本文選題：芘污染 + 化學(xué)氧化��； 參考：《上海大學(xué)》2015年碩士論文

【摘要】：原位化學(xué)氧化技術(shù)因其去除效率高、周期短,越來(lái)越成為土壤修復(fù)的熱點(diǎn)。然而,化學(xué)氧化去除污染物的同時(shí),對(duì)土壤本身帶來(lái)的影響仍需考慮。本研究主要考察了兩種化學(xué)氧化方式,過(guò)硫酸鹽氧化和芬頓氧化,對(duì)芘污染的土壤進(jìn)行了氧化去除。在對(duì)這兩種氧化方式進(jìn)行條件優(yōu)化的基礎(chǔ)上,測(cè)定了氧化對(duì)土壤的理化性質(zhì)、土壤酶活性以及芘的存在形式的影響,并進(jìn)而對(duì)氧化后的土壤質(zhì)量進(jìn)行了評(píng)估;在對(duì)芘污染土壤進(jìn)行化學(xué)氧化處理的基礎(chǔ)上,選擇黑麥草作為修復(fù)植物,繼續(xù)修復(fù)氧化處理的土壤,并進(jìn)一步提高了芘的去除率。主要結(jié)果如下:(1)實(shí)驗(yàn)采用焦磷酸鈉(SP)、EDTA、氨三乙酸(NTA)以及草酸鈉(OA)為絡(luò)合劑,絡(luò)合三價(jià)鐵離子并進(jìn)一步催化過(guò)氧化氫來(lái)氧化處理土壤中的芘。在測(cè)定不同的絡(luò)合劑對(duì)絡(luò)合鐵離子催化降解芘的同時(shí),還通過(guò)監(jiān)測(cè)實(shí)驗(yàn)中過(guò)氧化氫的含量考察了絡(luò)合劑對(duì)過(guò)氧化氫分解的影響。SP有減緩過(guò)氧化氫分解的效果,其余螯合劑效果不佳。通過(guò)氧化處理后,對(duì)芘的降解率最高的是OA,其次是EDTA,SP及NTA。芘氧化前有三種形態(tài)(殘?jiān)鼞B(tài),吸附態(tài),可生物利用態(tài)),在氧化后芘主要是以吸附態(tài)和可生物利用態(tài)存在。(2)實(shí)驗(yàn)證明,在過(guò)硫酸鈉劑量為0.0872 g/g土樣時(shí),過(guò)硫酸鹽對(duì)芘的去除效果最好;通過(guò)響應(yīng)曲面優(yōu)化分析發(fā)現(xiàn),溫度、H2O2用量、Fe2+用量之間的交互作用顯著影響過(guò)硫酸鹽氧化的效果,當(dāng)芘污染土樣(500 mg/kg)用量為5 g時(shí),加入0.375 mol/L的Fe2+2.62 ml、30%的H2O2 0.58 ml、溫度為50°C時(shí),芘的降解率可高達(dá)94%。(3)過(guò)硫酸鹽氧化和芬頓氧化影響了土壤的物理化學(xué)性質(zhì)。磷酸酶受芬頓氧化影響較大。脲酶和蔗糖酶受兩種氧化方式的影響較大,其活性分別下降了95%和80%以上。總氮和總有機(jī)質(zhì)在氧化后也有不同程度的降低。速效磷經(jīng)過(guò)過(guò)硫酸鹽氧化后降低較為明顯。大多數(shù)的可生物利用態(tài)被化學(xué)氧化的方式去除;吸附態(tài)的芘較氧化前的上升較為明顯。經(jīng)過(guò)計(jì)算得到的SEI土壤評(píng)價(jià)參數(shù)土壤經(jīng)過(guò)氧化后,其土壤質(zhì)量有所提升。(4)本研究根據(jù)活化條件的需要設(shè)計(jì)了容量為12 kg土的氧化裝置。并用帶有溫控功能的加熱裝置為實(shí)驗(yàn)提供相應(yīng)的溫度要求。經(jīng)過(guò)氧化處理后,土壤多酚氧化酶(PPO)和脫氫酶(DHA)的活性均顯著的下降,而土壤過(guò)氧化氫酶(CAT)的活性明顯增大。通過(guò)60天的黑麥草種植,PPO和DHA的活性均可以恢復(fù)到最初的水平,但是CAT的活性仍維持在較高的水平;芘的濃度降低至130 mg/kg,去除率從50%提高到73%。
[Abstract]:Because of its high removal efficiency and short cycle, in situ chemical oxidation technology has become a hot spot in soil remediation. However, the effect of chemical oxidation on soil itself is still to be considered. In this study, two kinds of chemical oxidation methods, persulfate oxidation and Fenton oxidation, were studied to remove pyrene contaminated soil. On the basis of optimizing the conditions of these two oxidation modes, the effects of oxidation on soil physical and chemical properties, soil enzyme activity and the forms of pyrene were determined, and the soil quality after oxidation was evaluated. On the basis of chemical oxidation treatment of pyrene contaminated soil, ryegrass was selected as the remediation plant to continue to repair the oxidized soil, and the pyrene removal rate was further improved. The main results are as follows: (1) in this experiment, sodium pyrophosphate was used to oxidize pyrene in soil using sodium pyrophosphate (SPP), ammonium triacetate (NTAA) and sodium oxalate (OAA) as the complexing agents. The trivalent iron ions were complexed and hydrogen peroxide was further catalysed to oxidize pyrene in soil. The catalytic degradation of pyrene by complex iron ion was determined by different complexing agents, and the effect of complexing agent on the decomposition of hydrogen peroxide was investigated by monitoring the content of hydrogen peroxide in the experiment. Sp had the effect of slowing down the decomposition of hydrogen peroxide. The other chelating agents are not effective. After oxidation treatment, the highest degradation rate of pyrene was OA, followed by EDTA-SP and NTA. Before pyrene oxidation, there are three forms (residual state, adsorptive state, bioavailable state, pyrene adsorbed state and bioavailable state.) the results show that when the dosage of sodium persulfate is 0.0872 g / g soil sample, the pyrene exists mainly in adsorptive state and bioavailability state. The effect of persulfate on the removal of pyrene was the best, and the interaction between the amount of H _ 2O _ 2 and Fe _ 2 was found to have a significant effect on the oxidation of persulfate. When the amount of pyrene contaminated soil was 500 mg / kg, 5 g / kg of pyrene contaminated soil was found to be affected by the interaction between the amount of H _ 2O _ 2 and Fe _ 2. The degradation rate of pyrene was as high as 94mg / kg when 0.375 mol/L Fe2 (2.62 ml / L) 30% H2O2 (0.58 ml) at 50 擄C) persulfate oxidation and Fenton oxidation affected the physical and chemical properties of the soil. Phosphatase was greatly affected by Fenton oxidation. Urease and sucrase were greatly affected by the two oxidation modes, and their activities decreased by more than 95% and 80%, respectively. Total nitrogen and total organic matter also decreased in varying degrees after oxidation. The available phosphorus decreased obviously after persulfate oxidation. Most of the bioavailable states were removed by chemical oxidation, and the pyrene of adsorbed state increased more obviously than that before oxidation. The soil quality of SEI soil was improved by oxidation. (4) according to the need of activation condition, the oxidation device with capacity of 12kg soil was designed in this study. And the heating device with temperature control function provides the corresponding temperature requirements for the experiment. After oxidation treatment, the activities of PPO and DHA decreased significantly, but the activities of catalase CAT increased significantly. After 60 days of ryegrass cultivation, the activity of PPO and DHA recovered to the initial level, but the activity of CAT remained at a higher level, and the concentration of pyrene decreased to 130 mg / kg, and the removal rate increased from 50% to 73%.
【學(xué)位授予單位】：上海大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：X53;X173

【共引文獻(xiàn)】

相關(guān)期刊論文 前1條

1 李實(shí);張翔宇;潘利祥;;重金屬污染土壤淋洗修復(fù)技術(shù)研究進(jìn)展[J];化工技術(shù)與開(kāi)發(fā);2014年11期

，

本文編號(hào)：1984094