镍/铁二元金属催化降解水体中的莠去津和对氯苯酚

在一定反应条件下,考察了Ni/Fe二元金属对不同取代基上Cl原子的脱除特性。实验以莠去津和对氯苯酚(p-CP)为研究对象,在水溶液中进行了脱氯降解。结果表明,与金属Fe0相比,Ni/Fe对莠去津和p-CP均有明显的催化脱氯降解效果。单位比表面Ni/Fe对p-CP和莠去津的表观反应速率常数分别为:kSA=7.61×10-4(min-1.m-2)和k′SA=5.64×10-3(min-1.m-2),说明Ni/Fe对三氮苯环上Cl原子有更强的脱除特性。不同反应pH对Ni/Fe降解p-CP的影响比莠去津小,反应60 min,p-CP在pH=2.0、3.0、4.0和未调节pH条件下的脱氯效率分别为43%、44%、35%和28%;120 min分别为69%、62%、57%、48%。而莠去津在pH=4.0和未调节pH条件下几乎没有还原,主要是受氯化物本身性质的影响。另外,通过反应体系的电化学测试表明,在Ni/Fe催化还原莠去津和p-CP的过程中,反应中主要的还原剂是Fe0溶解产生并吸附在催化剂表面的H2。     

550g/L硝磺·莠去津悬浮剂防除玉米田杂草药效试验

采用田间小区试验考察安徽省化工研究院研制的550 g/L硝磺·莠去津悬浮剂对玉米田一年生杂草的防除效果及对玉米的安全性。结果表明:550 g/L硝磺·莠去津悬浮剂在制剂用量为1200~3600 mL/hm2时,对玉米田马唐、稗草、反枝苋及铁苋菜均具有良好的防效,且对玉米安全。药后30 d,总杂草株防效为89.4%~92.6%,鲜重防效为92.9%~97.5%。     

甘蔗除草剂的更新

由于阿特拉津的除草效果正在逐年下降，因此必须更新甘蔗的除草剂。     

Atrazine Causes Autophagy- and Apoptosis-Related Neurodegenerative Effects in Dopaminergic Neurons in the Rat Nigrostriatal Dopaminergic System

Atrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR) is widely used as a broad-spectrum herbicide. Animal studies have demonstrated that ATR exposure can cause cell death in dopaminergic neurons. The molecular mechanisms underlying ATR-induced neuronal cell death, however, are unknown. In this study, we investigated the autophagy and apoptosis induced by ATR in dopaminergic neurons in vivo. Wistar rats were administered with ATR at doses of 10, 50 and 100 mg/kg body weight by oral gavage for three months. In terms of histopathology, the expression of autophagy- and apoptosis-related genes as well as proteins related to the Beclin-1/B-cell lymphoma 2 (Bcl-2) autophagy and apoptosis pathways were examined in the rat nigrostriatal dopaminergic system. We observed degenerative micromorphology indicative of neuronal apoptosis and mitochondrial autophagy by electron microscopy in ATR-exposed rat striatum. The rat ventral mesencephalon in the ATR-exposed groups also showed increased expression of Beclin-1, LC3-II, Bax and Caspase-9, and decreased expression of tyrosine hydroxylase (TH), Bcl-xl and Bcl-2. These findings indicate that ATR may induce autophagy- and apoptosis-related changes in doparminergic neurons. Furthermore, this induction may be regulated by the Beclin-1 and Bcl-2 autophagy and apoptosis pathways, and this may help to better understand the mechanism underlying the neurotoxicity of ATR.     

饮用水中持久性有机污染物的去除效能

长江南京段的水质虽能常年保持在Ⅱ~Ⅲ类,但原水中甲苯、三氯苯和邻二苯甲酸二丁酯等微量持久性有机物检出表明长江南京段的水源水已呈现微污染特征。该文以长江南京段原水作为研究对象,以提高出水水质为目标,研究了水源水持久性有机物的种类和特定有机污染物(阿特拉津和氯苯类化合物),考察强化滤池、活性炭滤池工艺去除水中污染物的效能。结果表明长江南京段水源水中检出持久性有机物为65种,其中以脂肪烃类有机物、芳香类有机物、酯类有机物、醇类有机物及酮类有机物为主,5类有机物的总量约占总的持久性有机物的90%以上;长江南京段水源水中未检出阿特拉津,检出1,2,4-三氯苯,其含量为0.249μg/L。强化过滤和活性炭过滤工艺对原水中的持久性有机物都有较好的去除效果,其中活性炭工艺要优于强化过滤工艺。     

阿特拉津高效降解菌株的筛选和降解特性研究

用富集培养法从城市污水处理厂的污泥中分离得到一株能够降解除草剂阿特拉津的降解菌株,命名为L-1。接种于500mg.L-1的阿特拉津无机盐培养基,96h对阿特拉津的降解率达到94.8%,降解效果理想,对其进行菌种的初步鉴定并对其降解特性进行研究。结果表明,该菌株被鉴定为节杆菌(Arthrobacter sp.)。通过室内降解效果优化试验,确定菌株L-1对阿特拉津最佳降解条件:温度为30℃,初始pH值范围为7~8。     

引入Cu2+的沉积物吸附阿特拉津多元回归模型

为揭示重金属存在条件下沉积物(生物膜)吸附阿特拉津( atrazine,AT)的复合污染规律,通过编程研究筛选优化沉积物吸附AT多元回归吸附模型(atrazine-multiple regression adsorption model,ATMRAM),以定性变量的方式将共存的Cu2(外因)引入模型中,建立包含Cu2+影响的沉积物吸附ATCu2+-MRAM.经分析发现,Cu2的存在会抑制AT在沉积物上的吸附,且Cu2+质量浓度越大其抑制作用越强,Cu2+质量浓度为75 mg/L时的抑制程度比15 mg/L时的抑制程度提高1倍以上;Cu2+对沉积物组分(铁氧化物和有机质)的吸附能力产生一定影响,会使各组分的吸附能力减弱8.75％～19.40％.     

电催化氧化降解内分泌干扰物阿特拉津

为探索一种降解阿特拉津的新型有效方法,以Sb掺杂钛基SnO2电极为阳极,不锈钢板为阴极,采用电催化氧化技术对阿特拉津废水进行降解,研究不同影响因素对阿特拉津降解效果的影响,并分析阿特拉津的降解途径.结果表明:当电流密度为200 A/m2、阿特拉津初始质量浓度为10 mg/L、溶液pH值为6.97、反应30 min后,阿特拉津去除率达100%,此时能耗仅为6.67×10-2kWh/g.阿特拉津的电催化氧化降解过程主要为脱烷基、脱氯-羟基化、烷基氧化等反应,伴随着阿特拉津的降解,生成OHA、DAA、ANE等一系列中间产物.电催化氧化方法可经济、有效地去除水中阿特拉津.     

我国东北地区玉米田除草剂使用现状、问题及若干新品种

简要论述了目前我国东北地区玉米田除草剂品种使用现状、存在问题及若干新品种.     

Declines in Reproductive Condition of Male Largemouth Bass (Micropterus salmoides) Following Seasonal Exposure to Estrogenic Endocrine-Disrupting Compounds

Reproductive abnormalities, that could lead to possible effects at the population level, have been observed in wild fish throughout the United States, with high prevalence in largemouth bass (LMB; Micropterus salmoides) and smallmouth bass (Micropterus dolomieu). Estrone (E1) and atrazine (ATR) are common environmental contaminants often associated with agricultural land use. 17alpha-ethinylestradiol (EE2) is a contaminant associated with wastewater treatment effluent, and a representative, well-studied estrogen commonly used for fish toxicity testing. Our objective was to assess whether early gonad recrudescence in adult fish was a period of sensitivity for alterations in reproductive condition and function. Adult male LMB were exposed from post-spawning to early gonad recrudescence to either a mixture of E1 (47.9 ng/L) + ATR (5.4 µg/L), or EE2 (2.4 ng/L) in outdoor experimental ponds. Gonad samples were collected from fish just prior to the start of exposure (July), at the end of the exposure period (December), the following spring just prior to spawning (April), and post spawning (May). Gonadosomatic index (GSI) was significantly reduced in E1 + ATR-exposed and EE2-exposed males compared to control at every post-exposure time point. Reduced sperm count and sperm motility were observed in the mixture treatment (E1 + ATR) compared to the control. Sperm motility was also reduced in the EE2 treatment. These data together indicate that estrogenic endocrine-disrupting compounds can lessen the reproductive condition of adult male LMB, and that effects of exposure during early gonad recrudescence can persist at least through the subsequent spawning cycle.