers during the project operation period can be permanently monitored, especially suitable for landfill sites and other complex conditions. Geomembrane seepage prevention project with a bad environment and serious corrosion pollution. Of course, the cost and cost of various types of sensors, detection electrodes and associated monitoring systems in the above methods are often high. Therefore, in actual engineering, it is necessary to select a suitable leakage monitoring method according to economic and engineering importance.

2.2 Defect detection of completed construction
MTT assay for inhibition of proliferation of SK-N-SH cells by spironolactone SK-N-SH cells with good growth state were adjusted to a cell concentration of 2×10 6 cells/mL and seeded in 96-well plates at 200 μL per well. Two duplicate wells were set and cultured in an incubator at 37 ° C and 5% CO2. The culture time of each group was 4, 8, 16, 24 and 48 h. 4 h before the termination of the culture, 20 μL LTTT solution (5 g/L) was added, and incubation was continued for 4 hours in the incubator. After centrifugation, the culture supernatant in the 96-well plate was discarded. 150 μL of DMSO was added to each well, and the mixture was shaken to make the crystals sufficiently dissolved. The plate reader was used to measure the absorbance at a wavelength of 570 nm, and the cell proliferation inhibition rate was calculated. The cell proliferation inhibition rate = (A control group – A experimental group) / A control group × 100%.

In order to facilitate the application and popularization of aquaculture geomembrane manufacturers defect detection in the case of dipole method with covering material at the running stage, domestic and foreign scholars have done a lot of research and optimization on dipole method. Becket al. conducted research and statistics on the existing electrical detection equipment and technology in the US market. It is believed that the discovery of deep filler detection, “mirror” charge and AC filtering can effectively improve the dipole method in various complex coverage situations. The accuracy of the detection. Beck [56] improved the existing dipole detection equipment, provided electrical noise cancellation for the DC power supply, and provided GPS data recording and orientation indicators for the dipole probe, greatly improving the dipole. The detection accuracy of the method can effectively reduce the detection voltage and ensure detection safety. Xiao et al. used dipole method to test the leakage detection of landfills, and explored the leakage size of the gravel, the size of the defect, the model of the percolation layer and the infiltration of water (or leachate) to the landfill. The impact of the test. Peggs et al. and Ramsey et al. conducted a comparative analysis of leak detection tests on conventional liners and new conductive gaskets, confirming the practicality of conductive gaskets in leak detection. Youngblood et al., Abigail et al., Ng et al. demonstrated the superiority of conductive pads through a series of field test tests – which can be used for leak detection when it is difficult or impossible to detect using conventional non-conductive pads, such as on film. There are deep protective layer covering, poor contact between the liner and the underlying layer, poor soldering, and wrinkles in the environmental geomembrane for sale. Sirieix et al. used resistivity tomography to detect leakage of conductive pads, and compared the results of two different arrays of dipole array and Winner-Schlumberger. Finally, low resistance was solved by PSO sampling. Detection of LDPE geomembrane for sale defects under the rate and ultra-thin mat. Through the continuous introduction and improvement of new technologies, new materials and new equipment, the applicability and detection accuracy of the dipole method in the detection of aquaculture geomembrane factory price defects during operation are effectively improved. Prota et al. conducted a survey of ore heap leaching projects in high-altitude areas of the Andes, confirming that improved dipole detection equipment can quickly scan large areas to quickly assess the damage of textured geomembrane factory price. Nosko et al. used the arc test method and the dipole method to achieve accurate detection of LDPE geomembrane factory price defects of different sizes during construction and operation, which provided the possibility of “zero leakage” of LDPE geomembrane manufacturers anti-seepage engineering.

Existing research and engineering practice show that the dipole method is a superior environmental geomembrane manufacturers defect detection method. Compared with the permanent monitoring system represented by the electrode grid method, the dipole method is flexible and portable, simple in operation and cost. Advantages such as low cost, suitable for existing projects without a monitoring system. In addition, compared with earth and stone, the reservoir water has a higher conductivity, which allows the dipole method to obtain higher detection accuracy, and the dipole probe can be placed along the surface of the high quality LDPE geomembrane or protective layer in the reservoir water. And drag, so the dipole method is also applicable to the detection of textured geomembrane factory price integrity during the operation of textured geomembrane factory price anti-seepage earth-rock dam project.

3. Geomembrane defect detection method summary and repair technology

3.1 Summary of defect detection methods
On the basis of the working principle and advantages and disadvantages of various low cost textured geomembrane defect detection methods, the application of different methods in different projects is summarized and analyzed, so that the suitable LDPE geomembrane for sale defect detection methods are selected according to different stages and different engineering characteristics.

Whether it is during construction or operation, electrical detection methods are more widely applicable than conventional detection methods. For the exposed textured geomembrane for sale without a protective layer during the construction period, the arc method has the characteristics of high detection accuracy and wide application range, which is worthy of recommendation. For construction projects that require real-time monitoring during operation, such as landfills and ore heap leaching, a permanent monitoring system represented by the electrode grid method may be considered. The dipole method is suitable for the detection of defects after the laying of the protective layer on the film during the construction period, and for the completion of construction without the need for permanent leakage monitoring during the operation period, especially for the hydraulic engineering represented by the environmental geomembrane manufacturers anti-seepage earth-rock dam. It is recommended to use.

3.2 Geomembrane defect processing technology
At the same time as the detection of geomembrane defects (including detection and monitoring) at various stages, the necessary LDPE geomembrane for sale defects should be treated as necessary. Due to the different causes of high quality LDPE geomembrane defects and engineering operating conditions during construction and operation, the corresponding low cost textured geomembrane defect treatment techniques are also different.

During the construction period, when the aquaculture geomembrane manufacturers defects are detected, the repair methods commonly used in the project include spot welding, patching, and capping. Among them, spot welding is used to repair small surface scratches, small local flaws or areas where the thickness of the textured geomembrane factory price is reduced; patches are used to repair damage in the form of large holes, tears, etc., and each patch is required to be at least more than the defects It is 150mm long and must be rounded; when it is covered, along low cost textured geomembrane is used to repair a long unqualified weld. If the engineering quality operation requirements are not met after a repair, the damaged LDPE geomembrane factory price should be removed and replaced with a new low cost textured geomembrane. The use of these methods to repair the LDPE geomembrane manufacturers defects that occur during the construction period can improve the integrity of the textured geomembrane factory price anti-seepage system.

For the textured geomembrane factory price anti-seepage project that has been put into use, due to the complicated repair conditions, the textured geomembrane for sale defect repair requirements are very high, generally, need to repair the construction conditions without water or landfill, and the covering material on the membrane needs to be removed. Under suitable conditions, it is also considered to lay a layer of a good quality high quality textured geomembrane on the cover layer, but the engineering cost is high.

In addition to the above-mentioned conventional repair techniques, Darilek et al. proposed an electrophoresis method for repairing aquaculture geomembrane factory price defects, using the principle that charged clay particles move toward defects under the action of an electric field and automatically blocks the defects of the LDPE geomembrane manufacturers, thereby limiting defects. Further development of leakage. Kambham et al. proposed a mathematical model for simulating leakage of electrophoresis blocks and simulated them. The analysis shows that the formation process of electrophoresis blocks is closely related to the voltage gradient and the compression coefficient of clay. Darilek et al. and Yeung et al. respectively confirmed the effectiveness of electrophoresis for sealing defects by laboratory test and large-scale test. In the laboratory test, the leakage of 8-10 mm oval defects was significantly reduced under the action of electrophoresis. Corapcioglu et al. verified the effectiveness of electrophoresis to block defects, and pointed out the relationship between voltage, electrode area, initial concentration of suspension and electrophoresis block generation efficiency; higher voltage or larger electrode area will accelerate the generation of electrophoresis blocks. At the same time, when the electrode is blocked by electrophoresis, the electrode should be as close as possible to the liquid surface. Han et al. and Kim et al. conducted a three-dimensional leak simulation test to evaluate the field applicability of plugging defects by electrophoresis and evaluated the influencing factors. Electrophoresis can theoretically solve the problem of environmental geomembrane manufacturers defect repair during the operation period of the project. The actual project implementation effect needs further application and research.

Regardless of the construction period or the operation period, after the completion of the LDPE geomembrane for sale defect repair (including repair), it is generally necessary to re-examine the repaired part. If there is still a defect (leakage) problem, secondary treatment is required to ensure that the repair effect is safe and reliable.

4. Conclusion

As a kind of flexible film anti-seepage material, aquaculture geomembrane factory price is difficult to avoid due to various reasons in practical engineering anti-seepage application. This paper summarizes the research results and current status of LDPE geomembrane manufacturers defect detection (including quality inspection and leakage monitoring) at home and abroad and classifies and compares various detection methods in stages. The analysis shows that the electric detection (monitoring) method has clear principles. It is easy to operate and accurate in positioning. It is suitable for the detection of defects in the construction period and operation period of LDPE geomembrane for sale anti-seepage engineering. It can be considered to be preferred. Of course, due to the complexity and uncertainty of high quality LDPE geomembrane defects, some existing defect detection methods have yet to be further studied and practiced to improve the convenience and accuracy of detection and reduce the cost of detection.