European starling nestling response to chlorpyrifos exposure in a corn agroecosystem

European starling (Sturnus vulgaris) nestlings were used as a surrogate to study the effect of chlorpyrifos application to a corn agroecosystem on songbird reproduction. Chlorpyrifos was applied in a T‐band at 1.3 kg AI/ha, and residues were measured in soil, earthworms, ground‐dwelling insects, and diet items collected from the crop of starling nestlings. Chlorpyrifos levels in soil peaked at 34.2 μg/g, 4 days post‐application, and dissipated to trace levels by 64 days post‐application. Concentrations of chlorpyrifos in earthworms and ground‐dwelling insects reached 0.9 and 0.7 ug/g, respectively. Starling nestling diet items included invertebrates from eight orders with chlorpyrifos concentrations ranging from trace levels to 10.6 μg/g in earthworms. Nestling brain and plasma cholinesterase (ChE) activity and body mass measurements were taken at 3, 8, and 13 days post‐hatch (DPH). Adult starling fecundity was also measured. Body mass differences between treatment and reference site nestlings at 3 and 13 DPH were not significant at α = 0.05. However, 8 DPH nestlings from the Treatment Site had a transient reduction in weight (p = 0.03) when compared with 8 DPH reference nestlings. There were no significant differences in brain or plasma ChE activities of 3, 8, or 13 DPH nestlings. Further, multiple measures of fecundity (i.e., clutch size, hatching percentage, and fledging percentage) indicated that chlorpyrifos application did not affect starling nestling survival to fledging, as the values from the Treatment and Reference Site were nearly identical. This screening‐level study suggests that although one age group of starling nestlings from the Treatment Site weighed less than their Reference Site counterparts, a single T‐band application of chlorpyrifos did not impair starling nesting success.     

Energy reduction of a submerged membrane bioreactor using a polytetrafluoroethylene (PTFE) hollow-fiber membrane

The fiber length and packing density of the PTFE membrane element were increased. The MBR was stably operated under an SAD^m of 0.13 m³·m^-2·hr^-1. Specific energy consumption was estimated to be less than 0.4 kWh·m^-3. In this study, we modified a polytetrafluoroethylene (PTFE) hollow-fiber membrane element used for submerged membrane bioreactors (MBRs) to reduce the energy consumption during MBR processes. The high mechanical strength of the PTFE membrane made it possible to increase the effective length of the membrane fiber from 2 to 3 m. In addition, the packing density was increased by 20% by optimizing the membrane element configuration. These modifications improve the efficiency of membrane cleaning associated with aeration. The target of specific energy consumption was less than 0.4 kWh·m^-3 in this study. The continuous operation of a pilot MBR treating real municipal wastewater revealed that the MBR utilizing the modified membrane element can be stably operated under a specific air demand per membrane surface area (SAD_m) of 0.13 m³·m^-2·hr^-1 when the daily-averaged membrane fluxes for the constant flow rate and flow rate fluctuating modes of operation were set to 0.6 and 0.5 m³·m^-2·d^-1, respectively. The specific energy consumption under these operating conditions was estimated to be less than 0.37 kWh·m^-3. These results strongly suggest that operating an MBR equipped with the modified membrane element with a specific energy consumption of less than 0.4 kWh·m^-3 is highly possible.     

Organizational issues for disseminating recycling technologies of carbon fiber-reinforced plastics in the Japanese industrial landscape

Journal of Material Cycles and Waste Management - Carbon fiber-reinforced plastics (CFRP) are used for structural materials in the aircraft and automotive industries due to their lightweight and...     

Use of an ultraviolet light-activated persulfate process to degrade humic substances: effects of wavelength and persulfate dose

Environmental Science and Pollution Research - Natural organic matter (NOM), commonly found in surface and ground waters, form disinfection by-products in drinking water. Generally, advanced...     

Sesquiterpene Hydrocarbons: Kairomones with a releaser effect in the sexual communication of the white-spotted longicorn beetle, <Emphasis Type="Italic">Anoplophora malasiaca</Emphasis> (Thomson) (Coleoptera: Cerambycidae)

Summary.  We conducted a series of experiments with the white-spotted longicorn beetle Anoplophora malasiaca (Thomson), and its host plant, Citrus unshiu, to examine the origin of the sesquiterpene hydrocarbons (SHCs; including β-elemene, β-caryophyllene, α-humulene, α-farnesene, and several unidentified compounds) that are contained in the elytra of the beetles and act as an attractant. In the laboratory, mechanically wounded citrus branches, as well as those fed upon by A. malasiaca, attracted males more frequently than intact branches. Solid phase microextraction (SPME) and subsequent analyses by gas chromatography (GC) analyses detected measurable SHCs from the air around both mechanically wounded and beetle-infested branches, as well as trace amounts from intact branches. The SHCs were also detected for a certain time from beetles that had fed on the citrus branches, but the amounts decreased rapidly after they were removed from the host. This decrease generally corresponded with a reduction of attractiveness of the beetles in a behavioural assay. Isolated females acquired the SHCs after exposure to, but not upon contact with, other females that had fed on C. unshiu branches. We hypothesize that the citrus SHCs are adsorbed in, retained on, and released from the wax layer of the beetle elytra. Since these compounds are released from branches when beetles feed, they may indirectly signal the presence of beetles to others in the field. The high response rate to SHCs by males is likely representing mate searching behavior. The SHCs act as kairomones with a releaser effect in the communication system of A. malasiaca. Hiroe Yasui, Toshiharu Akino, Midori Fukaya: These authors contributed equally to this article.     

Evaluation of an electrolysis apparatus for inactivating antineoplastics in clinical wastewater

We recently reported a system for inactivating antineoplastics in which sodium hypochlorite is supplied by the electrolysis of sodium chloride solution. In this study, we designed an electrolysis apparatus for inactivating the cytotoxicity of antineoplastics in clinical wastewater using the system. The apparatus consists of an electrolysis cell with platinum-iridium electrodes, a pool tank, a circulating system for wastewater, a safety system for explosive gas and overflow, and an exhaust duct. The free chlorine concentration increased linearly up to 6500 mg l(-1), and pH also increased to 9.0-10.0 within 2h, when 0.9% sodium chloride solution was electrolyzed. We examined its efficacy with model and clinical wastewaters. The reciprocal of dilution factor for disappearance of cytotoxicity using Molt-4 cells was compared before and after electrolysis. In the model wastewater, that was 9.10 x 10(4) before electrolysis, and 3.56 x 10(2) after 2h of electrolysis. In the clinical wastewater (n=26), that was 6.90 x 10(3)-1.02 x 10(6) before electrolysis, and 1.08 x 10(2)-1.45 x 10(4) after 2h of electrolysis. Poisonous and explosive gases released by the electrolysis were measured; however, they were found to be negligible in terms of safety. The environmental load was evaluated by carbon dioxide generation as an index and it was found that the carbon dioxide generated by the electrolysis method was 1/70 lower than that by the dilution method with tap water. Moreover, the cost of the electrolysis method was 1/170 lower than that of the dilution method. This method was found to be both effective and economically valuable.     

Phytotoxicities of fluoranthene and phenanthrene deposited on needle surfaces of the evergreen conifer, Japanese red pine (Pinus densiflora Sieb. et Zucc.)

Polycyclic aromatic hydrocarbons (PAHs) have been widely studied with respect to their carcinogenic and mutagenic effects on animals and human cells. Phenanthrene (PHE) and fluoranthene (FLU) effects on the needle photosynthetic traits of 2-year-old Japanese red pine (Pinus densiflora Sieb. et. Zucc.) seedlings were investigated. Three months after fumigation of foliage with solutions containing these PAHs (10 microM each), FLU had negative effects on net photosynthesis at near-saturating irradiance, stomatal conductance, initial chlorophyll fluorescence, and the contents of total chlorophyll, magnesium, and ribulose 1,5-bisphosphate carboxylase (rubisco) of current-year needles. PHE had similar negative effects to FLU but in lesser magnitude. The effects of the PAHs were mitigated by the addition of an OH-radical scavenger (mannitol) into the PAH solutions. PAHs deposited on the surface of pine needles may induce the generation of reactive oxygen species in the photosynthetic apparatus, a manner closely resembling the action of the herbicide paraquat.     

Why is competition more intense if food is supplied more slowly?

We investigated competition for food among two groups of six clone amagos (salmonids), Oncorhynchusmasoumacrostomus, in a laboratory experiment with different rates of food input. We examined the effect of temporal clumping of food resources on the inequality of food sharing between competitors. Monopolization of food by dominants was greater at a low input rate (one food item per 10 s) than at a high input rate (1 food item per 1 s). Aggressive behavior by dominants was more frequent at the low input rate than at the high input rate; its purpose was presumably to interfere with the feeding behavior of subordinates. We assessed the relative importance of three foraging factors (the number of approaches to food items, the chance per approach and the gain per chance) in enhancing inequality in food gain between individuals. Dominants had a disproportionately high chance per approach and gain per chance at the low input rate, but not at the high input rate. The chance of obtaining a food item per approach depended on how many competitors approached simultaneously. The gain per chance depended on the competitive ability of the approaching fish. There was an interaction between these components, such that the number of approaches affected the chance per approach and gain per chance. We evaluated the independent effect of the chance per approach, and showed that it was higher for dominants than for subordinates at the low input rate, but not at the high input rate. This implies that subordinates changed their behavior and became more likely to avoid approaching food at the same time as dominants at the low input rate. Received: 13 August 1996 / Accepted after revision: 30 November 1996     

Enhanced degradation of carbazole and 2,3-dichlorodibenzo-p-dioxin in soils by Pseudomonas resinovorans strain CA10

We studied the degradation of carbazole (CAR) and 2,3-dichlorodibenzo-p-dioxin (2,3-DCDD) in soils inoculated with carbazole- and dioxin-degrader Pseudomonas resinovorans strain CA10. By using Tn5-based transposon delivery systems, this bacterium was chromosomally marked with a tandem green fluorescent protein (gfp) gene. Real-time competitive PCR and direct counting using the (gfp) marker were employed to monitor the total number of carbazole 1,9a-dioxygenase gene (carAa) and survival of CA10 cells in the soil and soil slurry microcosms. Bioaugmentation studies indicated that the survival of the marked CA10 cells in soil microcosms was strongly influenced by pH and organic matter. While the number of the marked CA10 cells decreased rapidly in pH 6 with low organic matter, a high cell density was maintained in pH 7.3 with 2.5% organic matters up to 21 days after inoculation. In pH 7.3 soil, the period needed for complete degradation of CAR (100 microg kg(-1)) was markedly shortened from 21 to 7 days by the inoculation with the CA10 cells. Single inoculation of CA10 cells into the soil slurry system of 2,3-DCDD-contaminated soil enhanced the degradation of 2,3-DCDD from 25.0% to 37.0%. In this system, the population density of CA10 cells and the total number of carAa gene were maintained up to 14 days after inoculation. By repeated inoculation (every 2 days) with CA10 cells each at a density of 10(9) CFU g(-1) of soil, almost all of the 2,3-DCDD (1 microg kg(-1)) was degraded within 14 days. Results of these experiments suggest that P. resinovorans strain CA10 may be an important resource for bioremediation of CAR and chlorinated dibenzo-p-dioxin in contaminated soils.