Model Test Study on the Enhancement of Ecological Self-Repairing Ability of Surface Slope Soil by New Polymer Composites

Are biodegradable mulch films a sustainable solution to microplastic mulch film pollution? A biogeochemical perspective

Mulch film residue contributes significantly to global plastic pollution, and consequently biodegradable mulch films (BDMs) are being adopted as a solution. BDMs decompose relatively quickly, but their complete biodegradation requires suitable conditions that are difficult to achieve in nature, causing biodegradable microplastics (bio-MPs) to be more likely to accumulate in soil than traditional microplastics (MPs). If BDMs are to be considered as a sustainable solution, long-term and in-depth studies to investigate the impact of bio-MPs on the biogeochemical processes are vital to agroecosystems operation and ecosystem services supply. Although bio-MP-derived carbon can potentially convert into biomass during decomposition, its contribution to soil carbon stocks is insignificant. Instead, given their biodegradability, bio-MPs can result in greater alterations of soil biodiversity and community composition. Their high carbon-nitrogen ratios may also significantly regulate various processes involved in the natural decomposition and transformation of soil organic matter, including the reduction of nutrient availability and increase in greenhouse gas emissions. Soil ecosystems are complex organic entities interconnected by disturbance-feedback mechanisms. Given the prevailing knowledge gaps regarding the impact of bio-MPs on soil biogeochemical cycles and ecosystem balance, this study emphasized the safety and sustainability assessment of bio-MPs and the prevailing comprehensive challenges.

A State-of-the-Art Review of Organic Polymer Modifiers for Slope Eco-Engineering

In slope ecological restoration projects, reinforcing soil and promoting vegetation growth are essential measures. Guest soil spraying technology can be used to backfill modified soil and vegetation seeds onto the slope surface, resulting in successful ecological restoration. The use of organic polymer modifiers to reinforce soil has several benefits, such as high strength, effective results, and low pollution levels. Organic polymer soil modifiers can be divided into two categories: synthetic polymer modifiers and biopolymer modifiers. This paper provides a thorough review of the properties and interaction mechanisms of two types of polymer modifiers in soil consolidation. The properties of organic polymer modifiers make them applicable in soil and vegetation engineering on slopes. These modifiers can enhance soil mechanics, infiltration, and erosion resistance and promote vegetation growth. Therefore, the suitability of organic polymer modifiers for soil and vegetation engineering on slopes is demonstrated by their properties and potential for improvement in key areas. Furthermore, challenges and future prospects for slope protection technology using organic polymer modifiers are suggested.

Ecological membrane for slope engineering based on red bed soil

Ecological slope protection projects (such as the reinforcement of low slopes by plants and ecological restorations of the soil of high steep rocky slopes) are essential for restoring the natural environment. In this study, red bed soil and composite polymer adhesive materials were used to develop an ecological membrane for application in slope ecological protection. The basic physical and mechanical properties of the ecological membranes with different material percentages were studied through tensile strength test and viscosity test, the effect of different material percentages on the properties of ecological membranes was studied, and the soil protection performance and ecological restoration performance were studied through anti-erosion and plant growth tests. The results show that the ecological membrane is soft and tough, with high tensile strength. The addition of the red bed soil can enhance the strength of the ecological membrane, and the ecological membrane with 30% red bed soil has the highest tensile strength. The ecological membrane has considerable tensile deformation capability and viscosity, and up to 100% by mass, the more composite polymer adhesive materials added, the greater the tensile deformation capability and viscosity. And the ecological membrane can enhance the anti-erosion performance of the soil. This study clarifies the development and technology of the ecological membrane, reveals the effect of different material percentages on the properties of ecological membrane, and analyzes the slope ecological protection mechanism of the ecological membrane, thereby providing theoretical and data support for its development, improvement, and application.

Experimental Study on Ecological Performance Improvement of Sprayed Planting Concrete Based on the Addition of Polymer Composite Material

Sprayed planting concrete (SPC) can be used for the ecological restoration of rocky steep slopes. It is a kind of outside-soil material with excellent soil and slope stabilization performance, and plants can grow in SPC, thus achieving harmony between engineering stability and ecological restoration and improving the landscape and ecosystem. The addition of cement is the key to allowing SPC to achieve slope stabilization and prevent soil erosion. However, the addition of cement can cause SPC to have high alkalinity, overheating (cement generates hydration heat), and excessive hardening, which are not conducive to the growth of plants and can lead to poor ecological performance of SPC for slope ecological restoration. We studied the improvement of the ecological performance of SPC by using a polymer composite material composed of a polymer adhesive material and a polymer water-retaining material. This paper studied the improvement effects of the polymer composite material on the ecological performance of SPC used in slope ecological restoration through a laboratory erosion resistance test and a plant growth test. The results showed that SPC with the addition of polymer composite material can reduce its cement content by about 50% while still retaining excellent erosion resistance performance when it is used in slope ecological restoration. Additionally, the plant germination rates and plant heights when using the SPC improved by polymer composite material were increased by 190% and 110%, respectively. These results show that polymer composite material can significantly improve the ecological performance of SPC and effectively improve its slope ecological restoration effects. This study provides theoretical and technical support for the application of SPC in ecological restoration on rocky steep slopes.