咪唑类[PF6]^-型离子液体萃取胺类化合物

以眯唑类[PF6]^-型离子液体1-丁基-3-甲基咪唑六氟磷酸盐（[Bmim][PF6]）、1-己基-3-甲基咪唑六氟磷酸盐（[Hmim][PF6]）和1-辛基-3-甲基咪唑六氟磷酸盐（[Omim][PF6]）对苯胺、对氯苯胺等7种胺类化合物的萃取，考察了溶液初始浓度、相比、盐类、pH及离子液体眯唑基团上取代烷基对萃取平衡的影响，并研究了萃取过程的热效应。实验结果表明：溶液初始浓度对分配系数影响较小；相比10：1是离子液体对胺类化合物的溶解饱和临界点，当相比大于10：1时，分配系数降低；NaCl、K2SO4可以增大萃取分配系数，ZnSO4对分配系数几乎没有影响；pH增加，分配系数增大；离子液体对不同取代基的胺类萃取能力有较大的差异，咪唑基团上取代烷基的长度对不同胺类物质的分配系数影响较显著；萃取过程属于焓增大的吸热过程。     

阴-阳离子有机膨润土制备及其对铅离子的吸附

用十八烷基三甲基溴化铵（STAB）和十二烷基苯磺酸钠（SDBS）共同改性膨润土制备阴．阳离子有机膨润土，并用红外光谱分析法、热分析法和X粉晶衍射分析进行了表征；考察了阴-阳离子有机膨润土对铅离子的吸附性能。结果表明，用0．5CEC（cationexchangecapacity）十八烷基三甲基溴化铵和0．4CEC十二烷基苯磺酸钠改性的膨润土吸附铅的效果最佳；阴-阳离子有机膨润土吸附铅离子的能力比改性前明显增加，达到吸附平衡所需要的时间缩短；pH值强烈影响有机膨润土对铅离子吸附；有机膨润土对铅离子等温吸附过程符合Langmuir吸附模型；吸附热力学分析表明该吸附是一个放热过程，降低温度有利于铅离子的吸附。     

咪唑类［PF6］-型离子液体萃取胺类化合物

以咪唑类[PF6]-型离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim][PF6])、1-己基-3-甲基咪唑六氟磷酸盐([Hmim][PF6])和1-辛基-3-甲基咪唑六氟磷酸盐([Omim][PF6])对苯胺、对氯苯胺等7种胺类化合物的萃取,考察了溶液初始浓度、相比、盐类、pH及离子液体咪唑基团上取代烷基对萃取平衡的影响,并研究了萃取过程的热效应.实验结果表明:溶液初始浓度对分配系数影响较小;相比10:1是离子液体对胺类化合物的溶解饱和临界点,当相比大于10:1时,分配系数降低;NaCl、K2SO4可以增大萃取分配系数,ZnSO4对分配系数几乎没有影响;pH增加,分配系数增大;离子液体对不同取代基的胺类萃取能力有较大的差异,咪唑基团上取代烷基的长度对不同胺类物质的分配系数影响较显著;萃取过程属于焓增大的吸热过程.     

5种吸附剂对水中离子液体的吸附性能

实验研究了蒙脱土、活性白土、人造沸石、活性炭和水滑石5种吸附材料在25℃和50℃下对[Bmim]Cl的吸附过程,结果表明,蒙脱土对离子液体的去除效果最好,温度对活性炭的吸附有一定的影响,而对其他吸附剂的影响不大,说明这些无机矿物发生了离子交换型吸附过程。实验进一步研究了蒙脱土在25℃下对[Bmim]Cl、[Bmim]BF4、[Bmim]PF6、[Bmim]DBP、[Hmim]Cl和[Omim]Cl 6种离子液体的吸附行为,结果表明,对于阳离子相同的离子液体,阴离子对吸附影响不大;对于阴离子相同的离子液体,其饱和吸附量随着阳离子链长的增加而减小。     

不同咪唑基离子液体改性PbO_2电极降解苯酚废水

以5种不同结构的咪唑基离子液体为电沉积溶液的添加剂,采用电沉积法制备了改性钛基PbO_2电极。通过扫描电子显微镜(SEM)、X射线衍射(XRD)对电极表面形貌、晶体结构进行表征。以苯酚为电催化目标降解物,对不同电极氧化去除苯酚及COD的活性进行考察比较;同时,以水杨酸为捕捉剂,通过高效液相色谱(HPLC)分析技术对不同电极体系中羟自由基(·OH)的生成量进行检测。结果表明,阳离子烷基支链长度及阴离子的改变均会对PbO_2电极的表面形貌、结晶取向及电催化活性产生一定影响,且后者的影响作用较前者更为突出。[Emim]Br和[Emim]PF_6改性电极的电催化活性比较相近,均明显低于[Emim]BF_4改性电极。固定阴离子为BF_4~-,3种不同烷基支链长度离子液体对PbO_2电极活性的改进效果顺序为[Bmim]BF_4[Emim]BF_4[Hmim]BF_4。此外,不同改性电极对苯酚废水COD去除率的高低与·OH的生成量多少一致,表明苯酚的电化学氧化降解主要是由·OH间接氧化引起的。     

次甲基蓝比色法用于地面水中阴离子洗涤剂的测定

水中阴离子洗涤剂的测定方法有次甲基蓝比色法,红外光谱法、气相色谱法,高压液相色谱法和原子吸收光谱法。美、日等国都提出以次甲基蓝比色法作为测定水中阴离子洗涤剂的标准方法,并规定水中阴离子洗涤剂的最高允许浓度为0.5mg/l。次甲基蓝比色法是基于阴离子洗涤剂(主要是直链烷基苯磺酸钠,还有烷基磺酸钠和烷基硫酸钠)能与次甲基蓝生成脂溶性的蓝色离子对化合物,用氯仿萃取,在波长622nm处测定氯仿层的吸     

流动注射分光光度法研究离子强度对活性炭吸附阴、阳离子染料的影响

运用流动注射分光光度法，考察了不同离子强度(NaCl)下，在水溶液中表面带负电的活性炭分别吸附阴、阳离子染料的动力学行为。实验结果表明，对于所考察的2种阳离子染料和3种阴离子染料，活性炭的表观吸附速率常数均随着离子强度的增大而增大。这种加速吸附效应的出现，主要是因为离子强度的增大促进了活性炭表面与染料之间的非静电力作用。     

含氯代烃废水的生物毒性与处理方法探讨

卤代烃是在有机物分子中的碳原子上，用卤素基团取代出氢的卤化产物，这个变化使有机物的生物毒性增大，这是卤素有机态毒性的体现；另一方面，卤代烃在生物水解或降解过程中，又会重新释放出带正电荷的卤素，与水结合后成为次卤酸而具有无机态卤素的生物毒性。作者在提出这种卤代烃生物毒性学说的基础上，提出了一系列在含卤代烃废水预处理与生物处理中的解毒、降毒、抗毒和减荷及提高可生化性的措施，以提高含卤代烃废水的综合处理效率。     

土壤石油烃污染的植物毒性及植物-微生物联合降解

通过盆栽实验研究了土壤石油烃污染对玉米和水稻根伸长的影响，并在土壤中接种经过筛选得到的石油烃降解菌，研究石油烃降解菌对石油烃毒性的影响以及对土壤中石油烃的降解。研究结果表明，石油烃浓度低于1 000 mg/kg时对玉米的根系生长有一定的刺激生长作用，随着石油烃浓度的增加，刺激根长生长的作用逐渐降低，研究结果表明，水稻根长受石油烃影响较小。通过对不同处理土壤中石油烃降解的研究结果表明，土壤中种植水稻对石油烃有一定的降解作用，但是不同处理下土壤中的石油烃降解率不同，其中水稻微生物联合处理下土壤中石油烃的降解速率最快，培养期内的降解效率达到53.3%。     

水溶性离子液体对甲苯的吸收效果及影响因素

选择3种水溶性离子液体(十二烷基咪唑氯盐(DDMIM Cl)、十二烷基咪唑硝酸盐(DDMIM NO_3)、十二烷基咪唑双氰胺盐(DDMIM DCA))作为研究对象寸模拟曱苯废气进行吸收实验,研究了吸收液的吸收性能、甲苯浓度、吸收液浓度、进气气速以及盐度等因素对吸收效果的影响以及加热蒸馏法对吸收液的再生与甲苯回收的可行性。结果表明:不同的离子液体对甲苯的吸收率不同J)DMIM DCA的吸收效果最好在质量分数为5%时,初始吸收率达到98%,饱和吸收量为53.39 mg·L~(-1),而DDMIM CKDDMIM NO_3对甲苯的初始吸收率在92%左右,饱和吸收量分别为33.60,37.01 mg·L~(-1);甲苯饱和吸收量与吸收液浓度、甲苯进气浓度呈正相关,与进气气速、含盐度呈负相关;传质系数与甲苯进气浓度、进气气速以及含盐度呈正相关,与吸收液浓度呈负相关;采用加热蒸馏法进行甲苯回收及吸收液再利用时用苯的回收效率达到85%~90%且甲苯的饱和吸收量随着重复利用次数的增加而基本保持不变。因此利用离子液体溶液处理甲苯废气理论上是可行的。     

Physiological and biochemical responses of rice seeds to phosphine exposure during germination

Rice seeds (Tianyou, 3618) were used to examine the physiological and biochemical responses to phosphine exposure during germination. A control (0 mg m⁻³) and four concentrations of phosphine (1.4 mg m⁻³, 4.2 mg m⁻³, 7.0 mg m⁻³ and 13.9 mg m⁻³) were used to treat the rice seeds. Each treatment was applied for 90 min once per day for five days. The germination rate (GR); germination potential (GP); germination index (GI); antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and lipid peroxidation measured through via malondialdehyde (MDA) were determined as indicators of the physiological and biochemical responses of the rice seeds to phosphine exposure. These indicators were determined once per day for five days. The results indicated that the GR, GP and GI of the rice seeds markedly decreased after phosphine exposure. The changes in the activities of the antioxidant enzymes due to the phosphine exposure were also significant. The exposure lowered the CAT and SOD activities and increased POD activity in the treated rice seeds compared with controls. The MDA content exhibited a slow increase trend with the increase of phosphine concentration. These results suggest that phosphine has inhibitory effects on seed germination. In addition, phosphine exposure caused oxidative stress in the seeds. The antioxidant enzymes could play a pivotal role against oxidative injury. Overall, the effect of phosphine on rice seeds is different from what has been reported previously for insects and mammals.     

Bioremediation of HCH-contaminated soil: elimination of inhibitory effects of the insecticide on radish and green gram seed germination

The effects of technical grade hexachlorocyclohexane (tech-HCH) on the germination of different seeds were tested. Two types of seeds, radish and green gram showed marked reduction in germination percentage and seeding vigour index. The abnormalities and reduction in germination increased with increasing concentration of tech-HCH. At 100 microg HCH level the germination of radish and green gram seeds was inhibited almost completely on moist filter paper and soil. Protease and amylase activities were reduced in seeds grown in soil spiked with tech-HCH. Bioremediation of HCH-spiked soils with a HCH-degrading microbial consortium helped in eliminating the toxic effects of tech-HCH towards seed germination. The degradation of 25 microg tech-HCH g(-1) soil was complete by 120 h. The seed germination and the activities of the assayed enzymes, amylase and protease, were same as before or better in bioremediated soils.     

Effects of composting on phytotoxicity of spent pig-manure sawdust litter

The phytotoxicity of spent pig-manure sawdust litter (spent litter) was evaluated during further composting. Aqueous extracts of the spent litter were prepared by shaking the sample with water (1:10 w/v), and the toxicity of these extracts was determined on relative seed germination, relative root elongation and germination index (GI, a factor of relative seed germination and relative root elongation). The sensitivity of six plant species, namely Brassica parachinensis (Chinese cabbage), Brassica albogalera (Chinese kale), Allium sativum (onion), Cucumis sativus (cucumber), Amaranthus espinosus (Chinese spinach), and Lycopersicon esculentum (tomato) were compared. The effect of different moisture levels during composting on the phytotoxicity of the spent litter was also examined. Phytotoxicity of the spent litter was only evident during the earlier stage of composting (first 14 days) and, that seed germination and root elongation reached 100% (same as the control) towards the end of the composting. The concentrations of the major inhibitors, water-extractable Cu and Zn, and NH4(+)-N of the spent litter, declined during composting, indicating that these inhibitors were gradually eliminated as composting proceeded. Multiple regression analysis showed that the NH4(+)-N content of the spent litter was the most important chemical factor affecting phytotoxicity of the plant species selected for this study. Relative root elongation and GI were more sensitive indicators of phytotoxicity than seed germination. In the present study, the GI's of all plant species were >80% at day 60, indicating that the spent litter had reached its maturation by day 60. The responses of different plant species to the water-extracts of the spent litter were different. Among the six species, Chinese cabbage and Chinese spinach were the most sensitive species, and tomato and cucumber were the least sensitive species to indicate phytotoxicity of the spent litter. Moisture adjustment during the composting process did not affect the results of the phytotoxicity test.     

Germination of Medicago sativa is inhibited by soluble compounds in cement dust

Deposition of cement dust on soils and plant surfaces is known to affect plant growth and the species composition of plant communities, but little is known about its effects (and those of its pH and constituents) on germination. Therefore, the aim of this study was to assess the toxicity of an aqueous cement extract, constituents of the extract and pH on the germination of seeds of a selected species, Medicago sativa. First, the effects of the extract were tested in assays with concentrations and exposure durations ranging from 0 to 1.0 g/mL and 4 to 96 h, respectively. At 0.8 g/mL, the extract strongly inhibited germination; a 4-h exposure reduced the germination rate, from 77?±?1.8 to 50?±?2.6 % (mean ± SE), while 8-h exposure completely inhibited it. Further, treatment at this concentration killed the non-germinating seeds, thus the inhibition was due to toxic effects. Neither the pH of the extract nor the concentration of its main soluble elements separately (K, Ca, S, Na, or Cr) caused the toxicity since germination rates were not significantly reduced when these variables were tested individually. However, a mixture of the elements in solution reduced germination rates, suggesting that they have adverse synergistic effects.     

Effects of distillery waste on the performance of Cicer arietinum L

The impact of distillery effluent in various concentrations (1, 2.5, 5, 10, 25, 50, 75 and 100%) on the seed germination, Speed of Germination Index, growth behaviour, leaf area, biomass, net primary productivity, pigment content, reproductive capacity, seed output, seed weight, seed density and the seed protein content of Cicer arietinum L. plants was investigated. The percentage and speed of germination of seeds were increasingly retarded with increase in effluent concentration and at 100% concentration there was no germination. The seedlings exhibited maximum shoot length at 5% concentration and maximum root length at 2.5% concentration. The values of root and shoot lengths, leaf area, biomass, net primary productivity, pigment content, reproductive capacity, seed output, seed weight, seed density and seed protein content in pot plants exhibited a gradual increase from the control up to 5% concentration and decreases at higher concentrations. The very high BOD load and the presence of excessive concentrations of soluble salts could be responsible for the toxicity of the effluent. The effluent at up to 5% concentration was, however, beneficial for the overall growth parameters studied and can thus be used as a liquid fertilizer.     

Phytotoxicity of nanoparticles: inhibition of seed germination and root growth

Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC50) of nano-Zn and nano-ZnO were estimated to be near 50mg/L for radish, and about 20mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles.     

Growth stimulation of Triticum aestivum seedlings under Cr-stresses by non-rhizospheric pseudomonad strains

Four chromium-resistant non-rhizospheric strains SPCr-1, SPCr-2, SPCr-3 and SPCr-4 (Pseudomonads), which were isolated from the effluents of an ICI paint factory and could tolerate 2-3 mg ml(-1) chromium in a minimal medium and 40 mg ml(-1) in a rich medium, were used to inoculate seeds of Triticum aestivum. Both inoculated and non-inoculated seeds were germinated and grown under different concentrations of chromium salts (K2CrO4, 0, 100, 250, 500; CrCl3, 0, 250, 500, 1000 microg ml(-1)). Germination and growth parameters were severely affected by chromium-salts. K2CrO4 had more drastic effects than CrCl3 treatments. Seedlings had a hard and brittle texture and showed symptoms of hypertrophy. Brown spots on leaves and stems were visible and the tips of leaves were bifurcated and curled. The root system was also impaired, ranging from a browning of the tip to complete destruction of cortical tissues. Under chromium-stress conditions, inoculated plants had significantly better germination and growth as compared to non-inoculated treatments. Bacterial growth enhancement of seedlings was associated with reduced chromium-uptake, increased auxin content and the formation of stress specific proteins. With bacterial inoculations, symptoms of chromium toxicity were reversed, especially at lower concentrations of chromium salts.     

Seeds’ physicochemical traits and mucilage protection against aluminum effect during germination and root elongation as important factors in a biofuel seed crop (Ricinus communis)

We determined the length, volume, dry biomass, and density in seeds of five castor bean cultivars and verified notable physicochemical trait differences. Seeds were then subjected to different toxic aluminum (Al) concentrations to evaluate germination, relative root elongation, and the role of root apices’ rhizosphere mucilage layer. Seeds’ physicochemical traits were associated with Al toxicity responses, and the absence of Al in cotyledons near to the embryo was revealed by Al-hematoxylin staining, indicating that Al did not induce significant germination reduction rates between cultivars. However, in the more sensitive cultivar, Al was found around the embryo, contributing to subsequent growth inhibition. After this, to investigate the role of mucilage in Al tolerance, an assay was conducted using NH₄Cl to remove root mucilage before or after exposure to different Al concentrations. Sequentially, the roots were stained with hematoxylin and a quantitative analysis of staining intensity was obtained. These results revealed the significant contribution of the mucilage layer to Al toxicity responses in castor bean seedlings. Root growth elongation under Al toxicity confirmed the role of the mucilage layer, which jointly indicated the differential Al tolerance between cultivars and an efficient Al-exclusion mechanism in the tolerant cultivar.     

Effect of cadmium on germination, amylases and rate of respiration of germinating pea seeds

Growth of embryonic axis of germinating pea seeds (Pisum sativum cv. Bonneville) was significantly inhibited by as low as 0.25 mM cadmium and the elongation of the radicle was affected more severely than that of the plumule. Total amylolytic activity, as well as activities of alpha- and beta-amylases, diminished progressively with increasing concentrations of the metal in the media. The deleterious effect on alpha-amylase persisted throughout, whereas beta-amylase activity recovered with time. The rate of respiration of seeds, measured by oxygen uptake, was markedly impeded by cadmium and the phase of rapid and linear development of respiratory activity (after 3 days of imbibition) was almost completely, suppressed in the presence of higher concentrations (1 mM) of the metal. The observed impact of cadmium on starch mobilization and on respiratory activity are discussed in relation to its adverse effects on seed germination.     

Environmental effects of nanosilver: impact on castor seed germination, seedling growth, and plant physiology

Increasing use of nanoparticles in daily products is of great concern today, especially when their positive and negative impact on environment is not known. Hence, in current research, we have studied the impact of silver nanoparticle (AgNPs) and silver nitrate (AgNO₃) application on seed germination, root, and shoot length of castor bean, Ricinus communis L. plant. Silver nanoparticles had no significant effects on seedling growth even at higher concentration of 4,000 mg L^?1, while the silver in bulk form as AgNO₃ applied on the castor bean seeds inhibited the seed germination. Silver uptake in seedlings of the castor seeds on treatment with both the forms of silver was confirmed through atomic absorption spectroscopy studies. The silver nanoparticle and silver nitrate application to castor seeds also caused an enhanced enzymatic activity of ROS enzymes and phenolic content in castor seedlings. High-performance liquid chromatography analysis of individual phenols indicated enhanced content of parahydroxy benzoic acid. These kinds of studies are of great interest in order to unveil the movement and accumulation of nanoparticles in plant tissues for assessing future applications in the field or laboratory.