Overexpression of ATP sulfurylase in Indian mustard: effects on tolerance and accumulation of twelve metals

Indian mustard [Brassica juncea (L.) Czern.] transgenics overexpressing ATP sulfurylase (APS plants) were shown previously to have higher levels of total thiols, S, and Se. The present study explores the effect of ATP sulfurylase overexpression on tolerance and accumulation of other metals, both oxyanions and cations, reasoning that some anions may react directly with ATP sulfurylase, while other ions may be bound by its thiol end products. The APS transgenics were compared with wild-type plants with respect to tolerance and accumulation of As, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, V, W, and Zn, supplied individually in agar medium (seedlings) or in hydroponics (mature plants). At the seedling stage, APS transgenics were more tolerant than wild type to As(III), As(V), Cd, Cu, Hg, and Zn, but less tolerant to Mo and V. The APS seedlings had up to 2.5-fold higher shoot concentrations of As(III), As(V), Hg, Mo, Pb, and V, and somewhat lower Cr levels. Mature APS plants contained up to 2.5-fold higher shoot concentrations of Cd, Cr, Cu, Mo, V, and W than wild type. They also contained 1.5- to 2-fold higher levels of the essential elements Fe, Mo, and S in most of the treatments. Mature APS plants showed no differences in metal tolerance compared with the wild type. Overexpression of ATP sulfurylase may be a promising approach to create plants with enhanced phytoextraction capacity for mixtures of metals.     

Assessment of manure phosphorus export through turfgrass sod production in Erath County, Texas

A best management practice (BMP) for exporting manure phosphorus (P) in turfgrass sod from the North Bosque River (NBR) watershed in central Texas was assessed using a geographic information system (GIS). The NBR watershed has a mandate to reduce the total annual P load to the NBR by 50% as a result of total maximum daily load regulation. Since dairy waste applications to fields are identified as the major nonpoint source of P to the river, innovative BMPs, such as export of manure P in turfgrass, will be needed to achieve the 50% reduction. However, methods are needed to evaluate the feasibility of these innovative management practices prior to their implementation. A geospatial database of suitable turfgrass production sites was developed for Erath County using GIS. Erath County largely encompasses the upper portion of the NBR watershed. Information from field experiments, production practices, and ground-truthing was used to search, analyze, and verify a geospatial database developed from national and regional sources. The integration and analyses of large databases supports the search by turf producers for sites suitable for turfgrass sod production in Erath County. In addition, GIS enables researchers and regulators to estimate manure P exports and reduced P loading due to implementation of the manure export BMP on a county scale. Under optimal conditions 198,000 kg manure P yr(-1) could be used and 114,840 kg manure P yr(-1) exported from the NBR watershed through implementation of a system using dairy manure to produce turfgrass sod. This is the equivalent of the manure P applied from 10,032 dairy cows yr(-1) and exported from 5808 dairy cows yr(-1). Application of GIS to large-scale planning and decision-making transcends traditional field-scale applications in precision agriculture.     

Does the selection of ISO 14001 registrars matter? Registrar reputation and environmental policy statements in China

This study investigates the relationship between characteristics of environmental policy statements and the reputations of ISO 14001 registrars who had performed certification audits of firms operating in mainland China. Three characteristics of environmental policy statements were examined: (1) The conformance of the policy to strict interpretations of the international standard; (2) The policy statement's adherence to the good practice guidelines specified in ISO 14004; and, (3) Self-reported evaluations of the policy statement's effectiveness as implemented. Data from 106 facilities in Beijing, Shanghai and Guangzhou reveal that registrar quality has a relatively weak, positive relationship with conformance to both ISO 14001 standards and to ISO 14004 guidelines, but no relationship was observed with the self-reported data. Additional findings are that the use of foreign registrars is significantly associated with the adoption of ISO 14004 guidelines and that conformance with ISO 14001 standards is somewhat higher for international joint ventures and foreign-owned firms than for state-owned enterprises.     

Laboratory stabilization/solidification of tank sludges: GAAT, OHF, and combined tank sets

Highly radioactive, mixed-waste sludges that have been collected at Oak Ridge over several decades are being combined for treatment and disposal. Stabilization of the sludges in the different tank sets was tested prior to the proposed combination and treatment. This paper, which follows a previous article on the Melton Valley Storage Tank/Bethel Valley Evaporator Storage Tank set, documents the testing of the Gunite and Associated Tank and Old Hydrofracture Facility tank sets, as well as the combined sludges of all the Oak Ridge National Laboratory tank sets; the third paper on this subject will discuss efforts to maximize the sludge loading. The grout formulations were tested in the laboratory with surrogates. A wet-sludge loading of 60wt% resulted in strong wasteforms with no free water and gave a volume increase of about 30-40vol%. The Resource Conservation and Recovery Act metals included in the surrogate testing were silver, cadmium, chromium, lead, selenium, thallium, zinc, and mercury. The grout formulations stabilized these metals within the Universal Treatment Standards limits. In addition, a grout leachability index of about 10.0-12.0 was measured for both (85)Sr and (137)Cs, meeting the recommended requirement of >6.0.     

Anatomical and experimental evidence for particulate feeding in<Emphasis Type="Italic"> Lucinoma aequizonata</Emphasis> and<Emphasis Type="Italic"> Parvilucina tenuisculpta</Emphasis> (Bivalvia: Lucinidae) from the Santa Barbara Basin

Previous nutritional models for adults of the lucinid bivalve Lucinoma aequizonata contend that symbiotic chemoautotrophic bacteria provide most of the organic carbon for the host. The existence of this symbiosis, coupled with the hosts distinctive anatomical features, shaped the impression that particulate feeding was not a significant part of L. aequizonata nutrition. Here, we use several techniques to show that particulate feeding is a consistent and important part of the L. aequizonata nutritional strategy. Histological and scanning electron microscopy observations reveal that the gills of L. aequizonata, like those of the lucinid Parvilucina tenuisculpta, have functional mucociliary epithelia, able to transport captured particles to the mouth. Observations of gut content and radiolabeled feeding experiments indicate that L. aequizonata does ingest and assimilate carbon from particulate organic matter. Furthermore, molecular identification of a broad spectrum of organisms in the guts of native adult specimens demonstrates that L. aequizonata is non-selective when ingesting organic material, and has a mixotrophic diet.Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by P.W. Sammarco, Chauvin     

Biodegradation of phthalate esters by two bacteria strains

In this study two aerobic phthalic acid ester (PAE) degrading bacteria strains, DK4 and O18, were isolated from river sediment and petrochemical sludge, respectively. The two strains were found to rapidly degrade PAE with shorter alkyl-chains such diethyl phthalate (DEP), dipropyl phthalate (DPrP), di-n-butyl phthalate (DBP), benzylbutyl phthalate (BBP) and diphenyl phthalate (DPP) are very easily biodegraded, while PAE with longer alkyl-chains such as dicyclohexyl phthalate (DCP) and dihexyl phthalate (DHP) and di-(2-ethylhexyl) phthalate (DEHP) are poorly degraded. The degradation rates of the eight PAEs were higher for strain DK4 than for strain O18. In the simultaneous presence of strains DK4 and O18, the degradation rates of the eight PAEs examined were enhanced. When the eight PAEs were present simultaneously, degradation rates were also enhanced. We also found that PAE degradation was delayed by the addition of nonylphenol or selected polycyclic aromatic hydrocarbons (PAHs) at a concentration of 1 microg/g in the sediment. The bacteria strains isolated, DK4 and O18, were identified as Sphigomonas sp. and Corynebacterium sp., respectively.     

Effects of the mosquito larvicide GB-1111 on bird eggs

Golden Bear Oil (GB-1111; legal trade name for GB-1313) is a petroleum distillate used in the United States and other countries as a mosquito larvicide. As part of an evaluation of the potential effects of GB-1111 on birds, fertile eggs of mallards (Anas platyrhynchos) and bobwhite (Colinus virginianus) were incubated in the laboratory, and treated on day 4 of incubation with external applications equivalent to either 0, 1/3, 1, 3 or 10 times the maximum rate (X) of 47 l/ha (5 gal/A) of field application of GB-1111. Hatching success was significantly reduced in mallards treated at 3 and 10 times the maximum field application, with a calculated approximate LD50 of 1.9 times the maximum field application. Most mortality occurred within a week of treatment. Hepatic P450-associated monooxygenase activity (ethoxyresorufin-O-dealkylase; EROD) was negatively related to dose. In the 3X group there was a significant increase in the concentration of hepatic reduced glutathione (GSH) but a decrease in protein-bound thiols (PBSH). Hatching success of bobwhite was marginally reduced at the highest level of treatment (10X). Other effects at this level in bobwhite included a significant increase in incidence of abnormal embryos or hatchlings, lower body and liver weights, and a two-fold increase in hepatic microsomal EROD activity in hatchlings. The recommended maximum rate of field application of GB-1111 is unlikely to impair the survival or development of bobwhite embryos but is potentially toxic to mallard embryos under conditions of larvicide drift or spray overlap.     

Field investigation into unsaturated flow and transport in a fault: model analyses

Results of a fault test performed in the unsaturated zone of Yucca Mountain, Nevada, were analyzed using a three-dimensional numerical model. The fault was explicitly represented as a discrete feature and the surrounding rock was treated as a dual-continuum (fracture-matrix) system. Model calibration against seepage and water-travel-velocity data suggests that lithophysal cavities connected to fractures can considerably enhance the effective fracture porosity and therefore retard water flow in fractures. Comparisons between simulation results and tracer concentration data also indicate that matrix diffusion is an important mechanism for solute transport in unsaturated fractured rock. We found that an increased fault-matrix and fracture-matrix interface areas were needed to match the observed tracer data, which is consistent with previous studies. The study results suggest that the current site-scale model for the unsaturated zone of Yucca Mountain may underestimate radionuclide transport time within the unsaturated zone, because an increased fracture-matrix interface area and the increased effective fracture porosity arising from lithophysal cavities are not considered in the current site-scale model.     

Effects of basic oxygen furnace slag and inorganic nutrients on the germination of resting cysts of two toxic dinoflagellates

Effects of basic oxygen furnace (BOF) slag, inorganic nutrients and H2S on the germination of resting cysts of two toxic dinoflagellates Alexandrium catenella/tamarense and Gymnodinium catenatum were studied in batch cultures. The germination rate of the test species has increased by 23-25%, when the concentration of NO3--N or H2S in culture medium has increased to 2.0 ppm. At the treatment of enriched NH4+-N and PO43--p, the germination of resting cyst was increased. Nevertheless, the increased range in germination rates was less than those of NO3--N and H2S. When BOF slag in culture medium increased to 50 mg/ml (or 500 g/m2), the cyst germination rate fell to less than 5%. At higher level of concentrations germination was completely inhibited. Adding BOF slag to the culture medium reduced the concentration of inorganic salts and H2S in seawater and sediments, resulting in the inhibition of cyst germination. These findings demonstrate the potential use of BOF slag on the sediments seed bank of red tide organism because it has an ability to inhibit resting cysts germination.     

PeLM: modeling of pesticide-losses through runoff and sediment transport

A GIS-aided pesticide loss model (PeLM) was developed to simulate pesticide losses through surface runoff and sediment transport in watershed systems. The PeLM could tackle the movement of eroded soil along with surface runoff as well as the pesticide losses in adsorbed and dissolved phases. The contributions of different soil types in the sediment were also examined. The model was applied to the Kintore Creek Watershed of southern Ontario, Canada. The simulation results were verified through observed data, indicating a correlation level of 0.89-0.98. The results also showed that clay particles usually held the largest share of contributions to pesticide losses through soil erosion. This study is significant in the efforts for modeling nonpoint source pollution in watershed systems. It provides useful information and support for the related decisions of watershed management.