Research On Environmental Friendly Technology Of Generating Fumigant And Recycling Fumigating Residue

Fumigating is the most effective method to kill pests in grain depots. Phosphineis not only the safest fumigant under use, but also the only allowable fumigant inmost countries. But because of using just a fumigant in a long time and working outof line, the fumigant do little effect to pests in recent years. At the same thefumigating residue with large amount of phosphor is difficult to deal with andendangers people so it must be embedded under earth. It not only pollutes the earthand water, but also wastes lots of aluminas. According to the peculiarity of fumigating in grain depots and depending on theacquired technology of generating fumigating effectively, this experiment tried to findout the best reaction condition about the hydrolyzing reaction of aluminum phosphide.The research proved churned up by CO2 not only had a better churn-effect, but alsomade the reaction solution being acidic then accelerated the reaction; holding thereaction temperature between 40℃ and 55℃ made the reaction going on drasticallyand prevented vapor which was carried by phosphine into grain depots. Proved by applying test in the grain depot, this improved technology owed thecharacteristics as quickness, stabilization, security, low energy consumption andkilled pests effectively. Get rid of the poison in fumigating residue without generating othercontamination. And the common dried method was more suited the requests ofdisposing the residue, at the same time using this method also could get aluminassamples with good capability. Character the samples by such analysis methods as XRD, TEM, BET, EPMA,XPS and TPD and find that: Firing the nano-aluminas samples at 500℃, obtainγ-Al2O3 with high surface area and pore volume, respectively as 267.66m2.g-1 and0.61cm3.g-1; fired at 1000℃, γ-Al2O3's surface area and pore volume were stillremained as 161.87m2.g-1 and 0.58cm3.g-1. Thus, this experiment could obtainγ-Al2O3 with high thermal stability. P entered the crystal lattice of the samples and took up the cavities of 2tetrahedron in spinel aluminas. Then it was extruded out of the crystal lattice after thesamples were fired at high temperature, thus delayed the phase transition from spinelaluminas to the corundum phase leading to the increasing thermal stability of samples,but it did little effect to the samples' surface acidity.