Solid phase extraction for evaluation of occupational exposure to Pb (II) using XAD-4 sorbent prior to atomic absorption spectroscopy.

Lead is an important constituent widely used in different industrial processes. For evaluation of workers' exposure to trace toxic metal of Pb (II), solid-phase extraction (SPE) was optimized. SPE using mini columns filled with XAD-4 resin was developed with regard to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume, elution volume, the amount of resins, and sample matrix interferences. Lead ions were retained on a solid sorbent and then eluted, followed by a simple determination of analytes with flame atomic absorption spectrometery. The obtained recoveries of metal ions were greater than 92%. This method was validated with 3 different pools of spiked urine samples; it showed a good reproducibility over 6 consecutive days as well as 6 within-day experiments. This optimized method can be considered successful in simplifying sample preparation for a trace residue analysis of lead in different matrices when evaluating occupational and environmental exposures is required.     

The CO2 abatement cost curve for the Thailand cement industry

The cement industry is one of the largest carbon dioxide (CO₂) emitters in the Thai industry. The cement sector accounted for about 20,633 kilotonnes (ktonnes) CO₂ emissions in 2005 in Thailand. A bottom-up CO₂ abatement cost curve (ACC) is constructed in this study for the Thai cement industry to determine the potentials and costs of CO₂ abatement, taking into account the costs and CO₂ abatement of different technologies. The period of 2010–2025 is chosen as the scenario period. We analyzed 41 CO₂ abatement technologies and measures for the cement industry. Using the bottom-up CO₂ ACC model, the cost-effective annual CO₂ abatement potential for the Thai cement industry during the 15 year scenario period (2010–2025) is equal to 3095 ktonnes CO₂/year. This is about 15% of the Thai cement industry’s total CO₂ emissions in 2005. The total technical annual CO₂ abatement potential is 3143 ktonnes CO₂/year, which is about 15.2% of the Thai cement industry’s total CO₂ emissions in 2005. We also conducted a sensitivity analysis for the discount rate parameter.     

AHP based life cycle sustainability assessment (LCSA) framework: a case study of six storey wood frame and concrete frame buildings in Vancouver

Construction and building industry is in dire need for developing sustainability assessment frameworks that can evaluate and integrate related environmental and socioeconomic impacts. This paper discusses an analytic hierarchy process (AHP) based sustainability evaluation framework for mid-rise residential buildings based on a broad range of environmental and socioeconomic criteria. A cradle to grave life cycle assessment technique was applied to identify, classify, and assess triple bottom line (TBL) sustainability performance indicators of buildings. Then, the AHP was applied to aggregate the impacts into a unified sustainability index. The framework is demonstrated through a case study to investigate two six storey structural systems (i.e. concrete and wood) in Vancouver, Canada. The results of this paper show that the environmental performance of a building in Canada, even in regions with milder weather such as Vancouver, is highly dependent on service life energy, rather than structural materials.     

Sub-lethal toxic effects of deltamethrin on blood biochemical parameters of Japanese quail,Coturnix japonica

Feeding deltamethrin-contaminated grains to domestic poultry, such as quails may result in toxic effects in these birds. This study was done to investigate the effects of recommended doses of deltamethrin, sometimes used in grain storage silos, on Japanese quail (Coturnix japonica). Quails were fed grains contaminated with 0.25 and 0.50 mg deltamethrin per kg diet for 21 days and the effects on survival and blood biochemical parameters were studied. Plasma uric acid, creatinine levels, and creatinine phosphokinase activity in the blood were increased. Aspartate aminotransferase and lactate dehydrogenase activities and glucose levels significantly increased in birds treated with the high dose of deltamethrin. Alanine aminotransferase activity and albumin or cholesterol levels were not changed, and acetylcholinesterase and alkaline phosphatase activities, total protein and globulin in plasma were decreased. Administration of 0.25 mg/kg deltamethrin caused increased blood triglyceride levels, 0.50 mg/kg deltamethrin decreased triglyceride levels.     

Ploidy-, gender-, and dose-dependent alteration of selected biomarkers in Clarias gariepinus treated with benzo[a]pyrene

Naturally-occurring and artificially-induced polyploids have been documented in various fish species but to date no comparison has been reported of the impacts of ploidy on fish biomarker responses to organic pollutants. This study describes effects of ploidy, gender, and dose on biliary fluorescent aromatic compound (FAC) concentrations, hepatic ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities in one of the most commonly cultured warm-water species, the African catfish Clarias gariepinus. Recently matured male and female diploid and triploid fish were intraperitoneally (i.p.) injected with 0, 5 or 25 mg/kg benzo[a]pyrene (BaP) and liver and gallbladder were sampled 48 hr later. No significant differences were found between ploidies in bile concentrations of 7,8 dihydrodiolbenzo[a]pyrene (7,8D BaP), 1-hydroxybenzo[a]pyrene (1-OH BaP) or 3-hydroxybenzo[a]pyrene (3-OH BaP). However, concentrations of the biliary FACs did differ between males and females at different dose of injection with generally higher concentrations in females at the low dose of BaP and higher concentrations in males at the higher BaP concentration. Hepatic EROD activity did not exhibit gender-dependent difference, whereas it was significantly higher in triploids than diploids. GST activities were not significantly influenced by any of the tested factors. This work advanced our understanding of the role of ploidy, gender, and dose in biotransformation of pollutants in fish.     

Gaseous and particulate emissions from thermal power plants operating on different technologies

This paper presents the assessment of gaseous and particulate emissions from thermal power plants operating on different combustion technologies. Four thermal power plants operating on heavy furnace oil were selected for the study, among which three were based on diesel engine technology, while the fourth plant was based on oil-fired steam turbine technology. The stack emissions were monitored for critical air pollutants carbon monoxide, carbon dioxide, oxides of nitrogen, sulfur dioxide, particulate matter, lead, and mercury. The pollutant emissions were measured at optimum load conditions for a period of 6 months with an interval of 1 month. The results of stack emissions were compared with National Environmental Quality Standards of Pakistan and World Bank guidelines for thermal power plants, and few parameters were found higher than the permissible limits of emissions. It was observed that the emissions carbon monoxide, oxides of nitrogen, and particulate matters from diesel engine-based power plants were comparatively higher than the turbine-based power plants. The emissions of sulfur dioxide were high in all the plants, even the plants with different technologies, which was mainly due to high sulfur contents in fuel.     

Sonophotocatalytic Degradation of Chitosan in the Presence of Fe(III)/H2O2 System

The degradation of chitosan by means of ultrasound irradiation and its combination with homogeneous photocatalysis (photo-Fenton) was investigated. Emphasis was given on the effect of additive on degradation rate constants. 24 kHz of ultrasound irradiation was provided by a sonicator, while an ultraviolet source of 16 W was used for UV irradiation. To increase the efficiency of degradation process, degradation system was combined with Fe(III) (2.5 × 10⁻⁴mol/L) and H₂O₂ (0.020–0.118 mol/L) in the presence of UV irradiation and the rate of degradation process change from 1.873 × 10⁻⁹−6.083 × 10⁻⁹ mol^1.7 L s⁻¹. Photo-Fenton process led to complete chitosan degradation in 60 min with the rate increasing with increasing catalyst loading. Sonophotocatalysis in the presence of Fe(III)/H₂O₂ was always faster than the respective individual processes. A synergistic effect between ultrasound and ultraviolet irradiation in the presence of Fenton reagent was calculated. The degraded chitosans were characterized by X-ray diffraction (XRD), gel permeation chromatography (GPC) and Fourier transform infrared (FT-IR) spectroscopy and average molecular weight of ultrasonicated chitosan was determined by measurements of intrinsic viscosity of samples. The results show that the total degree of deacetylation (DD) of chitosan change, partially after degradation and the decrease of molecular weight led to transformation of crystal structure. A negative order for the dependence of the reaction rate on total molar concentration of chitosan solution within the degradation process was suggested. Results of this study indicate that the presence of catalyst in the reaction medium can be utilized to reduce molecular weight of chitosan while maintaining the power of irradiated ultrasound and degree of deacetylation.