利用過硫酸鹽氧化地下水中有機污染物

CNU IR > College of Sustainable Environment and Recreation > Dept. of Environmental Engineering and Science (including master's program) > Dissertations and Theses > Item 310902800/9715

Please use this identifier to cite or link to this item: https://ir.cnu.edu.tw/handle/310902800/9715

Title:	利用過硫酸鹽氧化地下水中有機污染物 OXIDATION OF ORGANIC CONTAMINANTS WITH PERSULFATE IN GROUND WATER
Authors:	莊忠霖 Chung-Lin Chuang
Contributors:	Jin Anotai 盧明俊嘉南藥理科技大學：環境工程與科學系所
Keywords:	硫酸根自由基水合作用現地化學氧化再結晶作用 sulfate radicals recrystalized hydration In Situ Chemical Oxidation
Date:	2008
Issue Date:	2008-12-29 15:21:58 (UTC+8)
Abstract:	土壤與地下水中注入氧化劑或是污染物造成表面傳輸現象，而讓污染物轉變為低毒性之副產物，統稱為現地化學氧化法。利用過硫酸根與亞鐵離子、氧化鐵附膜石英砂與能量提供，產生強而有力的硫酸根自由基 (E0 = 2.6V)，達到破壞苯胺與三氯乙烯的結構，近而降低污染物的濃度。在降解苯胺實驗中，當將溶液溫度上升時，硫酸根自由基對於苯胺的去除效果增加，在溶液溫度為60℃的時候，3 小時反應後去除效果可以上升到90%。當過硫酸根與苯胺的莫耳比為20倍時，在30℃條件下降解苯胺的效果最佳，可達到45%的去除率。加入亞鐵離子作為催化劑的實驗中，發現亞鐵離子與過硫酸根的莫耳比為1.25時，降解苯胺的效果最佳。在降解三氯乙烯的實驗中發現到，加入氧化鐵附膜石英砂作為催化劑。經實驗結果推論，過硫酸根離子受到氧化鐵覆膜石英砂表面催化的效果，而形成硫酸根自由基，進而破壞三氯乙烯的結構。然而在反應中，有些微的亞鐵離子還原性溶出與三價鐵離子的再結晶作用。依據管柱實驗的結果，三氯乙烯氧化後，會釋放出氯離子，然而氯離子會干擾硫酸根自由基攻擊目標污染物。氧化鐵附膜石英砂的水合效果愈好，反應速率會加快。 In Situ Chemical Oxidation (ISCO) involves the injection or application of an oxidant into the subsurface to transform organic contaminants into less toxic byproducts. An accelerated reaction using persulfate (S2O82-) to destroy trichloroethylene (TCE) and aniline can be achieved via chemical activation with ferrous ions and energy to generate sulfate radicals (SO4-.) (E0 = 2.6V). The test result showed that the addition of ferrous accelerates the degeneration of aniline by persulfate. For the thermally activated persulfate oxidation experiment, the optimum persulfate/aniline concentration at 30℃ was at 5.4mM or 20/1. This ratio had given the highest aniline removal which is 45%. For the ferrous ion activated persulfate oxidation experiment, there is marginal difference in the result for the 30 min. experiment for the various ferrous/oxidant molar ratio. Thus, another series of experiment was conducted to determine the optimum ratio. A ferrous/persulfate molar ratio of 1.25 was observed to give the best degeneration efficiency. For the iron oxide-coated sand catalysis, 1g, 0.5g and 0.25g of iron oxide-coated sands were added to conduct the oxidation experiment at 25℃. Addition of iron oxide-coated sand accelerated the degradation of TCE by persulfate; the removal was 25%, 15% and 10%, respectively. During the reaction, ferrous ions were dissolved from the iron oxide surface in the range of 0.08~0.25 mg/l. Under this concentration range, the catalytic ability can be ignored according to the observation from the control experiment. Therefore, the major catalytic reaction came from the iron oxide-coated sand surface. However, the dissolved ferrous ions were recrystalized on the iron oxide surface. For the result of column study, the chloride ions affect persulfate oxidation. The reaction rate of degradation of TCE was increased when hydration was increased between TCE and iron oxide-coated sand.
Relation:	校內一年後公開，校外永不公開
Appears in Collections:	[Dept. of Environmental Engineering and Science (including master's program)] Dissertations and Theses

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	1467	View/Open

Loading...