Reclaimed water from small wastewater treatment facilities in the rural areas of the Beira Interior region (Portugal) may constitute an alternative water source for aquifer recharge. A 21-month monitoring period in a constructed wetland treatment system has shown that 21,500 m(3) year(-1) of treated wastewater (reclaimed water) could be used for aquifer recharge. A GIS-based multi-criteria analysis was performed, combining ten thematic maps and economic, environmental and technical criteria, in order to produce a suitability map for the location of sites for reclaimed water infiltration. The areas chosen for aquifer recharge with infiltration basins are mainly composed of anthrosol with more than 1 m deep and fine sand texture, which allows an average infiltration velocity of up to 1 m d(-1). These characteristics will provide a final polishing treatment of the reclaimed water after infiltration (soil aquifer treatment (SAT)), suitable for the removal of the residual load (trace organics, nutrients, heavy metals and pathogens). The risk of groundwater contamination is low since the water table in the anthrosol areas ranges from 10 m to 50 m. Oil the other hand, these depths allow a guaranteed unsaturated area suitable for SAT. An area of 13,944 ha was selected for study, but only 1607 ha are suitable for reclaimed water infiltration. Approximately 1280 m(2) were considered enough to set up 4 infiltration basins to work in flooding and drying cycles.
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机译:来自贝拉内陆地区(葡萄牙)农村地区小型废水处理设施的再生水可能构成含水层补给的替代水源。在人工湿地处理系统中进行的21个月监控期间显示,可以将21,500 m(3)年(-1)的处理过的废水(再生水)用于含水层补给。进行了基于GIS的多标准分析,结合了十个专题图以及经济,环境和技术标准,以生成适用于再生水渗透场所的位置图。入渗盆地的含水层补给区主要由深度大于1 m的人为溶胶和细砂组成,平均入渗速度可达1 m d(-1)。这些特性将为渗透后的再生水(土壤含水层处理(SAT))提供最终的抛光处理,适合去除残留负荷(痕量有机物,营养物,重金属和病原体)。地下水污染的风险很低,因为人为土壤区域的地下水位范围为10 m至50 m。另一方面,这些深度可以保证有一个适合SAT的不饱和区域。选择进行研究的面积为13944公顷,但只有1607公顷适合再生水渗透。大约1280 m(2)被认为足以建立4个渗透盆地,以进行洪水和干燥循环。
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