Department of Engineering and Environmental Technology, Federal University of Santa Maria, 98400-000, Frederico Westphalen, Rio Grande do Sul, Brazil.
Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Carlos, São Paulo, 13566-590, Brazil.
Water Res. 2020 Jul 1;178:115816. doi: 10.1016/j.watres.2020.115816. Epub 2020 Apr 19.
Universalising actions aimed at water supply in rural communities and indigenous populations must focus on simple and low-cost technologies adapted to the local context. In this setting, this research studied the dynamic gravel filter (DGF) as a pre-treatment to household slow-sand filters (HSSFs), which is the first description of a household multistage filtration scale to treat drinking water. DGFs (with and without a non-woven blanket on top of the gravel layer) followed by HSSFs were tested. DGFs operated with a filtration rate of 3.21 m m.d and HSSFs with 1.52 m m.d. Influent water contained kaolinite, humic acid and suspension of coliforms and protozoa. Physical-chemical parameters were evaluated, as well as Escherichia coli, Giardia spp. cysts and Cryptosporidium spp. oocyst reductions. Removal was low (up to 6.6%) concerning true colour, total organic carbon and absorbance (λ = 254 nm). Nevertheless, HMSFs showed turbidity decrease above 60%, E. coli reduction up to 1.78 log, Giardia cysts and Cryptosporidium oocysts reductions up to 3.15 log and 2.24 log, respectively. The non-woven blanket was shown as an important physical barrier to remove solids, E. coli and protozoa.
普及农村社区和土著人口的供水行动必须侧重于适应当地情况的简单、低成本技术。在这种情况下，本研究研究了动态砾石过滤器（DGF）作为家庭慢速砂滤器（HSSF）的预处理，这是首次描述用于处理饮用水的家用多级过滤规模。测试了具有和不具有无纺层的 DGF（在砾石层顶部）以及 HSSF。DGF 的过滤速度为 3.21 m m.d，HSSF 的过滤速度为 1.52 m m.d。进水含有高岭土、腐殖酸和大肠菌群和原生动物的悬浮固体。评估了物理化学参数，以及大肠杆菌、贾第虫属孢囊和隐孢子虫属卵囊的去除率。真色、总有机碳和吸光度（λ=254nm）的去除率较低（高达 6.6%）。然而，HMSF 表现出浊度降低超过 60%，大肠杆菌减少高达 1.78 对数，贾第虫属孢囊和隐孢子虫属卵囊减少高达 3.15 对数和 2.24 对数。无纺层被证明是去除固体、大肠杆菌和原生动物的重要物理屏障。
