关键词: 河湖复苏, 生物膜技术, 水环境治理, 生态修复, 菌藻生物膜技术, 耦合技术, 微生物

Abstract:

Restoration of river and lake ecosystems is crucial for current ecological environmental protection. With rapid industrialization and urbanization, rivers and lakes have endured varying degrees of pollution and ecological degradation. However, as people's awareness of environmental protection has been continuously enhanced and the concept of sustainable development has been deeply established in society, the ecological restoration of rivers and lakes has become an urgent task that cannot be delayed. In terms of river and lake restoration initiatives, a series of remediation measures using biofilm technology have gradually emerged, exhibiting significant advantages and substantial potential. Biofilms, which are composed of microorganisms and extracellular polymeric substances, can adsorb, degrade, and transform pollutants in water, and play a vital role in water purification. This study conducted an in-depth exploration of the latest progress and practical achievements of biofilm technology in the field of river and lake ecological restoration. First, the research and development of biofilm carriers are of utmost importance. As an essential foundation for the growth of microorganisms, the performance of biofilm carriers directly affects the biofilm formation and stability. The continuous emergence of new carrier materials provides a more suitable growth environment for microorganisms, and enhances the stability and functionality of biofilms. These new materials possess good hydrophilicity, a large specific surface area, and a suitable pore structure, which can effectively adsorb and immobilize microorganisms and promote the rapid formation and stable development of biofilms. For example, some nanomaterials and polymer composite materials have been applied for the preparation of biofilm carriers, which significantly enhances the performance of the carriers and purification efficiency of biofilms. The unique properties of nanomaterials, such as their small particle size and high surface activity, can enhance the adsorption capacity and catalytic activity of the carrier. In contrast, polymer composite materials combine the advantages of different polymers to achieve better mechanical strength and chemical stability. Second, the optimized design of the operating conditions of biofilm reactors cannot be overlooked. Parameters, such as temperature and water flow velocity, have a significant impact on the growth and purification efficiency of biofilms. By adjusting parameters such as the temperature and water flow velocity, the purification effect of biofilms can be maximized. This allows for more efficient removal of pollutants as the biofilm's metabolic activities are enhanced at the right temperature, and sufficient yet not excessive contact with contaminants is ensured by the proper water flow velocity, thereby significantly improving the overall ecological restoration performance of the biofilm system. In addition, the optimization of bacteria-algae biofilm technology has provided new opportunities for ecological restoration of rivers and lakes. Bacteria and algae are widely distributed in nature and can form a symbiotic system that works synergistically to improve the removal efficiency of pollutants. Bacteria can decompose organic pollutants and convert complex organic compounds into simpler substances that can be utilized by other organisms. In contrast, algae can absorb nutrients such as nitrogen, phosphorus, and carbon dioxide through photosynthesis and release oxygen, thereby providing a favorable aerobic environment for the growth of bacteria. By optimizing the composition and structure of the bacteria-algae biofilm, for example by adjusting the ratio of bacteria to algae and the thickness of the biofilm, their synergistic effect can be fully exerted to enhance the effect of ecological restoration. Simultaneously, the application of biofilm technology, coupled with other processes in river and lake ecological restoration, has attracted much attention. Combining physical and chemical methods can achieve complementary advantages and comprehensively improve the water quality. For instance, when biofilm technology is combined with physical methods, such as activated carbon adsorption and membrane separation, activated carbon can adsorb a large amount of organic substances and some heavy metals, while biofilms can further degrade and transform the adsorbed pollutants, effectively removing pollutants such as organic substances and heavy metals in water. When combined with chemical methods, such as chemical oxidation and precipitation, chemical oxidation can break down refractory organic pollutants into more biodegradable forms, and the biofilm can complete the final degradation and removal, improving the removal efficiency of refractory pollutants. Coupled applications can reduce the cost and operational difficulty of a single technology. For example, the use of biofilms can decrease the replacement frequency of activated carbon or membranes, and their combination with chemical methods can reduce the dosage of chemical agents required, thereby enhancing the feasibility and sustainability of ecological restoration. In practical applications, biofilm technology not only effectively promotes the restoration and stability of river and lake ecosystems but also significantly improves the overall water quality and ecological health level. Biofilm technology has the advantages of simple operation, low cost, and good purification effects and is applicable to the ecological restoration of rivers and lakes of different scales and types. By setting up biofilm reactors or placing biofilm carriers in rivers and lakes, water pollutants can be effectively removed, water quality can be improved, and the restoration and stable development of ecosystems can be promoted. For small rivers and lakes, the simple addition of biofilm carriers may be sufficient, whereas for large water bodies, more complex biofilm reactor systems may be required. In conclusion, biofilm technology has important research significance and broad application prospects in the field of river and lake ecological restoration and plays a pivotal role in promoting the sustainable development of river and lake ecosystems. Future research should conduct an in-depth exploration of the mechanism of biofilm technology applicable to the ecological restoration of rivers and lakes, understand the microscopic mechanism of the purification process, and optimize the design of carrier materials and reactor construction to improve the performance and efficiency of biofilms. Additionally, its application range should be expanded under different environmental conditions to adapt to various complex river and lake ecosystems. Notably, more scientific and efficient technical support can be provided in this way for the ecological restoration of rivers and lakes in China, rejuvenating rivers and lakes and making greater contributions to the realization of ecological environment protection and sustainable development.

Key words: river-lake restoration, biofilm-based technology, water environment government, ecological restoration, bacterial-algal biofilm technology, coupled technology, microorganism