Membrane and absorption processes in water treatment: adaptation to climate change

自1993年密尔瓦基市隐孢子虫病爆发以来，微滤（MF）和超滤（UF）膜基工艺越来越多地用于水处理厂升级和新厂。密西沙加、北湾和圣约翰是目前使用膜技术的城市。预计气候变化会导致地表水的质量发生变化，特别是在夏季，藻类的生长会大大增加，因此水处理厂需要适应这种变化。膜可能会更快地污染，因此溶解空气浮选（DAF）有望成为一种更流行的预处理形式。此外，活性炭（AC）吸附可能会更频繁地用于帮助控制与藻类有关的味道和气味事件。申请人建议采取三项措施来解决这些影响。首先，研究藻胁迫下溶气浮选（DAF）预处理对膜工艺性能的影响。DAF是一项成熟的技术，但DAF与中空纤维膜体系的相互作用研究很少。二是进一步开发具有低污染倾向的新型超滤膜材料。这项计划将包括优化这种膜的制备，检查它的抗氯性，用这种材料开发中空纤维，并在几个挑战水中测试它们。最后，评价了一种新的吸附剂/电化学再生工艺，该工艺在水处理中的应用可能比活性炭更实用。

Since the 1993 cryptosporidiosis outbreak in Milwaukee, WI, which impacted over 400,000 citizens, microfiltration (MF) and ultrafiltration (UF) membrane-based processes have been increasingly used in water treatment plant upgrades and new plants. Mississauga, ON, North Bay, ON and St. John's, NF are examples of cities now using membrane technology. Climate change is expected to produce changes in surface water quality, particularly much greater algal growth during summer months, thus water treatment plants will need to adapt. Membranes will likely foul more rapidly so dissolved air flotation (DAF) is expected to become a more popular form of pre-treatment. Also activated carbon (AC) adsorption will likely be used more frequently to help control algal-related taste and odour incidents. The applicant proposes to pursue three initiatives to address these impacts. First, to study the impact of dissolved air flotation (DAF) pretreatment on the performance of membrane processes under algal stress. DAF is an established technolgy but the interactions of DAF on hollow fibre membrane systems have hardly been studied. Second, to further develop a very promising new ultrafiltration membrane material with low fouling tendencies. This initiative will involve optimizing the preparation of this membrane, checking its chlorine resistance, developing hollow fibres from this material and testing them with several challenge waters. And finally, to evaluate a new adsorbent/electrochemical regeneration process which could potentially be more practical than AC for water treatment applications.