Spatial Relationships Between Water Quality and Pesticide Application Rates in Agricultural Watersheds

Pesticide applications to agricultural lands in California, USA, are reported to a central data base, while data on water and sediment quality are collected by a number of monitoring programs. Data from both sources are geo-referenced, allowing spatial analysis of relationships between pesticide application rates and the chemical and biological condition of water bodies. This study collected data from 12 watersheds, selected to represent a range of pesticide usage. Water quality parameters were measured during six surveys of stream sites receiving runoff from the selected watershed areas. This study had three objectives: to evaluate the usefulness of pesticide application data in selecting regional monitoring sites, to provide information for generating and testing hypotheses about pesticide fate and effects, and to determine whether in-stream nitrate concentration was a useful surrogate indicator for regional monitoring of toxic substances. Significant correlations were observed between pesticide application rates and in-stream pesticide concentrations (p < 0.05) and toxicity (p < 0.10). In-stream nitrate concentrations were not significantly correlated with either the amount of pesticides applied, in-stream pesticide concentrations, or in-stream toxicity (all p > 0.30). Neither total watershed area nor the area in which pesticide usage was reported correlated significantly with the amount of pesticides applied, in-stream pesticide concentrations, or in-stream toxicity (all p > 0.14). In-stream pesticide concentrations and effects were more closely related to the intensity of pesticide use than to the area under cultivation.     

Ten years later: The progress and future of integrating sustainable principles,practices, and metrics into remediation projects

In 2009, the Sustainable Remediation Forum released a white paper entitled “Integrating sustainable principles, practices, and metrics into remediation projects” (Ellis & Hadley, 2009, Remediation, 19, pp. 5–114). Sustainable remediation was a relatively new concept, and the white paper explored a range of approaches on how sustainability could be integrated into traditional remediation projects. This paper revisits the 2009 white paper, providing an overview of the early days of the evolving sustainable remediation practice and an assessment of the progress of sustainable remediation over the last 10 years with a primary focus on the United States. The current state of the sustainable remediation practice includes published literature, current practices and resources, applications, room for improvement, international progress, the virtuous cycle that applying sustainable remediation creates, and the status of the objectives cited in the 2009 white paper. Over the last decade, several sustainable remediation frontiers have emerged that will likely be a focus in advancing the practice. These frontiers include climate change and resiliency, weighting and valuation to help better consolidate different sustainable remediation metrics, programmatic implementation, and better integration of the societal impacts of sustainable remediation. Finally, as was the case for the 2009 white paper, this paper explores how sustainable remediation may evolve over the next 10 years and focuses on the events and drivers that can be significant in the pace of further development of the practice. The events and drivers include transformation impacts, societal influences, and the continued development of new technologies, approaches, and tools by remediation practitioners. The remediation industry has made significant progress in developing the practice of sustainable remediation and has implemented it successfully into hundreds of projects. While progress has been significant, an opportunity exists to implement the tenets of sustainable remediation on many more projects and explore new frontiers to help improve the communication, integration, and derived benefits from implementing sustainable remediation into future remediation projects.     

Environmental geochemistry of technetium

Technetium-99 (⁹⁹Tc) is a radioactive isotope with a half-life of 2.13 × 10⁵ year. ⁹⁹Tc is a major radionuclide contaminant of concern for the world. Therefore, detailed understanding of ⁹⁹Tc environmental chemistry is important for protecting human and ecological health. Here, we review the aqueous geochemistry of ⁹⁹Tc, focusing on chemical properties and behavior of ⁹⁹Tc in the hydrosphere and pedosphere. We describe the general chemistry of Tc including coordination chemistry, isotope chemistry and solid-state chemistry. Then we present anthropogenic and indigenous sources of ⁹⁹Tc and their environmental distribution. We also discuss the radiotoxicity of ⁹⁹Tc and the use of ⁹⁹Tc for medical purpose. Tc biogeochemistry is described through sorption and desorption reactions at the mineral–water interface, thermodynamic of surface complexation, abiotic and biotic redox reaction of Tc(VII). Finally, we summarize the ⁹⁹Tc remediation technologies including cement waste forms, natural remediation, vitrification, nuclear waste transmutation.     

Heterogeneous alternative catalysts: A bibliometric and systematic evaluation of their application in solar photocatalytic processes

The present study sought to objectively demonstrate how a researcher can, in a structured way, select relevant articles about alternative heterogeneous catalysts in photocatalytic processes. Therefore, the ProKnow-C (Knowledge Development Process – Constructivist) method was used to systematize the results found, with the application bibliometric and systematic analysis techniques for the evaluation of the results. The search string adopted as criteria was: solar photocatalysis AND heterogeneous catalysts OR alternative catalysts AND effluents. The databases were Web of Science, Science Direct and Scopus. The final bibliographic portfolio obtained for the research theme was made up of 19 articles. It was possible to verify advances in the number of publications on the theme over the evaluated period, with the Journal of Photochemistry and Photobiology A: Chemistry standing out in the final portfolio. Evaluating each article in the portfolio individually, it was possible to verify that most studies use combinations of catalysts already reported to create an alternative material to those already investigated in the literature. Those that use waste as catalysts chose to source this material from treatment plants and the steel industry. Around 58% of the papers used hydrogen peroxide in their processes, while 42% chose not to use it. Finally, approximately 63% of the papers in the portfolio used synthetic effluent in their processes, while the rest (37% of the research) chose to use real effluent. The results obtained in this research by applying the method can contribute to studies related to heterogeneous photocatalysis by alternative means over the years.     

Suggested Guidelines for Use of Avian Species as Biomonitors

An animal’s suitability as a biomonitor of environmental change can be determined by biological, reproductive and ecological characteristics determined at the class, order and species level. The animal’s habitat where the research is to be performed and the form, function and structure of the environmental change being studied within that habitat also determines suitability. Non-threatened populations of large, non-migratory, long-lived, seasonally-breeding tertiary avian predators, whose dietary preferences are narrow and known, can be useful as monitors of environmental chemical contaminants. If chemicals are being monitored, a quantifiable endpoint effect must be demonstrated in the species, or a similar species under experimental laboratory conditions. Logistical and economic issues as well as public and regulatory authority acceptance should also be considered when assessing the suitability of a species as a biomonitor.     

Copper activity in soil solutions of calcareous soils

Copper partitioning was studied in seven calcareous soils at moisture content corresponding to 1.2 times the field moisture content (soil water potential 7.84 J kg(-1)). Copper retention was accompanied by the release in soil solution of Ca(2+), Mg(2+), Na(+), and H(+), and the total amount of these cations released was 0.8 to 1.09 times the amount of Cu sorbed (mol(c):mol(c)). The relationships between Cu activity and pH, and the balance of cations in soils correspond with the surface precipitation of CuCO(3) as the main mechanism of Cu retention. The values of ion activity product of surface precipitate were close for all studied soils with the average log(IAP(CuCO(3)))=-15.51. The relationship between copper activity in soil solutions and soil properties is well fit by a regression relating pCu (-log copper ion activity) with soil pH, total Cu, and carbonate content.     

Consumer resource matching in urbanizing landscapes: are synanthropic species over-matching?

Population responses of synanthropic species to urbanization may be explained by the resource-matching rule, which postulates that individuals should distribute themselves according to resource availability. According to the resource-matching rule, urban habitats will contain greater densities if they provide better resources than rural habitats. However, because resource availability is density dependent, individuals in urban areas would ultimately achieve fitness levels comparable to, but no better than, individuals in less urban areas. Some ecologists suggest that synanthropic birds may not conform to the resource-matching rule and may instead overmatch (i.e., overexploit) in urban habitats, ultimately leading to lower fitness despite greater resource levels. Using the Northern Cardinal (Cardinalis cardinalis) as a focal species, we evaluated if Cardinal populations in urban and rural habitats were consistent with predictions of consumer resource matching. During 2003-2006 we documented population density, adult body condition, apparent survival, and annual reproductive productivity of Cardinals in riparian forest stands within urban (n = 8 stands) and rural (n = 6 stands) landscapes in Ohio, USA. Density of Cardinals in urban forests was four times that found in more rural forests. Mark-resight data from 147 males and 125 females over four years indicated that apparent survival rates were similar between urban and rural landscapes (phi = 0.64, SE = 0.039 for males and phi = 0.57, SE = 0.04 for females). Similarly, body condition indices of 168 males, 142 females, and 118 nestlings did not differ significantly between landscapes. Annual reproductive productivity (mean number of fledglings per pair over breeding season) of 294 pairs was comparable for urban (2.4 +/- 0.18 [mean +/- SE] and rural (2.1 +/- 0.18) young birds. Thus, contrary to recent suggestions, we find that high densities of certain synanthropic species in urban landscapes are consistent with expectations of consumer resource matching.     

Phenology of mixed woody-herbaceous ecosystems following extreme events: net and differential responses

Ecosystem responses to key climate drivers are reflected in phenological dynamics such as the timing and degree of "green-up" that integrate responses over spatial scales from individual plants to ecosystems. This integration is clearest in ecosystems dominated by a single species or life form, such as seasonally dynamic grasslands or more temporally constant evergreen forests. Yet many ecosystems have substantial contribution of cover from both herbaceous and woody evergreen plants. Responses of mixed woody-herbaceous ecosystems to climate are of increasing concern due to their extensive nature, the potential for such systems to yield more complex responses than those dominated by a single life form, and projections that extreme climate and weather events will increase in frequency and intensity with global warming. We present responses of a mixed woody-herbaceous ecosystem type to an extreme event: regional-scale pi?on pine mortality following an extended drought and the subsequent herbaceous green-up following the first wet period after the drought. This example highlights how reductions in greenness of the slower, more stable evergreen woody component can rapidly be offset by increases associated with resources made available to the relatively more responsive herbaceous component. We hypothesize that such two-phase phenological responses to extreme events are characteristic of many mixed woody-herbaceous ecosystems.     

Factors influencing the vertical distribution of microplastics in the beach sediments around the Ras Rakan Island,Qatar

Environmental Science and Pollution Research - Microplastic (MP) pollution is an emerging environmental problem, particularly in the marine environment, and nations are concerned about this issue....