目前正在评估使用臭氧和苯甲酸来提高传统慢速砂滤的处理性能。在1989年12月至1990年1月为期29天的过滤器运行期间，对臭氧消耗量为0.5和1.0 mg O3/mg非可蒸煮溶解有机碳（NPDOC）和苯甲酸盐消耗量为0.05和0.1 mg苯甲酸盐/mg NPDOC的情况进行了评估。六个中试过滤器以0.05 m/h的过滤速率运行，其配置旨在评估臭氧和苯甲酸盐添加对处理效率的单独和交互影响。运行期间，除对照组外，所有过滤器的水头损失均呈指数增长，表明滤饼- 类似的过滤过程发生在水柱过滤介质界面的schmutzdecke中。与对照、高苯甲酸盐或低臭氧和低苯甲酸盐过滤器相比，接受高臭氧剂量或高臭氧和高苯甲酸盐剂量的过滤器提供了更好的处理。与生物过滤相比，臭氧直接氧化在降低紫外吸收和THMFP方面发挥了更重要的作用。生物过滤比直接氧化对NPDOC去除的影响更大。臭氧氧化倾向于降低整个分子量（mw）光谱（1K道尔顿至100K道尔顿）的紫外吸收率； 将NPDOC重新分配到较低的mw部分；增加羧基酸度和亲水性；提高原水中可生物降解有机碳（BDOC）的含量。生物过滤倾向于去除功能化程度更高、分子量更低的亲水性材料。与此过滤器运行中的对照相比，添加苯甲酸盐并没有显著提高过滤器性能。新罕布什尔州朴茨茅斯和马萨诸塞州安多弗的设施正在进行或计划进行额外的试验性过滤器运行，以评估季节性和水源水影响。

The use of ozone and benzoic acid to enhance treatment performance of conventional slow sand filtration is presently under evaluation. Ozone at doses of 0.5 and 1.0 mg O3 consumed/mg nonpurgeable dissolved organic carbon (NPDOC) and benzoate at doses of 0.05 and 0.1 mg benzoate/mg NPDOC were evaluated during a 29 day filter run in December 1989-January 1990. Six pilot filters were operated at a filtration rate of 0.05 m/h in configurations designed to evaluate the separate and interactive effects of ozone and benzoate addition on treatment efficiency. Head loss during the run was exponential for all the filters, except the control, indicating that a cake-like filtration process was occurring in the schmutzdecke at the water column-filter media interface. Filters receiving either the high ozone dose or the high ozone and high benzoate dose provided better treatment compared to the control, high benzoate, or low ozone and low benzoate filters. Direct oxidation by ozone played a more significant role in reducing UV absorbance and THMFP than biological filtration. NPDOC removal was more influenced by biological filtration than direct oxidation. Ozonation tended to decrease the UV absorbance across the entire molecular weight (mw) spectrum (1K daltons to 100K daltons); redistribute the NPDOC into the lower mw fraction; increase carboxylic acidity and hydrophilicity; and increase the biodegradable organic carbon (BDOC) content of the raw water. Biological filtration tended to remove the more functionalized, lower molecular weight, hydrophilic material. The addition of benzoate did not significantly enhance filter performance compared to the control in this filter run. Additional pilot filter runs at the Portsmouth, New Hampshire and Andover, Massachusetts facilities are underway or planned to evaluate seasonal and source water effects.