Heavy metal concentrations in water, suspended matter, and sediment from Gökova Bay, Turkey

The contents of heavy metals (Fe, Mn, Pb, Cu, Cd, and Hg) dissolved in water and suspended solids of Gökova Bay—partly and fully sampled in 2005 and 2006, respectively—are quite higher than the average values encountered in uncontaminated sea water. The high concentrations are associated with terrestrial inputs from the mining zones and anthropogenic (domestic + industrial) sources. Moreover, the distribution of Fe and Cu is affected by primary production because these elements function as nutrients in biological activities. The Cr, Ni, and Fe concentrations of surface sediments are above the shale average. The Cr and Ni contents of surface sediments representative of river mouths strongly correlate with total phosphorus contents. In a sulfide-poor environment, Pb and Cu were concentrated at a higher ratio in surface sediments than Cd, probably due to higher stabilities of their surface complexes with amorphous iron oxides and clay minerals existing as major components in the sediments. The exceptional enrichment of Zn may be attributed to double oxide formation with amorphous iron oxides in sediments. The high metal values are most probably caused by terrestrial inputs from anthropogenic sources and the mining zones at the southeast part of the bay. The Al, Mn, Pb, Cu, Zn, and Hg contents are below the shale average. The low values have possibly originated from the coarse-grained sandy sediments having a low affinity for metals. There are no distinct differences in the metal distributions in water and suspended matter between the years 2005 and 2006 in the bay, probably due to low sedimentation rates.     

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.     

Economic analysis of biogas and compost projects in a palm oil mill with clean development mechanism in Malaysia

This article is a case study to compare the economic viabilities of biogas generation and compost projects in a palm oil mill in Malaysia with and without clean development mechanism (CDM). Biogas is captured from anaerobic ponds or digester tanks treating palm oil mill effluent (POME) and converted to green renewable electricity for grid connection, while compost is produced from the shredded empty fruit bunch and raw untreated POME. The both technologies were compared by considering the changes of the materials flow and energy balances. A palm oil mill with a capacity of 54?t fresh fruit bunch per hour has the potential to produce either 6.9?GWh of electricity from biogas or fertilizer equivalent to 488?t of nitrogen, 76?t of phosphorus and 1,065?t of potassium per year. The economic analysis for 10?years project term analysis indicated that CDM gave a significant impact and ensured economic viability for both projects with 25?% of internal rate of return (IRR), RM 12.39 million of net present value (NPV) and 3.5?years of payback period (PBP) for biogas project, whereas 31?% of IRR, RM 10.87 million of NPV and 2.9?years of PBP for compost project, respectively. In addition, sensitivity analysis indicated that the profitability of both projects will vary depending on the economic situation, such as electricity price which is based on the government policy, whereas compost price that depend on fertilizer market price with 43?% NPV change in 20?% range of fertilizer value.     

Determination of volatile organic compounds pollution sources in malaysian drinking water using multivariate analysis

A field investigation was conducted at all water treatment plants throughout 11 states and Federal Territory in Peninsular Malaysia. The sampling points in this study include treatment plant operation, service reservoir outlet and auxiliary outlet point at the water pipelines. Analysis was performed by solid phase micro-extraction technique with a 100 μm polydimethylsiloxane fibre using gas chromatography with mass spectrometry detection to analyse 54 volatile organic compounds (VOCs) of different chemical families in drinking water. The concentration of VOCs ranged from undetectable to 230.2 μg/l. Among all of the VOCs species, chloroform has the highest concentration and was detected in all drinking water samples. Average concentrations of total trihalomethanes (THMs) were almost similar among all states which were in the range of 28.4--33.0 μg/l. Apart from THMs, other abundant compounds detected were cis and trans-1,2-dichloroethylene, trichloroethylene, 1,2-dibromoethane, benzene, toluene, ethylbenzene, chlorobenzene, 1,4-dichlorobenzene and 1,2-dichloro - benzene. Principal component analysis (PCA) with the aid of varimax rotation, and parallel factor analysis (PARAFAC) method were used to statistically verify the correlation between VOCs and the source of pollution. The multivariate analysis pointed out that the maintenance of auxiliary pipelines in the distribution systems is vital as it can become significant point source pollution to Malaysian drinking water.     

Antibacterial and Catalytic Performance of Green Synthesized Silver Nanoparticles Embedded in Crosslinked PVA Sheet

Journal of Polymers and the Environment - In this research work, a green method of using Saussurea costus extract for the synthesis of silver nanoparticles (AgNPs) is developed. Analysis of the...     

Numerical investigation of geometrical defect in cold forging of an AUV blade pin head

The precision of cold forging parts becomes critical because the process depends on many factors such as the size and complexity of the parts. Defects negatively affect the assembly accuracy and the performance of the parts. Therefore, defects must be detected and prevented as soon as possible before the manufacturing process begins. The paper intends to investigate the geometrical defect of the cold embossing pin head, which may result in an inaccurate assembly of the blade. In this paper, defect formation was studied using DEFORM-2D based on material flow pattern and stress distribution. The defect was measured in terms of incomplete filling and geometries of the bulging. The effect of the distance to the edge (DTE) is significant to the formation of defects. The size of the bulge is reduced and the filling ability shows better performance as the DTE increases. The FE results are in good agreement with the experimental result.     

MULTIDISCIPLINARY PLANNING AND MANAGING OF WATER REUSE1

ABSTRACT: This paper examines a rapidly expanding area of water supplies, specifically water reclamation and reuse, and provides a comprehensive planning methodology for developing and evaluating water reuse alternatives. The methodology uses five phases: goal setting, identification of reuse opportunities, development and evaluation of planning alternatives, assessment of water reuse linkages, and making decisions and recommendations. A tool called “input-output modeling” is used in the third phase to present numerical data and choices. The methodology seeks to integrate the hydrologic and socio-economic aspects of water resources planning in the area of study. Water reuse may satisfy some of the increasing demands for water in the world, but water quality, economics, public attitudes, and legal and institutional constraints may impose limits on the extent to which it can be employed. The challenge in planning systems is to maximize the utilization of water reuse in the fact of these constraints. The importance of multidisciplinary collaboration cannot be overemphasized. This paper assesses the potential for water reclamation and reuse in developing countries by considering the relationships among the pertinent technical, social, economic, and environmental parameters. Generally, the planning process for water reuse has focused on specific technological processes, but in order to ensure the efficient transfer of waste water reuse technology into the society, the methodology seeks to provide a conceptual model which integrates the hydrologic and socioeconomic aspects of water resources planning and water reuse within the study area. (KEY WORDS: water reuse; water reclamation; planning; methodology; model; reuse technology; socio-hydrologic systems; socioeconomic systems.)     

Personality of young drivers in Oman: Relationship to risky driving behaviors and crash involvement among Sultan Qaboos University students

Objective: Drivers’ behaviors such as violations and errors have been demonstrated to predict crash involvement among young Omani drivers. However, there is a dearth of studies linking risky driving behaviors to the personality of young drivers. The aim of the present study was to assess such traits within a sample of young Omani drivers (as measured through the behavioral inhibition system [BIS] and the behavioral activation system [BAS]) and determine links with aberrant driving behaviors and self-reported crash involvement.

Methods: A cross-sectional study was conducted at the Sultan Qaboos University that targeted all licensed Omani's undergraduate students. A total of 529 randomly selected students completed the self-reported questionnaire that included an assessment of driving behaviors (e.g., Driver Behaviour Questionnaire, DBQ) as well as the BIS/BAS measures.

Results: A total of 237 participants (44.8%) reported involvement in at least one crash since being licensed. Young drivers with lower BIS–Anxiety scores and higher BAS–Fun Seeking tendencies as well as male drivers were more likely to report driving violations. Statistically significant gender differences were observed on all BIS and BAS subscales (except for BAS–Fun) and the DBQ subscales, because males reported higher trait scores. Though personality traits were related to aberrant driving behaviors at the bivariate level, the constructs were not predictive of engaging in violations or errors. Furthermore, consistent with previous research, a supplementary multivariate logistic regression analysis revealed that only driving experience was predictive of crash involvement.

Conclusions: The findings highlight that though personality traits influence self-reported driving styles (and differ between the genders), the relationship with crash involvement is not as clear. This article further outlines the key findings of the study in regards to understanding core psychological constructs that increase crash risk.