Synthesis and pesticidal activity of new N-alkyl-N-[1-(2-hydroxyphenyl) ethyl]amines

A series of novel N-alkyl-N-[1-(2-hydroxyphenyl) ethyl]amines were synthesized as potential new agents to control pests. Their structures were confirmed on the basis of IR, NMR and elemental analyses. Six new N-alkyl-N-[1-(2-hydroxyphenyl) ethyl]amines were prepared by reduction of corresponding Schiff bases using sodium borohydride in 80–87 % yields. These compounds were tested for their antifungal activity against two pathogenic fungi viz., Rhizoctonia bataticola ITCC 0482 and Sclerotium rolfsii ITCC 5226 and for insecticidal activity against insects of stored grain pest Callosobruchus analis. Fungicidal bioassay revealed that compound N-Decyl-N-[1-(2-hydroxyphenyl)ethyl]amine, was highly effective against R. bataticola (ED₅₀ 6.86 mg L^?1) which was comparable with that of commercial fungicide hexaconazole (ED₅₀ 6.35 mg L^?1). Also compounds N-Heptyl-N-[1-(2-hydroxyphenyl)ethyl]amine, N-Octyl-N-[1-(2-hydroxyphenyl)ethyl]amine and N-Nonyl-N-[1-(2-hydroxyphenyl)ethyl]amine displayed promising fungitoxicity against same pathogen. However, compound N-Heptyl-N-[1-(2-hydroxyphenyl)ethyl]amine was also found to be effective against S. rolfsii (ED₅₀ 4.92 mg L^?1 as against 1.27 mg L^?1 for hexaconazole). Compound N-Hexyl-N-[1-(2-hydroxyphenyl)ethyl]amine was most effective as insecticide followed by compound N-Octyl-N-[1-(2-hydroxyphenyl)ethyl]amine. LC₅₀ values for these compounds were 155.0 and 275.0 mg L^?1 respectively as against 36.70 mg L^?1 for commercial insecticide dichlorovos. The results obtained from bioassays indicate that this class of compounds can be utilized for the design of new substances endowed with pesticidal activities.     

微波诱导鳞片石墨-H2O2催化氧化处理甲基紫废水

研究微波诱导鳞片石墨-H2O2催化氧化处理甲基紫废水工艺,探讨各种因素的协同作用及对废水脱色效果的影响,并采用SEM、EDX、XRD和FTIR对新鲜及使用6次后的鳞片石墨进行表征。结果表明,微波诱导鳞片石墨-H2O2能高效快速降解废水中的甲基紫;在50mL初始pH为3,质量浓度为10mg／L的甲基紫废水中,H2O2用量1mL／L,鳞片石墨3g／L,微波输出功率259W,微波辐射时间9min的最佳处理工艺条件下,甲基紫脱色率达到了98．80％;微波、鳞片石墨、H2O2体系对甲基紫废水降解效果明显,产生协同效应。紫外-可见光谱分析表明,废水中甲基紫结构被破坏,但仍含有少量苯环等小分子。动力学研究表明,脱色反应符合一级反应动力学规律,反应速率常数^为0．42613min^-1,反应半衰期t。为1．626min。     

Degradation behaviour of pyrazosulfuron-ethyl in water as affected by pH

Pyrazosulfuron-ethyl, a new herbicide belonging to the sulfonylurea group, is used for weed control in rice crops growing in areas varying from acidic to alkaline soils. This study was undertaken to determine the degradation behaviour of pyrazosulfuron-ethyl in distilled water and buffer solutions at pH 4, 7 and 9. Degradation was pH-dependent and herbicide was least persistent in acidic pH followed by alkaline and neutral pH. The half-life of pyrazosulfuron-ethyl varied from 2.6 days (pH 4) to 19.4 days (pH 7) and half-life in distilled water was comparable to half-life at pH 7 buffer. HPLC analysis of different pH samples showed the formation of three metabolites viz., 5-(aminosulfonyl)-1-methyl-1H-pyrazole-4-carboxylic acid; ethyl 5-(aminosulfonyl)-1-methyl-1H-pyrazole-4-carboxylate and 2-amino-4,6-dimethoxy pyrimidine. The formation of pyrazosulfuron acid [5-([([(4,6-dimethoxy-2 pyrimidinyl)-amino]-carbonyl) amino]-sulfonyl)-1-methyl-1H-pyrazole-4-carboxylic acid] was not observed at any pH. The study indicated that the herbicide was least stable under acidic conditions and the predominant degradation route of pyrazosulfuron-ethyl in water is hydrolysis of sulfonamide linkage.     

Persistence of herbicide fenoxaprop ethyl and its acid metabolite in soil and wheat crop under Indian tropical conditions

The persistence of fenoxaprop ethyl {Ethyl (RS)-2-[4-(6-chloro-1,3-benzoxazol-2-yloxy) phenoxy] propionate} herbicide and its active metabolite fenoxaprop acid was investigated in soil and wheat crop. Fenoxaprop acid was prepared by alkaline hydrolysis of fenoxaprop ethyl. A HPLC method was developed in which fenoxaprop ethyl herbicide and its acid metabolite showed sharp single peak at 6.44 and 2.61 min respectively. The sensitivity of the method for ester and acid was 2 and 1 ng respectively with limit of detection of 0.1 and 0.05 μg mL^?1. The recovery of fenoxaprop ethyl and fenoxaprop acid from soil, wheat straw and grain ranged between 73.8–80.2%. In a field experiment fenoxaprop ethyl (Puma super® 10 EC) when applied to wheat crop at the rate of 120 g and 240 g a.i. ha^-1 as post emergence spray, fenoxaprop ethyl converted to fenoxaprop acid. Residues of fenoxaprop ethyl and acid dissipated in soil with a half-life of 0.5 and 7.3 days, respectively. At harvest no detectable residues of fenoxaprop ethyl or acid were observed in soil, wheat grain and straw samples.     

Effect of cycle time on biodegradation of azo dye in sequencing batch reactor

The effects of cycle time on the biodegradation of the azo dye remazol brilliant violet 5R (RBV-5R) were investigated in an anaerobic–aerobic sequencing batch reactor (SBR). System performance was determined by monitoring chemical oxygen demand (COD), color, anaerobic enzyme (azo reductase) and aerobic enzyme (catechol 2,3-dioxygenase), and aromatic amine concentration. SBR was operated in three different total cycle times (48 h, 24 h and 12 h), fed with a synthetic textile wastewater. In this study, the anaerobic period of SBR was found to allow the reductive decolorization of azo dye and the aerobic period was found to be effective on further COD removal after the anaerobic period. The percentage reductions in color by the anaerobic stage of the SBR were at 72%, 89% and 86% for the 24-h, 12-h and 6-h cycle times, respectively. Total COD removal efficiencies were over 75% for all operational conditions and about 70% of the COD removal was achieved in the first 3 h of anaerobic stages. During the decolorization of RBV-5R, two sulfonated aromatic amines (benzene-based and naphthalene-based) were formed and detected by HPLC. Aerobic phases of SBR with total cycle times of 48 h, 24 h and 12 h were able to remove benzene-based aromatic amines with removal efficiency of 64%, 92% and 89%, respectively. The results indicated that the best SBR performance in terms of color removal and aromatic amine degradation was achieved from total cycle time of 24 h.     

有机碳与温度对土壤吸附乙基叔丁基醚的影响

作为具有很大市场潜力的汽油添加剂乙基叔丁基醚(ETBE),国内对其在地下水土中的污染风险评价与迁移归宿研究甚少.通过静态吸附实验研究了ETBE在我国六种不同有机碳含量的标准土壤样品中的吸附特性.研究表明,在1～143 mg/L的实验浓度范围内ETBE在土壤样品中的吸附行为均呈良好的线性关系.ETBE在各土壤样品中吸附分...     

碱消解-P&T-GC-AFS法同时测定土壤中的甲基汞和乙基汞研究

建立了碱消解-吹扫捕集-气相色谱-原子荧光光谱法(P&T-GC-AFS)同时测定土壤中甲基汞和乙基汞的分析方法.样品在90℃条件下经氢氧化钾/甲醇消解2.5 h,调节pH为5.40,并丙基化衍生后,采用P&T-GC-AFS法测定.方法对甲基汞、乙基汞的线性相关系数分别为0.999 7、0.999 6,检出限分别为0.26、0.41 ng·g -1.在不同质量浓度水平上进行加标回收率实验,甲基汞、乙基汞的回收率分别为90.5%~93.3%、86.5%~89.6%.该方法样品前处理简单、检出限低,适合批量测定土壤中甲基汞和乙基汞.     

生物滴滤塔同步降解多组分挥发性有机物的实验研究

采用定向驯化活性污泥接种生物滴滤塔(BTF)同时处理甲苯、甲醇、丙烯酸乙酯挥发性有机化合物(VOCs)混合废气,考察BTF的长期稳定运行性能及微生物平均代谢活性.结果表明,混合气进口浓度低于910mg/m3时,BTF对VOCs混合废气总去除率可维持在80%以上,BTF可高效同步净化中低浓度VOCs混合废气;当进气负荷>120g/(m3·h)时,去除负荷趋于稳定,为100g/(m3·h)左右;CO2的生成量与混合废气的去除负荷的比值为1.731,表明BTF对此3种混合废气有较高程度的矿化;BTF对甲苯、甲醇、丙烯酸乙酯的降解行为符合Michaelis-Menten动力学模型,单位体积最大降解速率rmax分别是为90.9,50.5,58.5 g/(m3·h).平均吸光度(AWCD)值分析结果表明塔内微生物具有较高的代谢活性.     

Reaction of chlorimuron‐ethyl with diazomethane

Methylation of chlorimuron‐ethyl with etheral solution of diazomethane gave ethyl‐2‐[[[[(4‐chloro‐6‐methoxy‐2‐pyrimidinyl) N‐methylamino] carbonyl] N‐methylamino] sulfonyl] benzoate (dimethyl derivative of chlorimuron‐ethyl) as the major product along with 4‐chloro‐6‐methoxy‐2‐N‐methylamino pyrimidine, 2‐aminomethyl sulfonyl benzoic acid, ethyl‐2‐[(N‐methylamino) sulfonyl] benzoate, ethyl‐2‐[N,N‐dimethylamino) sulfonyl] benzoate and o‐benzoic sulf‐N‐methylimide as the minor products.     

固定床中好氧颗粒污泥动态吸附结晶紫染料

针对印染废水色度高,脱色难度大的问题,通过固定床工艺利用灭活的好氧颗粒污泥(AGS)对水中结晶紫(CV)进行动态吸附.通过对固定床高度、CV初始浓度和和流速对穿透曲线的影响进行探讨,采用Thomas模型和BDST模型对动态吸附试验所得数据拟合并获得了相应参数.试验结果表明,随着固定床高度的增加,穿透时间和饱和吸附时间延长;当CV初始浓度和流速增加时,穿透时间和饱和吸附时间急剧缩短.Thomas模型能够很好地描述AGS对CV的动态吸附动力学.当CV浓度为100mg/L,流速为8.3mL/min,固定床高度为20cm时AGS对CV的吸附动力学与Thomas模型拟合程度最好,相关系数为0.9813.BDST模型能准确预测穿透时间,平均误差小于10%.吸附CV染料后AGS可用无水乙醇进行再生.