Environmental Science

The synthesis of a novel nanocomposite sorbent material, copper ferrocyanide immobilized within a mesoporous ceramic matrix, and its use as a novel cesium sorbent material is reported in this paper. Complete removal of cesium was achieved in the presence of competing metal ions for solutions containing 2 ppm cesium under a variety conditions. Loading capacity of more than 1.35 mmol Cs per g of sorbent material has been achieved. The exceptionally fast binding kinetics and high loading capacity, resulting from the rigidly open pore structure and extremely high surface area of the sorbent materials, make them potentially very useful for the removal of cesium from nuclear wastes and contaminated groundwater.

Arsenic contamination of groundwater has recently commanded widespread public attention. Under many conditions, arsenic, and certain other environmentally relevant toxic metals such as chromium, exist in nature as oxyanions. Selective binding of anions is one of the ...

A long-term field experiment was conducted to determine the effect of the additions of urban waste compost on the physical and chemical properties and enzymatic activities in a calcareous soil (Fluventic Xerochrept). Total Porosity (pores >50 pm measured on thin soil sections from undisturbed samples by image analysis) was greater in the plots treated with compost than the control plots

The Orinoco Delta is one of the world’s last great river deltas with pristine ecosystems. But it is also an important oil and gas reservoir area. Currently, little scientific and factual knowledge is available to assess the effect of oil exploitation activities. Understanding vegetation and soils relationships is fundamental to delineate conservation strategies to maintain species richness, essential ecological processes and life support systems. To meet these needs, our research objectives were to characterize soil conditions supporting different vegetation units of the Lower Orinoco Plain and to relate soil characteristics with vegetation assemblages. For these purposes, surface and bottom soil samples were taken in 227 sites, which were distributed proportionally to each vegetation unit coverage. Samples were analysed for salinity, chlorides, carbonates, pH, organic carbon, exchangeable acidity, aluminium, hydrogen, calcium, potassium and sodium. Average thickness of the surface organic layer was 2.32 m, reaching 6 m in some places. Organic carbon content did not differ significantly among soils from different vegetation units. Lowest surface pH values were found in forests and meadows (< 4.5). Bottom pH was less variable and almost neutral. The highest salinity values were found in mangrove soils (1.80‰ ± 0.12), the lowest in palm forests (0.06‰ ± 0.02). Main differences among soil samples were related with cation exchange capacity (68.3 meq/100g ± 81.5), percent base saturation (91.9% ± 11.0), and acidity (2.30 meq/100g ± 3.46). Our results indicated that content of salts and cations and soil acidification were the main factors in determining vegetation arrangements. Keywords: soil acidity, organic matter, salinity, cation exchange capacity, mangroves, swamp forests, meadows.

Acid-sulphate soils are of major environmental concern in many wetlands. Severe acidification episodes have occurred worldwide because of the oxidation of iron sulphides to sulphuric acid by human activities, and diverse techniques have been set up to determine the presence of acid-sulphate soils. This paper evaluates the usefulness of four common easy-to-apply field survey tests for potential acid-sulphate diagnosis in some Histosols and Entisols in wetlands: incomplete oxidation by fast air-drying, incubation, fast oxidation with hydrogen peroxide, and the indirect determination of sulphide with lead acetate. Samples of 227 surface-organic and underlying mineral soils of poorly drained Histosols and Entisols of the Orinoco river delta plain were tested. Results showed that for highly organic samples the interpretation of results obtained from the acid-sulphate soil tests may be misleading, because they cannot be unambiguously related to the production of sulphuric acid derived from pyrite oxidation. Mineral samples yielded more reliable results. The incomplete oxidation by fast air-drying test did not induce significant acidification either in organic or in mineral samples; the final pH values were dependent on the original pH values. The fast oxidation with hydrogen peroxide test was effective with mineral samples. During the incubation test, the slower rate of pH decrease and the final values obtained with the organic samples suggested retardation in the rate and amount of acid generation by pyrite oxidation because of the concurrent oxygen consumption by organic matter and bacterial activity. The indirect determination of sulphide with lead acetate yielded only qualitative results in organic samples, but worked well in mineral samples, indicating a higher content of pyrite intermediates. Effective estimation of the actual presence and potential for acidification of soil is important, in order to avoid excessive or inappropriate amelioration techniques to prevent acid production.

It has been hypothesized that colloidal forms of trace metals can be reactive intermediaries in the scavenging processes leading to the removal of their particulate forms. A series of radiotracer experiments using natural colloidal organic matter from Galveston Bay, USA were carried out in order to test this hypothesis. Suspended particle uptake of originally colloidally bound trace metals occurred in

Approaches in environmental risk assessment for pesticides are becoming more and more realistic. Thereby, risk assessment has to be protective in a way that no long-lasting (adverse) effects on populations will occur in the environment. Since this imperative includes species generally showing high population vulnerability due to their life history traits, prospective risk assessment should be based on realistic worst cases. Based on life history traits, the purpose of the current study was to verify whether a worst case combination of low potential for intrinsic recovery and low ability for recolonisation can be found in the field. Combinations of traits related to dispersal ability and reproduction of macroinvertebrates were investigated using monitoring data from edge of field water bodies in Germany. The relative distribution of traits was analyzed across different agricultural regions and across sites of different potential for exposure to pesticides. Species were sorted in a tiered approach in order to gain a list of realistic worst case species. Life history traits were found equally distributed across different regions. Thereby, dispersal ability and voltinism were not randomly combined. Within the data analysed, low dispersal ability was found to be exclusive to semivoltine taxa. Owing to their appearance in reference sites, poor dispersal ability and a long time reproduction, three species were considered potentially worst case. The trait approach was found to be suitable in comparing trait distributions within different regions and in compiling a list of critical taxa for consideration in environmental risk assessment.

Standard species used in ecological risk assessment are chosen based on their sensitivity to various toxicants and the ease of rearing them for laboratory experiments. However, this mostly overlooks the fact that species in the field that may employ variable life-history strategies, which may have consequences concerning the vulnerability of such species to exposure with contaminants. We aimed to highlight the importance of copepods in ecology and to underline the need to include freshwater copepods in ecotoxicology. We carried out a literature search on copepods and Daphnia in ecology and ecotoxicology to compare the recognition given to these two taxa in these respective fields. We also conducted a detailed analysis of the literature on copepods and their current role in ecotoxicology to characterize the scale and depth of the studies and the ecotoxicological information therein. The literature on the ecology of copepods outweighed that in ecotoxicology when compared with daphnids. Copepods, like other zooplankton, were found to be sensitive to toxicants and important organisms in aquatic ecosystems. The few studies that were conducted on the ecotoxicology of copepods mainly focused on marine copepods. However, very little is known about the ecotoxicology of freshwater copepods. To enable a more realistic risk higher tier environmental risk assessment, we recommend considering freshwater copepods as part of the hazard assessment process. This could include the establishment of laboratory experiments to analyse the effects of toxicants on copepods and the development of individual-based models to extrapolate effects across species and scenarios.

The recently established Center for Fire Research and Outreach at the University of California, Berkeley has developed a web-based toolkit, the Fire Information Engine Toolkit (FIET), for wild- fire-related needs. The FIET is intended to meet the needs of diverse user groups (homeowners, decision-makers, including fire operations, and researchers) at a variety of scales (local, community, and regional levels) before,

In the present study, fly ashes (FAs) from four (4) lignite-fired power stations of Greece were utilized for the precipitation of hexavalent chromium [Cr(VI)] and other heavy metals (Cu, Ni, Pb and Zn) from aqueous solutions. Actually, representative FA samples from the region of Ptolemais, Northern Greece (PFA, intensely calcareous), Amynteon, Northern Greece (AFA, calcareous), Florina, Northern Greece (FFA, siliceous) and Megalopolis, Southern Greece (MFA, siliceous, barely Class C) were collected from the electrostatic precipitators of the respective power plants. Each FA sample was separated into five (5) different fractions with a grain diameter range of: [(0-25) (25-45) (45-90) (90-150) (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;150)] μm. The different FA grain fractions were evaluated in terms of their chemical composition, pH, loss on ignition (LOI) and CaOf (%). Since parameters such as free CaO (and consequently pH) and unburned carbon (Figs 1 and 2) are critical for the removal of heavy metals by inorganic adsorbents, it was necessary to test the FAs not only in an “as received” basis but also as a function of their particle size distribution. That is because fly ash is an extremely inhomogeneous material and different compounds are concentrated in the various fine and coarse particles; this process is influenced by both the extraction and combustion of lignite. Indeed, fine particles contain large amounts of CaOf and have no unburned carbon, while coarse particles obtain high percentages of LOI, because of their bigger density, which leads to their time-limited presence within the combustion chamber. The intermediate grain fraction presents larger percentages of silicon and less calcium. Batch adsorption experiments were carried out by adding 10g of each FA type and fraction in 50ml of Cr(VI)-Cu-Ni-Pb-Zn aqueous solution (1g of each metal/1L of solution) in glass tubes and then implementing mechanical stirring at 200rpm. The incubation period was set at 24h. The supernatant solution was filtered and subjected to spectroscopy using N, N-diphenyl carbazide reagent (at a wavelength of 540nm) to determine the remaining concentrations of Cr(VI) and to atomic adsorption spectroscopy (AAS) to determine that of the rest heavy metals. The transfer of Cr(VI) increases with time and reaches a maximum at 3 to 4h, depending on the FA sample. The uptake of all the pollutants, by all the examined samples, was completed after 4.5h, since no practical change was detected up to the period of 24h. It seems that, in the case of calcareous fly ashes from Northern Greece, fine-grained fractions are more effective in uptaking Cu, Ni, Pb and Zn but not Cr(VI). That fact is attributed to their high pH values (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;11.50) which are prohibitive for the removal of hexavalent chromium, although beneficial on the occasion of the rest metals. The higher adsorption of Cr(VI) at low pH values is attributed to the neutralization of negative surface charge by an excess of hydrogen ions, thereby facilitating the diffusion of dichromate ions and their adsorption on the adsorbent (FA). Thus, the various fractions of the silicious MFA were better at the precipitation of Cr(VI) but less capable of retaining Cu, Ni, Pb and Zn. It is verified, via this research study, that fly ashes can be more effective in the field of industrial wastewater remediation when separated into their fractions, as different groups of FA particles demonstrate different kinds of the desirable properties. It therefore depends on the nature of the pollutant-to-be retained, the optimum FA type (and fraction) to be selected.

... CA982125 Wet Oxidation of Phenolic Solutions over Heterogeneous Catalysts: Degradation Profile and Catalyst Behavior Safia Hamoudi, Fa~qal Larachi,1 and Abdelhamid Sayar! ... 29. Smith, JM, &amp;amp;amp;amp;quot;Chemical Engineering Kinetics,&amp;amp;amp;amp;quot; 3rd ed., p. 486. McGraw-Hill, New York,1981. ...

... John Njagi, Cristina Ispas and Silvana Andreescu. Analytical Chemistry 2008 80 (19), 7266-7274. ... Suresh K. Bhargava, James Tardio, Jaidev Prasad, Karl Föger, Deepak B. Akolekar, and Stephen C. Grocott. Industrial &amp;amp;amp;amp; Engineering Chemistry Research 2006 45 (4), 1221-1258. ...

Calculations of the QBO signal in SAGE II O3 and NO2 data between 1984 and 1991 are presented and have been investigated by using a two-dimensional model. The isentropic 2D model is a fully interactive radiative-dynamical-chemical model in which the eddy fluxes of chemical species are calculated in a consistent manner. The QBO in the model has been forced by relaxing the equatorial zonal wind toward the observations at singapore allowing the comparison of the model with observations from specific years. The model reproduces the observed vertical structure of the equatorial ozone anomaly with the well-known transition from dynamical to photochemical control at around 28 km. The model also reproduces the observed vertical structure of the SAGE II observed NO2 anomaly. The model studies have shown that it is the QBO modulation of NO2 which is the main cause of QBO signal in O3 above 30 km. The model also reproduces the observed latitudinal structure of the QBO signals in O3 and NO2. Due to the differing horizontal distribution of O3 and NOy the ozone signal shows a distinct phase change in the subtropics whereas the NO2 anomaly gives a broader signal.

This May 2004 application requested that the Ministry of the Environment (MOE) review O. Reg. 73/94, the General Regulation under the Ontario Environmental Bill of Rights, to determine whether the Ministry of Education (EDU) should be added as a prescribed ministry under the EBR.  When the EBR was first proclaimed in February 1994, the Ministry of Education was not listed as a prescribed ministry in O. Reg. 73/94.  Thus, the Ontario government of the day decided not to require EDU to develop a Statement of Environmental Values (SEV) and post notices on the Registry inviting public comments on proposed decisions for environmentally significant Acts and policies before the Minister makes decisions on these matters.  The applicants believe that the decision to exempt EDU from the EBR has had a negative impact on ministry decision-making related to the financing and support of environmental education and outdoor education.

Background on the 1999 EBR Application: In late 1999 a similar request for a review under the EBR was filed by one of the May 2004 applicants.  MOE accepted the review but took more than one year to complete it, and concluded that the purposes of the EBR would not be furthered by making EDU subject to the Act.  MOE's rationale was that in practice, few if any of EDU’s policies, Acts or regulations would need to be posted on the Registry, nor would they be open to review under the EBR.  MOE also noted that the public already has an existing right to send letters to the Minister of Education, requesting changes in policy decision.  While the 1999 request was denied by MOE, the ECO published an article about the issue of prescribing EDU in our 2000/2001 ECO annual report (see pp. 165-166).  The ECO did not agree with MOE's conclusions, noting that EDU is similar to a number of other currently prescribed ministries which do make some decisions that can have an effect on the environment, even though their core mandate is not environmental protection.  The ECO also argued that the right to mail a letter to a minister is not a reasonable replacement for the right to request a review under the EBR which is a much more transparent, public process including timelines, oversight by the ECO and accountability to the Ontario Legislature and the public.

The May 2004 application: The applicants drew on the previous 1999 application and the 2000/2001 ECO annual report in formulating their May 2004 application.  They noted that many things had changed since the original 1999 application was filed.  The applicants pointed to research delineating a decline in environmental literacy in Ontario and how this can be linked to real world problems:

1. Province-wide research on ecological literacy at secondary level

The applicants made reference to a number of research studies conducted between 1999 and 2004 by a team of researchers.  One of the applicants, Dr. Tom Puk of Lakehead University, was the principal researcher for all of the studies.  While the applicants did not provide copies of all of the studies, some of them were available in published journals.  The application also provided extensive extracts from the studies.

The key research study referred to by the applicants was a 2001 report on ecological literacy at secondary school level demonstrating that "students in Ontario are not ecologically literate because they are not being taught ecological education" because it is absent from the curriculum. 

Rhizobacteria are root-colonizing, non-pathogenic, and their association with the roots of plant improves productivity and tolerance of abiotic stress such as heavy metal toxicity. Inoculation against biotic stresses also increases tolerance against heavy metal toxicity. Rhizobacteria might also increase nutrient uptake from soils that prevents the uptake and accumulation of nitrates and phosphates in agricultural soils. Also, some useful bacteria-mediated plants showed gene-expressions during plant-rhizobacteria interaction. Mining activities affect plant and health via water through: the method of extraction; contamination of local water sources as well as having harmful effects on the environment such as beach erosion from sand mining or by longer term effects on reducing microbial and biodiversity populations. Here, we review the current understanding of the physiological implications of rhizobacteria in the alleviation of heavy metal toxicity in plants, enabling cross-protection in agricultural advancement systems affected by growing climatic changes in natural conditions.