甲胺磷在水-气界面挥发动力学研究

研究了挥发时间、温度和气流量对农药甲胺磷在水-气界面挥发行为的影响.挥发量采用气相色谱法检测,利用保留值定性,以外标法定量.研究结果表明,温度升高、气流量增大,使甲胺磷挥发量增大较快,二者是影响甲胺磷挥发的主要因素;挥发时间在4 h之内对甲胺磷挥发量影响较大,4 h之后基本无影响.通过试验还研究了甲胺磷在水-气界面的挥发动力学.根据实验结果,建立了甲胺磷在水-气界面挥发的动力学模型,比较实验值与动力学模型计算值,二者基本吻合,相对误差≤5%,这表明该动力学模型可以用于预测甲胺磷在水-气界面的挥发行为.     

Disappearance of dimethoate,methamidophos and pirimicarb in lettuce

Abstract

Foliar sprays of dimethoate at 150 or 300 g a.i./ha, methamidophos at 450 or 900 g a.i./ha and pirimicarb at 140 or 280 g a.i./ha were applied for control of the green peach aphid, Myzus pericae (Sulzer), and the lettuce aphid, Nasonovia ribisnigri (Mosley), about 2 weeks before the lettuce started heading, and again about 1 week from harvest. In lettuce, dimethoate partially oxidized to its oxon and pirimicarb converted to its methylamino‐ and/or formyl methylamino‐analogues. Most residues were present in the outer leaves which were exposed directly to the sprays; only traces of residues were detected in samples of the inner head leaves. Total residues disappeared rapidly. Pirimicarb was the least persistent and only traces of residues (<0.01 ppm) were detected in marketable heads. Concentrations of dimethoate, including the oxon and of methamidophos were well below their respective tolerances of 2 and 1 ppra respectively.     

纳米TiO2光催化降解有机磷农药的研究

通过实验,探讨了用纳米TiO2光催化处理有机磷农药模拟废水和实际应用的有机磷农药的可行性.实验表明,以测定不同时间PO43-的浓度来衡量有机磷的降解率,并以此来衡量有机磷农药及其中间产物降解的程度是合理的.光催化降解甲胺磷和水胺硫磷的结果,显示了有机磷农药的降解率与其结构有关.实际应用的有机磷农药也可用光催化降解.     

甲胺磷农药废水生化处理高效菌选育的研究

从用甲胺磷农药废水长期驯化的活污泥中，筛选得到两株降解甲胺磷农药废水中有机磷的高效菌，经鉴定一株为蜡样芽孢杆菌（Ｂａｃｉｌｌｕｓｃｅｒｅｕｓ）。另一株为嗜中温假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｍｅｓｏｐｈｉｌｉｃａ）。确定了上述高效菌的最适生长条件和降解有机磷的能力，混合高效菌的有机磷去除率达９９．７％。     

乙草胺、铜污染共存对土壤甲胺磷蚯蚓降解过程的影响研究

为揭示利用蚯蚓活动强化甲胺磷降解的可行性,采用了微宇宙培养方法,通过有蚯蚓和无蚯蚓的对比实验,考察了乙草胺和铜分别与甲胺磷共存条件下污染黑土中甲胺磷降解过程的动态变化.结果表明,无论是否加入蚯蚓,甲胺磷单一污染的土壤中甲胺磷的降解符合一级反应动力学规律;蚯蚓活动能促进甲胺磷降解过程的进行.土壤中乙草胺或铜与甲胺磷共存时,均明显地干扰了甲胺磷降解过程随时间的动态变化;根据化学结构分析,推测两者对甲胺磷降解规律的影响机制可能类似.铜与甲胺磷复合污染的土壤中甲胺磷含量明显高于乙草胺与甲胺磷复合组,说明铜较乙草胺对土壤甲胺磷降解过程的延缓作用更强.     

甲胺磷和乙草胺对产甲烷菌种群数量及其活性的影响

采用厌氧培养箱、气相色谱技术和MPN计数法,研究了甲胺磷和乙草胺在4种浓度(0 1、0 2、0 5和1 0mg·L-1)下对水稻田土壤产甲烷菌种群数量及其活性的影响。加甲胺磷后7d内刺激产甲烷菌种群的生长,数量增加0.2～44.1倍,每管的产甲烷量增加0.8～2.1倍,且刺激作用随药剂浓度的增加而增强;加乙草胺后7d内,产甲烷菌的生长受到抑制,数量下降了50%～99%,每管的产甲烷量显著减少,且抑制作用随药剂浓度的增加而增强。随着加药时间的延长,甲胺磷和乙草胺逐渐降解,产甲烷菌数量又恢复至原有水平。     

一种快速检测甲胺磷的方法

由于农药的不合理利用以及对检测速度的要求,本文应用水溶性碳化二亚胺(EDC)法将甲胺磷与BSA连接,合成了免疫抗原,经紫外扫描确定免疫抗原连接成功.用合成的免疫抗原免疫实验用大白兔,制备了甲胺磷的多克隆抗血清,效价达到1:1000000以上.经盲样检验,抗体灵敏性和特异性较好;在检测样品时最低检测极限为0.5 ng/g,达到国际同类检测试剂盒的水平;且可以在1.5 h内检测100多个样品.     

甲胺磷降解真菌的研究

从受甲胺磷长期污染的土壤样品中通过富集培养,亚硝基胍（ＮＴＧ）诱变处理,从中分离筛选到一株降解甲胺磷活性较高的Ｌ４８菌株。该菌株可以利用甲胺磷作为碳源和能源而生长,降解甲胺磷的最适温度为３０℃,最适宜ＰＨ值为７．０,其完整细胞悬液对３０００ｍｇ／Ｌ左右甲胺磷的降解率最高可达８３％。经初步鉴定该菌株为华丽曲霉Ａｓｐｅｒｇｉｌｌｕｓ．ｏｒａｎｔｕｓ。     

Preparation of colloidal gold immunochromatography strip for detection of methamidophos residue

Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide.Even a trace of its residue is harmful to humans and many animals.In this study,the synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed,and the preparation of colloidal gold immunochromatography strip was conducted for detection of Met residue.The size of colloidal gold particles was checked using a transmission electron microscope (TEM).The formation of antibody-coll...     

甲胺磷农药废水处理工艺研究

甲胺磷农药废水包括氯化废水和胺化废水,含有少量三氯硫磷、有机磷中间体、甲醇、氨、甲基氯化物和粗胺化合物。废水处理工艺条件的实验研究表明,在温度１００℃、压力７４．６６ｋＰａ、酸度ｐＨ１左右的条件下废水中的有机磷能有效地被酸解为无机磷化合物。