Polycyclic aromatic hydrocarbons (PAHs) removal by the tropical plant, Eleocharis ochrostachys, from contaminated water and sand using sub-surface flow system (SSF) was conducted for 80 days. E. ochrostachys was exposed to various concentrations of diesel (0.5, 1, 2 and 3% v/v). Treatments with and without the plant were conducted to analyse the effect of plants in removing PAHs. A liquid–liquid extraction method was used to extract the PAHs from the wastewater. The PAH removal with plants was significantly better than without plants (p<0.05). At diesel concentrations of 0.5, 1, 2 and 3%, the PAH removal percentages with plants were 89.1, 91.3, 73.0 and 71.6% from water and 95.3, 97.2, 97 and 86.2% from the sand, respectively, while the removals without plants were only 81.8, 81.0, 63 and 63.9% from water and 93.6, 93.9, 95.7 and 81.8% from the sand, respectively. Increasing colony-forming units (CFUs) surrounding the plant roots indicated enhanced growth of rhizobacteria, which could assist the removal of pollutants. Additionally, the gravel layers had removed the total suspended solid (TSS) from 87 to 98%.

使用地下流系统（SSF）将热带植物Eleocharis ochrostachys从污染的水和沙子中去除多环芳烃（PAHs）进行了80天。草被暴露于各种浓度的柴油（0.5、1、2和3％v / v）。进行有或没有植物的处理以分析植物在去除PAHs中的作用。采用液液萃取法从废水中提取多环芳烃。用植物去除PAH明显优于用植物去除PAH（p<0.05）。在柴油浓度为0.5％，1、2％和3％的情况下，从植物中去除PAH的百分比分别为89.1％，91.3％，73.0％和71.6％，从沙子中去除PAH的百分比分别为95.3％，97.2％，97％和86.2％，而没有植物的去除率分别来自水的81.8％，81.0％，63％和63.9％，来自沙子的分别为93.6％，93.9％，95.7％和81.8％。植物根部周围菌落形成单位（CFUs）的增加表明根际细菌的生长增强，这可能有助于去除污染物。此外，砾石层已将总悬浮固体（TSS）从87％降至98％。