Magic-Knezev Aleksandra, van der Kooij Dick
Water Quality and Public Health, Kiwa Water Research, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands.
Water Res. 2004 Nov;38(18):3971-9. doi: 10.1016/j.watres.2004.06.017.
A method for determining the concentration of active microbial biomass in granular activated carbon (GAC) filters used in water treatment was developed to facilitate studies on the interactions between adsorption processes and biological activity in such filters. High-energy sonication at a power input of 40 W was applied to GAC samples for the detachment of biomass which was measured as adenosine triphosphate (ATP). Modelling of biomass removal indicated that a series of six to eight sonication treatments of 2 min each yielded more than 90% of the attached active biomass. The ATP concentrations in 30 different GAC filters at nine treatment plants in The Netherlands ranged from 25 to 5000 ng ATP cm(-3) GAC, with the highest concentrations at long filter run times and pretreatment with ozone. A similar concentration range was observed in nine rapid sand (RS) filters. ATP concentrations correlated significantly (p<0.05) with total direct bacterial cell counts in each of these filter types, but the median value of the ATP content per cell in GAC filters (2.1 x 10(-8) ng ATP/cell) was much lower than in the RS filters (3.6 x 10(-7) ng ATP/cell). Average biofilm concentrations ranging from 500 to 10(5) pg ATP cm(-2) were calculated assuming spherical shapes for the GAC particles but values were about 20 times lower when the surface of pores >1 microm diameter is included in these calculations. The quantitative biomass analysis with ATP enables direct comparisons with biofilm concentrations reported for spiral wound membranes used in water treatment, for distribution system pipes and other aquatic environments.
开发了一种测定用于水处理的颗粒活性炭（GAC）过滤器中活性微生物生物量浓度的方法，以促进对此类过滤器中吸附过程与生物活性之间相互作用的研究。以40 W的功率输入对GAC样品进行高能超声处理，以分离作为三磷酸腺苷（ATP）测量的生物量。生物量去除的模型表明，一系列每次2分钟的六到八次超声处理可产生超过90%的附着活性生物量。荷兰九个处理厂的30个不同GAC过滤器中的ATP浓度范围为25至5000 ng ATP cm(-3) GAC，在较长的过滤器运行时间和臭氧预处理时浓度最高。在九个快速砂滤器（RS）中观察到类似的浓度范围。ATP浓度与每种过滤器类型中的总直接细菌细胞计数显著相关（p<0.05），但GAC过滤器中每个细胞的ATP含量中位数（2.1×10(-8) ng ATP/细胞）远低于RS过滤器（3.6×10(-7) ng ATP/细胞）。假设GAC颗粒为球形计算得出的平均生物膜浓度范围为500至10(5) pg ATP cm(-2)，但当这些计算中包括直径>1微米的孔的表面时，数值约低20倍。用ATP进行的生物量定量分析能够与报道的用于水处理的螺旋缠绕膜、配水系统管道和其他水生环境中的生物膜浓度进行直接比较。
