生物炭及其改进生态浮岛技术对景观水体的净化效果研究

Study on the Purification Effects of Biochar and Its Improved Ecological Floating Island Technology onLandscape Water Bodies

关键词:  风景园林  城市景观水体  生物炭  水体改善  生态浮岛

Key words:  landscape architecture  urban landscape water body  biochar  water body improvement  ecological floating island

摘要:

生物炭是一种新型吸附材料，常用于土壤改良及废水处理，但在城市景观水体中的应用研究尚不充分。首先通过对照实验，比较木质生物炭、杏核生物 炭、椰壳生物炭对总磷、总氮、氨氮、化学需氧量、浊度、色度、悬浮物的净化效果。结果显示，椰壳生物炭因其丰富的孔隙结构和表面官能团，净化能力优于 其他2种。随后选取椰壳生物炭与植物浮岛组合，对比单独生物炭浮岛与单独植物浮岛，发现“生物炭+植物”浮岛可在多项水质指标上实现更大幅度的下降，有 效抑制富营养化并改善水体视觉品质。研究表明，生物炭材料可显著提升景观水体质量，并作为基质应用于生态浮岛以进一步放大净化效益，为景观可持续技术 的优化与实践提供了新的参考依据。

Abstract:

Urban landscape waterbodies play a pivotal role in urban ecosystems, not only enriching the urban landscape but also making irreplaceable contributions to microclimate regulation, heat island mitigation, and leisure activities for residents. However, because of low flow rates and complex pollution sources, these waterbodies are often subject to eutrophication, algal blooms, and unpleasant odors, severely compromising both their ecological functions and aesthetic value. In response to these challenges, this study incorporates biochar and ecological floating island technology to examine the purification performance of biochar derived from different feedstocks, as well as the treatment efficacy of a "biochar + plants" combination, thereby offering a more targeted technical approach to waterbody restoration in landscape architecture. In the methodology, wood biochar (WB), apricot kernel biochar (AKB), and coconut shell biochar (CSB) were selected and analyzed via scanning electron microscopy and Fourier-transform infrared spectroscopy to elucidate their pore structures and surface functional groups. These biochar materials were then placed into glass containers simulating urban landscape waterbodies, alongside a control group. Every three days, eutrophication-related parameters such as total phosphorus, total nitrogen, ammonia nitrogen, and chemical oxygen demand were measured, while color, turbidity, and suspended solids were also monitored to quantitatively assess improvements in water quality and visual characteristics. After identifying the most effective biochar, additional comparative experiments were conducted using ecological floating islands as carriers, separately testing biochar alone, aquatic plants alone, and a "biochar+plants" combination. Statistical analysis was then used to determine the significance of differences among the various treatments. The results revealed that all three biochar types effectively reduced the concentrations of key pollutants, albeit with some variations for specific indicators. CSB exhibited the best overall performance, attributable to its richer pore structure and higher content of hydrophilic functional groups, thereby substantially lowering total phosphorus, total nitrogen, chemical oxygen demand, and color/turbidity. AKB showed a stronger capacity for ammonia nitrogen removal but was less effective than WB and CSB in improving color. Although WB demonstrated the ability to reduce eutrophication, it slightly increased the concentration of suspended solids. In the "biochar + plants" floating island tests, the synergistic effects of plant root uptake and biochar pore adsorption resulted in a more efficient reduction of nitrogen, phosphorus, and chemical oxygen demand compared to single-technology methods, while also curtailing potential nutrient release from biochar and greatly enhancing water clarity and visual quality. This study provides a new perspective on understanding the synergistic purification mechanisms of biochar and plant-based floating islands in urban landscape waterbodies and offers evidence-based references for landscape architecture in low-carbon water management and ecological design. In practical design and implementation, planners and designers should fully account for pollutant types, hydrological conditions, and aesthetic requirements, making judicious choices of biochar materials that have multi-scale pores and abundant functional groups, while balancing plant species selection for both landscape and purification needs. Additionally, it is important to dynamically adapt to different seasons, regions, and public expectations regarding waterbody visibility, ensuring alignment with local culture and natural conditions, and considering long-term maintenance and sustainability. By flexibly applying this combined biochar– plant floating island technology to urban waterbody treatment, not only can landscape quality be enhanced, but water-based ecological services can also be significantly improved, helping to build urban public spaces that are both visually appealing and ecologically resilient.