由于许多原因，饮用水中硫化氢的存在是不可取的，而不是 其中最少的是客户对味道和气味的投诉。强迫 通风曝气器已被证明能有效地从地下水中去除这种化合物 佛罗里达州然而，FDA中产生的环境（大表面积，高 含氧水）有利于广泛的微生物生长，尤其是在温暖的环境中 佛罗里达气候。这导致复杂的生物膜快速、规则和 需要彻底清洁，以最大限度地减少生物膜的形成，生物膜脱落并可能 导致水浊度高。安装FDAs之前，平均浊度 为0.4 NTU，最大为1.0 NTU，但安装后的平均浊度为 上升至2.1 NTU，最大值为9.3 NTU。显微镜检查 生物膜显示了包括原生动物、蓝藻、， 阿米巴、细菌和轮虫。 使用变性梯度凝胶电泳（DGGE）表明，该属细菌 亚硝基单胞菌是细菌区系的重要组成部分。微生物 检查表明，大肠菌群在生物膜内也很普遍 在水里离开FDA。这些细菌通常是阴沟肠杆菌和这种细菌 在处理厂供电的配电系统中经常发现。更多 对这些阴沟肠杆菌菌株的一些菌株的详细检查表明 FDA废水中发现的是克隆性的，这表明它们确实是克隆性的 在FDA中生长。泄殖腔肠杆菌表型特征的比较 在FDA废水和分配系统中发现的菌株表明 似乎有相同的起源。微生物数据检查 处理厂出水表明，常规采样很少检测到大肠菌群 每天都在进行。因此进行了一项研究，以确定大肠杆菌是否 微生物在消毒后存活。氯化后收集样品（目标 残留消毒剂为0.8 mg/L，接触时间至少为6小时） 检测100mL和2L样品。在104份100mL样本中，未发现任何样本 在104份2L样本中，有15份含有大肠菌群。大概 通过生物膜基质的碎片保护这些生物体免受游离氯的影响 包含在FDA废水中。假设一个有机体负责 2L样本呈阳性，约15%的水 大肠菌群的计算表明，最多可以有2.8 x 106个大肠菌群 通过处理厂进入配电系统。泄殖腔大肠杆菌菌株 存在于配水系统的水中（其他工作建议为生物膜衍生） 具有与在研究中发现的某些生物体相同的表型特征 FDA废水。因此，可以得出结论，大肠菌群在存活 消毒，进入配电系统，并在生物膜中建立自身。 实施了一项积极的FDA清洁计划，导致了重大的 FDA出水浊度的改善，平均值为 约0.6 NTU。对水的颗粒分析表明，生物膜继续存在 被排放到FDA废水中。进行了进一步的微生物学工作 确定FDAs出水中大肠菌群的水平。 在两个月的时间内收集并分析了FDA废水样本，并对其进行了分析 每次总大肠菌群呈阳性。大肠菌群密度通常在 10-100 cfu/mL范围，但有一次浓度大于2400 cfu/mL。FDAs出水中持续存在大肠菌群是导致 尽管消毒水中大肠菌群的检测频率 明显低于清洁方案之前

The presence of hydrogen sulfide in drinking water is undesirable for many reasons, not the least of which is the numerous customer complaints about taste and odor. Forced draft aerators have been shown to effectively remove this compound from groundwater in Florida. However, the environment produced in FDAs (large surface area, highly oxygenated water) is conducive to extensive microbial growth, particularly in the warm Florida climate. This results in a complex biofilm developing rapidly, and regular and thorough cleaning is required to minimize build up of biofilm which sloughs off and can result in water with high turbidity. Prior to installation of the FDAs the mean turbidity was 0.4 NTU with a maximum of 1.0 NTU but following installation the mean turbidity rose to 2.1 NTU with a maximum value of 9.3 NTU. Microscopic examination of the biofilm showed a complex community of organisms including protozoa, cyanobacteria, amoeba, bacteria and rotifers. Use of denaturing gradient gel electrophoresis (DGGE) showed that bacteria of the genus Nitrosomonas formed a substantial component of the bacterial flora. Microbiological examination showed that coliform organisms were also prevalent within the biofilm and in the water leaving the FDAs. These were often Enterobacter cloacae and this species was frequently found in the distribution system fed from the treatment plant. More detailed examination of a number of strains of these E.cloacae strains showed that those found in the FDA effluent were clonal in nature, indicating that they were indeed growing in the FDAs. Comparison of the phenotypic characteristics of the E.cloacae strains found in the FDA effluent and in the distribution system indicated that they appeared to have the same origin. Examination of the microbiological data for the treatment plant effluent showed that coliforms were seldom detected by routine sampling which was carried out daily. A study was therefore undertaken to determine if coliform organisms were surviving disinfection. Samples were collected after chlorination (target residual disinfectant was 0.8 mg/L and contact time was a minimum of six hours) and 100mL and 2L samples were examined. Of the 104 samples of 100mL, none were found to contain coliforms while 15 of 104 of the 2L samples contained coliforms. Presumably these organisms were protected from the free chlorine by pieces of biofilm matrix contained in the FDA effluent. Assuming that a single organism was responsible for the positive result in the 2L samples, and that approximately 15% of the water contained coliforms then calculations indicated that as many as 2.8 x 106 coliforms could be entering the distribution system through the treatment plant. A strain of E.cloacae present in the water of the distribution system (which other work suggested was biofilm-derived) had identical phenotypic characteristics to some of the organisms found in the FDA effluent. Thus it was concluded that coliform organisms were surviving disinfection, passing into the distribution system and establishing themselves in biofilms. An aggressive FDA cleaning program was implemented which resulted in a significant improvement in the turbidities recorded for the FDA effluent with a mean value of approximately 0.6 NTU. Particle analysis of the water suggested that biofilm continued to be sloughed off into the FDA effluent. Further microbiological work was undertaken to determine the levels of coliform organisms present in the effluent from the FDAs. Samples of FDA effluent were collected and analyzed over a two month period and were positive for total coliforms on every occasion. Coliform densities were generally in the 10-100 cfu/mL range but on one occasion the concentration was greater than 2400 cfu/mL. The continuing presence of coliforms in the effluent of the FDAs was cause for concern although the frequency of detection of coliforms in the disinfected water was markedly lower than before the cleaning regimen had be