Search results for "environmental engineering"
showing 10 items of 2674 documents
Energy intensity modeling for wastewater treatment technologies.
2018
Wastewater treatment plants (WWTPs) are energy intensive facilities; therefore increased pressure has been placed on managers and policy makers to reduce the facilities' energy use. Several studies were conducted to compare the energy intensity (EI) of WWTPs, which showed large dispersion in EI among the facilities. In the present study, the degree EI influenced WWTPs was tested using a set of technical variables by modeling the EI of a 305 WWTP sample grouped into five secondary treatment technologies. Results indicated the following two major findings: i) WWTPs using conventional activated sludge, extended aeration, trickling biofilters, and biodisks exhibited significant economies of sca…
The spatial dynamics of atmospheric pollution in Latvia and the Baltic Republics, as measured in mosses, topsoil and precipitation
1994
Atmospheric pollution in the Baltic countries of Estonia, Latvia, and Lithuania has been mapped using measurements of pollutant concentrations in mosses, topsoil and precipitation. Air masses from western Europe deposit industrial pollutants in the Baltic region and concentrations depend on meteorological conditions. Superimposed on this background is the pattern of deposits from local sources. Large areas receive neutral to basic precipitation due to cement industries and fly ash emissions from fossil fuel combustion. The burning of oil-shale in NE Estonia results in precipitation with pH values over 7.0, and high concentrations of V, Fe, and Cd. Heavy metal concentrations in the topsoil a…
Energy intensity of treating drinking water: Understanding the influence of factors
2017
Abstract To provide safe drinking water to urban populations, raw water must be treated in drinking water treatment plants, which are energy-intensive facilities. Previous studies have assessed energy intensity (EI: unit of energy required per unit of treated water) of conventional drinking water treatment plants, but they ignored variations related to water treatment trains. By modeling 179 facilities of four water treatment trains, we explored factors potentially affecting energy intensity, such as removal efficiencies of pollutants and treatment capacities of drinking water treatment plants. We also investigated the economies of scale in energy intensity of drinking water treatment plant…
Evolution of Bacterial Community in a Full-scale Biotrickling Filter by Fluorescence in Situ Hybridization (FISH)
2012
The performance of a full-scale biotrickling system for the treatment of exhaust gases from two different paint sources at a furniture facility, was investigated applying Fluorescense in situ hybridization (FISH). This technique allowed the detection of major bacteria groups and, therefore, helped in understanding complex microbial communities. The results indicated that Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria were more predominant than Firmicutes and Actiniobacterias. In addition, a variation in the composition of the bacterial community throughout the time of operation and with the paint source was observed. Betaproteobacteria showed similar r…
Biofiltration of ethyl acetate under continuous and intermittent loading
2007
A laboratory-scale peat biofilter was used for ethyl acetate removal from an air stream over a period lasting 1 yr. In a first stage, the biofilter was operated under continuous mode: a maximum elimination capacity of 400 g m−3 h−1 was obtained, and ethyl acetate was efficiently degraded with empty bed residence time (EBRT) as short as 22 s. The estimated yield coefficient, determined from the carbon dioxide production, resulted in 0.42 g dry biomass produced per gram of ethyl acetate consumed. The living and the dead cell concentrations were also monitored. The dead cell percentages varied between 18 and 85%, progressive increases in the dead cell percentages were achieved as EBRT decrease…
THE IMPACT OF TRAFFIC RELATED POLLUTION ON AIR QUALITY IN SIBIU REGION
2015
Urban areas represent the main zones of anthropogenic emissions and, at the same time, includes the largest number of population exposed to air pollution. Data related to traffic hot spots locations in Sibiu urban areas are presented and discussed in this paper. It is important to assess the impact of changing climate conditions and concentration of pollutants, these aspects are of special interest because of high and increasing population of urban regions exposed to consequences of climate change and air pollution. Paper tackling the problem of traffic related pollution and especially PM10 fraction as a novel research. No other research were previously done in Sibiu region emphasising part…
Influence of coordinated traffic lights parameters on roadside pollutant concentrations
2009
Abstract The paper examines the effects of coordinated traffic lights on CO and C 6 H 6 roadside concentrations in an urban area of Palermo in Southern Italy. Traffic loop detectors and one pollution-monitoring are used to collect data for use in DRACULA traffic microsimulator software. CO and C 6 H 6 roadside concentrations associated with varying cycle and offset times of the coordinated traffic lights are estimated using a neural network. Two functions were set up describing the relations of pollutant concentrations in term of cycle and offset time.
Phytoremediation and Plant-Assisted Bioremediation in Soil and Treatment Wetlands: A Review
2015
Phytoremediation is a technology that is based on the combined action of plants and their associated microbial communities to degrade, remove, transform, or immobilize toxic compounds located in soils, sediments, and more recently in polluted ground water and wastewater in treatment wetlands. Phytoremediation could be used to treat different types of contaminants including petroleum hydrocarbons, chlorinated solvents, pesticides, explosives, heavy metals and radionuclides in soil and water. The advantages of phytoremediation compared to conventional techniques are lower cost, low disruptiveness to the environment, public acceptance, and potentiality to remediate various pollutants. The use …
Soil Heavy Metals Patterns in the Torino Olympic Winter Games Venue (E.U.)
2008
International audience; The city of Torino (45°N, 7°E NW Italy) has a long history of heavy industry. Additional sources of potential pollutants originate from transport such as car emissions. We selected an area potentially at high risk of contamination: it is sandwiched between roads, the circular Turin highway and the motorway which connects to France, and a landfill where special and hazardous solid wastes from industry are disposed of. Our main aim was i) to discriminate between these sources of heavy metals (HM) and ii) to assess a simplified HM transfer scenario. We started with air diffusion models (inputs were meteo and chemistry of the particulate), then we described topsoils (12 …
Dispersion models and air quality data for population exposure assessment to air pollution
2014
Evaluating the extent of exposure to chemicals in absence of continuous measurements of their concentration in air and direct measures of personal exposure is crucial for epidemiological studies. Dispersion models can be a useful tool for reproducing spatio-temporal distribution of contaminants emitted by a specific source. However, they cannot easily be applied to short-term epidemiological studies because they require precise information on daily emission scenarios for a long time, which are generally not available. The aim of this study was to better assess the exposure in the industrial area of Brindisi, which suffers from various critical epidemiological situations, by integrating air …