Civil and Environmental Engineering Department, The University of Alabama in Huntsville, Huntsville, AL 35899, USA.
Civil and Environmental Engineering Department, The University of Alabama in Huntsville, Huntsville, AL 35899, USA.
Sci Total Environ. 2022 Feb 25;809:152161. doi: 10.1016/j.scitotenv.2021.152161. Epub 2021 Dec 4.
Remote areas, where centralized water supply cannot reach, rely heavily on decentralized supply systems such as slow sand filters (SSFs). Groundwater used to be a reliable water source; yet, the advent of micropollutants (MPs) has raised concerns over its quality. In this study, an enhanced slow sand filtration utilizing graphene oxide (GO)-coated sand prepared via a simple thermal method was employed to remove two representative MPs, atrazine (ATZ) and atenolol (ATL), from real groundwater for drinking water treatment. The removal of ATZ and ATL was studied in a bench-scale enhanced SSF using GO-coated sand in comparison with the conventional plain sand. The results showed that the GO-coated sand performed better in the removal of ATZ, ATL, and total organic carbon (TOC), as well as turbidity reduction. Moreover, in order to study the role of the schmutzdecke in MPs' removal small lab-scale columns with and without schmutzdecke growth were set up. The results indicated the enhanced removal capacity of the coated sand toward ATZ, ATL, and TOC could mainly be attributed to the GO coating layer, not the schmutzdecke. Hence, if the coated sand is to be used in field SSFs for the removal of organic contaminants, the schmutzdecke growing phase might not be needed. A preliminary techno-economic analysis was performed to evaluate the practicability of enhanced SSF and GO was found to dominate the overall cost. For a community-level or a household-level SSF, the extra cost using GO-coated sand may be $0.34 and $3.25 per m of water if the GO price is $10 and $100 per kg, respectively.
偏远地区由于无法集中供水，严重依赖分散式供水系统，例如慢砂滤池（SSF）。地下水曾经是可靠的水源；然而，由于微污染物（MPs）的出现，人们开始担心其水质。在这项研究中，采用简单的热法制备的氧化石墨烯（GO）涂覆砂的强化慢砂滤池被用于去除实际地下水中的两种代表性 MPs，即莠去津（ATZ）和阿替洛尔（ATL），以进行饮用水处理。在使用 GO 涂覆砂的台式强化 SSF 中研究了 ATZ 和 ATL 的去除情况，并与传统的普通砂进行了比较。结果表明，GO 涂覆砂在去除 ATZ、ATL 和总有机碳（TOC）以及降低浊度方面表现更好。此外，为了研究 schmutzdecke 在 MPs 去除中的作用，建立了带有和不带有 schmutzdecke 生长的小型实验室规模柱。结果表明，涂覆砂对 ATZ、ATL 和 TOC 的增强去除能力主要归因于 GO 涂层，而不是 schmutzdecke。因此，如果要在野外 SSF 中使用涂覆砂去除有机污染物，则可能不需要生长 schmutzdecke 的阶段。进行了初步的技术经济分析，以评估强化 SSF 的实用性，结果发现 GO 占据了总成本的主导地位。对于社区级或家庭级 SSF，如果 GO 的价格分别为每公斤 10 美元和 100 美元，则使用 GO 涂覆砂的额外成本可能分别为每米水 0.34 美元和 3.25 美元。
