过硫酸钠在常温条件下反应速率低,对有机污染物的降解效果不显著。然而,在热、过渡金属离子(Fe2+、Fe3+等)、OH-等条件的激发下,会活化分解为·SO4-(E0=2.6V),反应速率大幅度提升。既然过硫酸钠在多种条件下均可被,那么,过硫酸钠在不同条件下被的机理特征及作用效果又如何呢?下面
顺酐厂家为您分析:
Sodium persulfate has a low reaction rate at room temperature and has no significant degradation effect on organic pollutants. However, under the excitation of heat, transition metal ions (Fe2+, Fe3+, etc.), OH -, etc., it will be activated and decomposed into · SO4- (E0=2.6V), greatly increasing the reaction rate. Since sodium persulfate can be activated under various conditions, what are the mechanism characteristics and effects of sodium persulfate activation under different conditions? The manufacturer of maleic anhydride will analyze for you:
(1)热
(1) Thermal activation
升温30°以上,过硫酸钠被产生硫酸根自由基:体系温度大于50℃,反应1周左右,过硫酸钠对TPH的降解效率大于90%。
When the temperature is raised to above 30 ° C, sodium persulfate is activated to produce sulfate radicals: the system temperature is greater than 50 ° C, and the reaction lasts for about one week. The degradation efficiency of sodium persulfate on TPH is greater than 90%.
(2)金属离子
(2) Metal ion activation
过硫酸钠被Fe(II)或Fe(III)发生系列反应:Fe(II)过硫酸钠效率高、反应剧烈、现象明显,体系升温明显,反应1周左右,过硫酸钠对TPH降解率大于90%,对PAHs也有良好的降解效果。
Sodium persulfate is activated by Fe (II) or Fe (III) and undergoes a series of activation reactions: Fe (II) activates sodium persulfate with high efficiency, intense reaction, and obvious phenomenon. The system heats up significantly, and the reaction lasts for about one week. Sodium persulfate has a degradation rate of over 90% for TPH and also has a good degradation effect on PAHs.
(3)过氧化氢
(3) Hydrogen peroxide activation
过硫酸钠被过氧化氢或过碳酸钠产生硫酸根自由基:该反应体系为双氧化系统(由一种氧化剂另一种氧化剂),反应剧烈,升温明显,反应1周左右,过硫酸钠对TPH降解效率大于90%,对PAHs也有良好的降解效果,对有机氯农药类污染物也有一定的降解能力。
Sodium persulfate is activated by hydrogen peroxide or sodium percarbonate to produce sulfate radical: This reaction system is a double oxidation system (activated by one oxidant and another oxidant), with intense reaction and significant temperature rise. After about one week of reaction, sodium persulfate has a degradation efficiency of over 90% for TPH, good degradation effect on PAHs, and certain degradation ability for organochlorine pesticide pollutants.
(4)碱
(4) Alkali activation
控制体系pH>11时,过硫酸钠被碱产生羟基自由基:碱反应体系对pH要求较高,随pH升高反应速率有升高趋势,pH升13~14时,反应速率升高幅度渐缓。但采用这种方式后期需要投加酸性物质中和强碱性,对土壤体系理化性质影响较大。
When the control system pH is greater than 11, sodium persulfate is activated by alkali to produce hydroxyl radical: the alkali activated reaction system has high requirements for pH, and the reaction rate tends to increase with the increase of pH, and when the pH rises to 13~14, the reaction rate increases gradually. However, using this activation method in the later stage requires the addition of acidic substances to neutralize strong alkalinity, which has a significant impact on the physical and chemical properties of the soil system.
相对了解机理来说,大家更关注不同方式过硫酸钠的性能以及对有机污染物的降解能力。
Compared to understanding the mechanism, people are more concerned about the performance of different activation methods to activate sodium persulfate and its ability to degrade organic pollutants.
分别将热、Fe(II)、过氧化氢、碱4种方式的过硫酸钠作用于总石油烃(TPH)、多环芳烃(PAHs)、有机氯农药3种典型有机污染土壤中进行实验,得出以下结论:
The sodium persulfate activated by heat, Fe (II), hydrogen peroxide and alkali was tested in three typical organic polluted soils, namely Total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides, and the following conclusions were drawn:
热、Fe(II)、过氧化氢、碱4种方式对土壤中TPH的降解效果良好,降解效率均可达90%以上。
The four activation methods of heat, Fe (II), hydrogen peroxide, and alkali have good degradation effects on TPH in soil, with degradation efficiency reaching over 90%.
热、碱2种方式对土壤中多环芳烃、有机氯农药的降解能力相对Fe(II)、过氧化氢2种方式较弱。
The degradation of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides in soil by thermal and alkaline activation modes is weaker than that by Fe (II) and hydrogen peroxide activation modes.
过氧化氢过硫酸盐虽然效率高、污染物降解效果好,但对过氧化氢的消耗量较大,过氧化氢的少量多次添加有利于维持氧化能力的同时节约氧化剂。
Although hydrogen peroxide activates persulfate with high efficiency and good pollutant degradation effect, it consumes a large amount of hydrogen peroxide. Adding a small amount of hydrogen peroxide multiple times is beneficial for maintaining oxidation capacity while saving oxidants.
说了这么多,对于过硫酸钠来说,究竟选择哪种方式呢?在工程应用中,影响过硫酸钠方式选择的因素很多,比如污染物类型、水文地质条件、污染状况、修复方式、修复目标、资金投入等都会影响方式的选择。所以,在修复工程中,根据实际情况合理选择才是过硫酸钠方式选择的正确打开方式呢。更多的相关内容就来我们网站
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Having said so much, which activation method should I choose for sodium persulfate? In engineering applications, there are many factors that affect the selection of sodium persulfate activation methods, such as pollutant types, hydrogeological conditions, pollution conditions, remediation methods, remediation targets, and financial investment, which all affect the selection of activation methods. So, in repair engineering, choosing the correct activation method for sodium persulfate based on the actual situation is the correct one. For more related content, come to our website http://www.jnjhhg.cn Consult!