The photo-Fenton process is recognized as a promising technique towards microorganism disinfection in wastewater, but its efficiency is hampered at near-neutral pH operating values. In this work, we overcome these obstacles by using the heterogeneous photo-Fenton process as the default disinfecting technique, targeting MS2 coliphage in wastewater. The use of low concentrations of iron oxides in wastewater without H₂O₂ (wüstite, maghemite, magnetite) has demonstrated limited semiconductor-mediated MS2 inactivation. Changing the operational pH and the size of the oxide particles indicated that the isoelectric point of the iron oxides and the active surface area are crucial in the success of the process, and the possible underlying mechanisms are investigated. Furthermore, the addition of low amounts of Fe-oxides (1 mg L⁻¹) and H₂O₂ in the system (1, 5 and 10 mg L⁻¹) greatly enhanced the inactivation process, leading to heterogeneous photo-Fenton processes on the surface of the magnetically separable oxides used. Additionally, photo-dissolution of iron in the bulk, lead to homogeneous photo-Fenton, further aided by the complexation by the dissolved organic matter in the solution. Finally, we assess the impact of the presence of the bacterial host and the difference caused by the different iron sources (salts, oxides) and the Fe-oxide size (normal, nano-sized).

中文翻译：

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氧化铁介导的半导体光催化与异质光芬顿处理废水中的病毒。氧化物粒径的影响

光芬顿法被认为是一种用于废水中微生物消毒的有前途的技术，但在接近中性的pH操作值时，其效率受到了限制。在这项工作中，我们通过使用非均质的光芬顿法作为默认消毒技术，针对废水中的MS2噬菌体，克服了这些障碍。低浓度氧化铁在无H ₂ O _2的废水中的使用（纤铁矿，磁赤铁矿，磁铁矿）已证明受限于半导体介导的MS2失活。改变操作的pH值和氧化物颗粒的尺寸表明，氧化铁的等电点和活性表面积对于该方法的成功是至关重要的，并且研​​究了可能的潜在机理。此外，在系统中添加少量的Fe-氧化物（1 mg L ^-1）和H ₂ O ₂（1、5和10 mg L ^-1）极大地增强了灭活过程，导致在所用的磁性可分离氧化物的表面上发生了非均质的光芬顿过程。另外，铁在主体中的光溶解导致均匀的光芬顿，进一步受溶液中溶解的有机物络合的辅助。最后，我们评估细菌宿主的存在的影响以及由不同铁源（盐，氧化物）和铁氧化物尺寸（正常，纳米尺寸）引起的差异。