McDowall Bridget, Hoefel Daniel, Newcombe Gayle, Saint Christopher P, Ho Lionel
CRC for Water Quality and Treatment, Australian Water Quality Centre, SA Water Corporation, PMB 3, Salisbury, SA 5108, Australia.
Water Res. 2009 Feb;43(2):433-40. doi: 10.1016/j.watres.2008.10.044. Epub 2008 Nov 5.
Geosmin is a secondary metabolite that can be produced by many species of cyanobacteria and Actinomycetes. It imparts a musty/earthy taste and odour to drinking water which can result in consumer complaints and a general perception that there is a problem with the water quality. As geosmin is recalcitrant to conventional water treatment, processes are sought to ensure effective removal of this compound from potable water. Biological filtration (biofiltration) is an attractive option for geosmin removal as this compound has been shown to be biodegradable. However, effective biofiltration of geosmin can be site specific as it is highly dependent upon the types of organism present and there is often an extended acclimation period before efficient removals are achieved. We report here, a novel approach to enhance the biofiltration of geosmin by seeding sand filter columns with a bacterial consortium previously shown to be capable of effectively degrading geosmin. Geosmin removals of up to 75% were evident through sand columns which had been inoculated with the geosmin-degrading bacteria, when compared with non-inoculated sand columns where geosmin removals were as low as 25%. These low geosmin removals through the non-inoculated sand columns are consistent with previous studies and were attributed to physical/abiotic losses. The presence of an existing biofilm was shown to influence geosmin removal, as the biofilm allowed for greater attachment of the geosmin-degrading consortium (as determined by an ATP assay), and enhanced removals of geosmin. Minimal difference in geosmin removal was observed when the geosmin-degrading bacteria were inoculated into the sand columns containing either an active or inactive biofilm.
土臭素是一种次生代谢产物，可由多种蓝细菌和放线菌产生。它会给饮用水带来一股霉味/土腥味，从而导致消费者投诉，并普遍让人觉得水质存在问题。由于土臭素对传统水处理方法具有抗性，因此需要寻求能有效从饮用水中去除这种化合物的工艺。生物过滤是去除土臭素的一个有吸引力的选择，因为这种化合物已被证明具有生物可降解性。然而，土臭素的有效生物过滤可能因地点而异，因为它高度依赖于所存在的生物体类型，而且在实现高效去除之前通常需要较长的适应期。我们在此报告一种新方法，即通过向砂滤柱接种先前已证明能够有效降解土臭素的细菌聚生体，来增强土臭素的生物过滤效果。与未接种土臭素降解菌的砂柱相比，接种了土臭素降解菌的砂柱对土臭素的去除率高达75%，而未接种的砂柱对土臭素的去除率低至25%。未接种砂柱对土臭素的低去除率与先前的研究一致，归因于物理/非生物损失。研究表明，现有生物膜的存在会影响土臭素的去除，因为生物膜能使土臭素降解菌聚生体更好地附着（通过ATP测定确定），并提高土臭素的去除率。当将土臭素降解菌接种到含有活性或非活性生物膜的砂柱中时，观察到土臭素去除率的差异极小。
