Basalt fiber is a continuous fiber drawn from natural basalt. It is produced by melting basalt material at temperatures ranging from 1450℃ to 1500℃ and then rapidly drawing it through a platinum-rhodium alloy wire-drawing die. Pure basalt fiber typically has a brown color. Basalt fiber is a new type of inorganic, environmentally friendly, high-performance fiber material, composed of oxides such as silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, iron oxide, and titanium dioxide. Basalt continuous fibers are not only highly strong but also possess excellent properties such as electrical insulation, corrosion resistance, and high-temperature resistance. Moreover, the production process of basalt fiber ensures minimal waste generation, low environmental pollution, and the ability of the product to degrade directly in the environment without any harm, making it a genuinely green and eco-friendly material. China has listed basalt fiber as one of the four key fibers for development (carbon fiber, aramid, ultra-high molecular weight polyethylene, and basalt fiber) and has achieved industrial production. Basalt continuous fibers have been widely applied in various fields, including fiber-reinforced composites, friction materials, shipbuilding materials, thermal insulation materials, the automotive industry, high-temperature filtration fabrics, and protective applications.

Basalt fiber has a smoother surface with lower surface energy. After surface modification, nano-SiO2 particles are added to increase the roughness of the fiber surface, enhancing the effective contact area between microorganisms and the carrier. The presence of cations on the modified surface raises the potential of the carrier, making it positively charged. This promotes microbial immobilization through electrostatic attraction, facilitating immobilization. The active functional groups on the modified surface increase the surface energy of the carrier, containing hydroxyl, carbonyl, or carboxyl groups, which positively affect the adhesion and growth of microorganisms on the carrier surface. Through the surface modification of basalt fiber carriers, they achieve good hydrophilicity and microbial loading performance, enabling them to carry more biomass and maintain a high level of microbial activity for extended periods. This allows for more effective degradation of pollutants in water bodies through biofilm methods.