Institutional deficiencies and capacity building constraints: the dilemma for environmentally sustainable development in Africa

SUMMARY

The authors question Africa's ability to achieve sustainable development in view of the erosion of its institution building capacity, a problem compounded by the alarming rate of Africa's continuing marginalisation in the world economy. The situation has been provoked by inappropriate domestic policies which have not only compromised Africa's competitiveness, but also made it particularly vulnerable given the increasing globalisation of markets and factors of production. The benefits associated with effective global economic participation transcend direct financial gains and include technology transfers, technical and managerial skills transfers, and other skills transfers associated with the ‘learning and doing’ process. These benefits are instrumental in the development of the economic, administrative, legislative and social institutions that prescribe the organisational and managerial structure of an economy and define its capacity for sustainable growth. In Africa, the absence of such structures has undermined development efforts and created large impoverished populations. But poverty in living standards is not only prevalent, there is also the acute poverty in knowledge and skills which is so damaging to institution building capacity. The socio-economic impact is manifest in dilapidated infrastructure, decaying institutions, the exodus of the professional and managerial cadre, and the almost total disintegration of society. It is within this context that Africa's ability to evolve and effectively manage sustainable development policies is questioned. The study concludes that the continent's capacity to initiate sound environmental and sustainable development policies depends crucially on its ability to develop appropriate and functional institutions.     

Detecting and quantifying reductive dechlorination under monitored natural attenuation conditions

Field sampling and testing were used to investigate the relationship between baseline geochemical and microbial community data and in situ reductive dechlorination rates at a site contaminated with trichloroethene (TCE) and carbon tetrachloride (CTET). Ten monitoring wells were selected to represent conditions along groundwater flow paths from the contaminant source zone to a wetlands groundwater discharge zone. Groundwater samples were analyzed for a suite of geochemical and microbial parameters; then push‐pull tests with fluorinated reactive tracers were conducted in each well to measure in situ reductive dechlorination rates. No exogenous electron donors were added in these tests, as the goal was to assess in situ reductive dechlorination rates under natural attenuation conditions. Geochemical data provided preliminary evidence that reductive dechlorination of TCE and CTET was occurring at the site, and microbial data confirmed the presence of known dechlorinating organisms in groundwater. Push‐pull tests were conducted using trichlorofluoroethene (TCFE) as a reactive tracer for TCE and, in one well, trichlorofluoromethane (TCFM) as a reactive tracer for CTET. Injected TCFE was transformed to cis‐ and trans‐dichlorofluoroethene and chlorofluoroethene, and, in one test, injected TCFE was completely dechlorinated to fluoroethene (FE). In situ TCFE transformation rates ranged from less than 0.005 to 0.004/day. In the single well tested, injected TCFM was transformed in situ to dichlorofluoromethane and chlorofluoromethane; the TCFM transformation rate was estimated as 0.001/day. The results indicate that it is possible to use push‐pull tests with reactive tracers to directly detect and quantify reductive dechlorination of chlorinated ethenes and ethanes under monitored natural attenuation conditions, which has not previously been demonstrated. Transformation rate estimates obtained with these techniques should improve the accuracy of contaminant transport modeling. © 2012 Wiley Periodicals, Inc.     

COMBINED SEWER OVERFLOW CONTROL THROUGH IN-RECEWING WATER STORAGE: AN EFFICIENCY EVALUATION1

ABSTRACT: A demonstration and efficiency evaluation project was conducted for the flow balancing method (FBM) facility, a combined sewer overflow (CSO) storage facility at Fresh Creek in Brooklyn, New York City. The FBM is a curtained tank located directly in the receiving water that captures CSO. The CSO floats on top of and displaces Fresh Creek saltwater before it is pumped back to the publicly owned treatment works (POTW). The facility was a pilot scale subject to the full CSOs. The purpose of the project was to show how the FBM can withstand severe weather and tidal conditions and to develop a procedure for estimating CSO control efficiency (percentage of CSO pumped back to the POTW). The procedure proved successful and incorporated specific conductivity as a tracer in mass balance equations. These equations provided estimates of the net percent, capture-pumpback of the CSO using the FBM, including the amount of Fresh Creek water that was included in the pumpback to the P01W. The efficiency was directly related to the volume of the CSO and the pumpback rate and ranged from a low of 3.3 percent for the largest event to a high of 76.9 percent for the smallest event. Recent FBM enlargement should result in substantial increases in CSO control. The FBM facility has operated successfully for over five years, withstanding ice storms, near hurricane force winds and up to 7 ft tidal range.     

Quantitative determination of fluorochemicals in municipal landfill leachates

Twenty-four fluorochemicals were quantified in landfill leachates recovered from municipal refuse using an analytical method based on solid-phase extraction, dispersive-carbon sorbent cleanup, and liquid chromatography/tandem mass spectrometry. The method was applied to six landfill leachates from four locations in the US as well as to a leachate generated by a laboratory bioreactor containing residential refuse. All seven leachates had the common characteristic that short-chain (C₄-C₇) carboxylates or sulfonates were greater in abundance than their respective longer-chain homologs (?C₈). Perfluoroalkyl carboxylates were the most abundant (67 ± 4% on a nanomolar (nM) basis) fluorochemicals measured in leachates; concentrations of individual carboxylates reaching levels up to 2800 ng L⁻¹. Perfluoroalkyl sulfonates were the next most abundant class (22 ± 2%) on a nM basis; their abundances in each of the seven leachates derived from municipal refuse were greater for the shorter-chain homologs (C₄ and C₆) compared to longer-chain homologs (C₈ and C₁₀). Perfluorobutane sulfonate concentrations were as high as 2300 ng L⁻¹. Sulfonamide derivatives composed 8 ± 2.1% (nM basis) of the fluorochemicals in landfill leachates with methyl (C₄ and C₈) and ethyl (C₈) sulfonamide acetic acids being the most abundant. Fluorotelomer sulfonates (6:2 and 8:2) composed 2.4 ± 1.3% (nM basis) of the fluorochemicals detected and were present in all leachates.     

Inorganic nanoparticles enhance the production of reactive oxygen species (ROS) during the autoxidation of L-3,4-dihydroxyphenylalanine (L-dopa)

Public concerns over the toxicity of nanoparticles (NPs) are growing due to the rapid development of nanotechnology. An important mechanism of nanotoxicity is oxidative stress resulting from reactive oxygen species (ROS). In this study, the chemical production of ROS by inorganic NPs oxidizing the mammalian phenolic compound, l-3,4-dihydroxyphenylalanine (l-dopa) was evaluated using a ROS sensitive dye, 2′,7′-diclorodihydrofluorescin (DCFH). CeO₂, Fe₂O₃ and Fe⁰ NPs enhanced ROS production during the autoxidation of l-dopa by more than four-fold in reactions that were dependent on O₂. This is the first report of chemical ROS production due to interaction of phenolic compounds with NPs. Mn₂O₃ oxidized DCFH in a reaction that did not require O₂ or l-dopa, suggesting a direct redox reaction between the Mn₂O₃ and the dye. CeO₂, Mn₂O₃ and to a lesser extent Fe⁰ formed clear electron paramagnetic resonance (EPR) signature for hydroxyl radicals when incubated in aerobic aqueous suspensions with spin traps. The results indicate that NPs can generate ROS via chemical reactions with medium components and biomolecules susceptible to oxidation, such as l-dopa. NPs were reactive whereas micron-sized particles were not. The combined assay with l-dopa and DCFH is a method proposed to screen for chemical ROS production by NPs.     

RISK ASSESSMENT METHODOLOGY FOR KARST AQUIFERS: (1) ESTIMATING KARST CONDUIT-FLOW PARAMETERS

Quantitative ground-water tracing of conduit-dominated karst aquifers allows for reliable and practical interpretation of karst ground-water flow. Insights into the hydraulic geometry of the karst aquifer may be acquired that otherwise could not be obtained by such conventional methods as potentiometric-surface mapping and aquifer testing. Contamination of karst aquifers requires that a comprehensive tracer budget be performed so that karst conduit hydraulic-flow and geometric parameters be obtained. Acquisition of these parameters is necessary for estimating contaminant fate-and-transport. A FORTRAN computer program for estimating total tracer recovery from tracer-breakthrough curves is proposed as a standard method. Estimated hydraulic-flow parameters include mean residence time, mean flow velocity, longitudinal dispersivity, Peclet number, Reynolds number, and Froude number. Estimated geometric parameters include karst conduit sinuous distance, conduit volume, cross-sectional area, diameter, and hydraulic depth. These parameters may be used to (1) develop structural models of the aquifer, (2) improve aquifer resource management, (3) improve ground-water monitoring systems design, (4) improve aquifer remediation, and (5) assess contaminant fate-and-transport. A companion paper demonstrates the use of these hydraulic-flow and geometric parameters in a surface-water model for estimating contaminant fate-and-transport in a karst conduit. Two ground-water tracing studies demonstrate the utility of this program for reliable estimation of necessary karst conduit hydraulic-flow and geometric parameters.     

The world conservation strategy: Environmental education and local initiative

Summary In the spring of 1981, Tufts University and the International Union for the Conservation of Nature began teaching the World Conservation Strategy to environmentalists working at the local level. The fourteen-week course that they offered was the first of a series of initiatives to increase public awareness of the need for local action toward the solution of global environmental problems. The success of the first course has encouraged other groups to adapt it to their own social and ecological settings, but there is a pressing need for even more public education. While several aids to teaching the World Conservation Strategy are now being developed to give local conservation educators access to the Strategy, the initiative for bringing the World Conservation Strategy to the public should continue to come from these local leaders. Frank Thibodeau is an environmental biologist and policy analyst with MA and PhD degrees from Tufts University. He is currently a Research Associate in the Department of Urban and Environmental Policy at Tufts, preparing a book on the World Conservation Strategy as a foundation for local environmental initiative under the auspicies of IUCN and the World Wildlife Fund. In addition to his writing and teaching related to the Strategy, he maintains an active research program examining the development of national and international strategies for the preservation of genetic diversity. Hermann H. Field, an urban planner and Fellow of the American Institute of Architects, was director of the Planning Office of the Tufts-New England Medical Center in downtown Boston for 12 years. In 1972 he initiated and then directed a new graduate department of Urban and Environmental Policy at Tufts University. Since 1978 he has been Professor Emeritus in Environmental Planning there. In addition to continued involvement in his department he is active on a range of levels in conservation from the local to the international, including membership on IUCN's Commission on Environmental Planning.     

A two-region nonequilibrium model for solute transport in solution conduits in karstic aquifers

A two-region nonequilibrium model was used to calibrate initial solute-transport parameter estimates generated from tracer-breakthrough curves (TBCs) developed from tracer tests conducted in uni-axial solution conduits in karstic aquifers. Two-region nonequilibrium models account for partitioning of solute into mobile- and immobile-fluid regions to produce a more representative model fit to the strong tails associated with TBCs than do equilibrium models. The nonequilibrium model resulted in an increase in average flow velocities and a decrease in longitudinal dispersion coefficients over comparable estimates using an equilibrium model. Increases in velocity and decreases in dispersion were obtained at the expense of including parameters that describe solute partitioning and mass transfer rate for the mobile- and immobile-fluid regions. In addition, nonidentifiable sorption and mass transfer parameters for the immobile-fluid regions could only be described in terms of upper and lower bounds using readily determined identifiable ratios representing solute partitioning and system constraints based on known physical properties. The identifiable ratios and system constraints serve to minimize model nonuniqueness and renders the nonidentification problem trivial.     

Interpreting methamphetamine levels in a high-use community

Introduction  

Illicit drug use is a largely hidden phenomenon, and population measures are notoriously problematic. Reliable and valid data for local, regional, and national public health and other interventions are needed.     

Anaerobic biodegradability and methanogenic toxicity of key constituents in copper chemical mechanical planarization effluents of the semiconductor industry

Copper chemical mechanical planarization (CMP) effluents can account for 30-40% of the water discharge in semiconductor manufacturing. CMP effluents contain high concentrations of soluble copper and a complex mixture of organic constituents. The aim of this study is to perform a preliminary assessment of the treatability of CMP effluents in anaerobic sulfidogenic bioreactors inoculated with anaerobic granular sludge by testing individual compounds expected in the CMP effluents. Of all the compounds tested (copper (II), benzotriazoles, polyethylene glycol (M(n) 300), polyethylene glycol (M(n) 860) monooleate, perfluoro-1-octane sulfonate, citric acid, oxalic acid and isopropanol) only copper was found to be inhibitory to methanogenic activity at the concentrations tested. Most of the organic compounds tested were biodegradable with the exception of perfluoro-1-octane sulfonate and benzotriazoles under sulfate reducing conditions and with the exception of the same compounds as well as Triton X-100 under methanogenic conditions. The susceptibility of key components in CMP effluents to anaerobic biodegradation combined with their low microbial inhibition suggest that CMP effluents should be amenable to biological treatment in sulfate reducing bioreactors.