Determination of trace metal concentrations in soil profiles of municipal waste dumps in Nigeria

The concentrations of trace metals (Cd, Pb, Cu, Cr, Fe, Ni, Zn and Co) were studied in soil profiles of eight municipal waste dump sites in Warri metropolis. The results indicate that concentrations of trace metals varied widely among the different dumpsites and decreased with depths in a studied soil profile. The accumulation pattern for the heavy metals in the soil profiles follows the order: Fe > Pb > Mn > Co > Cr > Zn > Ni > Cu > Cd. The concentrations of metals found in these sites was below the Canadian remediation criteria for land for agricultural, residential and commercial/industrial purposes except for the cadmium levels in some sites that exceeded criterion values for agricultural and residential. In such sites, remedial actions are required before any form of chosen development can take place. The levels of heavy metals found in these dump sites were higher than that of the control site. The examined metals showed no significant correlation with soil physicochemical properties at the surface horizon, which is suggestive evidence that these metals arise from anthropogenic input.     

Predicting the combustion behaviour of compression ignition engine fuelled with biodiesel from Stoechospermum marginatum,a macro algae

Environmental Science and Pollution Research - Biodiesel is one among the recent developments in the field of renewable energy research. To enhance the combustion characteristics of compression...     

Distribution of polycyclic aromatic hydrocarbons in urban stormwater in Queensland, Australia

This paper reports the distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in wash-off in urban stormwater in Gold Coast, Australia. Runoff samples collected from residential, industrial and commercial sites were separated into a dissolved fraction (<0.45 μm), and three particulate fractions (0.45-75 μm, 75-150 μm and >150 μm). Patterns in the distribution of PAHs in the fractions were investigated using Principal Component Analysis. Regardless of the land use and particle size fraction characteristics, the presence of organic carbon plays a dominant role in the distribution of PAHs. The PAHs concentrations were also found to decrease with rainfall duration. Generally, the 1- and 2-year average recurrence interval rainfall events were associated with the majority of the PAHs and the wash-off was a source limiting process. In the context of stormwater quality mitigation, targeting the initial part of the rainfall event is the most effective treatment strategy. The implications of the study results for urban stormwater quality management are also discussed.     

Molecular Transport of Xylene Through Palm Pressed Fibre Filled Low Density Polyethylene: Role of Fibre Content,Alkali Treatment and Particle Size

We report in this paper the transport of an aromatic solvent, xylene through palm pressed fibre filled low density polyethylene composites studied at three different temperatures (40, 60, and 80 °C) by conventional weight-gain method. The diffusion parameters were investigated with special reference to the effect of fibre content, temperature and particle size. The effect of alkali treatment on solvent uptake was also analyzed. The transport coefficients of diffusion, permeation and sorption were determined to evaluate the influence of interface bonding on transport properties. The van’t Hoff relationship was used to determine the thermodynamic parameters and was found that the estimated free energies of sorption were all positive, indicating non-spontaneity of the solubility of PPF/LDPE composites. The first order kinetic rate constant and swelling parameters were also evaluated.     

Chicken manure biochar as liming and nutrient source for acid Appalachian soil

Acid weathered soils often require lime and fertilizer application to overcome nutrient deficiencies and metal toxicity to increase soil productivity. Slow-pyrolysis chicken manure biochars, produced at 350 and 700°C with and without subsequent steam activation, were evaluated in an incubation study as soil amendments for a representative acid and highly weathered soil from Appalachia. Biochars were mixed at 5, 10, 20, and 40 g kg into a Gilpin soil (fine-loamy, mixed, active, mesic Typic Hapludult) and incubated in a climate-controlled chamber for 8 wk, along with a nonamended control and soil amended with agronomic dolomitic lime (AgLime). At the end of the incubation, soil pH, nutrient availability (by Mehlich-3 and ammonium bicarbonate diethylene triamine pentaacetic acid [AB-DTPA] extractions), and soil leachate composition were evaluated. Biochar effect on soil pH was process- and rate-dependent. Biochar increased soil pH from 4.8 to 6.6 at the high application rate (40 g kg), but was less effective than AgLime. Biochar produced at 350°C without activation had the least effect on soil pH. Biochar increased soil Mehlich-3 extractable micro- and macronutrients. On the basis of unit element applied, increase in pyrolysis temperature and biochar activation decreased availability of K, P, and S compared to nonactivated biochar produced at 350°C. Activated biochars reduced AB-DTPA extractable Al and Cd more than AgLime. Biochar did not increase NO in leachate, but increased dissolved organic carbon, total N and P, PO, SO, and K at high application rate (40 g kg). Risks of elevated levels of dissolved P may limit chicken manure biochar application rate. Applied at low rates, these biochars provide added nutritional value with low adverse impact on leachate composition.     

Continuous, intermittent and passive sampling of airborne VOCs

Long sampling periods are often advantageous or required for measuring air quality and characterizing exposures. However, sampling periods exceeding 8 to 24 h using thermally desorbable adsorbent tube (TDT) samplers for the measurement of airborne volatile organic compounds (VOCs) face several challenges, including maintaining stable and low flow rates, and avoiding breakthrough of the adsorbent. These problems may be avoided using intermittent sampling; however, the literature contains few if any reports that have evaluated this technique in environmental, occupational or other applications. The purpose of this study is to evaluate continuous, intermittent and passive sampling methods using both laboratory and real-world tests. Laboratory tests compared continuous and intermittent (active) samplers in a controlled dynamic test gas generation system. Field tests used side-by-side active and passive samplers in an office, home workshop and four smokers' homes. All samples were analyzed for a wide range of VOCs by GC-MS. In most instances, intermittent sampling yielded better reproducibility (duplicate precision of 10 +/- 6%) than continuous low-flow sampling (18 +/- 5%), in part due to difficulty maintaining low flows. Concentrations obtained using intermittent sampling agreed with those for continuous sampling, with downward biases resulting primarily from errors in flow rate measurements. In the field, more VOC species were detected using active rather than passive sampling. Passive measurements were 12% lower than continuous measurements, a difference attributed to declining uptake rates at higher concentrations over the 3 to 4 d sampling period. Overall, most measurements obtained using the three sampling methods agreed within 20% for a wide range of concentrations (0.1 to 230 microg m(-3)). Both passive and intermittent sampling approaches are suitable for long sampling periods, but intermittent sampling provides greater flexibility with respect to sampling period, and permits the use of multi-bed adsorbents that can capture a wider range of VOCs.     

Characterization of particle number concentrations and PM<Subscript>2.5</Subscript> in a school: influence of outdoor air pollution on indoor air

Background, Aim and Scope  

The impact of air pollution on school children’s health is currently one of the key foci of international and national agencies. Of particular concern are ultrafine particles which are emitted in large quantities, contain large concentrations of toxins and are deposited deeply in the respiratory tract.     

Regional intergovernmental institutions: Participation benefits and costs

Evaluators frequently cite the absence of effective participation by constituent governments and the need for consensus or even unanimity prior to action as the causes of poor performance by regional resource management institutions. Major governments either will not join the regional institution, will not participate even if legally members, or will exercise a veto over many important management projects.This paper examines the variables that may cause these problems and provides an improved understanding of why rational political actors would act in ways that inhibit the efficient management of resources. Among the principal variables determining participation are expected benefits of collective decisions, perceived losses of autonomy and representation, the number and homogeneity of other participants, decision costs, and the decision rule used to determine actions. Analysis of these factors suggests why consensus and unanimity decision rules are frequently chosen and why participation is usually limited.     

Tissue distribution of 210Po and 210Pb in select marine species of the coast of Kudankulam, southern coast of Gulf of Mannar, India

Activities of ²¹⁰Po and ²¹⁰Pb in various tissues of four species of decapod crabs and two species of cephalopod mollusks (cuttlefishes) of Kudankulam coast were studied. A non-uniform distribution of these radionuclides was observed between the organs. Of all the tissues, ²¹⁰Po and ²¹⁰Pb were found accumulated more in the hepatopancreas and intestine of crabs and in the digestive gland, shell gland, and intestine of cephalopods. Among crabs, Charybdis lucifera registered a little higher ²¹⁰Po and ²¹⁰Pb activities. The cephalopod species Loligo duvauceli displayed higher ²¹⁰Po and ²¹⁰Pb in some organs when compared to Sepia pharaonis. The muscle of all the species registered lower activity. In cephalopods, the activity ratio of ²¹⁰Po/²¹⁰Pb fell within the range of 1?C2 for most of the organs, and in crab tissues, it varied from 1.7 to 31.4. The biological concentration factor for organs of cephalopods ranged from 1.2 ×10³ to 4.3 ×10⁵ for ²¹⁰Po and 4.8 ×10² to 8.4 ×10⁴ for ²¹⁰Pb and for organs of crabs it varied between 2.0 ×10⁴ and 1.9 ×10⁶ for ²¹⁰Po and 9.2 ×10² and 2.4 ×10⁴ for ²¹⁰Pb. The study revealed that the organs associated with digestion and metabolism displayed a higher activity concentration than the other tissues. A significant variation in the accumulation of ²¹⁰Po and ²¹⁰Pb was noted between species (P?<?0.05). The activity levels recorded are in agreement with values recorded in related organisms in other parts of the world. The data generated will act as a reference database for these organisms of this coast in which a nuclear power station is under construction.