東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

The abiotic transformation of nitroa...

Hakala, Jacqueline Alexandra.

FindBook

Google Book

Amazon

博客來

The abiotic transformation of nitroaromatic pesticides by iron(II) and dissolved organic matter.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
正題名/作者:	The abiotic transformation of nitroaromatic pesticides by iron(II) and dissolved organic matter./
作者:	Hakala, Jacqueline Alexandra.
面頁冊數:	142 p.
附註:	Adviser: Yu-Ping Chin.
Contained By:	Dissertation Abstracts International68-12B.
標題:	Biogeochemistry. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3292722
ISBN:	9780549362944

The abiotic transformation of nitroaromatic pesticides by iron(II) and dissolved organic matter.
Hakala, Jacqueline Alexandra.

The abiotic transformation of nitroaromatic pesticides by iron(II) and dissolved organic matter. - 142 p.

Adviser: Yu-Ping Chin.

Thesis (Ph.D.)--The Ohio State University, 2008.

Nitroaromatic pesticides are hydrophobic contaminants that can accumulate in sediments by the deposition of suspended solids from surface waters. Fe(II) and dissolved organic matter (DOM), present in suboxic and anoxic zones of freshwater sediments, can transform nitroaromatic pesticides in natural systems. In this study, the abiotic chemical transformation of pentachloronitrobenzene, trifluralin and pendimethalin was studied in controlled laboratory systems containing Fe(II) and fulvic acid DOM isolates, and in natural pore waters collected from a freshwater wetland. Geochemical parameters affecting reactivity in the natural wetland were also monitored.

ISBN: 9780549362944Subjects--Topical Terms:

545717
Biogeochemistry.

The abiotic transformation of nitroaromatic pesticides by iron(II) and dissolved organic matter.
LDR:05494nam 2200349 a 45 001 942930
005 20110520
008 110520s2008 ||||||||||||||||| ||eng d
020 $a 9780549362944
035 $a (UMI)AAI3292722
035 $a AAI3292722
040 $a UMI $c UMI
100 1 $a Hakala, Jacqueline Alexandra. $3 1266962
245 1 4 $a The abiotic transformation of nitroaromatic pesticides by iron(II) and dissolved organic matter.
300 $a 142 p.
500 $a Adviser: Yu-Ping Chin.
500 $a Source: Dissertation Abstracts International, Volume: 68-12, Section: B, page: 7874.
502 $a Thesis (Ph.D.)--The Ohio State University, 2008.
520 $a Nitroaromatic pesticides are hydrophobic contaminants that can accumulate in sediments by the deposition of suspended solids from surface waters. Fe(II) and dissolved organic matter (DOM), present in suboxic and anoxic zones of freshwater sediments, can transform nitroaromatic pesticides in natural systems. In this study, the abiotic chemical transformation of pentachloronitrobenzene, trifluralin and pendimethalin was studied in controlled laboratory systems containing Fe(II) and fulvic acid DOM isolates, and in natural pore waters collected from a freshwater wetland. Geochemical parameters affecting reactivity in the natural wetland were also monitored.
520 $a Rapid reduction of pentachloronitrobenzene to pentachloroaniline was observed in controlled systems in the presence of Fe(II) and DOM fulvic acid isolates from surface waters (pseudo-first-order half-life, t1/2 ≈ 30 min to 4 h). DOM in unfiltered systems inhibited iron colloid formation and possibly limited the formation of reactive Fe(II)-iron colloid surface complexes, causing reductive transformation in Fe(II)-DOM media to be slower in some cases relative to Fe(II)-only controls. Conversely, in 0.45-microm-filtered solutions pentachloronitrobenzene reduction in Fe(II)-DOM media was faster than the Fe(II)-only controls, suggesting that DOM enhances the reductive capacity of Fe(II) in the absence of iron colloids.
520 $a Differential pulse polarography (DPP) scans of natural wetland pore waters collected from Old Woman Creek (OWC; located in northern Ohio) revealed that a variety of redox-active metals exist naturally in OWC pore waters. Fe(III)-organic and Fe(II) species increased to a depth of &sim;30 cm from the sediment-water interface, and a maximum for dissolved Mn(II) was observed at &sim;6 cm depth. Dissolved Fe(II) was necessary for rapid pentachloronitrobenzene reduction in natural pore water (< 24 hr), and faster reduction was observed with increased pore water pH. Pentachloronitrobenzene reduction in "pH-adjusted" pore waters (acidified to pH 2.5 after pore water extraction and raised to the native pH (between 6.7 to 7.6) prior to reaction) was similar to that observed in a model system containing Fe(II) and an aquatic fulvic acid isolate. Conversely, pentachloronitrobenzene reduction in fresh, unaltered pore water was slower than that observed in "pH-adjusted" pore water. This indicated that the Fe(II) speciation and reductive capacity differs between unaltered and "pH-adjusted" samples due to a rearrangement of the naturally-occurring Fe complexes with pH-adjustment.
520 $a Trifluralin and pendimethalin reduction occurred in controlled systems containing Fe(II) and DOM surface water isolates, and in natural pore waters collected from OWC. Dissolved Fe(II) was necessary for trifluralin and pendimethalin reduction to occur, and pendimethalin reduction was faster in solutions containing Fe(II) and Suwannee River, Georgia, fulvic acid isolate relative to reactions containing Fe(II) and Pony Lake, Antarctica, fulvic acid isolate. DOM source material did not affect reactivity for trifluralin in similar systems. The reduction rate increased with increased pH for both compounds. Natural pore waters reduced both trifluralin and pendimethalin, and trifluralin degraded to multiple byproducts while pendimethalin only degraded to one major byproduct. Comparison of pseudo-first-order rate constants between controlled systems containing Fe(II) and OWC fulvic acid isolate, and natural sediment pore waters collected from OWC, showed that trifluralin and pendimethalin reduction in controlled systems was an order of magnitude faster relative to natural pore waters.
520 $a This study is the first to investigate nitroaromatic pesticide reduction in the presence of Fe(II) and DOM surface water isolates, and in natural benthic pore waters that contain high concentrations of dissolved Fe(II) and DOM. Although pentachloronitrobenzene, trifluralin and pendimethalin were reduced both in controlled systems and natural pore waters, reduction in unaltered pore waters was roughly an order of magnitude slower than in systems containing Fe(II) and fulvic acid isolates. These data show that controlled systems over-estimate nitroaromatic pesticide reactivity in natural systems, and also suggest that Fe(II) is naturally complexed to Fe(II)-stabilizing ligands in anoxic environments. Future work is necessary to elucidate the speciation of Fe(II) complexes present in natural anoxic environments.
590 $a School code: 0168.
650 4 $a Biogeochemistry. $3 545717
650 4 $a Chemistry, Inorganic. $3 517253
650 4 $a Chemistry, Organic. $3 516206
650 4 $a Geochemistry. $3 539092
690 $a 0425
690 $a 0488
690 $a 0490
690 $a 0996
710 2 $a The Ohio State University. $3 718944
773 0 $t Dissertation Abstracts International $g 68-12B.
790 $a 0168
790 1 0 $a Chin, Yu-Ping, $e advisor
791 $a Ph.D.
792 $a 2008
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3292722