Background

Taste and odor problem in drinking water is one major concern for consumers and water supply. Exploring the odor characteristics and the major odor causing compounds in the source water is the base for odor control in drinking water treatment plant (WTP). In this study, focusing on a newly constructed reservoir with Huangpu River as the source water, the occurrence of typical odorants and their variations were first identified. Correspondingly, the removal behavior in an ozone/GAC advanced treatment process was investigated.

Results

The results indicated that 2-methylisoborneol (2-MIB), geosmin (GSM), and bis (2-chloroisopropyl) ether (BCIE) have major contribution to the musty/earthy and chemical/septic odors in the source water, respectively. Pre-ozonation alone (1 mg L⁻¹) showed limited removal for 2-MIB and BCIE, at less than 30% and 20%, respectively, while combining with coagulation, sedimentation, and sand filtration, the removals were improved to higher than 50%. After post-ozonation, the desired removal was achieved at a 1.5 mg L⁻¹ dosage with all the odorants decreased below the corresponding odor threshold concentrations (OTCs) in the effluents. Furthermore, at a 1 mg L⁻¹ post-ozone addition, by combining with subsequent GAC process, the odor problem was solved as well.

Conclusion

To resolve the odor problem in the drinking water, the concentrations of the odorants at less than their OTCs need to be achieved. As 2-MIB and BCIE have low reactivity towards direct ozonation, a subsequent GAC is needed with a moderate dosage of post-ozonation (1 mg L⁻¹). Thus, for the odor problem in the source water, the suggested operation is: 1 mg L⁻¹ of pre-ozonation in combination with coagulation, sedimentation, and sand filtration, followed by a 1 mg L⁻¹ dosage of post-ozonation and finished by a GAC process.

中文翻译：

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基于臭氧化/ GAC深度处理的复杂气味控制：在一家大型水处理厂中的优化和应用

背景

饮用水中的味道和气味问题是消费者和供水的主要问题之一。探索饮用水源中的气味特征和主要的引起气味的化合物，是饮用水处理厂（WTP）进行气味控制的基础。在这项研究中，针对以黄浦江为水源的新建水库，首先确定了典型气味的发生及其变化。相应地，研究了臭氧/ GAC深度处理过程中的去除行为。

结果

结果表明，2-甲基异冰片酚（2-MIB），土臭味素（GSM）和双（2-氯异丙基）醚（BCIE）分别对源水中的霉味/土味和化学/腐臭味有重要贡献。单独的预臭氧化处理（1 mg L ^-1）显示2-MIB和BCIE的去除率有限，分别低于30％和20％，同时结合凝结，沉淀和砂滤，去除率提高到高于50％。后臭氧处理后，以1.5 mg L ^-1的剂量实现了所需的去除效果，所有臭味剂均降低到流出物中相应的臭味阈值浓度（OTC）以下。此外，在臭氧后添加1mg L ^-1时，通过与随后的GAC工艺相结合，也解决了气味问题。

结论

为了解决饮用水中的异味问题，需要使异味剂的浓度低于其OTC的浓度。由于2-MIB和BCIE对直接臭氧化反应的反应性较低，因此需要随后的GAC，且需要适量的臭氧化后剂量（1 mg L ^-1）。因此，对于原水中的气味问题，建议的操作是：进行臭氧化前的1 mg L ^-1结合凝结，沉淀和砂滤，然后进行臭氧处理后的1 mg L ^-1剂量，并进行由GAC流程完成。