Volatile emissions from the flea beetle Altica litigata (Coleoptera: Chrysomelidae) associated with invasive Ludwigia hexapetala

The flea beetle Altica litigata (Chrysomelidae) is an insect herbivore to plants within the families Lythraceae and Onagraceae, including ornamentals such as crape myrtle, Lagerstroemia spp. This insect is important both as a pest species and as a naturally occurring biological control agent due to its aggregate feeding behavior, which typically results in severe defoliation of the host plant. Despite the negative economic impact to ornamentals and contrary benefits as a biological control agent, there are few reports on the semiochemical communication of this family of insects. Uruguayan primrose-willow (Ludwigia hexapetala) is an invasive aquatic weed in California and serves as a host to A. litigata. To better characterize this association, the volatile emissions of A. litigata were collected while the flea beetles were: in containers by themselves, in containers with L. hexapetala leaves, in situ on L. hexapetala leaves in a growth chamber, and in situ on L. hexapetala leaves in the field. For comparison, the volatile emissions of A. litigata associated with two subspecies of creeping water primrose (L. peploides) were also evaluated. Two himachalene-type sesquiterpenes, showing the same carbon skeleton as compounds previously reported from Aphthona flava and Epitrix fuscula, were detected as volatiles from A. litigata.     

Health risk assessment of organochlorine pesticides with emphasis on DDTs and HCHs in abandoned agricultural soils

The aim of this study was to evaluate the consequence of changing land use from agriculture land to other use purposes with respect to OCPs non-cancer and cancer risk on human health, based on concentrations of DDTs and HCHs in soils collected from 55 locations representing 12 different land use types. There were no non-cancer risks of DDTs and γ-HCHs on adults and children, and there were very low cancer risks of DDD, o,p'-DDE, DDT, α-HCH, β-HCH, γ-HCH based on their total concentrations in all samples. Nonetheless, there were significant correlations of DDT to its metabolites (DDE and DDD) (r = 0.506 and r = 0.648) and DDE to DDD (r = 0.438) both at p < 0.01. OCP levels should be routinely monitored in different environmental media and food in order to verify whether there is fresh input. Their potential risks on human health should also be assessed.     

Non-hazardous waste generation characteristics and recycling practices in Saskatchewan and Manitoba,Canada

The paper presents the results on the analysis of non-hazardous waste generation characteristics and recycling practices in Saskatchewan (SK) and Manitoba (MB) using the biennial waste reports published by Statistic Canada. The objectives are to examine the waste generation rates from both residential and non-residential sources from 1998 to 2010, and to evaluate the effectiveness of their recycling programs and regulations. In spite of the many similarities between the provinces, MB on average generated 17.5 % more residential waste than SK, and about 15 % less non-residential waste than SK during the study period. It appears that MB waste generation characteristics were very different from SK and the rest of Canada. The amount of MSW generation in MB was, to a certain degree, independent from the economic factors. Assuming status quos conditions, the linear models predicted that the per capita MSW generations in MB would be about 33 % lower than SK in 2020. Data from this study suggest that (1) curbside recycling programs and (2) pay-as-you-throw collection systems may be important factors for increasing diversion rate in SK. It is also found that the non-residential waste generation in Canada was substantially larger than the residential waste generation during the 13-year period.     

Wash water in waterworks: contaminants and process options for reclamation

Reclamation of clean water from filter backwash water was studied through pilot-scale experiments.The pilot plant consisted of clarification,sand-filtration,and ultrafiltration modules in sequence,with a provision to bypass the sand filter.Clean water that conformed to World Health Organization (WHO) guidelines on Potable Quality was reclaimed.Turbidity,aluminum and iron were found to be critical contaminants in process selection and design.Clarification,followed by sand filtration,was found to be the minim...     

Influence of bacteria on Pb and Zn speciation, mobility and bioavailability in soil: A laboratory study

A soil column experiment was carried out to investigate the effects of inoculation of bacteria on metal bioavailability, mobility and potential leachability through single chemical extraction, consequential extraction and in situ soil solution extraction technologies. Results showed that bacteria inoculated, including Azotobacter chroococcum, Bacillus megaterium and Bacillus mucilaginosus, may pose both positive and negative impacts on bioavailability and mobility of heavy metals in soil, depending on the chemical nature of the metals. The activities of bacteria led to an increase of water dissolved organic carbon (DOC) concentration and a decrease of pH value, which enhanced metal mobility and bioavailability (e.g. an increase of water-soluble and HOAc-soluble Zn). On the other hand, bacteria could immobilize metals (e.g. a great reduction of water-soluble Pb) due to the adsorption by bacterial cell walls and possible sedimentation reactions with phosphate or other anions produced through bacterial metabolism.     

Kinetic studies on phosphorus sorption by selected soil amendments for septic tank effluent renovation

A systematic kinetic study of phosphorus (P) sorption by various materials in the soil infiltration system of septic tanks was undertaken by following the time course of P sorption by sorbents in contact with various P solutions over periods up to 360 days. Uptake of P seemed to consist of two distinct stages. Initial uptake was very rapid and this phase was completed in 4 days or less. A slower removal stage followed for some materials over many months. Phosphorus sorption during the fast reaction stage appeared to be associated with the soluble Ca content of the materials. The fast reaction of calcareous materials accounted for the bulk (>70%) of the total P removed. Merribrook loamy sand exhibited the highest proportion of P sorption during the slow phase. It should be noted, however, that for solution P concentrations in the range found in typical effluents (∼ ∼20 mg L⁻¹) the fast reaction phase seemed to be responsible for virtually all P removed. None of the six kinetic formulae examined possessed the sophistication and detail needed to portray accurately the time course of P sorption for all the sorbents investigated. The Elovich equation and the kinetic modification of the Freundlich isotherm expression appeared to provide a reasonable fit of the experimental data.     

Energy maximization by selective feeding on tissues of the venerid clam <Emphasis Type="Italic">Marcia hiantina</Emphasis> in the marine scavenger <Emphasis Type="Italic">Nassarius festivus</Emphasis> (Gastropoda: Nassariidae)

Feeding selectivity of the intertidal scavenging gastropod Nassarius festivus on four types of tissue (soft tissue, adductor muscle, foot, mantle margin) of the venerid clam Marcia hiantina was studied by field observations and laboratory experiments. Both approaches showed similar results with the soft tissue and adductor muscle being much preferred. As the energy content of the four types of tissue was similar and individuals of N. festivus rearing in different types of tissue obtained similar growth rates both in shell length and in body wet weight, differential consumption was most likely determined by the palatability of the tissues. Energy intake in a meal for N. festivus was estimated at 10.92, 9.17, 3.86 and 2.02 cal meal⁻¹ ind⁻¹ for soft tissue, adductor muscle, mantle margin, and foot, respectively. In view of the small size and sporadic distribution of the carrion, and intense competition among the conspecifics, selective feeding on more palatable tissues maximizes energy intake for scavengers like N. festivus.     

Photoreduction of Cr(VI) in wastewater by anodic nanoporous Nb2O5 formed at high anodizing voltage and electrolyte temperature

Environmental Science and Pollution Research - In this study, nanoporous anodic film was produced by anodization of niobium, Nb in a fluoride ethylene glycol electrolyte. The effect of anodization...     

Controlled release fertilizers (CRFs) for climate-smart agriculture practices: a comprehensive review on release mechanism,materials, methods of preparation,and effect on environmental parameters

Environmental Science and Pollution Research - Fertilizers play an essential role in increasing crop yield, maintaining soil fertility, and provide a steady supply of nutrients for plant...