過硫酸鈉在常溫條件下反應(yīng)速率低,對有機(jī)污染物的降解效果不顯著。然而,在熱、過渡金屬離子(Fe2+、Fe3+等)、OH-等條件的激發(fā)下,會(huì)活化分解為·SO4-(E0=2.6V),反應(yīng)速率大幅度提升。既然過硫酸鈉在多種條件下均可被,那么,過硫酸鈉在不同條件下被的機(jī)理特征及作用效果又如何呢?下面
順酐廠家為您分析:
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)熱
(1) Thermal activation
升溫30°以上,過硫酸鈉被產(chǎn)生硫酸根自由基:體系溫度大于50℃,反應(yīng)1周左右,過硫酸鈉對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)金屬離子
(2) Metal ion activation
過硫酸鈉被Fe(II)或Fe(III)發(fā)生系列反應(yīng):Fe(II)過硫酸鈉效率高、反應(yīng)劇烈、現(xiàn)象明顯,體系升溫明顯,反應(yīng)1周左右,過硫酸鈉對TPH降解率大于90%,對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)過氧化氫
(3) Hydrogen peroxide activation
過硫酸鈉被過氧化氫或過碳酸鈉產(chǎn)生硫酸根自由基:該反應(yīng)體系為雙氧化系統(tǒng)(由一種氧化劑另一種氧化劑),反應(yīng)劇烈,升溫明顯,反應(yīng)1周左右,過硫酸鈉對TPH降解效率大于90%,對PAHs也有良好的降解效果,對有機(jī)氯農(nóng)藥類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)堿
(4) Alkali activation
控制體系pH>11時(shí),過硫酸鈉被堿產(chǎn)生羥基自由基:堿反應(yīng)體系對pH要求較高,隨pH升高反應(yīng)速率有升高趨勢,pH升13~14時(shí),反應(yīng)速率升高幅度漸緩。但采用這種方式后期需要投加酸性物質(zhì)中和強(qiáng)堿性,對土壤體系理化性質(zhì)影響較大。
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.
相對了解機(jī)理來說,大家更關(guān)注不同方式過硫酸鈉的性能以及對有機(jī)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.
分別將熱、Fe(II)、過氧化氫、堿4種方式的過硫酸鈉作用于總石油烴(TPH)、多環(huán)芳烴(PAHs)、有機(jī)氯農(nóng)藥3種典型有機(jī)污染土壤中進(jìn)行實(shí)驗(yàn),得出以下結(jié)論:
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:
熱、Fe(II)、過氧化氫、堿4種方式對土壤中TPH的降解效果良好,降解效率均可達(dá)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%.
熱、堿2種方式對土壤中多環(huán)芳烴、有機(jī)氯農(nóng)藥的降解能力相對Fe(II)、過氧化氫2種方式較弱。
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.
過氧化氫過硫酸鹽雖然效率高、污染物降解效果好,但對過氧化氫的消耗量較大,過氧化氫的少量多次添加有利于維持氧化能力的同時(shí)節(jié)約氧化劑。
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.
說了這么多,對于過硫酸鈉來說,究竟選擇哪種方式呢?在工程應(yīng)用中,影響過硫酸鈉方式選擇的因素很多,比如污染物類型、水文地質(zhì)條件、污染狀況、修復(fù)方式、修復(fù)目標(biāo)、資金投入等都會(huì)影響方式的選擇。所以,在修復(fù)工程中,根據(jù)實(shí)際情況合理選擇才是過硫酸鈉方式選擇的正確打開方式呢。更多的相關(guān)內(nèi)容就來我們網(wǎng)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.m9660.cn Consult!