The increasing demand for wastewater treatment has become a notable trend for addressing global water scarcity. However, composite fouling is a significant challenge for wastewater distribution engineering systems. This study provides an approach using nanobubbles (NBs) to control composite fouling. The antifouling capacities of three types of NBs (oxygen, nitrogen, and helium), six oxygen concentrations, and two application procedures (prevention and removal) are investigated. The results show that NBs effectively mitigate composite fouling—including biofouling, inorganic scaling, and particulate fouling—in comparison with the no-NBs group. More specifically, hydroxyl radicals generated by the self-collapse of NBs oxidize organics and kill microorganisms in wastewater. The negatively charged surfaces of the NBs transform the crystalline form of CaCO₃ from calcite to looser aragonite, which reduces the likelihood of ion precipitation. Furthermore, the NBs gas-liquid interfaces act as gas “bridges” between colloidal particles, enhancing the removal of particles from wastewater. While oxygen NBs have greater anti-fouling capacity than nitrogen and helium NBs, oxygen NBs at low concentrations (∼5%) increase total fouling. Lastly, although the NBs inhibit the growth of fouling, they do not significantly remove the already adhered fouling in no-NBs treated groups. This study anticipates that the application of NBs will address the significant fouling issue for various wastewater distribution engineering systems in order to meet the global challenge of sustainable water supplies.

废水处理需求的不断增长已成为解决全球水资源短缺的显着趋势。然而，复合污垢对废水分配工程系统来说是一个重大挑战。这项研究提供了一种使用纳米气泡（NB）来控制复合污垢的方法。研究了三种类型的NB（氧气、氮气和氦气）、六种氧气浓度和两种应用程序（预防和去除）的防污能力。结果表明，与无 NB 组相比，NB 有效地减轻了复合污垢，包括生物污垢、无机结垢和颗粒污垢。更具体地说，纳米贝斯自崩解产生的羟基自由基会氧化有机物并杀死废水中的微生物。NB 的带负电荷的表面将 CaCO ₃的晶体形式从方解石转变为松散的文石，从而降低了离子沉淀的可能性。此外，纳米贝斯气液界面充当胶体颗粒之间的气体“桥梁”，增强了废水中颗粒的去除。虽然氧气纳米比亚比氮气和氦气纳米比亚具有更强的防污能力，但低浓度（~5%）的氧气纳米比亚会增加总污垢。最后，尽管纳米粒子抑制了污垢的生长，但它们并没有显着去除无纳米粒子处理组中已经粘附的污垢。本研究预计，纳米贝斯的应用将解决各种废水分配工程系统的严重污垢问题，以应对可持续供水的全球挑战。