Herbivore-Induced Extrafloral Nectar Production in Lima Bean Plants Enhanced by Previous Exposure to Volatiles from Infested Conspecifics

In response to herbivory by spider mites (Tetranychus urticae), lima bean plants produced significantly greater quantities of extrafloral nectar (EFN) than intact conspecific plants. Moreover, EFN amounts of infested plants depended on exposure to odor of infested neighbor plants. Two d after spider mite infestation, a test plant produced more EFN when exposed prior to infestation to volatiles from infested neighbor plants than when exposed to volatiles from uninfested conspecific plants. However, this effect was only detectable 2 d after spider mite infestation and vanished 4 d after infestation. These results suggest that EFN production is enhanced during the earlier stages of damage by T. urticae in response to previous exposure to volatiles from infested neighbor plants.     

Responses to Green Leaf Volatiles in Two Biogeoclimatic Zones by Striped Ambrosia Beetle, Trypodendron lineatum

Experiments in the Coastal Western Hemlock (CWH) biogeoclimatic zone on the British Columbia (BC) coast and the Interior Douglas-fir (IDF) biogeoclimatic zone in the BC interior revealed pronounced differences in the effect of six-carbon green leaf volatiles on the response by striped ambrosia beetles, Trypodendron lineutum to multiple funnel traps baited with the aggregation pheromone lineatin. In the IDF zone, four green leaf alcohols [1-hexanol, (E)-2-hexen-1-ol, (Z)-2-hexen-1-ol, and (Z)-3-hexen-1-ol], released alone or in a quaternary blend at ca. 4 mg/24 hr/compound, caused a 63–78% reduction in trap catches. Two aldehydes, hexanal and (E)-2-hexenal, released together at ca. 13.0 mg/24 hr/compound were weakly disruptive in one of two experiments. Conversely, in the CWH zone, the two aldehydes together caused a slight, but significant, increase in the response over that to lineatin in one of two experiments, and the blend of all four alcohols caused only weak disruption of response in one of two experiments. None of the alcohols released alone was bioactive. These results may reflect adaptations that ensure accurate host location in the two ecological zones. In the CWH zone, T. lineatum attacks conifer logs almost exclusively, and surrenders the cut or broken stump habitat to Gnathotrichus spp. In the IDF zone, T. lineatum readily attacks the base of trees killed by bark beetles or fire and may utilize green leaf alcohols to detect and avoid the vertical silhouettes represented by nonhost angiosperms such as black cottonwood and trembling aspen.     

Behaviorally Active Green Leaf Volatiles for Monitoring the Leaf Beetle, Diorhabda elongata, a Biocontrol Agent of Saltcedar, Tamarix spp.

Biological activity and chemistry of host plant volatiles were investigated for Diorhabda elongata, Brullé (Coleoptera: Chrysomelidae), a biological control agent for the invasive tree, saltcedar (Tamarix spp., Tamaricaceae). Gas chromatographic–electroantennographic detection (GC-EAD) analysis of volatiles collected from adult D. elongata feeding on saltcedar foliage or from saltcedar foliage alone showed 15 antennally active compounds. These compounds were more abundant in collections from beetle-infested foliage. Antennally active compounds were identified by GC–mass spectrometry (MS) and confirmed with authentic standards. The emissions of the most abundant GC-EAD-active compounds, green leaf volatiles (GLV), were quantitated by GC-MS. A blend of four GLV compounds, mimicking the natural blend ratio, was highly attractive to male and female D. elongata in the field, and a combination of GLV and male-produced aggregation pheromone attracted significantly greater numbers of D. elongata than did either bait alone. A preliminary experiment with a blend of seven additional GC-EAD-active saltcedar volatiles did not show any behavioral activity. The combination of the pheromone and the green leaf odor blend could be a useful attractant in detecting the presence of the biocontrol agent, D. elongata, in stands of saltcedar newly colonized by the beetle.Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.     

Leaf Volatiles from Nonhost Deciduous Trees: Variation by Tree Species, Season and Temperature, and Electrophysiological Activity in Ips typographus

The leaf volatiles emitted from four nonhost tree species of Ips typographus, i.e. Betula pendula, B. pubescens, Populus tremula, and Sambucus nigra, were collected outdoors by headspace sampling in situ and analyzed by GC-MS. Three major classes of compounds, aliphatics [mainly green-leaf volatiles (GLVs)], monoterpenes, and sesquiterpenes, existed in all the deciduous tree species investigated. In June, when the bark beetles are searching in flight for host trees, GLVs mainly consisting of (Z)-3-hexenyl acetate and (Z)-3-hexen-1-ol were the dominant constituents in B. pendula and S. nigra. In B. pubescens and P. tremula, sesquiterpenes (and their derivatives) and monoterpenes made up the major part of whole volatile blends, respectively. Surprisingly, sesquiterpene alcohols and other oxides released from B. pubescens in considerable amounts were not found in the closely related species, B. pendula. By August, both the total volatiles and individual compounds significantly decreased, mainly due to the maturation of leaves, since the light intensity and temperatures during sampling were the same as in June. There were almost no volatiles detected from P. tremula and S. nigra leaves in August. The total emissions from these deciduous species were significantly different among the species, with B. pubescens releasing 5–10 times more than other species. Under the conditions of constant light intensity and humidity, emissions of both total volatiles and most individual components of severed B. pendula and S. nigra branches (with fresh leaves) increased according to a saturation curve from 16°C to 40°C. Ips typographus antennae responded strongly to green leaf alcohols: (Z)-3-hexen-1-ol, 1-hexanol, and (E)-2-hexen-1-ol, but not to aldehydes or acetates in GC-EAD analyses of B. pendula and B. pubescens leaf volatiles. No antennal responses to monoterpenes, sesquiterpenes, or sesquiterpene oxides were found. These three antennally active GLVs emitted from nonhost tree leaves might be indicators of a wrong habitat in the host selection of conifer bark beetles.     

Identification of Volatiles That Are Used in Discrimination Between Plants Infested with Prey or Nonprey Herbivores by a Predatory Mite

Carnivorous arthropods can use herbivore-induced plant volatiles to locate their herbivorous prey. In the field, carnivores are confronted with information from plants infested with herbivores that may differ in their suitability as prey. Discrimination by the predatory mite Phytoseiulus persimilis between volatiles from lima bean plants infested with the prey herbivore Tetranychus urticae, or plants infested with the nonprey caterpillar Spodoptera exigua, depends on spider mite density. In this article, we analyzed the chemical composition of the volatile blends from T. urticae-infested lima bean plants at different densities of spider mites, and from S. exigua-infested plants. Based on the behavioral preferences of P. persimilis and the volatile profiles, we selected compounds that potentially enable the mite to discriminate between T. urticae-induced and S. exigua-induced volatiles. Subsequently, we demonstrated in Y-tube olfactometer assays that the relatively large amounts of methyl salicylate and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene emitted by T. urticae-infested bean plants compared to S. exigua-infested plants enable the predators to discriminate. Our data show that specific compounds from complex herbivore-induced volatile blends can play an important role in the selective foraging behavior of natural enemies of herbivorous arthropods.     

Biosynthesis of Defensive Allomones in Leaf Beetle Larvae: Stereochemistry of Salicylalcohol Oxidation in Phratora vitellinae and Comparison of Enzyme Substrate and Stereospecificity with Alcohol Oxidases from Several Iridoid Producing Leaf Beetles

(7S)-[²H₅]-Salicylalcohol (3) and (7R)-[²H₁]-salicylalcohol (5) have been synthesized in order to examine the stereospecificity of salicylalcohol oxidase from the defensive secretion of the salicylaldehyde-producing leaf beetle Phratora vitellinae. Oxidation was found to proceed by selective removal of the C(7)-H_R hydrogen atom (Re-specificity) to yield salicylaldehyde. (7S)-[²H₆]-Benzylalcohol (9) was also oxidized Re-specifically to benzaldehyde, but in much lower yield, indicating the importance of the orthohydroxy group of salicylalcohol in substrate enzyme binding. The stereospecificities of terpenoid oxidases from six species of iridoid-producing leaf beetle were examined using (1R,8R)-[²H₂]-8-hydroxygeraniol (10), and were all found to oxidize the substrate Re-specifically. Cross-activity of oxidation was found in a number of species, with P. vitellinae able to oxidize terpenoid (10) and two of the iridoid-producing species able to oxidize salicylalcohol analogue (3), again with Re-specificity. However, when the two substrate analogs were presented together, in equal concentrations, preferential oxidation of the natural analog was observed in each case. The kinetics of oxidation for a number of terpenoid and aromatic alcohols by the defensive secretion of the iridoid-producing leaf beetle Phaedon armoraciae have been studied, revealing a large difference between the rate of (primary, allylic) terpenoid alcohol oxidation and the rate of salicylalcohol oxidation, thus accounting for the observed selectivity.     

Use of chitosan for removal of bisphenol a from aqueous solutions through quinone oxidation by polyphenol oxidase

In this study, a combined use of biopolymer chitosan and oxidoreductase polyphenol oxidase (PPO) was applied to the removal of bisphenol A (BPA) as an endocrine disrupting chemical from aqueous solutions. The optimum conditions for the enzymatic quinone oxidation of BPA were determined to be pH 7.0 and 40°C. Quinone derivatives generated were chemisorbed on chitosan beads, and BPA was completely removed at 4–7 h. The removal time was shortened with an increase in the amount of dispersed chitosan beads or the PPO concentration. In addition, the initial velocity of quinone oxidation increased with an increase in the amount of chitosan beads. The use of chitosan in the form of porous beads was more effective than the use of chitosan in the form of solutions or powder. It was found that an important factor for this procedure was a high‐specific surface area of chitosan beads and heterogeneous reaction of quinone derivatives enzymatically generated with chitosan. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

A Novel Approach for Isolation of Volatile Chemicals Released by Individual Leaves of a Plant in situ

A glass chamber designed specifically for collecting volatile chemicals from individual leaves of a plant in situ is described. The effectiveness of the chamber was demonstrated by collecting volatile chemicals from single leaves of two plant species, potato (Solanum tuberosum) and broad bean (Vicia faba), before and after mechanical damage. The glass chamber, in conjunction with thermal desorption, enables reduction of the entrainment time and thereby allows the monitoring of compounds released by leaf damage in successive 5-min periods. An intact broad bean leaf, in the middle of the day, produces small amounts of the green leaf volatiles (E)-2-hexenal and (Z)-3-hexen-1-ol. However, during the first 5 min after mechanical damage, large amounts of (Z)-3-hexenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol are produced. The decline in production of (Z)-3-hexenal and (E)-2-hexenal is fast, and after 10 min, these compounds reach very low levels. (Z)-3-Hexen-1-ol shows an increase for the first 10 min and then a gradual decline. An intact potato leaf, in the middle of the day, produces very small amounts of the sesquiterpene hydrocarbons -caryophyllene and germacrene-D. After being damaged, the profile of released volatiles is different from that of broad bean. In potato, damage is associated with release of large amounts of green leaf volatiles and sesquiterpene hydrocarbons. Compounds such as (Z)-3-hexenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol are released in high amounts during the first 5 min after damage, but after 10 min, these drop to very low levels. High release associated with damage is also observed for -caryophyllene, (E)--farnesene, germacrene-D, and -bisabolene. The highest level is reached 5 min after damage and 15 min later, these compounds drop to low levels. The significance of compounds released after plant damage is discussed.     

Use of Slime Waste from Nuclear Power Plants in a System for Chemical Purification of Water

The possibility of using slime waste generated in chemical purification of NPP sewage instead of lime is investigated. The main properties of the products obtained under different temperatures and different rates of heat treatment are determined.     

用沸腾锅炉回收利用造气炉渣技术总结

用沸腾锅炉回收利用低热值造气炉渣，使之再次燃烧，生产蒸汽，是低热值造气炉渣研究开发的新发展。根据实际生产应用情况和经济效益分析，证实了这一技术的合理性、经济性     

Anionic/Cationic Membranes Obtained by a Radiation Grafting Method for Use in Waste Water Treatment

Investigations were carried out on different ionic membranes, which were prepared by radiation-induced graft copolymerization. Cationic (low density polyethylene (LPDE)-g-poly(acrylic acid) (PAAc)) and cationic/anionic (LDPE-g-P(AAc/4-vinyl pyridine (4VP)) membranes) were used to elucidate the possibility of their practical use. The metal uptake via their functional groups was determined by using atomic absorption and X-ray fluorescence. The amount of metal uptake by the prepared membranes increased significantly as the pH of the metal feed solution increased (pH ≤ 5·3) and the chelated metal ions were easily desorbed by treating the membrane with 0·1 M HCl for 2h at room temperature. The maximum uptake for a given metal was higher for the cationic/anionic membranes than for the cationic ones. The selectivity of the cationic/anionic membranes towards different metals was investigated using mixtures of two or three metals in the same feed solution. The membranes showed high selectivity towards Fe(III ) ions. Characterization of the graft copolymers containing metals was determined by thermogravimetric analysis (TGA) and X-ray diffraction (XRD). TGA results showed that the decomposition of the graft copolymer in the presence of chelated metal ion occurred at temperatures above 300°C. The XRD of LDPE-g-P(AAc/4VP) treated with Fe(III ) at various concentrations showed that the crystallinity decreased to a certain limiting value. The complexed copolymers could be recycled several times and showed high selectivity to the Fe(III ) ion in the presence of the other metal ions investigated. This may make such grafted membranes acceptable for practical use in waste water treatment. © 1997 SCI     

An empirical model for kinetics of boron removal from boron-containing wastewaters by ion exchange in a batch reactor

In this study, it was investigated boron removal from boron containing wastewaters prepared synthetically. The experiments in which Amberlite IRA 743, boron specific resin was used was carried out in a batch reactor. The ratio of resin/boron solution, boron concentration, stirring speed and temperature were selected as experimental parameters. The obtained experimental results showed that percent of boron removal increased with increasing ratio of resin/boron solution and with decreasing boron concentration in the solution. Stirring speed and temperature had not significant effects on the percent of total boron removal, but they increased the starting boron removal rate. As a result, it was seen that about 99 % of boron in the wastewater could be removed at optimum conditions. On the other hand, the process kinetics were predicted by using heterogeneous fluid-solid reaction models. It was seen statistically that the kinetics of this process agreed the pseudo- second order model, as follows: X_Bl(1−X_B) = 11,241.5[OH][C]^−1.76[S/L]^2.17exp(−19,57l.2/RT)t^1.24     

Granulation of Fe-Al-Ce nano-adsorbent for fluoride removal from drinking water by spray coating on sand in a fluidized bed

A technology for the granulation of Fe-Al-Ce nano-adsorbent (Fe-Al-Ce) in a fluidized bed was developed. The coating reagent, a mixture of Fe-Al-Ce and a polymer latex, was sprayed onto sand in a fluidized bed. The granule morphology, coating layer thickness, granule stability in water and adsorption capacity for fluoride was investigated by analyzing samples for different coating time. The coating amount was from 3% to 36%. With increasing coating amount, granule stability decreased and adsorption capacity increased. FTIR analysis showed that the latex can react with active hydroxyl on the Fe-Al-Ce adsorbent, which led to a decrease of the adsorption capacity. Coated granules with a coating amount of 27.5% had a fluoride adsorption capacity of 2.22 mg/g (coated granules) at pH 7 and initial fluoride concentration of 0.001 M. A column test showed that 300 bed volumes can be treated with the effluent under 1.0 mg/L at an initial fluoride concentration of 5.5 mg/L, space velocity of 5 h^− 1 and pH of 5.8. The coating granulation of the Fe-Al-Ce adsorbent can produce granules that can be used in a packed bed for the removal of fluoride from drinking water.     

An empirical model for kinetics of boron removal from boroncontaining wastewaters by the electrocoagulation method in a batch reactor

Boron removal from boron containing wastewaters prepared synthetically via the electrocoagulation method was studied. The experiments in which aluminum plate electrode was used were carried out in a batch reactor. The solution pH, initial boron concentration, current density, type of supporting electrolyte, temperature of solution and stirring speed were selected as experimental parameters. The obtained experimental results showed that efficiency of boron removal increased with increasing current density and decreased with increasing boron concentration in the solution. Supporting electrolyte had not significant effects on the percent of total boron removal. pH was very important parameter effecting boron removal and optimum pH was determined to be 8.0. This pH value reached an agreement with activity-pH diagrams for Al⁺³ species in equilibrium with Al(OH)₃ and boron species in aqueous media. As a result of increasing interaction between boron ions and dissolved aluminum ions in solution, the increasing solution temperature increased boron removal efficiency. Increasing stirring speed decreased boron removal efficiency where the increasing stirring speed decreased the capability of floc formation of aluminum ions. As a result, it was seen that about 99% of boron in the wastewater could be removed at optimum conditions. In addition, the process kinetics was predicted by using heterogeneous fluid–solid reaction models. It was seen statistically that the kinetics of this process agreed with the pseudo-second-order model as follows: X_B/(l−X_B) = 18,241[OH][C]^−3.45[CD]^7.79[t]^1.41[S]^−3.65exp[−30,668/RT].     

The development of a digestion procedure for the determination of metals in gum obtained from deposits in internal combustion engines by ICP-OES

The accurate determination of metals in gum (deposits found in internal combustion engines) is strongly influenced by a selection of the right sample digestion method. The difficult and heterogeneous nature of this kind of sample, and its unpredictable reaction behavior are the major obstacles in getting correct analytical results. The studies were implemented with one sample called “reference sample”. Two digestion procedures were tested in this work. The dry ashing procedure was followed by another dissolution procedure with HF and heating, in order to complete the dissolution of the ash in the samples. The process was performed in 36 h. The second digestion procedure was implemented in closed system (pressurized) with 2 mL of HNO₃ and 2 mL of H₂SO₄. This last one presented a reduction of 80.5% time-consuming in relation to the first one (dry ashing). Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Ni, Pb, Si, and Zn were determined in 14 samples of gum by ICP-OES. The wet closed system digestion procedure showed efficiency in the Cr, Cu, Fe, K, Ni, Pb, Si, and Zn determination. The correlation matrix results contribute to the characterization studies of the gum formation process, as well as the corrosion of the motor parts and fuel quality control.     

腐植酸作为天然有机物(NOM)的主要类型对环糊精聚氨酯去除水中异味的影响

目前,水处理机构普遍认为,天然有机物会妨碍活性炭的吸附位点与异味化合物结合,进而导致对甲萘烷醇和2-甲基异茨醇的清除效率下降。腐植酸也被认为具有相同的作用。对于城市水处理系统来说,饮用水中异味化合物如甲萘烷醇和2-甲基异茨醇的清除至关重要。已证实,环糊精聚氨酯可清除水中有机污染物,但不会显著降低天然有机物的含量。我们希望确定在有天然有机物存在的条件下,该聚合物是否能够有选择地去除甲萘烷醇和2-甲基异茨醇。本研究以腐植酸为天然有机物代表,因腐植酸约占天然有机物的70%。研究表明,不同浓度腐植酸的存在不会影响甲萘烷醇和2-甲基异茨醇的清除,使用环糊精聚合物,90%的异味化合物被去除。同时,紫外分析表明只有少量的腐植酸(3%～20%)被去除。     

火电厂高盐高氨氮废水电解除氨氮及制氯性能研究

通过电化学试验测定了4种钛基金属氧化物DSA阳极的析氯、析氧电位,优选了Ti/Ru O2-Ir O2(R2)电极进行高盐高氨氮废水的电解试验,研究电流密度、TDS、pH、极板清洗等因素对电解除氨氮及制氯过程的影响。试验结果表明:电流密度、极板清洗对氨氮的平均降解速率影响较大,而水样的pH、TDS的影响较小。高盐废水中氨氮的电解降解过程符合准零级反应动力学规律。