INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY (IJEST)
Year:2010 | Volume:7 | Issue:4 (28)|Papers Count:20

This study investigated the sorption behaviour of two endocrine disrupting chemicals; 17 b-estradiol (E2) and 17b-ethinylestradiol and their thermodynamic properties in an activated sludge biomass. The partition coefficient values measured for E2 and EE2 at varying temperatures range from 245- 604 L/kg (log Kd 2.39-2.78) and 267-631 L/kg (Log Kd 2.43-2.80), respectively. The Kd values were inversely related to temperature. The average percentages of E2 and EE2 adsorbed to the solid phase at 4.3 % dry solid were 87.2 % and 92.5 %, respectively. Sorption of E2 and EE2 to the activated sludge biomass was found to be spontaneous and entropy retarded with DG values in the range of -13 to -16 KJ/mol and ΔS value of -105.2J/mol/K and 96.7 J/mol/k for E2 and EE2, respectively. The enthalpy changes for E2 and EE2 were - 45.7KJ/mol and - 43.4KJ/mol respectively, demonstrating that the sorption process is exothermic. The values of the enthalpy changes also show that the mechanism of sorption is physisorption with some element of chemisorption.

The present study aims to estimate biogas potential of two Russian landfills situated in the republic of Tatarstan and in Moscow Region. Due to environmental, economic, social and energetic consideration of biogas for human being, utilization of such a by-product would be of high concern. To date, there are seven biogas utilization projects which have been developed and implemented at municipal solid waste landfills of Russia. The purpose of the research was to determine the biogas potential at the closed landfills. During the studies held in 2008; sampling, transportation, storage of biogas and landfill soil samples, laboratory investigations; physicochemical and analytical methods for measuring of proteins, carbohydrates and fats in the organic part of the soil and the analysis of empirical data by the methods of computer modeling and mathematical statistics were carried out. The obtained results of the research; concentrations of biogas components: methane, carbon dioxide, carbon oxide, nitrogen, hydrogen and oxygen, gas flows, composition of the organic part of the fields and analysis of gas distribution on the surface of the landfills; has shown scientific and practical importance. Results could be used for the assessment of biogas potential at the landfills for further biogas utilization projects implementation with electrical or thermal energy production.

Physiographic factors along with edaphic conditions play a crucial role in establishment of plant species throughout a region. Identification of the most effective factors is of high importance in sustainable management of a forest ecosystem. This study aims to investigate the relationships between understory vegetation and some environmental factors in natural forest ecosystems. This study has been carried out among the Fagetum orientalis communities of Ramsar Region, located in the north of Iran. For this purpose, 105 releves were sampled by a randomizedsystematic method throughout the study area, using the Braun-Blanquet scale. Physiographic parameters such as elevation, as well as slope and orientation were measured. By identification of the herb-layer vegetation contained in each sampling, vegetation composition and cover abundance of species were separately identified. Then, the aforementioned properties of soil were entirely measured in the taken samples. Cluster analysis and detrended correspondence analysis have been applied to classify the site. Moreover, in order to determine the relation between species composition and environmental factors, canonical correspondence analysis was used. Results showed a significant relation between distribution of plant types and environmental factors. Eventually, environmental factors including slope, orientation, silt percent, pH, organic matter and soluble phosphorous were among the most effective factors in establishment of Hedera pastuchowii, Solanum kieseritzkii, Oplismenus undulatifolius, Sedum stoloniferum, Rubus hyrcanus and Saxifraga cymbalaria species.

The biodegradability of polycyclic aromatic hydrocarbons such as naphthalene, fluorene, anthracene and phenanthrene by a halotolerant bacterial consortium isolated from marine environment was investigated. The polycyclic aromatic hydrocarbons degrading bacterial consortium was enriched from mixture saline water samples collected from Chennai (Port of Chennai, salt pan), India. The consortium potently degraded polycyclic aromatic hydrocarbons (>95%) at 30g/L of sodium chloride concentration in 4 days. The consortium was able to degrade 39 to 45% of different polycyclic hydrocarbons at 60 g/L NaCl concentration. Due to increase in salinity, the percent degradation decreased. To enhance polycyclic aromatic hydrocarbons degradation, yeast extract was added as an additional substrate at 60g/L NaCl concentration. After the addition of yeast extract, the consortium degraded>74 % of polycyclic aromatic hydrocarbons at 60 g/L NaCl concentration in 4 days. The consortium was also able to degrade PAHs at different concentrations (5, 10, 20, 50 and 100 ppm) with 30g/L of NaCl concentration. The polycyclic aromatic hydrocarbons degrading halotolerant bacterial consortium consists of three bacterial strains, namely Ochrobactrum sp., Enterobacter cloacae and Stenotrophomonas maltophilia.

In the study, the relationship between some aquatic insect species (Ephemeroptera, Plecoptera, Trichoptera and Odonata) and some heavy metals (cadmium, lead, copper, zinc, nickel, iron and manganese) and boron were assessed using data obtained from the Ankara Stream, which flows through Ankara, the capital city of Turkey and receives high organic and industrial wastes. Sampling was carried out monthly along the Ankara Stream in 1991. Environmental data were used to explain biological variation using multivariate techniques provided by the program canonical correspondence analysis ordination. The ordination method canonical correspondence analysis was applied to evaluate the relationships between environmental variables and distribution of aquatic insect larvae. Data sets were classified by two way indicator species analysis. In this study, aquatic insecta communities have been shown by canonical correspondence analysis ordination as related to total hardness, pH, cadmium, lead, copper, zinc, nickel, iron, manganese and boron. Cadmium, lead, copper and boron exceeded limits of the United States Environmental Protection Agency criteria for aquatic life. Trichopteran, Dinarthrum iranicum was an indicator of two way indicator species analysis and was placed close to the arrow representing copper. Odonate, Aeschna juncea was an indicator of two way indicator species analysis in site 10 and was placed close to the arrows representing manganese, lead, and nickel. Trichopteran, Cheumatopsyche lepida and odonate, Platycnemis pennipes were indicators of two way indicator species analysis for sites 6, 7, 11, 14, 15, 18 and were placed close to the arrows representing cadmium, boron, iron and total hardness.

To analyze the variation of physiological responses between Nymphaea tetragona Georgi. And Pontederia cordata L. and the water qualities under aeration conditions, the selected plants were cultivated in 12 purifying-tanks (aeration, non aeration), to treat heavily polluted river water. The characteristics of both plants were investigated, which included contents of chlorophyll and soluble protein, activities of peroxidase and catalase, accumulations of nitrogen and phosphorus, densities of tillers and roots, lengths of roots, culms and leaves, biomass of roots and shoots. The water qualities were analyzed correspondingly. Results indicated that aeration affected morphological and physiological characteristics of the plants and the water qualities and effects became more significant on N. tetragona than P. cordata. Biomass and length of roots, culms and leaves under the non aeration conditions exceeded that under the aeration conditions. Aeration contributed to the activities increase of peroxidase and catalase of the roots and the contents decrease of chlorophyll and soluble protein of the leaves. Nitrogen and phosphorus contents of the roots, culms and leaves increased under the non aeration conditions. Aeration resulted in tillers and roots densities of N. tetragona decreased, while they increased for P. cordata. Total phosphorus and soluble phosphorus removals decreased 8.42% and 8.05% in the tank with N. tetragona under the aeration conditions. In the tank with P. cordata, total nitrogen and NH4+-N removals increased 14.44% and 16.06% under the aeration conditions. This work provided valuable.

Tidal excursion is an important parameter that indicates hydraulic and mixing characteristics of estuarine environments. Prediction of the tidal excursion length provides a proper tool for environmental management of estuaries. In this study, the governing equations of the salinity transport were scaled first to recognize the effective dimensionless parameters of tidal excursion length. Then, a laterally averaged two-dimensional numerical model called CE-QUAL-W2 was used as a virtual laboratory to simulate the salinity intrusion length. Existing field data of Limpopo estuary, as a case study, was used for calibration and verification of the model and reasonable agreement was observed between the model results and the field data. Finally, the verified model was used to assess the influences of the governing parameters. The results showed that simple power functions can be used to describe the effects of dimensionless parameters obtained by scaling of the governing equations. As a result, a new formula in form of a power function was derived to predict the tidal excursion length based on the geometric and hydrodynamic characteristics of alluvial estuaries. Comparison of the computed tidal excursion lengths using the derived formula with the observed measurements in several estuaries showed the robustness of the developed formula.

This study investigated simultaneous removal of lead and ethylenediaminetetraacetic acid from synthetic wastewater samples using granular activated carbon adsorption. Data from a 1×10-4 M lead-ethylenediaminetetraacetic acid adsorption isotherm study fitted well to Freundlich isotherm. Furthermore, for the pH-dependent 1×10-4 M leadethylenediaminetetraacetic acid study both lead and ethylenediaminetetraacetic acid adsorptions increased reaching values of 82% and 93% respectively at pH 5.8. However, a further increase in pH resulted in decreasing but near equal lead and ethylenediaminetetraacetic acid removals. Results for the 2×10-4 M lead-ethylenediaminetetraacetic acid system showed a behavior that was qualitatively similar to the 1×10-4 M lead-ethylenediaminetetraacetic acid findings. However, the 1×10-3 M lead-ethylenediaminetetraacetic acid study showed only a decreasing adsorption trend. An increasing-decreasing type lead/ethylenediaminetetraacetic acid adsorption behavior was also noted for the 1×10-4 M lead/2×10-4 M ethylenediaminetetraacetic acid system. Nevertheless for the 2×10-4 M lead/1×10-4 M ethylenediaminetetraacetic acid system, lead removal at increased pH was comparatively higher. Furthermore, results from a continuous column study completed at 1×10-4 M lead and 0.75×10-4 M ethylenediaminetetraacetic acid showed high saturation times both for lead and ethylenediaminetetraacetic acid. Results from the present work show that a notable removal of aqueous phase lead and ethylenediaminetetraacetic acid could be achieved using activated carbon adsorption. The details related to the effect of pH and pollutants’ concentration on the overall adsorption efficiency, as reported in the present work, would be of much use for an effective carbon adsorption process design for the treatment of respective wastewaters.

The influence of plant primary compounds on the activity of soil microbial communities under heavy metal stress was studied in a pot-culture field experiment conducted in a green house. Amaranthus spinosus was cultivated in an agricultural soil previously amended in the laboratory with solutions of different trace elements in two separate treatment modes: singly and in combination. Culture-independent metabolism based indices such as the rate of carbon and nitrogen mineralization, microbial biomass carbon and soil basal respiration were monitored fortnightly over a period of six weeks. Result shows that plant detritus have significant modifying effect on soil microbe-metal interactions. Data on microbial and biochemical processes in the respective mesocosms did not vary from control; not even in mesocosms containing very high concentrations of copper, zinc and nickel. The soil microbial biomass carbon and the rate of carbon and nitrogen cycling were not impeded by the respective metal treatment while the respiration responses increased as a result of increase in metabolic activity of the soil microbes. The plant based substrates enabled the soil microflora to resist high metal contamination because of its tendency to absorb large amounts of inorganic cations.

The objectives of this study are to investigate the levels of noise pollution in some hospitals in Taiwan and to study the effects of noise pollution on the physiological and psychological reactions and  annoyance response of medical care staff, patients and visitors in these hospitals. An instrument for the measurement of sound level was used and a self-answered survey questionnaire on noise pollution was administered. Results showed that the daily average sound levels measured inside these hospitals during daytime were between 52.6 and 64.6 decibels. These are higher than the current daytime environmental noise limit of 50 decibels in Taiwan. Most nursing staff members expressed that “talking of visitors or patient’s family members” is the major source of noise inside the wards, whereas “talking of visitors or patient’s family members” and “children playing” are the two major noise sources outside the wards. However, most patients or visitors claimed that “doors opening or closing” and “patients moaning or crying” are the two major sources of noise inside the wards. “Footsteps,” “renovation of hospitals,” “talking of visitors or patient’s family members,” “shouting of nursing staff” and “doors opening or closing” are the five major noise sources outside the wards. To conclude, noise pollution inside and outside the wards either directly or indirectly affects, in a simultaneous manner, the subjective perception of noise, emotions, physiology and experience of noise inside and outside the wards of both the medical care staff and the patients and visitors.

One of the most important objectives of a manufacturing firm is the efficient design and operation of its supply chain to maximize profit. Paper is an example of a valuable material that can be recycled and recovered. Uncertainty is one of the characteristics of the real world. The methods that cope with uncertainty help researchers get realistic results. In this study, a two-stage stochastic programming model is proposed to determine a long term strategy including optimal facility locations and optimal flow amounts for large scale reverse supply chain network design problem under uncertainty. This network design problem includes optimal recycling and collection center locations and optimal flow amounts between the nodes in the multi-facility environment. Proposed model is suitable for recycling/ manufacturing type of systems in reverse supply chain. All deterministic, stochastic models are mixed-integer programming models and are solved by commercial software GAMS 21.6/CPLEX 9.0.

During estuarine mixing, dissolved metals come into the particulate phase due to the flocculation processes. Such processes are biologically vital. In the present study, controlling mechanisms of elemental flocculation during estuarine mixing in northern and southern estuaries of Iran in relation to the various physical and chemical parameters of waters have been compared. Except for zinc and lead, for other studied elements in Minab River, water flocculate at higher rates in comparison with the rivers flowing into the Caspian Sea. Redox potential might have negative effect on flocculation process in Minab Estuary. Contrary to rivers flowing into the Caspian Sea, in Minab River elemental flocculation is governed by dissolved organic carbon and it shows a non-liner and conservative behavior during estuarine mixing which implies that dissolved organic carbon originates from terrigenous source. The results also shows that maximum removal of elements occurs in lower salinities (1.5 to 5.8‰) for the rivers in North of Iran and 3.3 to 11.4‰ for Minab River in South of Iran. Flocculation of studied metal in different rivers results in reduction of overall metal pollution load by various percentages. The initial metal contents on river water and mean discharge of river might lead to higher flocculation rates.

Due to increasing motorization, construction of flyovers and growth in transport network, the noise level has exceeded the prescribed limits in many Indian cities. The health implications of high noise levels are being identified as hypertension, sleeplessness, mental stress, etc. Due to this adverse effect of noise level, it is essential to assess the impact of traffic noise on residents and road users. This research is an effort to quantify and analyze the traffic noise emissions along bus rapid transit corridor in Delhi. Field measurements were carried out to understand and assess various aspects of the impact of bus rapid transit system corridor on land use and social lives of residents and road users. The present analysis presents the comparison between observed and predicted noise level at selected corridors and also describes the mitigatory measures to overcome such type of traffic noise pollution through design of noise barrier along the road and motivate people towards the use of public transport system.

Granular activated carbon produced from palm kernel shell was used as adsorbent to remove copper, nickel and lead ions from a synthesized industrial wastewater.Laboratory experimental investigation was carried out to identify the effect of pH and contact time on adsorption of lead, copper and nickel from the mixed metals solution. Equilibrium adsorption experiments at ambient room temperature were carried out and fitted to Langmuir and Freundlich models. Results showed that pH 5 was the most suitable, while the maximum adsorbent capacity was at a dosage of 1g/L, recording a sorption capacity of 1.337mg/g for lead, 1.581mg/g for copper and 0.130mg/g for nickel. The percentage metal removal approached equilibrium within 30 min for lead, 75min for copper and nickel, with lead recording 100%, copper 97% and nickel 55% removal, having a trend of Pb2+> Cu2+>Ni2+. Langmuir model had higher R2 values of 0.977, 0.817 and 0.978 for copper, nickel and lead respectively, which fitted the equilibrium adsorption process more than Freundlich model for the three metals.

Water quality monitoring in developing countries is inadequate, especially in stream water affected by urban effluents and runoff. The purpose of this study was to investigate heavy metal contaminants in the Nakivubo Stream water in Kampala, Uganda. Water samples Nakivubo Channelized Stream, tributaries and industrial effluents that drain into the stream were collected and analysed for the total elemental concentration using flame atomic absorption spectrophotometer. The results showed that: 1) the wastewater was highly enriched with lead and manganese above the maximum permissible limit; 2) the levels of dissolved oxygen were below the maximum permissible limit, while the biological oxygen demand was above the maximum permissible limit. All industrial effluents/wastewater were classified as strong (>220mg/L). Factor analysis results reveal two sources of pollutants; 1) mixed origin or chemical phenomena of industrial and vehicular emissions and 2) multiple origin of lead (vehicular, commercial establishment and industrial). In conclusion, Nakivubo Channelized Stream water is not enriched with heavy metals. These heavy metals (lead, cadmium and zinc) were rapidly removed by co-precipitation with manganese and iron hydroxides and total dissolved solids into stream sediments. This phenomena is controlled by pH in water.

Oil spills is one of the most important hazards in the estuarine and coastal water. In recent decades, engineers try to predict the status of oil slick to manage the pollution spreading. The prediction of oil slick transport is carried out mainly by means of numerical models. In the current study, the development and application of a two-phase fluid flow model to simulate oil transport in the marine environment are presented. Different transport and fate processes are included in the developed model. The model consists of the Lagrangian method for the advection process, the Random Walk technique for horizontal diffusion process and the empirical equations for the fate processes. The major forces for driving oil particles are fluid current, wind speed and turbulent flow. Therefore, the multi-component hydrocarbon method has been included to the developed model in order to predict fate processes. As prediction of particle velocity components is of major importance for oil slick advection, therefore the binomial interpolation procedure has been chosen for the particle velocity components computations. In addition, shoreline boundary condition is included in the developed model to simulate shore response to oil slick transport near the beaches. The results of the model applications are compared with the analytical solutions, experimental measurements and other numerical models cited in literature. Comparisons of different sets of results represent the capability of developed model to predict the oil slick transport. In addition, the developed model is tested for two oil spill cases in the Persian Gulf.

The objective of the study is to reveal the seasonal variations in the river water quality with respect to heavy metals contamination. To get the extend of trace metals contamination, water samples were collected from twelve different locations along the course of the river and its tributaries on summer and the winter seasons. The concentrations of trace metals such as cadmium, cromium, copper, cobalt, iron, manganese, nickel, lead, mercury and zinc were determined using atomic absorption spectrophotometer. Most of the samples were found within limit of Indian drinking water standard (IS: 10500). The data generated were used to calculate the heavy metal pollution index of river water. The mean values of HPI were 36.19 in summer and 32.37 for winter seasons and these values are well below the critical index limit of 100 because of the sufficient flow in river system. Mercury and chromium could not be traced in any of the samples in the study area.

Activated carbon produced from fluted pumpkin (Telfairia occidentalis) seed shell was utilized for the removal of lead (II) ion from simulated wastewater. Adsorption tests were carried out in series of batch adsorption experiments. Several kinetic models (Bhattacharya-Venkobacher, Elovich, pseudo first and second order, intra-particle and film diffusion) were tasted for conformity to the experimental data obtained. The Langmuir and Freundlich adsorption models were also used to test the data. The amount of lead (II) ion adsorbed at equilibrium from a 200mg/L solute concentration was 14.286mg/g. The experimental data conform very well to the pseudo-second order equation where equilibrium adsorption capacities increased with increasing initial lead (II) concentration. The rate of the adsorption process was controlled by the film (boundary layer) diffusion as the film diffusion co-efficient values obtained from data analysis were of the order of 10 6cm2/s. From the plots, the linear regression coefficient (R2) of the Langmuir model was higher than that of the Freundlich: the adsorption isotherm obeyed the Langmuir model better than the Freundlich model.

Methylene blue has been proposed as a new analytical reagent for the catalytic spectrophotometric determination of thallium (I). It reacts with ascorbic acid in acidic medium to form a colorless product. Thallium (I) increases the rate of reaction and it can be determined base on its catalytic effect on the reaction. The reagents and manifold variables influences on the sensitivity were investigated and the optimum conditions were established. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance of methylene blue at 664 nm. A fixed time method of 180.0 s from initiation of the reaction was used. Under optimum conditions, the proposed method allows the determination of thallium concentrations in the range 3.0-200mg/mL with a detection limit of 0.09mg/mL. This method is free from of most interference. The results of the proposed method for water samples were comparable with atomic absorption spectroscopy and were found to be in good agreement.

Integrated pest management programs are very important in the control of invertebrate pests within apple orchards. Many current integrated pest management strategies concentrate on specialist predatory species. However, generalist beneficial insects, such as several mite species, must also be fully researched for their potential in controlling pests. Previous research has shown that the generalist predatory mite Anystis baccarum (Linnaeus) can offer much potential in controlling invertebrate pests within Northern Irish apple orchards. However, apple growers have been mis-identifying this beneficial species as the economic pest European fruit tree red spider mite, Panonychus ulmi (Koch). As a result, unnecessary pesticide applications have been applied against what has now been confirmed as a beneficial species. To aid apple growers in the identification of A. baccarum, identification cards were produced. Positive uptake of the cards by many apple growers has resulted in correct identification of A. baccarum from P. ulmi, and therefore, a reduction in chemical pesticide applications. The benefits of A. baccarum within orchard ecosystems is discussed.