| 28
January
2010
Solar-Powered Irrigation Significantly Improves Diet and Income in Rural Sub-Saharan Africa
Solar-powered drip irrigation systems significantly enhance household incomes and nutritional intake of villagers in arid sub-Saharan Africa, according to a new Stanford University study published in the Proceedings of the National Academy of Sciences (PNAS). The two-year study found that solar-powered pumps installed in remote villages in the West African nation of Benin were a cost-effective way of delivering much-needed irrigation water, particularly during the long dry season.
28
January
2010
Biofuel Development Shifting From Soil To Sea
Scripps scientists see algae as a “green bullet,” science and society’s best hope for a clean bioenergy source that will help loosen broad dependence on fossil fuel, counteract climate warming, and power the vehicles of the future.
20
November
2009
Harvesting Energy From Nature's Motions
By taking advantage of the vagaries of the natural world, Duke University engineers have developed a novel approach that they believe can more efficiently harvest electricity from the motions of everyday life.
10
July
2009
Dr. Rashidi's Wind Turbine Tower - Fenn College of Engineering, Cleveland State University
On May 12, 2009, Cleveland State University hoisted its first wind tower amplification system to the rooftop of its Plant Services Building located at the corner of Chester Ave. and E. 24th Street.
The system, designed by Dr. Majid Rashidi of CSU’s Fenn College of Engineering, is a wind deflecting structure with small-scale turbines that can generate power at low wind speeds.
“The operating principle of this system is based on air velocity amplification,” Dr. Rashidi explains. “When air or any fluid flows onto and around a structure, the flow stream lines assume a velocity profile according to the shape of the structure. As a result, the flow velocity may be amplified at certain locations near the structure.
24
November
2008
'Fish Technology' Draws Renewable Energy From Slow Water Currents
Slow-moving ocean and river currents could be a new, reliable and affordable alternative energy source. A University of Michigan engineer has made a machine that works like a fish to turn potentially destructive vibrations in fluid flows into clean, renewable power.
06
March
2008
PumpSmart® Control Systems Improve Fuel Blending Operations at Ethanol Facility
The requirement to precisely and efficiently inject ethanol as a gasoline fuel blend led a refinery management company to install an in-line process pump equipped with the PumpSmart's control system from ITT Goulds Pumps unit – allowing a constant pressure to be maintained throughout the injection process.
06
March
2008
New anti-moisture membrane for construction
Moisture damage in buildings is a familiar and frequent problem. A new product system from Trelleborg could be the solution.
16
August
2007
Watertight sealing technology for drinking water
Trelleborg Sealing Solutions has developed an O-Ring material for drinking water applications that is both effective and long lasting
14
August
2007
Automating Wastewater Treatment
Wastewater treatment is a biological process, which means it uses bugs, or bacteria, to do all the work. The bugs feed on the waste matter and need oxygen to survive. Too little oxygen or too little food and the bugs begin to stress and become less effective. Too much food leads to too many bugs, which overloads the system. These crucial variable can be controlled by automation.
02
July
2007
The secret to keeping Hamburg dry
EPDM and Butyl membranes will keep the city of Hamburg dry. The latest project to improve the security of the city’s dike system is a runway for the Airbus A-380 aircraft facility that will be secured with membranes.
20
June
2007
Crystal Clear Solution
From concept to initial sale, ITT's Sanitaire launched an entirely new technology for treating wastewater in only 18 months. Municipal and industrial customers, especially in water-scarce regions, wanted a more efficient system for cleaning wastewater to use for irrigation or process water, or to discharge into streams with zero harm to the ecosystem.
04
January
2007
TORESA: Toolkit for remote sensing assessment and environmental monitoring of mining activities
TORESA has six modules: Geophysics, Hydrogeological Modeling, Processing of Satellite Images, Chemical and Mineral Identification; Environmental Soundings and Risk Assessment. The results are included in a Geographic Information System (GIS), which will provide future plans for environmental mine management. The results are presented as a digital data base on the Environmental Mining Management website (GAM).
04
January
2007
Efficiency of permeable reactive barriers to treat of acid mine effluents
Acid Mine Drainage (AMD) is the most serious environmental problem facing the Canadian Mineral Industry today. Acid Mine Drainage results from oxidation of sulphide minerals (e.g. pyrite or pyrrhotite) contained in mine waste or mine tailings. It is characterised by acid effluents rich in heavy metals that are released into the environment. A new acid remediation technology is presented in this paper by which metallurgical residues from the aluminium extraction industry are used to construct permeable reactive barriers (PRB) to treat acid mine effluents
This paper describes column tests performed to simulate a PRB constructed using BauxsolTM, a chemically and physically treated bauxite refinery residue, as a reactive material. This experimentation shows promising results in neutralizing pH and removing metals from acidic mine effluents.
04
January
2007
The Vetiver System: Proven and Green Environmental Solutions
Vetiver grass (Chrysopogon zizanioides L.) is a perennial, tropical/sub tropical grass that has been used extensively world wide for soil erosion and sediment control and steep slope stabilisation for the last 20 years. Recently vetiver has also been used successfully for mine site rehabilitation in Australia, China, Latin America and South Africa, including stabilisation of steep slopes associated with bunds, tailings dams, and revegetation of mine tailings. Important attributes of vetiver grass are highly tolerant to: 1) Extreme acidity, alkalinity, sodicity, salinity and climatic conditions; 2) Very high levels of heavy metals, pollutants and nutrients; 3) It is sterile and has no potential to become a weed.
09
October
2006
Technology Advancements in Small Wind Turbines
Advancements in wind turbine technology have been growing rapidly. In the shadows of multi-megawatt wind turbines is another growing sector within this industry: residential wind. Improved airfoil designs for maximum efficiency at low wind speed, high efficiency direct drive permanent magnet alternators, improved governing methods and highly sophisticated controls and inverters now allow home owners to interface directly with utility companies or design off-grid systems. These systems are increasing energy independence, competing with current energy prices and reducing environmental impacts.
09
October
2006
A Tidal Generator
The tidal action of the seas of the world is influenced by the rotation of the earth and the gravitational influence of the moon. There is enough energy in the world’s tidal activity to provide electricity to the planet if there is a way to harness it all.
01
August
2006
Sistema Fotossíntese de Manejo da Água na Agricultura Irrigada (Portuguese Version)
O Projeto Fotossíntese promove o uso racional da água na irrigação de agriculturas intensivas e na irrigação caseira e condominial. Seu objetivo é obter o máximo de produção agrícola por cada gota de água utilizada. O método consiste em identificar as irradiações solares que dão origem à fotossíntese e geram a energia necessária para a circulação da água e dos nutrientes no interior das plantas, de acordo com as condições de umidade do solo na região radicular dos plantios. O resultado é a aplicação de água na quantidade e no momento ideais para o plantio que se deseja irrigar com a conseqüente preservação ambiental.
01
August
2006
Photosynthesis System for Managing Water in Irrigated Agriculture
The Projeto Fotossíntese (Photosynthesis Project) promotes the rational use of water in the irrigation of intensive arable farming, and the supply of water to homes and apartment buildings. Its objective is to maximize agricultural production for each drop of water used. The method consists of evaluating the solar irradiation which gives rise to photosynthesis and generates the necessary energy for the circulation of water and nutrients inside the plants, according to the moisture conditions of the soil around the roots of the crops. The result is that water is applied in the optimum amount, and at the ideal moment for the crop being irrigated, resulting in environmental conservation.
06
January
2006
A novel renewable energy solution to energy pollution
Geomagmatic technology differs from geothermal technology in that geothermal technology requires water and steam or steam under pressure for a geothermal project to take place. The word geomagmatic
is not yet found in the dictionary.
Additionally, geomagmatic technology requires that the installation of a geomagmatic device be calibrated in accordance with the resource available. The resource available is selected in gigawatts per cubic kilometer or (GW/Km3)
The resource must always be supported by a continual reservoir of magmatic material that recharges the resource, as in the Ring of Fire. A geothermal resource needs to be developed and a rate of steam production determined. This requires two perforations as a rule. One to send millions of gallons of water down to a underground heat source and the other to return it in the form of steam to the turbines on the surface.
Power Tube uses one perforation and an assembly plant manufactured unit. Therefore it can be said that a geothermal plant is always a prototype, that is why it is so costly, while a Power Tube relies only on the depth of the heat source, and the added length of the thermal riser.
04
January
2006
Removing CO2 from the Source
Greenhouse gas (GHG) levels have been rising in the atmosphere dramatically since the beginning of the industrial revolution and particularly since post-WWII. Of these carbon dioxide is the most important. Global climate change is a major and critical consequence of increasing GHGs. The CO2 increase is driven by burning hydrocarbons as a fuel source. To minimize this impact it is necessary to capture CO2 as well as other GHG. Several strategies are discussed including pre-combustion, enhanced combustion and post-combustion approaches. No technology currently available is economic enough to gain wide implementation. Carbozyme is working on a new, high efficiency, ultra-low cost CO2 capture technology that may satisfy the price/performance requirements.
01
December
2005
Bioaugmentation as a Strategy for In Situ Bioremediation: When Does It Work?
Microorganisms degrade pollutants thanks to their metabolic machin-
ery and their capacity to adapt to inhospitable environments. They are key players in remediation and site restoration, but their efficiency depends on the chemical nature of the pollutants (structure and concentration), their availability to the microorganisms, and the physicochemical characteristics of the environment. The capacity of a microbial population to degrade pollutants in an environmental matrix (soil, sediment, sludge, wastewater, etc.) can be enhanced either by stimulating the indigenous microorganisms by adding nutrients or electron acceptors (biostimulation) or by introducing specific competent microorganisms to the local population (bioaugmentation). Many biotic and abiotic factors make bioaugmentation a relatively unpredictable strategy of bioremediation. The addition of exogenous microorganisms may be justified for the treatment of recalcitrant compounds in sites devoid of significant populations of biodegrading microorganisms. Field practice shows that under optimal local environmental conditions the rate and extent, and, sometimes, the spectrum of pollutant degradation may be enhanced upon addition of an inoculant to remediate a chemical plume. However the most successful cases of bioaugmentation occur in confined systems, such as bioreactors in which the conditions can be controlled to favour survival and prolonged activity of the exogenous microbial population.
22
November
2005
Development of a molecular toolbox for monitoring degradative bacteria in environmental samples
We are currently developing a molecular toolbox using nucleic acid techniques enabling monitoring of presence and activity of key degradative bacteria in environmental samples. These joint projects employ a range of different strategies aiming at various genetic markers suitable for detecting abundance and specific catabolic activity
21
November
2005
Survival of Escherichia coli in groundwater
The survival of Escherichia coli in groundwater was studied and included a literature study, a laboratory study and a field investigation. From the literature it was found that every study conducted on the survival of bacteria in groundwater, has its own limitations, resulting in variations of the prediction of the survival of microorganisms in groundwater. The survival of microorganisms is affected by a number of environmental factors such as the bacterial type, sunlight, rainfall, soil moisture and holding capacity, temperature, soil composition, pH, presence of oxygen and nutrients, the availability of organic matter and antagonism from soil micro-flora. Although many factors have been identified, it appears that many factors are still unknown. However, there is enough evidence that survival of Escherichia coli in groundwater does occur. One thing still unknown is whether Escherichia coli or other pathogens are still a disease agent after spending some time underground. From the laboratory and field investigation it is concluded that there is a decline in bacterial numbers over time; that Escherichia coli survived for more than 40 days in the laboratory; that Escherichia coli does survive in the environment; that Escherichia coli numbers in the soil are higher than in the subsurface water and that Escherichia coli can move from surface water to groundwater.
21
November
2005
Predicting bacterial transport in the vicinity of drinking-water wells: what column- and field-scale tracer tests can tell us and what they cannot
Accurate prediction of subsurface bacterial transport is important for well head protection, but generally necessitates site-specific information obtained from transport studies that involve media from the area of the aquifer around the well. Because of the difficulties of running such experiments in the field, studies involving bacterial transport through geologic media usually are conducted on the column scale. However, there is a growing body of evidence suggesting that bacterial transport observed in small-scale injection and recovery tests performed in granular, drinking-water aquifers is considerably greater than that observed for a similar distance through columns of repacked sediments in which the pore structure has been altered. However, even in situ injection and recovery tests using labeled bacteria may not yield results that allow accurate prediction of the transport of bacterial pathogens from a contaminant source to a drinking-water well. In part, this is because such tests are not designed to assess the effects of ecological factors, such as the effects of grazing by indigenous protozoa, in-situ growth, and environmental carrying capacity, upon the abundance of bacteria being advected through an aquifer towards a well. Accounting for these ecosystem-level parameters can necessitate additional types of in situ tests.
12
May
2005
Managed groundwater recharge: A powerful tool for efficient management of water resources in arid regions
The Phoenix metropolitan area, a group of more than twenty municipalities, is the fastest growing population center and the sixth largest urban area in the United States. Located in a semiarid region of North America, it has very limited surface water resources. Surface water comes from the Salt River and its tributaries as runoff from snow accumulated during the winter in distant mountains to the north during wet climatological cycles. In prehistoric times and until the 1940’s agriculture predominated in this “the Valley of the Sun”. The large alluvial aquifer system that underlies this region provided sufficient groundwater to boost agricultural products after the advent of the turbine pump in the late 1920’s. This intensive use of groundwater resulted in several undesirable impacts among them groundwater level declines, land subsidence and groundwater quality deterioration. In 1980 a strict groundwater code was adopted for the state and areas of closely regulated groundwater abstraction were established. Increased water conservation was mandated from the municipal and industrial water users and better management practices were required in agriculture. Artificial groundwater recharge and water reuse were promoted and extensively adopted. A long aqueduct brought water from the Colorado River and added a new water source. Public information and education in schools provide guidance and encourage conservation. This has created a public water conscience. Water exchanges with neighboring states will soon augment the groundwater stored in the local aquifers using large recharge facilities. The coordinated use of all these water management techniques will continue to provide the necessary resources to support the population growth.
11
May
2005
A current overview of permeable reactive barrier technology
Permeable reactive barriers have been successfully implemented worldwide as a groundwater remediation technology. In-situ PRB technology involves the construction of a permeable wall or barrier, containing appropriate reactive materials, across the path of a contaminant plume. As the contaminated groundwater passes through the wall, the contaminants are removed through chemical or physical processes. The technology is particularly attractive for the remediation of contaminated groundwater because of the high rates of degradation, the granular iron is relatively inexpensive, the process requires no external energy supply and because most compounds are degraded with production of few, if any, hazardous (chlorinated) organic by-products.
11
May
2005
Passive permanganate remediation of a solvent DNAPL source zone
Permanganate remediation was conducted in southern Florida at a small industrial site with TCE and 1,1,1-TCA contamination down to 70 ft bgs in a sand aquifer. The permanganate solution was injected into the DNAPL source zone where a small mass of residual TCE DNAPL caused this zone to have TCE concentrations exceeding 10,000 ug/L, with small zones approaching TCE saturation. The KMnO4 injections successfully destroyed essentially all of the DNAPL present in the source zone with no apparent displacement of contaminant mass to zones outside the treatment zone. Following KMnO4 treatment, natural attenuation processes quickly reduced concentrations in the plume to below MCLs for both TCE and TCA. Furthermore, natural attenuation processes have strongly reduced both TCE and TCA concentrations within the treatment zone since KMnO4 treatment ceased and the rate of natural attenuation suggests that MCLs will be achieved in 2005.
09
May
2005
Aquifer artificial recharge: A method for an efficient management of water resources in arid zones (in Spanish)
El rápido crecimiento de la población mundial ha hecho que en muchas zonas de clima arido y semiárido la demanda de sus limitados recursos hídricos haya aumentado notablemente en las últimas décadas. Las condiciones climatológicas de esas regiones son propicias para la producción de varias cosechas anuales lo cual contribuye al aumento de población en ellas. El uso conjunto de aguas superficiales y subterráneas usando recarga artificial de los acuíferos es el modo mas efectivo de conseguir la utilización mas eficiente de los recursos hídricos en estas zonas
20
August
2004
Environmental Monitoring and Measurement Advisor – A New Expert System
The Environmental Monitoring and Measurement Advisor (EMMA) is a prototype expert system developed in 2002 under a National Science Foundation grant to facilitate systematic planning for environmental monitoring. In addition to powerful attributes of the Corvid software that facilitate
programming with complex decision rules, an attractive feature is the ability to use Windows-based frames in which additional information can be provided. This feature was used extensively in the development of EMMA as a way to enhance the technical transfer capabilities of the
product by providing the user with guidance and in-depth information about the questions being asked and the answers given. The expert system was designed for two types of users: (1) busy executives and project managers who want the best answers and advice as quickly as possible and, (2) students and less experienced practitioners who want to learn more about the complex subject of environmental
monitoring.
16
August
2004
High permeability layers for remediation of groundwater: Go wide not deep
A dual porosity, nitrate reactive porous media layer comprised of wood particles with very high primary permeability (K~1 cm/s) was used to successfully treat nitrate in a shallow sand and gravel aquifer in southern Ontario. Nitrate concentrations of 1.3-14 mg N/L in the aquifer were attenuated to < 0.5 mg N/L in the reactive layer. Borehole dilution testing indicated that groundwater velocities in the reactive layer, although variable, averaged five times higher than in the surrounding aquifer, suggesting that the layer was capturing groundwater flow from deeper in the aquifer.
06
June
2003
SF Prospector: A new economic development tool for the city of San Francisco
SF prospector is a web-based GIS application developed by GIS Planning for the City and County of San Francisco Mayor’s Office of Business and Economic Development using ArcIMS. SF Prospector includes features such as user-defined site selection, demographic analysis and business competition/synergy reports. Users can search for vacant commercial building space or available developable land by detailed geographic areas including ZIP Code, Supervisor District, Redevelopment Project Area or Neighborhood.
Users are able to view interactive layers of GIS information on the map including aerial photography, Enterprise Zones, Renewal Communities, Open Space, Waterways, City Facilities, Supervisor Districts, Traffic Counts, Public Transportation, ZIP Codes and land use designations. These layers of information are described in a map legend.
28
October
2002
Groundwater-surface water interaction and nitrate origin in municipal water supply aquifers, San Jose, Costa Rica
Deterioration of groundwater quality by anthropogenic input of nitrate is a significant issue in the Central Valley of Costa Rica. Nearly 50% of the municipal water supply in the valley is derived from volcanic aquifers. Nitrate concentrations in municipal supply wells have been steadily increasing in recent years. In some cases, nitrate levels are above or near the WHO drinking water standard. The major sources of nitrate are fertilizer application by coffee plantations and untreated domestic sewage. It is not clear if groundwater is recharged mainly by direct soil infiltration or from downward leakage of polluted rivers. Groundwater surface water interactions in the system are complex. Rivers are alternately losing and gaining along their reaches, according to the influence of geology and seasons. Precipitation, river and groundwater samples were collected over a 10-month period from the river Mancarrón watershed for geochemical and isotopes analyses. These data were used to elucidate the source(s) of nitrate and pathways of its transport within the
hydrologic system.
28
October
2002
Evaluation of the origin of groundwater nitrate in the city of La Plata - Argentina, using isotope techniques
The objective of the study was to establish the origin of the nitrate contamination causing deterioration of the groundwater in the city of La Plata aquifer. This is the first irnportant city in Argentina that had used groundwater as a water supply since the end of past century. Today, half the total potable water (100 hm3/year) is provided by wells located in the urban area (50 hm3/year). However, most of the groundwater present nitrate concentration above the permissible level of 45 mg/L in Argentina. Based on the existence of about 20,000 hectares of agricultural land in the vicinity of the city, it was postulated that the nitrate was related to the high use of fertilizers in these areas. However, a detailed evaluation of the groundwater flow system and the nitrate pattern in the study area, suggested that the source of the groundwater nitrate is related to leaking from the sewage network and old septic systems. This hypothesis is supported by 15N analysis on nitrate collected in the agricultural and urban areas. Rural areas only show high nitrate concentration in shallow wells located close to septic systems and barnyards. These groundwaters also show very enriched 15N content, typical of nitrate derived from animal and human waste. In general. the agricultural areas show nitrate concentration much lower than 45 mg/L with δ15N values lower than the nitrate of animal and human origin.
The groundwater from pumping wells located upgradient of the City of la Plata has nitrate concentration and δ15N values similar than the groundwater collected in the agricultural areas. The high nitrate groundwater (> 90 mg/L) collected from pumping wells inside the La Plata show more enriched δ15N values than the groundwater from agricultural areas. The δ15N and nitrate concentration patterns observed along the groundwater flow system from the rural areas toward the city of la Plata indicate than an in-situ source associated to leakage from the sewage system and old septic systems is the main source of the nitrate contamination affecting the groundwater in the City of La Plata.
26
October
2002
Nitrate geochemistry of a regional aquifer in an agricultural landscape, Woodstock, Ontario, Canada
Nitrate concentrations in the Thornton Well Field, near Woodstock, Ontario, have been steadily increasing since 1980. Geochemical and hydrogeological tools were used to ascertain the source and location of the elevated nitrate concentrations and to determine the factors that control nitrate concentrations in the groundwater flow system from the recharge area to the production wells. This study highlights the complexity of regional groundwater flow systems in relationship to the nitrate geochemistry. This investigation is a part of a major research project involving hydrogeology and the use of dating techniques to evaluate the long-term water quality of the Thornton Well Field. The main source of nitrate to the production wells lies in the west region and is associated mainly with the application of organic fertilizers. The main factors that control the distribution of nitrate in the aquifer are regional groundwater flow direction and redox
conditions.
26
June
2002
Cleaning of Residual SO2 Gas Emissions with Hydrogen Peroxide
The paper presents a comparison between the conventional methods of SO2 gas cleaning with the hydrogen peroxide scrubbing process. The reaction is conducted in scrubbing columns in which the SO2 gas stream flows through water continuously dosed with H2O2, according to the equation:
SO2 (g) + H2O2 (aq) = H2SO4 (aq).
The chemical reaction is virtually instantaneous, may be automatically controlled by SO2 monitoring, and has the important feature of not generating solid residues.
26
June
2002
Advances in NOx Removal in Smelter Acid Plants
Increasing NOx levels in smelter gases have become a serious issue for acid plant operators leading to problems with both stack emissions and product acid quality. A further complication which results from high NOx levels is the difficulty of safely carrying out maintenance work on plant equipment containing NOx rich acid residues. This paper discusses the chemistry of NOx formation and its subsequent distribution through the acid plant. This is followed by a review of the methods which have historically been applied to combat the impact of NOx on acid plant operation and a new approach which targets gas phase NOx destruction within the acid plant in order to eliminate all the problems associated with high NOx levels. This technology, which involves the selective catalytic reduction of NOx prior to the acid plant converter, is described and 2 years of successful operation of this system at a European plant are reviewed.
25
June
2002
Influence of Environmental Regulations on the Design of Barrick Goldstrike's Roaster Off-gas Cleaning Circuit
Barrick Gold recently implemented an oxygen roasting process to treat carbonaceous ore from its Goldstrike property in Nevada. One of the key project challenges was the design of the roaster gas cleaning system, which was driven by the requirements of a strict air permit and the need to achieve very high reliability. The roaster gas systems include multiple stages of wet particulate collection, a dual-alkali SO2 scrubber, mercury scrubbing, CO oxidation and NOx reduction. This paper describes the gas system, the influence of regulations on project implementation, and performance of the system.
23
November
2001
Evaporation in salt lakes in Northern Chile
This study analyzes the main factors influencing evaporation in salt lakes found in closed basins in northern Chile and presents the results of the evaluation of renewable groundwater resources carried out using this framework. The field work was carried out in 1990 and the results and main conclusions of this study are currently been used in evaluation of water resources in Northern Chile. The mining sector is the main user of water resources in closed basins. The potential impact of mining activities in springs and surface water feeding the lakes and lagoons can be mitigated by the use of groundwater to restore the water level required to maintain the flora and fauna in these ecosystems.
19
November
2001
Groundwater protection: An integrated view based on wellhead protection areas and vulnerability maps
Analysis of groundwater quality protection programs in many countries reveals two lines of action, which are applied nearly always independently. One focus on water supply wells, by establishing wellhead protection areas (WHPA). The second approach controls the land use in relation to aquifer vulnerability properties and the recognition of the importance of groundwater for a specific location. The WHPA is normally defined from horizontal flow time, horizontal distance from wells and proportion of recharge area.
The objective of this paper is to present technical tools that permit the development of groundwater protection programs based on these techniques and on control of land occupation. Both techniques were evaluated with regard to their limitations, applicability and especially their feasibility for protection of aquifers in Ibero-America.
02
April
2001
The Emergence of Ecological Engineering and Green Technology
Traditional engineering relies mainly on human control processes occurring in human-created, "hard" structures, and it is reliant upon fossil resources, including both energy and materials. In contrast, ecological engineering attempts to utilize natural processes occurring in natural land- and waterscapes (i.e., "soft" structures), which are driven primarily by natural energy (solar and gravity).
05
February
2001
Arsenic Management in Copper Smelters
As a consequence of environmental regulations there is a significant increase in the amount of arsenic residues, which will have to be managed in a safe way, whether for its recovery or disposal.
05
February
2001
Beware of nitrate
Several studies have reported the presence of high concentration of nitrate in some sectors of the Santiago aquifer . Due to an increasing groundwater demand from this aquifer for potable water, and since the presence of nitrate in drinking water poses health risks for the population, the authors argue that it is important to better characterize the nitrate contamination in the aquifer and evaluate the contaminant risk for the wells used for potable water.
30
December
2000
Ecological engineering and wetlands
Ecological engineering, also referred to as ecotechnology, is emerging as a new interdisciplinary branch of engineering that shares concepts from closely allied disciplines of environmental engineering, ecology and biotechnology. Ecological engineering uses either natural ecosystems or constructed systems that imitate natural ecosystems to deal with environmental and pollution control problems. In recent years, there is a growing interest in applying ecotechnology in environmental management. Recognizing this interest, the Hydrotechnical Division of the Canadian Society for Civil Engineering organized a national lecture tour on wetlands in March to raise awareness of this emerging technology among engineers and environmental professionals across Canada. This article highlights some basic concepts and definitions of ecological engineering and wetlands, and identifies some possible challenges in applying this technology in Canada.
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