The following is the first draft of an academic paper. Please help me polish the language.
<3 Results
3.3 Influence of geotextile weaving type on its filtration characteristics
To study the influence of the fiber weaving type on the filtration performance of geotextiles used for preventing BEP, a 200 g/m2 nonwoven geotextile and a 200 g/m2 flat wire woven geotextile (referred to as woven geotextile) were selected in the experiments. As shown in Figure 8, the GR value of the woven geotextile was significantly higher than that of the nonwoven geotextile, and the gap between the two increased over time. This shows that the clogging degree of woven geotextiles was much higher than that of nonwoven geotextile. 
For the woven geotextile in Test-5, the GR value of the system before 120 minutes was stable, fluctuating around 7.6. From 120 to 240 minutes, the GR25 significantly increased and reached 9.96 at 240 minutes. After 240 minutes, the GR25 showed a slow upward trend. At the end of the experiment, the GR25 of the system (10.40) was greater than 3, indicating a severe clogging of the woven geotextile. For the nonwoven geotextile in Test-2, the GR value of the system was flat before 240 minutes. Then the GR25 gradually decreased to 2.60 (720 minutes), which was less than 3, indicating no severe clogging in the nonwoven geotextile filter.
 
Figure 8. Variation of gradient ratio of 200g non-woven geotextile and woven geotextile systems over time
Figure 11 shows the variation of flow rate for the 200 g/m2 nonwoven geotextile and woven geotextile over time. From Figure 9, it is found that the flow rate of the nonwoven geotextile was significantly higher than that of the woven geotextile. After 100 min, the gap between the two further increased. At 720 minutes, the flow rate of the nonwoven geotextile was 260 mL/min, while that of the woven geotextile was 120 mL/min. The flow rate of the nonwoven geotextile was 117% higher than that of the woven geotextile. The reduction in flow rate for the woven geotextile was the result of combined effect of sand clogging and geotextile clogging. The flow rate of nonwoven geotextile dropped sharply at 120 minutes, and then it decreased lowly. However, the flow rate of nonwoven geotextile dropped more slowly compared to that of woven geotextile. During the test, the flow rate of the nonwoven geotextile decreased from 320 mL/min to 260 mL/min, with a decrease of 18.8%. The flow rate of the woven geotextile decreased from 207 mL/min to 120 mL/min, with a decrease of 42%. Compared with the nonwoven geotextile, the woven geotextile exhibited a larger decrease in flow rate, indicating a more severe clogging of the woven geotextile.
 
Figure 9. Variation of flow rate of geotextiles with different weaving types over time>

4 Filtration mechanism
4.1 Filtration mechanism for nonwoven geotextile
After the test, pictures of the nonwoven geotextile were taken (Figure 10), and the distribution law of clogged particles on the nonwoven geotextile were observed using scanning electron microscopy. Due to the similar distribution law of clogged substances on the nonwoven geotextile in different tests, the geotextiles from Test-2 and Test-3 were selected for analysis as examples. It is observed that a small amount of sand particles were attached to the surface of the nonwoven geotextile, and the amount of clogging particles on the surface of the 300 g/m2 nonwoven geotextile was higher than that of 200 g/m2 geotextile. By the partially enlarged images, it is found that most of clogging particles were attached to the surface of the geotextile, with only a few embedded inside the geotextile.
The geotextiles were dried and weighed after the test, and the mass of the 200 g/m2 and 300 g/m2 nonwoven geotextiles increased by 0.27 g and 0.55 g, respectively. The increase in mass of the 300 g/m2 nonwoven geotextile was larger than that of the 200 g/m2 nonwoven geotextile. Overall, only a small amount of sand particles were attached to the surface or embedded inside the geotextile, with the increase in mass less than 1 g.
Figure 10. Pictures of nonwoven geotextile after test
To further analyze the clogging mechanism of nonwoven geotextiles, the variation of permeability coefficient for different soil layers over time in Test-3 is presented in Figure 11, which could be used to analyze the changes in particle structure of different soil layers during the test. Based on Figure 9, it is found that the permeability coefficient of the nonwoven geotextile and 3 mm thickness soil layer below it was the smallest. The lower the sand sample was, the greater the permeability coefficient of the sand layer was, indicating that clogging mainly occurred in the area near the geotextile filter layer. Under seepage force action, the fine sand particles in the lower layer of sand migrated upwards and accumulated near the lower surface of the nonwoven geotextile, forming a thin soil layer of low permeability-filter cake18,19, reducing the permeability of the nonwoven geotextile and its adjacent area. Hence the sand particles embedded inside the geotextile were not the main cause of clogging in the nonwoven geotextile, and the main reason for clogging was the deposition of fine sand particles on the upstream surface of the filter layer, forming a thin layer of filter cake. 
 
Figure 11. Variation of permeability coefficient of soil layers with different thicknesses in Test-3>