岛屿环境下水泥屋顶和水泥路面雨水径流水质特性及其用作饮用水的可行性

Water quality characteristic of rainfall runoff on the cement roof and cement road in the island environment and its feasibility as the drinking water resource

以岛屿典型集水面(水泥路面和水泥屋顶)的雨水径流为研究对象,系统分析了雨季和旱季雨水径流的水质历时变化特征,并对岛屿收集雨水用作饮用水的可行性进行了分析。结果表明:雨季由于降雨强度大且降雨集中,水质明显好于旱季;屋顶受环境及人为因素干扰小,水质好于路面。建议收集雨水顺序为雨季屋顶>旱季屋顶>雨季路面,旱季路面水质较差,不建议收集。岛屿不同环境下收集的雨水水质分析结果表明,超出生活饮用水卫生标准的指标主要有色度、浊度、少量金属(铝和铅)、氨氮、有机物和微生物等,且超标指标在降雨初期随降雨时间的增加而迅速降低,之后逐渐趋于稳定。因此,对初期雨水进行弃流可极大改善收集雨水水质。雨水径流饮用水化可行性分析结果表明,根据降雨情况和集水面性质,采取合理的弃流方案并结合过滤和消毒等净化工艺,可实现雨水饮用水化。研究结果可为降雨量丰富的岛屿及东南亚和南亚的"一带一路"沿线国家利用雨水解决饮用水问题提供借鉴。

Rainwater harvesting offers an considerable potential as an alternative drinking water supply in the island environment.In this study,the changes in the water quality of rainfall runoff collected from roof and road were analyzed in the rainy season and the dry season,and its feasibility as the drinking water resource was also evaluated.Results showed that due to heavy and concentrated rainfall in rainy season,its water quality was significantly better than that in the dry season.Due to slight environmental and human disturbance for the roofrunoff,its water quality of was better than that of the road-runoff.The order of rainwater harvesting was recommended as roof-runoff in rainy season>roof-runoff in dry season>road-runoff in rainy season,and roadrunoff in the dry season was not recommended due to its poor water quality.The water quality indexes beyond the standards for drinking water were color,turbidity,metal ions,ammonia nitrogen,organic compounds and microbiological contaminants,which presented a rapid decrease trend along the early rainfall duration,and then gradually reached stable.Therefore,the water quality could be greatly improved by discarding the initial rainwater.Then the remained rainwater could be collected and treated by filtration and disinfection to meet the standards for drinking water.On the basis of rainfall conditions and qualities of catchment area,the reasonable discarding scheme and the following filtration and disinfection could realize the yield of potable water from rainfall.These results provide a theoretical basis for the effective utilization of rainwater in the rich rainfall islands and countries along'Belt and Road'.