Wastewater treatment by slow sand filters using uncoated and iron-coated fine sand: impact of hydraulic loading rate and media depth
Wastewater treatment by slow sand filters using uncoated and iron-coated fine sand: impact of hydraulic loading rate and media depth
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DOI：
10.1007/s11356-018-3551-4
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发表时间：
2018-10
影响因子：
5.8
通讯作者：
Srishti Verma;A. Daverey;Archana Sharma
中科院分区：
文献类型：
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作者：
Srishti Verma;A. Daverey;Archana Sharma
以未涂覆细砂（SSFu）和铁涂覆细砂（SSFco）为填料，研究了两种慢砂滤池（SSFs）对城市污水的处理效果。砂涂层的影响;水力负荷率（HLR）（0.56，0.85，和1.12厘米/小时）;和过滤器深度（22，32，和42厘米）进行了评价。砂涂层在所有深度对SSF的废水处理没有任何显著影响（p> 0.05）。总悬浮物（TSS）、化学需氧量（COD）和磷酸盐的去除率随曝气时间的增加而降低。另一方面，介质深度对浊度、TSS、COD和总大肠菌群（TC）的去除有积极影响。在0.56 cm/h的流速下，每个研究参数的平均去除率，即，在滤层深度d42处，SSFu和SSFco的浊度、TSS和COD分别为94.3%、90.1%和56%;两种过滤器都能有效地去除总大肠菌群（> 90%）和粪大肠菌群（高达99%），但对硝酸盐的去除效果不佳。SEM照片证实，由于微生物在砂表面的定殖，在SSFu中观察到频繁的堵塞。SSFco内未形成生物膜或微生物定植，这可能是SSFco不间断运行的原因。总体而言，覆膜砂有利于SSF的长期运行。
Two lab-scale slow sand filters (SSFs), packed with uncoated fine sand (SSFu) and iron-coated fine sand (SSFco), were operated to study their efficiency in treating municipal wastewater. The effects of sand coating; hydraulic loading rates (HLRs) (0.56, 0.85, and 1.12 cm/h); and filter depths (22, 32, and 42 cm) were evaluated. Sand coating did not have any significant effect on wastewater treatment by the SSF at all depths (p> 0.05). The removals of total suspended solids (TSS), chemical oxygen demand (COD), and phosphate decreased with increase in HLR. On the other hand, media depth had positive effects on the removal of turbidity, TSS, COD, and total coliforms (TC). At HLR of 0.56 cm/h, the average removals of each studied parameter, i.e., turbidity, TSS, and COD, at filter depth d42in SSFuand SSFcowere 94.3, 90.1, and 56% and 92.7, 93, and 30.95%, respectively. Both filters efficiently removed the total coliforms (> 90%) and fecal coliform (up to 99%) but inefficient in nitrate removal. Frequent clogging was observed in SSFudue to the colonization of microorganisms on the sand surface, which was confirmed by SEM images. Biofilm formation or microbial colonization was absent in SSFco, which might be responsible for uninterrupted operation of SSFco.Overall, the sand coating is beneficial for long-term operation of SSF.