羟基自由基快速去除表面有机磷污染实验研究

Rapid Elimination of Surface Organophosphorous Pollutants Using Hydroxyl Radical

针对近年来不断发生的有机物磷污染事件,通过强电场电离放电方法把H2Ogas和O2电离,制取以·OH为代表的活性自由基溶液,以喷洒的方式对2种模拟有机磷污染物敌敌畏和氧乐果进行表面快速去除研究.结果表明,在pH=6,模拟平面上敌敌畏和氧乐果初始浓度为60μg·cm-2的情况下,当·OH喷洒密度增加到3.9μg·cm-2时,短时间内敌敌畏和氧乐果去除率均可达90%以上,矿化率也分别达到64%和72%.随着pH值的不断增大,有机物的去除率均表现为先略有降低而后迅速增大,在接近中性时最低;其中敌敌畏和氧乐果在pH=12时的去除率要比pH=6时分别高出约21%和26%.四因素三水平正交试验表明以喷洒方式去除表面有机磷污染起主要作用的是·OH.

According to the frequency of contamination accident for organic compounds in recent years,two kinds of organophosphorus pesticides dichlorvos and omethoate,as the simulated organic pollutants,were rapidly eliminated using spraying hydroxyl radical produced by strong electric-field ionization discharge method on an aluminium flat plate about 160 cm2.The high concentration aqueous ·OH solution was produced from H2Ogas and O2 with plasma reaction.In a condition,where pH is 6 and the initial densities of dichlorvos and omethoate on the simulation plane are both 60 μg·cm-2,when the spray density of ·OH reaches 3.9 μg·cm-2,removal efficiencies of dichlorvos and omethoate are 90%,and mineralization rates are 64% and 72%,respectively.The effect of pH for removal efficiency was also investigated.The results found that the removal efficiency of organophosphorus pollutants first decreased slowly and then increased fast with the increase of pH from 2 to 12 and the lowest removal rate appeared when pH close to neutral.The degradation rates of dichlorvos and omethoate both ascend by 21% and 26% respectively with pH 12 than that of pH 6.Four factors and three levels orthogonal test indicated that the degradation by ·OH played a major role at the surface oxidation removal rapid of organophosphorus pollutants in a short period of time.