臺灣博碩士論文加值系統

全滅草( CNP )係非荷爾蒙型接觸性土壤處理之水田除草劑,其化學結構較
護谷( Nitrofen )多一個 Cl 基之化合物,護谷因可能導至畸型而於民國
72 年在臺灣地區全面禁用,其在環境中的殘存行徑,包括其在土壤中吸附
及移動等之資料及其生物試驗的結果已被多位學者作廣泛性的研究,但全
滅草在環境中行徑的探討方面則甚為缺乏. 1989 年 S.Hatakeyama 等人
曾就日本國內幾種常用之除草劑(CNP, Oxadizon,Butachlor,
Benthiocarb,Symetryne),作對淡水蝦類急性毒性的試驗,發現其中則以全
滅草( CNP )的毒性最大,因此其在環境中的殘存實有瞭解之必要,1991
年 S.Hatakeyama 等人則針對全滅草在水中對浮游生物生殖作用的影響設
計實驗研究,發現其與護谷一樣確實有顯著的阻礙生物的生殖作用.本篇旨
在研究全滅草在環境中的消失與移動,包括其在溫度,濕度及殺菌與否控制
的不同土壤中的行為,和在不同溫度,濕度,pH值及殺菌與否的條件下,全滅
草在水中的消失行為.更為瞭解全滅草在土壤中的吸附,本篇設計了不同溫
度下的等溫批次試驗,並作不同土壤的土壤管柱以觀察其在土壤中的移動,
及以地下水污染潛能之數學模式( GWP ),評估在本省之土壤與雨量條件
下,全滅草對地下水污染之影響.依本篇試驗的結果認為:影響全滅草在土
壤中的消失行為最大的因子為土壤中有機質的含量,土壤濕度及土壤溫度.
在有機質含量高的有機質土中,全滅草的消失最快,在土壤濕度為田間容水
量的 90% 時,其分解速率亦最快,而在溫度較高的土壤中,其分解亦快.影
響全滅草在水中的消失行為則以水樣的 pH 質影響最為顯著,在 pH 7.0
的水中,其分解最慢,而在偏酸或偏鹼的環境中,都有促進其分解的效果.一
般說來,全滅草的分解作用並包含了理化性的水解,及生物性的分解作用.
關於全滅草在水－土壤中的吸附試驗的結果,可得知土壤中若含高量的有
機質則其吸附量亦大.而其吸附的行為亦頗符合 Fleundlich eq.其等溫吸
附曲線的形狀為 C 型,即全滅草在水與土壤間的吸附有固定的分配比例;
最後在全滅草於土壤管柱中的移動實驗部分,其結果我們可以認為其在土
壤中的移動性很小,皆分佈在表層以下 5 公分內,再以 GWP模式評估的結
果來看,其污染地下水的可能性很小,但由於其大都聚積在土壤的表層,在
雨量大的地區,則可能由於逕流水而污染到灌溉水.

The chemical structure of chlornitrofen ( 4-nitrophenyl
2,4,6-trichlorophenyl ether ) is similar to nitrofen,which had
been banned in Taiwan since 1983.Nitrofen had been studied on
the residues and distribution in the environment,but the
research on the chlornitrofen in the field was poor.In this
study,four experiments were performmed to access the influence
on the environment.(1.)the dissipation in soils,(2.)dissipation
in aquatic environment,(3.)sorption on soils,(4.)movement in
the soil columns.And then used the model of GWP ( Groundwater
pollution potential model )to evaluate whether chlornitrofen
polluted the environment or not. The most important factor to
influence the dissipation of chlornitrofen in the soils and
water are soil temperature and soil moisture content.On the
conditions of 35 ℃ and the moisture is 90 % field capacity,the
rate of dissipation is faster then the others;As to the
dissipation of chlornitrofen in the aquatic environment,it
indicates,by the experiment,when the pH at 7.0,it was the most
slow-witted,and it got faster at pH 6.5 & 8.5 respectively.And,
by the way,we know that the degradation of chlornitrofen in the
soils and water included the biological effect and hydrolysis.
The residal data from experiments also showed that the dissi-
pation of chlornitrofen in the soils and water follows the
first order kinetics. Experiments on sorption on the soils
showed the results agreed to Freundlich equation and the
sorption isotherm curve is C-type,it indicates that the
equilibrium isotherm for the sorption of chlornitrofen on soils
are linear and compatible with partition theory. After leached
in the soil columns for 60 days treated with chlornitrofen,most
of pesticides were retained in the upper 5 cm of soil layers in
the columns.After using the model of GWP to evluate the
possibility to pollute groundwater,we know that it should spend
a long time to get there and the residual mass percentage is
negligible.