Changing consumption patterns and CO2 reduction

Today, most countries are facing national CO₂ targets focused on production and direct energy use. However, two important driving forces are increased consumption and changing consumption patterns. In this paper, we analyse the impact from household consumption on CO₂ emissions. Household energy use is taken into account, as is the consumption of commodities and services produced by industry. Based on Danish data, we estimate the CO₂ impact from different commodities. Further, we analyse the impact of changes in commodity mix in Danish household consumption in the period from 1966 to 1992. The results show that the change in commodity mix has been insufficient to compensate for the overall growth in Danish consumption. Further, we see that the consumption of food is a main contributor to overall Danish CO₂ emissions.     

Flow-rate and pollution characteristics of domestic wastewater

The characteristics of the flow-rate and pollution parameters of the domestic wastewater of a medium-size city (Sivas, Turkey) have been investigated. The design and the operating parameters of a wastewater treatment plant appropriate to such a settlement were also studied. Daily and monthly flow-rate measurements and wastewater samples were taken at the outlet. Peak values of the flow-rate were observed between the hours 09:00 and 14:00. Domestic wastewater production per capita was determined as 170.6 litres per day. The wastewater biological reaction ratio coefficient (k), the BOD₅/COD ratio and the BOD₅/N ratio varied in the ranges 0.113–0.312, 0.44–0.67 and 3.1–9.5 per day, respectively. Daily pollution load parameters per capita were determined as follows: 47.3 g for BOD₅, 85.3 g for COD, 34.9 g for suspended solids, 7.9 g for nitrogen and 1.32 g for phosphorus.     

Description and application of the EAP computer program for calculating life-cycle energy use and greenhouse gas emissions of household consumption items

Focusing on reduction in energy use and greenhouse gas emissions, a life-cycle-based analysis tool has been developed. The energy analysis program (EAP) is a computer program for determining energy use and greenhouse gas emissions related to household consumption items, using a hybrid calculation method. EAP consists of a number of fill-in screens corresponding to steps in the hybrid method, which in their turn correspond to different stages in life-cycles of consumer goods. The database incorporated in EAP comprises data about energy use and emissions of the main greenhouse gases (CO₂, CH₄and N₂O) concerning materials, economic sectors, means of transport, etc. The use of the program in several projects showed the applicability and usefulness of EAP in research and policy. In this article, EAP is applied to food: French beans as a metaphor for fruit and vegetables.     

An econometric time-series analysis of global CO2 concentrations and emissions

This paper extends previous work on the econometric modelling of CO₂ concentrations and emissions. The importance of such work rests in the fact that models of the Cohen-Labys variety represent the only alternative to scientific or physical models of CO₂ accumulations whose parameters are inferred rather than estimated. The stimulation for this study derives from the recent discovery of oscillations and cycles in the net biospheric flux of CO₂. A variety of time series tests is thus used to search for the presence of normality, stationarity, cyclicality and stochastic processes in global CO₂ emissions and concentrations series. Given the evidence for cyclicality of a short-run nature in the spectra of these series, both structural time series and error correction models are applied to confirm the frequency and amplitude of these cycles. Our results suggest new possibilities for determining equilibrium levels of CO₂ concentrations and subsequently revising stabilisation policies.     

Analysis and interpretation of the monitoring data for C2–C11 hydrocarbons in the atmosphere of a rural Portuguese site

This paper focuses the application of a measurement technique for determining atmospheric C₂–C₆ hydrocarbons after canister sampling and analysis by gas chromatography/flame ionisation detection (GC/FID), as well of an adsorption-sampling technique for C₆–C₁₁ compounds and GC/FID analysis after thermal desorption and cryogenic concentration. Tens of samples collected at Giesta, a rural area located 20 km to the SE of the coastal Portuguese city of Aveiro, were analysed. The characterisation of C₂ C₁₁ hydrocarbons is presented, considering seasonal variations, diurnal cycles, the influence of air masses and different photochemical conditions. Ratios between hydrocarbons and principal components analysis were applied to differentiate between biogenic and anthropogenic sources.     

Separate determination of PM10 emission factors of road traffic for tailpipe emissions and emissions from abrasion and resuspension processes

Little is known about the relevance of mechanically produced particles of road traffic from abrasion and resuspension processes in relation to the exhaust pipe particles. In this paper, emission factors of PM₁₀ and PM₁ for light and heavy-duty vehicles were derived for different representative traffic regimes from concentration differences of particles and nitrogen oxides (NO_x) in ambient air upwind and downwind of busy roads, or alternatively of kerbsides and nearby background sites. Hereby, PM₁ was interpreted as direct exhaust emissions and PM₁₀-PM₁ as mechanically produced emissions from abrasion and resuspension processes. The results show that abrasion and resuspension processes represent a significant part of the total primary PM₁₀ emissions of road traffic. At sites with relatively undisturbed traffic flow they are in the same range as the exhaust pipe emissions. At sites with disturbed traffic flow due to traffic lights, emissions from abrasion/resuspension are even higher than those from the exhaust pipes.     

Spatial and diurnal variations in concentration of atmospheric NOx along urban-rural roadways in Nanjing, Southeastern China

Atmospheric NO_x concentrations (including NO₂ and NO) on the roadside environments of urban trunk, belt highway and suburban road as well as a reference in a forest area were measured. NO_x concentrations on roadside environments tended to be higher than that on the reference. With the exception of suburban road, NO_x concentrations over both of the urban trunk and belt highway exceeded the limited value of National Air Environmental Quality Standards. Gradient measurement of NO_x on the downwind side of the belt highway shows that it declined to background level over 100 m from the road edge.     

Preparation, characterisation and testing of photocatalytic polymeric membranes with entrapped or suspended TiO2

Various cellulose triacetate (CTA) or polysulfone (PSf) membranes with entrapped polycrystalline TiO₂ were prepared by using different methods of the so-called phase inversion process. Porosity and permeability of the membranes increased by increasing the amount of entrapped TiO₂ while rejection decreased. The photoactivity of entrapped TiO₂ for the degradation of congo-red was compared with that of the same quantity of suspended TiO₂ and the results indicated that TiO₂ was always more efficient when used in suspension. A hybrid configuration consisting of a continuous membrane photoreactor with the photocatalyst in suspension showed to be the most promising one.     

A statistical model for predicting carbon monoxide levels

This paper presents a statistical model that is able to predict carbon monoxide (CO) concentrations as a function of meteorological conditions and various air quality parameters. The experimental work was conducted in an urban atmosphere, where the emissions from cars are prevalent. A mobile air pollution monitoring laboratory was used to collect data, which were divided into two groups: a development group and a testing group. Only the development dataset was used for developing the model. The model was determined by using a stepwise multiple regression modelling procedure. Thirteen independent variables were selected as inputs: non-methane hydrocarbon (NMHC), methane (CH₄), suspended dust, carbon dioxide (CO₂), nitrogen oxide (NO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), wind speed, wind direction, temperature, relative humidity and solar energy. It was found that NO has the most effect on the predicted CO concentration. The contribution of NO to the CO concentration variations was 91.3%. Adding in the terms for NO₂), NMHC and CH₄ improved the model by only a further 2.3%. The derived model was shown to be statistically significant, and model predictions and experimental observations were shown to be consistent.     

Computational modelling of NOx removal by selective non-catalytic reduction

This paper presents the results of computational kinetic modelling of the removal of nitrogen oxides (NO_x) from flue gases by selective non-catalytic reduction (SNCR) process using urea as a reducing agent. CHEMKIN and SENKIN computer codes were used with latest reaction mechanism parameters for simulated conditions in an isothermal plug flow reactor. Flue gas initial conditions were simulated as 70 litres/min propane containing 500 ppm background NO_x. A range of molar ratios was studied at optimum temperature. Carbon monoxide and hydrogen were investigated as potential enhancers to lower the temperature window. The modelling results suggested that the optimum temperature for peak reduction was around 1075°C with optimum molar ratios of 1.5. Hydrogen was found to be an efficient enhancer. The optimum residence time was found to be about 80 milliseconds.     

Sustainable urban transportation: impact of CO2 mitigation strategies on local pollutants

This paper assesses CO₂ mitigation strategies in Delhi and Mumbai against the dynamics of local pollutants. After testing against techno-economic feasibility, compressed natural gas (CNG) technology, four-stroke two-wheelers and battery-operated vehicles (BOV) were selected as candidate options for Mumbai and Delhi. Multiple constrained optimisation for finding out the optimal mix of vehicles to meet the travel demand under the business-as-usual scenario for the period of CO₂ mitigation targets of 5, 10, 15, 20, 25% resulted in reduced stock of diesel and petrol vehicles, with the reduction spanning over different points of the above time period. In the case of Mumbai, battery-operated three-wheelers dominated the vehicular mix, with the share of CNG vehicles remaining at a standard level. CO₂ reduction targets did not influence the CNG option significantly. CO₂ mitigation influenced the dynamics of local pollutants considerably in both Delhi and Mumbai. In Delhi, TSP and SOx reduction levels against the CO₂ mitigation target were found to be significant. In Mumbai, the percentage reduction in local pollution (TSP in particular) was higher than the target CO₂ reduction. Local pollutants other than TSP and SO_x showed an increasing trend against the CO₂ mitigation strategies in Delhi. In the case of Mumbai, all non-target pollutants showed a falling trend against the CO₂ mitigation strategies, though insignificantly for pollutants other than TSP and SO_x.     

An ozone climatology: relationship between meteorology and ozone in the Southeast USA

A statistical analysis of ozone (O₃) concentrations and meteorological parameters was performed to determine the relationship between meteorological changes and ambient O₃ concentrations in the Southeast United States. The correlation between average daily maximum O₃ concentration and various meteorological variables was analysed on a monthly basis from April through October during 1980-1994. The correlations were strongest during the summer months, particularly June, July, and August. Analysis of long term O₃ concentration trends indicates increasing trends during the 1980s and decreasing trends during the early 1990s.     

Exploratory study of some potential environmental impacts of CO2 sequestration in unmineable coal seams

An initial investigation into the potential environmental impacts of CO₂ sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production, using a CO₂ injection process (CO₂-ECBM). A high volatile bituminous coal, Pittsburgh No. 8, was reacted with synthetic produced water and gaseous carbon dioxide at 40°C and 50 bar to evaluate the potential for mobilisation of toxic metals during CO₂-ECBM/sequestration. Microscopic and X-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction and chemical analysis of the synthetic produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilising toxic trace elements from coal beds are important factors to be considered when evaluating deep, unmineable coal seams for CO₂ sequestration.     

The application of the RAINS model for Greece

In order to comply in 2010 with the emission ceilings proposed by European commission under the convention on transboundary air pollution, Greece has to develop and implement a cohesive strategy affecting all the sectors of the economy. The RAINS model was used for the evaluation of the environmental and economic impacts arising from the use of a number of control technologies under alternative energy scenarios. To this purpose a number of modifications regarding the input databases of RAINS were made. The analysis clearly reveals that the reduction of SO₂ emissions can be achieved in a lower cost compared to the reduction of NO_x emissions. Moreover, the complementarity of CO₂ abatement policies and the SO₂/NO_x abatement policies is also accented.     

Heavy metal speciation and mobility assessment of arid soils in the vicinity of Al Ain landfill, United Arab Emirates

Sixty-four surface soil samples taken in the vicinity of Al Ain landfill were analysed for cadmium, chromium, copper, nickel, lead and zinc by inductively coupled plasma spectroscopy. Extraction techniques were used to establish the association of the total concentrations of the six metals in the soil samples with their contents in the exchangeable, carbonate, iron/manganese oxides, and residual fractions. In the investigated soils, the recorded concentrations were as follows: 0.043 mg kg^-1 for cadmium, 19.1 mg kg^-1 for chromium, 53.3 mg kg^-1 for copper, 60 mg kg^-1 for nickel, 13.7 mg kg^-1 for lead, and 117 mg kg^-1 for zinc. Cadmium, chromium, nickel, lead and zinc concentrations in the investigated soil samples reflect the natural background values in shale, whereas copper is slightly enriched. I-geo (geoaccumulation index) values of the metals in the soils under study indicate that they are uncontaminated with cadmium, chromium, nickel, lead and zinc, but contaminated to moderately contaminated with copper. Heavy metal contents in the sediments were found to be significantly influenced by different physico-chemical parameters. The effect of these parameters can be arranged in the following order: clay fraction > carbonate fraction > silt fraction > organic matter fractions. A sequential extraction procedure showed that the total concentrations of the heavy metals are largely bound to the residual phase (retained 71.4% of cadmium, 77.8% of chromium, 75% of copper, 47% of nickel, 62.8% of lead, and 75.8% of zinc). A likely sequence of mobility in the investigated soils is as follows: chromium > lead > nickel > cadmium > zinc > copper.     

Source contribution of atmospheric aerosols in Bangkok metropolitan area by CMB8 receptor model

The CMB₈ model was applied for source apportionment of particulate matter in Bangkok area. The 24 h of ambient data were collected and analysed for elemental composition during December 1996 to January 1997 by high volume air samplers at a station in Bangkok, Thailand. Seven source profiles and the average mass concentrations of 42 ambient data were used to run the chemical mass balance (CMB₈) model. The source apportionment by CMB₈ gave similar results comparing with factor analysis – multiple regression (FA–MR) model of the same data. The results revealed that major sources of particulate matter in Bangkok were: soil (33%), road dust (33%) and automobile (15%). The minor source contributions were: sea salt (4.34%), refuse incineration and biomass burning (0.84%), steel mill (0.62%) and fuel oil combustion (0.35%). The lack of source profile for biomass or open burning in Bangkok resulted in much lower predicted contribution of this source when compared to that from FA–MR. When apply this CMB₈ model with daily ambient data, the result revealed that one fourth of daily CMB₈ source apportionment had high value of ² (>4). These exceedance values of Chi² also point out that one of the selected sources (biomass burning) may not be the true contributing sources. Presumably, accurate biomass burning source profile is needed to improve the CMB calculation of source contributions for particulate matter in Bangkok metropolitan area.     

Differential water quality in confined and free-flowing water bodies, Lebanon

Integrated management of water resources is a major critical issue to be addressed in combating water stress in developing countries, such as Lebanon. At present, surface water is not properly used in Lebanon. This emphasises the importance of assessing surface water quality as a projected means to increase water availability. This study involves two different water bodies, the freely flowing Nahr-Ibrahin River and the Qaraaoun Reservoir, an impoundment of the Litani River. Water samples were collected from 16 chosen sites of each water body at four different dates during the dry season. Measured water parameters were temperature, pH, conductivity, BOD, HCO₃^-, Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, PO₄^3-, NO_{3-, NH3, Fe, Mn, Zn, Pb, and Cd. Statistical analysis of the data revealed significant differences in water quality. The differences could be attributed to the fact that whereas the Qaraaoun reservoir is receiving domestic waste discharges that lead to an increase in the CO2 content and a pH decrease, the Nahr-Ibrahim River is influenced by agricultural runoffs and industrial discharges that increase the pH values. Consequently, the water metal speciation of the two water bodies was different. The study indicated that the differential quality of the two water bodies could be attributed to the nature of the water resources and exposure to contaminants. This is crucial in recommending intervention studies to protect quality and promote the role of surface water use, as an integrated component of water management in Lebanon.}     

Atmospheric particulate matter in the city of Sao Carlos/SP, Brazil

This paper presents experimental data and source apportionment simulations on particulate matter (PM₁₀ and PM_2.5) in the atmosphere of Sao Carlos/SP, Brazil. Both a Hi-vol sampler equipped with glass fibre filters and a Dichotomous sampler with nucleopore filters were used. The collected material was analysed for total carbon, using a thermometric method, and for traces of several chemical species, using X-ray fluorescence spectroscopy. Source apportionment estimations were made with a chemical mass balance receptor model software (CMB8), with source profiles taken and adapted from the literature. The results indicate that both PM₁₀ concentration and source apportionment vary seasonally, and that vegetative burning can be a significant source of PM₁₀ in the dry season     

Analysis of radioisotope concentrations in sediments using γ-ray spectrometry

The concentrations of some naturally occurring radioisotopes in sediments of the Kufranja river basin in Jordan were determined by means of γ-ray spectrometry with precise calibration of energy and efficiency. The nuclides' concentrations were found by either direct measurement of their activities, as in the case of ²²⁶Ra and ⁴⁰K, or through the measurements of the activities of their daughters with short half-lives, as in the case of ²³⁸U and ²³²Th. Furthermore, the hazard index, the radium equivalent activity and the absorbed dose rate for each of these nuclides had been calculated. It turned out that the concentrations of radioisotopes in sediments of the studied area were below the standard limits and the human effective dose equivalent ranged from 23.8 to 35.7 μSv/yr.     

Sensitivity analysis of the CERES-wheat model for variations in CO2 and meteorological factors in Northwest Turkey

Plant growth is very sensitive to variations in atmospheric factors. Possible effects of climate change on plant growth can be estimated and evaluated using the crop growth simulation models. In this study, the CERES (Crop Environment Resource Synthesis)-wheat model was applied to two consequent growing seasons (1997–1998 and 1998–1999) in order to determine the model sensitivity on the changes in several meteorological factors such as air temperature, precipitation, solar radiation and carbon dioxide (CO₂) concentration. In the model, the air temperature variations were applied from ±1°C up to ±2°C and CO₂ were changed in the range of 20% to 100%, while the solar radiation, precipitation were varied between 10% and 20%. Biomass and the grain yield of the wheat crop were influenced positively by the increased combination of the solar radiation, air temperature and CO₂. However, low crop responses to the variations in precipitation were unexpected.