砂垫层控制活性炭滤池无脊椎动物穿透研究

Penetration control of invertebrates in the granular activated carbon filtration process with sand bed

摘要:

为控制无脊椎动物穿透带来的过滤水感官问题和潜在的安全风险,添加一系列不同粒径和不同高度的砂垫层于5根活性炭(Granular activated carbon,GAC)滤柱中．在10个月的连续运行期间,滤柱出水中共检出7类无脊椎动物(其中轮虫和甲壳类生物为优势种群)．结果表明：砂垫层的添加可以有效防止无脊椎动物的穿透,且随着砂垫层高度的增加去除率逐渐升高,轮虫和体长大于200 μm无脊椎动物的去除率分别达46.6％和85.5％,石英砂粒径对轮虫的去除影响较大;砂垫层可以有效去除水中颗粒物,且出水中颗粒数与无脊椎动物丰度显著相关．

Abstract:

In view of the aesthetic problem and potential threat to safe drinking water caused by invertebrates, a series different depth of sand beds were located under granular activated carbon (GAC) media in five pilot-GAC filtration (GACF) columns to restrict invertebrates’ penetration into the distribution system. During the study period of 10 months, 7 groups of invertebrates (rotifers and crustaceans as the predominant species) were detected in the filtrates of the five GACF columns. The experimental results indicated that invertebrates could be removed effectively with the added sand beds compared with the sand bed-free GACF column. The mean abundances of invertebrates decreased significantly with the increase of the depth of sand beds. The 46.6 ％ of rotifers and 85.5％ of larger invertebrates (size>200 μm) could be removed from the filtrate. Sand sizes had a greater impact on rotifers removal than larger invertebrates. Also increasing removal ratios of particle matter were detected with the sand beds added. Further data analysis showed that there was significant correlation between the mean values of particle counts and abundances of invertebrates in the filtrates.