MONITORING SUSPENDED PARTICULATE MATTER IN PUERTO RICO: FIELD MEASUREMENTS AND REMOTE SENSING1

ABSTRACT: The spatial distribution of suspended particulatematter (SPM) was estimated in Mayagüez Bay on the west coast of Puerto Rico by using traditional ship board measurements and remotely sensed data acquired over four days during January 1990. This effort was part of a joint project between NASA and the University of Puerto Rico to develop techniques to monitor the water quality of a Caribbean coastal zone. This paper presents the methods and algorithms developed to map and analyze short term changes in the source and spatial distribution of SPM in Mayagüez Bay by using remotely sensed data acquired by the Calibrated Airborne Multispectral Scanner (CAMS). A PC-based data acquisition system was developed to record continuous ship measurements of select in- water variables. Spectral reflectances derived from CAMS red and near-IR data were corrected for atmospheric effects and then used to generate maps of SPM. These maps displayed SPM plumes associated with the mouths of the bay's three river systems. Significant day-to-day differences in the spatial characteristics were observed, suggesting that changes in river discharge occurred. However, an analysis of estimated river discharge, sediment yield, local wind field, and thermal river plume indicates that observed sediment plumes result primarily from wind-driven resuspension events.     

Regional or global WEEE recycling. Where to go?

If we consider Waste Electrical and Electronic Equipment (WEEE) management, we can see the development of different positions in developed and developing countries. This development started with the movement of WEEE from developed countries to the developing countries. However, when the consequences for health and the environment were observed, some developing countries introduced a ban on the import of this kind of waste under the umbrella of the Basel Convention, while some developed countries have been considering a regional or global WEEE recycling approach. This paper explores the current movements between Source and Destination countries, or the importers and exporters, and examines whether it is legal and why illegal traffic is still rife; how global initiatives could support a global WEEE management scheme; the recycling characteristics of the source an destination countries and also to ascertain whether the principle of Extended Producer Responsibility (EPR) has been established between the different stakeholders involved in WEEE management.Ultimately, the Full Extended Producer Responsibility is presented as a possible solution because the compensation of the environmental capacity for WEEE recycling or treatment could be made by the contribution of extra responsibility; and also generating an uniform standard for processing WEEE in an environmentally sound manner could support the regional or international solution of WEEE and also improve the performance of the informal sector.     

Is Denser Greener? An Evaluation of Higher Density Development as an Urban Stormwater‐Quality Best Management Practice1

Abstract: A simple spreadsheet model was used to evaluate potential water quality benefits of high‐density development. The question was whether the reduced land consumed by higher density development (vs. standard suburban developments) would offset the worse water quality generated by a greater amount of impervious surface in the smaller area. Total runoff volume and per acre loadings of total phosphorous, total nitrogen, and total suspended solids increased with density as expected, but per capita loadings and runoff decreased markedly with density. For a constant or given population, then, higher density can result in dramatically lower total loadings than more diffuse suburban densities. The model showed that a simple doubling of standard suburban densities [to 8 dwelling units per acre (DUA) from about 3 to 5 DUA] in most cases could do more to reduce contaminant loadings associated with urban growth than many traditional stormwater best management practices (BMPs), and that higher densities such as those associated with transit‐oriented development could outperform almost all traditional BMPs, in terms of reduced loadings per a constant population. Because higher density is associated with vibrant urban life, building a better city may be the best BMP to mitigate the water quality damage that will accompany the massive urban growth expected for the next several decades.     

Predicting the Impacts of Future Sea-Level Rise on an Endangered Lagomorph

Human-induced global climate change presents a unique and difficult challenge to the conservation of biodiversity. Despite increasing attention on global climate change, few studies have assessed the projected impacts of sea-level rise to threatened and endangered species. Therefore, we estimated the impacts of rising sea levels on the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) across its geographic distribution under scenarios of current conditions, low (0.3-m), medium (0.6-m), and high (0.9-m) sea-level rise. We also investigated the impacts of allowing vegetation to migrate upslope and not allowing migration and of two land-use planning decisions (protection and abandonment of human-dominated areas). Not surprisingly, under all simulations we found a general trend of decreasing total potential LKMR habitat with increasing sea-level rise. Not allowing migration and protecting human-dominated areas both tended to decrease potential LKMR habitat compared with allowing migration and abandoning human-dominated areas. In conclusion, conservation strategies at multiple scales need to be implemented in order to reduce the impact of global climate change on biodiversity and endangered species. At the regional level, managers must consider land-use planning needs that take into account the needs of both humans and biodiversity. Finally, at the local scale those agencies that are in charge of endangered species conservation and ecosystem management need to rethink static approaches to conservation or else stand by and watch ecosystems degrade and species go extinct. This can be accomplished by bioclimatic reserve systems where climatically underrepresented areas are included in conservation planning along with the standard concerns of threat, opportunity, connectivity, and viability.     

Practical applications of the fenton reaction to the removal of chlorinated aromatic pollutants

BACKGROUND: Chlorophenols (CPs) constitute a group of organic pollutants that are introduced into the environment as a result of several man-made activities, such as uncontrolled use of pesticides and herbicides, and as byproducts in the paper pulp bleaching. Promising removal technologies of chlorinated aromatics consist in the application of advanced oxidation processes (AOPs) that can provide an almost total degradation of a variety of contaminants. Among these, wide application find Fenton systems based on generation of reactive species having a high oxidizing power, such as hydroxyl radical HO*. Our objective was that of determining the overall degradation efficiency of the model compound 2,4-dichlorophenol (DCP) by thermal Fenton-type oxidation systems with a view toward defining in more details relevant process parameters, the effect of reaction temperature and of co-catalyst Cu2+. METHODS: Reaction conditions were similar to those generally adopted as optimal in many practical applications, i.e. pollutant/Fe2+ (as FeSO4) ratio ca. 20, Fe2+/Cu2+ (co-catalyst) 2:1, pH adjusted and controlled at pH 3, and H2O2 in excess (up to four-fold over the stoichiometric amount required for complete mineralization). RESULTS AND DISCUSSION: The results demonstrate that it is advantageous to carry out the reaction at a temperature markedly higher (70 degrees C) than ambient. The stepwise addition of H2O2 in aliquots yields an efficient transformation, while allowing a convenient control of the reaction exothermicity. Under these conditions, the essentially complete removal of the initial DCP is accomplished using just one equiv of H2O2 during 15 min; excess H2O2 (5 equivalents) yields extensive substrate mineralization. Also relevant, at 70 degrees C dechlorination of the initial DCP (and of derived reaction intermediates) is remarkably extensive (3-5% residual TOX), already with the addition of 1 equiv of H2O2. At the end of the reaction, IC and IC-MS analyses of the solution reveal that only low-molecular weight carboxylic acid (acetic, formic, oxalic, malonic, tartaric, etc.) contribute to the residual TOC. CONCLUSIONS: The whole of the results herein point to the advantage of performing the process at temperatures substantially higher than ambient (70 degrees C). Under the conditions adopted, almost complete degradation of the initial toxic compound can be achieved using hydrogen peroxide in fair excess (e.g., 3.5 equiv H2O2). RECOMMENDATIONS AND OUTLOOK: In applying practical Fenton-type degradation systems to heavily polluted wastes, either for the pre-treatment of waters with a high COD value prior to biodegradation or for complete mineralization of pollutants, the set up of appropriate reaction conditions appears to be a key factor. Also, it is desirable to keep the concentration of iron salts within the lower limits in order to minimize the production and disposal of iron oxide sludges.     

Influences, practices and opportunities for environmental supply chain management in Nova Scotia SMEs

Executives are increasingly paying attention to the importance of supply chain management [Lambert DM, Cooper MC. Issues in supply chain management. Industrial Marketing Management 2000;29(1):65–83; Hagelaar GJLF, van der Vorst JGAJ. Environmental supply chain management: using life cycle assessment to structure supply chains. International Food and Agribusiness Management Review 2002;4:399–412]. The management of the supply chain can be a central aspect of a company's competitive advantage [Preuss L. Rhetoric and reality of corporate greening: a view from the supply chain management function. Business Strategy and the Environment 2005;14:123–139]. SCM also offers considerable opportunities to reduce a company's environmental impact. The supply chains of three small and medium enterprises (SMEs) operating in the Burnside Industrial Park in Nova Scotia, Canada were investigated to explore the opportunities to improve environmental performance of SMEs linked in supply chains. This study confirmed that time and, to a lesser degree, financial resources to address solid waste and energy issues are the greatest limiting factors. Small suppliers, and even to a certain degree medium-sized enterprises, have difficulties in allocating resources to initiatives that are not viewed as directly related to their core function, namely manufacturing the product or providing the service. This study clearly demonstrated that opportunities exist to reduce greenhouse gas emissions and solid waste. Although, the benefits that would be gained from the implementation of any of the individual actions in the supply chains explored in this study are individually small, the cumulative benefits that could be achieved among supply chains and within industrial parks are substantial, given the number of small- and medium-sized enterprises.     

Formation of volatile halogenated by-products during chlorination of isoproturon aqueous solutions

The present paper deals with the formation of volatile halogenated by-products (POX) during the chlorination (160 mg/l) of aqueous solutions of the herbicide isoproturon (40 mg/l). Chlorination reactions have been carried out over 48 h, at ambient temperature, at two pHs (6 and 9) and in the presence or not of bromide ions (80 mg/l). The main results obtained have been as follows: (1) in the presence of bromide, isoproturon degradation is rather fast and it results affected by pH, complete isoproturon degradation is achieved within 1 and 15 min at pH 6 and 9, respectively; (2) in the absence of bromide herbicide degradation is slow (complete degradation is achieved within 180 min) and it is not affected by pH; (3) at pH 6, regardless of the presence of bromide, the maximum amount of POX formed is low (approximately 15 micromol X-/l) and remains constant during the reaction; (4) at pH 9 the amount of POX formed is far greater and continuously increases during the reaction, reaching a value of about 110 micromol X-/l after 48 h; (5) two different groups of by-products have been identified by solid phase micro extraction (SPME)-gas chromatography (GC)-mass spectrometry (MS) for the reactions carried out with or without bromide; among them, aliphatic as well as aromatic by-products containing chlorine, bromine or both halogens are present even though the most abundant are halogenated-methane derivatives (haloforms); pH value affects the amount of these by-products but does not modify their chemical nature.     

Global DNA methylation in earthworms: a candidate biomarker of epigenetic risks related to the presence of metals/metalloids in terrestrial environments

In this work, possible relationships between global DNA methylation and metal/metalloid concentrations in earthworms have been explored. Direct correlation was observed between soil and tissue As, Se, Sb, Zn, Cu, Mn, Ag, Co, Hg, Pb (p < 0.05). Speciation results obtained for As and Hg hint at the capability of earthworms for conversion of inorganic element forms present in soil to methylated species. Inverse correlation was observed between the percentage of methylated DNA cytosines and total tissue As, As + Hg, As + Hg + Se + Sb (β = −0.8456, p = 0.071; β = −0.9406, p = 0.017; β = −0.9526, p = 0.012 respectively), as well as inorganic As + Hg (β = −0.8807, p = 0.049). It was concluded that earthworms would be particularly helpful as bioindicators of elements undergoing in vivo methylation and might also be used to assess the related risk of epigenetic changes in DNA methylation.     

Identifying Urban Features from LiDAR for a High‐Resolution Urban Hydrologic Model

Light Detection and Ranging (LiDAR), is relatively inexpensive, provides high spatial resolution sampling at great accuracy, and can be used to generate surface terrain and land cover datasets for urban areas. These datasets are used to develop high‐resolution hydrologic models necessary to resolve complex drainage networks in urban areas. This work develops a five‐step algorithm to generate indicator fields for tree canopies, buildings, and artificial structures using Geographic Resources Analysis Support System (GRASS‐GIS), and a common computing language, Matrix Laboratory. The 54 km² study area in Parker, Colorado consists of twenty‐four 1,500 × 1,500 m LiDAR subsets at 1 m resolution with varying degrees of urbanization. The algorithm correctly identifies 96% of the artificial structures within the study area; however, application success is dependent upon urban extent. Urban land use fractions below 0.2 experienced an increase in falsely identified building locations. ParFlow, a three‐dimensional, grid‐based hydrological model, uses these building and artificial structure indicator fields and digital elevation model for a hydrologic simulation. The simulation successfully develops the complex drainage network and simulates overland flow on the impervious surfaces (i.e., along the gutters and off rooftops) made possible through this spatial analysis process.