- 期刊
- OpenAccess
磷化氫在鐵質雜糧圓筒倉之垂直穿透及分布
Vertical Penetration and Distribution of Phosphine in Corn and Sorghum Stored in Steel Silos
摘要
儲藏玉米或高粱等雜糧之鐵質圓筒倉，直徑10.55 m，高12 m。使用氣體循環裝置之倉庫，從倉外倉頂加裝一10.16 cm (4 in)塑膠管至地面，接一送風機通至倉底通風道，形成一密閉氣體循環系統。兩組外徑4 mm之氣體採樣管各5根，於空倉時，一組裝於中央，另一於內緣。各組採樣管在倉內一端分別開口於0、3、6、9及12 m等深度；另一端通至倉外。施藥後每24 h，採取各層深度之氣體樣品，送入EC80型磷化氫偵測器偵測磷化氫氣體濃度，以瞭解其垂直穿透性及在倉內之分布。燻蒸時，含磷化鋁57%之Detia bag blanket施放於積穀表面。藥劑與空氣中之水分作用，產生磷化氫氣體。施藥後24 h，各試驗倉磷化氫氣體濃度最高。沒有氣體循環之倉庫，磷化氫氣體藉由重力及擴散作用由積穀表面向下穿透。施藥後24 h，在積穀表面之磷化氫濃度最高，以後因氣體擴散、吸附及分解，磷化氫氣體濃度逐漸降低。在穀層中，往下深度增加，磷化氫濃度逐漸降低。在施藥後24-120 h間，每次偵測得各層深度之磷化氫氣體，其最高與最低之濃度比為1:0.02-1:0.14，即磷化氫之最低濃度僅為最高之2-14%。氣體循環之倉庫，磷化氫氣體由倉頂吸出，由通風管送至倉底，再經積穀上行。施藥後24-120 h，每次測得各層磷化氫氣體，其最高與最低之濃度比為1:0.81-1:0.98，即磷化氫之最低濃度為最高之81-98%。在氣體循環裝置之倉庫，不論對預置於積穀表面之玉米象(Sitophilus zeamais Motschulsky)或擬穀盜(Tribolium castaneum (Herbst))，或積穀表面穀樣中害蟲，經燻蒸後，防治效果均達100%。
並列摘要
Silos of 10.55 m in diameter and 12 m in height were made of corrugated circular steel for corn or sorghum storage.Some were equipped with circulatory systems consisting of a plastic pipe 10.16 cm (4 in)in diameter from the top to the bottom.Before loading,two sets of gas sampling lines,4 mm in diameter,containing five lines each,were installed in the center and on the circumference of the silo.The openings in each set were at depths of 0,3, 6,9 and 12 m.The gas samples were measured using an EC80 phosphine monitor every 24 h after fumigant application.Phosphine was generated by Detia bag blankets containing 57.6% aluminum phosphate placed on the surface of the grain mass.Generally,the highest concentration of phosphine was obtained 24 h after application in each silo.In silos without a circulatory system,phosphine penetrated down to the bottom through interstitial spaces in the corn or sorghum column.The concentration at the surface,where application was made, was the highest at 24 h.The concentration dropped thereafter due to diffusion,adsorption and decomposition.The deeper into the column,the lower the phosphine concentration was. In each measurement during 24-120 h after fumigant application,the ratios of the highest to lowest phosphine concentration,was between 1:0.02 and 1:0.14,i.e.,the lowest phosphine concentration was only 2-14%of the highest.In silos with a circulatory system,phosphine was sucked into an aeration pipe from the top and sent to the bottom of the silo,then moved upwards through the grain mass.During 24-120 h after fumigant application,the ratios of the highest to lowest phosphine concentration was within 1:0.81 and 1:0.98,i.e.,the lowest concentration was 81-98%of the highest.In the circulatory silo,mortality rates for test insects placed on the surface of grain or insects obtained from grain samples showed 100% control.