臭氧/氯消毒中藻类有机物生成消毒副产物的特征

饮用水源地藻华会释放大量藻类有机物(AOM),AOM与氯消毒剂反应生成的消毒副产物(DBPs)会给饮用水用户带来不容忽视的健康风险。为此,探究了臭氧/氯消毒对AOM结构和DBPs生成的影响。结果表明,臭氧氧化能有效去除AOM中芳香蛋白和酚类、叶绿素a、藻蓝蛋白结构物质,但是对腐殖酸类结构的去除效果相对较差。DBPs生成总量随臭氧投加浓度的升高而增加,其中主要是三氯甲烷(TCM);卤代乙腈和卤代酮的生成总量随臭氧投加浓度的变化趋势不明显。延长臭氧接触时间会明显增加1 h氯化中TCM的生成量,氯化24 h时DBPs生成总量与臭氧接触时间无关。在臭氧/氯消毒过程中,AOM的DBPs生成潜能低于天然有机物(NOM)。AOM有利于一溴一氯乙腈的生成,而NOM会生成更多的二氯乙腈。     

Field solar E. coli inactivation in the absence and presence of TiO2: is UV solar dose an appropriate parameter for standardization of water solar disinfection?

Evaluation of solar treatment in the absence and presence of TiO₂ has been made to assess its effectiveness in reducing bacterial load with respect to drinking water standards.Field experiments under direct solar radiation were carried out using a compound parabolic collector (CPC) placed at the Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. Water contaminated with E. coli K12 was exposed to sunlight in different seasons. The obtained results indicate that the presence of TiO₂ accelerates the detrimental action of light. Total photocatalytic disinfection was obtained in both periods of year and no bacterial recovery was observed during 24 h after stopping sunlight exposure. In the absence of TiO₂, total disinfection was not always reached; and bacterial recovery was observed, especially when inactivation was not complete. Bacterial decay was mainly dependent on light intensity. It was also demonstrated that solar UV dose is not a pertinent parameter to standardize solar disinfection. The influence of the following topics on solar water disinfection is also studied in this paper: (a) UV and total solar spectra characteristics (b) volume of phototreated water (c) post-irradiation events.     

活性氧在造纸废水处理中的应用

本文阐述了活性氧的性质、活性氧的生产方法、活性氧在造纸废水处理中的应用，并提出了用活性氧处理造纸废水的流程。     

Comparison of electrochemical method with ozonation, chlorination and monochloramination in drinking water disinfection

Electrochemical process in chloride-free electrolytes was proved to be powerful in disinfection due to the strong oxidants produced in the electrolysis and no formation of disinfection byproducts (DBPs). In this study, disinfection experiments were conducted by electrochemical treatment compared with ordinary and advanced methods (ozonation, chlorination and monochloramination), with Escherichia coli (E. coli) K-12, Staphylococcus aureus (S. aureus) A106, Bacillus subtilis (BST) and an isolated Bacillus as the representative microorganisms. Firstly, factor tests were performed on E. coli to obtain the optimal conditions of the four disinfection procedures. At their respective optimal condition, CT (concentration of disinfectant × contact time) value of a 4-log E. coli inactivation was 33.5, 1440, 1575, 1674 mg min L⁻¹ for electrochemical process, ozonation, chlorination and monochloramination, respectively. It was demonstrated that the disinfection availability was in the following order: electrochemical process > ozonation > chlorination > monochloramination, which could be attributed to the hydroxyl radical generated in the electrolysis, with strong oxidizing ability and non-selectivity compared with the other three disinfectants. Moreover, the disinfection efficacy of the four disinfection procedures was compared for four different bacteria. It was found that the disinfection efficacy was similar for the selected four bacteria in electrochemical process, while in the other three treatments inactivation of the two Bacillus was much slower than E. coli and S. aureus. As a result, the non-selectivity of electrochemical disinfection with BDD anode to different kinds of microorganisms was further proved, which was primarily controlled by the hydroxyl radicals existed in the free state. For each bacterium, the order of disinfection availability of the four processes was consistent. Finally, scanning electron microscopy (SEM) was implemented to observe the cell morphology. It was shown that cell surface damage was more obvious in electrochemical system with strong oxidants compared with that after ozone treatment, while the integrity of cells were not affected in weak oxidizing chlorine and monochloramine.     

Drinking water disinfection by hemin-modified graphite felt and electrogenerated reactive oxygen species

The electrochemical inactivation of microorganisms by a hemin/graphite felt (GF) composite electrode was investigated, and Escherichia coli was treated as the testing species. The composite electrode was constructed by chemically bonding hemin molecules onto an amino-mineralized GF (AGF) surface. Then, the electrode was characterized systematically by electrochemical methods, and the kinetic parameters of the modified electrode were investigated. The hemin molecules on the surface of the composite electrode have high activity for the reduction of O₂. When the composite electrode was applied with negative potentials, the dissolved oxygen was electrochemically reduced to reactive oxygen species (ROS, such as H₂O₂ and OH) at the cathode surface. The ROS can cause biological damage and can eventually result in the death of bacteria. A sterilizing rate up to 99.9% could be obtained after 60 min of inactivation. Thus, this composite electrode could be applied to disinfect drinking water efficiently at a low potential (−0.6 V vs. SCE) without any addition of chloride.     

基于用户需求分析的办公桌面消毒台设计研究

目的 通过对用户需求的定量分析研究,挖掘办公桌面消毒台的潜在功能,为防控常态化背景下消毒类产品的迭代设计提供思路。方法 首先采用人物访谈、行为观察等调研方法获取19个关于办公消毒类产品的用户初始需求项。然后借助FKANO问卷调查及模型计算,对各需求项的属性逐一归类。剔除6个无差异需求后,将4个基本需求、6个期望需求以及3个魅力需求按照层次分析法(AHP)的分层规则,构建出层次分析模型并开展权重计算。最后将排序前八的需求项作为设计要素优先集合,以此产出设计策略并指导设计实践。结论 借助FKANO模型和层次分析法使用户需求分析流程更加客观完善,为办公桌面消毒类产品的功能升级给予了必要的数据支撑,为同类产品的优化改进提供了现实意义和参考价值。     

具身认知视域下的家居消毒产品设计与验证研究

目的 旨在探索具身认知理论在家居消毒产品上应用的可行性与成效,提出具身认知视角下的家居消毒产品设计策略,并通过设计实践及验证探索其合理性。方法 以具身认知设计策略为基础,设计了一款具有手部清洁消毒、个人物品消毒、空间温湿度监测功能的家居消毒产品,并采用1∶1纸模结合Arduino的形式产出可交互原型。为验证其科学性,设置具身设计为实验组,非具身设计为对照组,并进行对照实验。采用SAM情绪自我评定量表与SUS产品可用性量表分别对用户情绪及产品可用性进行测试验证。结果 在家居消毒产品的设计上,采用具身设计-实验组在用户愉悦度及产品可用性上均显著优于非具身设计-对照组。结论 将具身认知引入家居消毒产品的设计中,能有效地提升用户情绪及产品可用性,使用户保持健康。     

饮用水的微电解法灭菌研究

研究采用电化学处理方法代替氯液对饮用水进行灭菌的机理和影响因素,以斯懈用水灭菌途径的新思路。     

High Oxygen and High Carbon Dioxide Modified Atmospheres for Shelf-life Extension of Minimally Processed Carrots

The impact of high O₂+ high CO₂ modified atmospheres (MA), on the preservation of minimally processed carrots was studied. A combination of 50% O₂+ 30% CO₂ prolonged the shelf life of sliced carrots compared to storage in air by 2 to 3 d. When the carrots received a pre-treatment with a 0.1% citric acid dip and a sodium alginate edible coating prior to packaging, shelf life was extended by 5 to 7 d. Advantages and disadvantages of the proposed MA over previously recommended MA (1% O₂+ 10% CO₂), related to a range of physicochemical and microbiological characteristics of carrots are discussed.     

二氧化氯和超声波协同作用对鲜蛋表面消毒效果的研究

研究二氧化氯(ClO2)与超声波协同作用对鲜蛋表面大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的杀灭效果。二氧化氯浓度为0、30、40、50、60mg/L,单独作用及在59kHz 超声波协同作用下分别处理1、5、10min。结果表明：二氧化氯与超声波协同作用与二氧化氯单独作用相比,处理时间10min,对3 个菌种的杀菌量＞ 4.00(lg(CFU/ml)),二氧化氯浓度从60mg/L 降低为50mg/L;协同作条件下二氧化氯浓度50mg/L,对大肠杆菌、金黄色葡萄球菌的杀菌量＞ 4.00(lg(CFU/ml)),处理时间与单独作用相比从10min 缩短为5min。