Iranica Journal of Energy and Environment (IJEE)

221-225

Authors: M. Anbia, A. Sedighi, S. Salehi

In this study nano structured zeolite 13X as adsorbent for methane gas was used. Ni and Al ions were used to modify the pores of the zeolite and the methane gas adsorption capacity was measured at room temperature and pressure between 1 to 12 bars. The textural properties and structure order of the zeolite were studied by XRD and nitrogen adsorption-desorption analysis. Inductive coupled plasma (ICP) technique was used to determine the amounts of metals loaded on the zeolite.

233-242

Authors: M. G. Sobamowo

The rapid increase in technological innovations and utilizations have adversely affected the environment and consequently continued to constitute a threat to the future survival of human. To counter these assaults and the threats of further degradation of the environment and human health, the basic recommended approach for predicting the impact of the pollution and for the determination of the risk assessment strategies is through the use of mathematical models. Therefore, this work presents mathematical models for the prediction of the effects of combustion generated pollutants, such as Carbon-monoxide (CO) on human health. The developed coupled system of nonlinear partial differential equation for the ambient concentration of carbon mono-oxide in which the human subject was exposed to and the concentration of Carboxyhemoglobin (COHb) in the blood is solved numerically using Alternating-Direct Implicit (ADI) scheme. From the computations, the variables of the models show significant results in their variations and the standard error of the predicted results from the model range in between 0.5-0.85 for the different concentrations of ambient carbon monoxide. This established that the computed results show good agreement with available experimental data. Therefore, the model can be used as a means of controlling the effects of the pollutant on human health and the results will serve as a way of evaluating our technological injuries, effectively controlling our pollutants emissions and also as a tool for designing and developing better equipments and engines with lower carbon or pollutants emissions.

247-254

Authors: E. O. Dada, K. L. Njoku, A. A. Osuntoki and M. O. Akinola

Wetlands play important strategic ecological and life-supporting roles. As a result, they are continuously exposed to pollutants inflow including heavy metals. The aim of this research was to evaluate the heavy metal remediation potential of a tropical wetland earthworm, Libyodrilus violaceus. L. violaceus were exposed to soils contaminated with different concentrations of heavy metals using natural optimal soil density of 18 worms per kg soil, for 12 weeks. Relative to their initial concentrations, there were significant reductions of Zn, Pb and Cd at the end of the experiment. From the soil contaminated with a combination of Zn, Pb and Cd, the highest significant (p < 0.05) Cd reduction of 8.08 mg/kg soil occurred in the 12 th week, the highest significant (p < 0.05) Zn reduction of 37.47 mg/kg soil occurred in the 8 th week, while Pb recorded the highest but not significant (p > 0.05) reduction of 19.07 mg/kg in the 12 th week. The effect of addition of cow dung on the ability of L. violaceus to reduce heavy metals was generally low. L. violaceus is recommended as a good candidate for the remediation of low to moderate heavy metal contamination in wetland ecosystem.

262-267

Authors: N. Hairoma, M. G.Barzani and M. E. Toriman

An environmental study was carried out at Marang River, Terengganu on determination of river water quality trend variations temporally and spatially at seven sampling stations between 2012 and 2015. Sampling stations were selected along the river started from downstream to upstream; where each station was 2km apart from each other. Sampling was done twice at each sampling stations which were during low and high tides in November 2012 and also was repeated in November 2015. Both samplings were conducted during Northeast monsoon period. Selected water quality parameters such as salinity, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), pH and turbidity were measured using certified scientific instruments. One way ANOVA and Tukey Kramer multiple comparison were used for statistical analysis. This study revealed that there is significant temporal variation in DO and turbidity which was increased from downstream to upstream between 2012 and 2015 due to the increase of land use activities; while other parameters such as EC, salinity, TDS and pH were decreased. These results were concluded that global change coupled with the enactment of heavy storm and flood phenomenon during 2014 was lead to the rising of sea level and salinity dilution of the South China Sea.

274-281

Authors: K. Sharma, S. Jain and U. Chandrawat

Nano sized BaBiO3 is prepared through Pechini method and characterized by SEM, XRD, FTIR, DTTGA and UV DRS. The kinetic studies of adsorption and degradation phenomena involved in the photocatalytic degradation of Malachite Green dye using a batch reactor under visible light were investigated. Experiments were performed in a suspended BaBiO3 photocatalyst system. The effect of catalyst loading, solution pH and initial dye concentration on dye degradation is investigated. In addition, adsorption experiment is also performed which indicates that adsorption pattern follows Langmuir model. The decomposition of Malachite Green dye follows pseudo first order kinetics and the Langmuir-Hinshelwood mechanism is found to be valid. Different kinetic parameters for adsorption and photocatalytic degradation of dye are also determined.

294-303

Authors: M .Sathya, G. Muthuraman and S. Elumalai

A bulk liquid membrane (BLM) system contained Di (2-ethyl hexyl) phosphoric acid (D2EHPA) as an extractant was used for transport of malachite green (MG) dye from textile wastewater. D2EHPA present in n-hexane is an effective, efficient and highly selective carrier for the transport of MG dye through BLM. Maximum transport 88% was observed at 0.24M concentration of D2EHPA in the membrane phase and 7 moles concentration of acetic acid in the receiving phase after 300 min. The effect of parameters influencing the transport of MG dye such as pH and concentration of dye in the donor solution, extractant concentration in the membrane phase, nature of the organic solvent, the composition of receiving phase, stirring speed and kinetics parameter were elucidated. First order irreversible reaction kinetics k1 and k2 were applied for the transport of MG dye from aqueous phase BLM phase and BLM to acceptor phase. The accumulation of MG in BLM phase and the rate controlling step under different experimental conditions were also discussed. Finally, the proposed liquid membrane was effectively applied for MG dye transport from textile wastewater.

308-314

Authors: M. A. Olutoye, O. D. Adeniyi and A. S.Yusuff

The synthesis and characterization of clay-eggshell mixed catalysts was carried out for the transesterification of palm kernel oil using methanol as solvent. Clay from anthill and waste chicken eggshells were powdered and mixed via incipient wet impregnation in 50-50, 80-20 and 20-80% proportions of clay to eggshell on mass basis. The resulting mixtures were oven dried at 120 0 C and calcined in the furnance at 900 0 C for 4 hours. The uncalcined raw clay sample was characterized via the X-ray fluorescence method while the as-synthesized catalyst samples were characterized via the Fourier Transform Infrared Radiation Spectroscopy and Scanning Electron Microscopy. The performance of the as-synthesized catalysts was tested in transesterification of palm kernel oil (PKO) via a 2 level factorial experimental design optimizing four variables including reaction time, reaction temperature, methanol/oil molar ratio and catalyst loading in which case the yield was the required response. The 50-50 catalyst attained a maximum yield of 56.2% at 70 0 C, methanol/oil ratio of 12:1, reaction time of 180 min, catalyst loading of 5 wt.% compared to the 65.2% achieved with the 80-20 catalyst at 90 0 C, methanol/oil ratio of 12:1, reaction time of 180 min., catalyst loading of 5 wt% and the 70.7% obtained for the 20-80 catalyst at 70 0 C, methanol/oil ratio of 12:1, reaction time of 180 min, catalyst loading of 3 wt%, thus, indicating mixed effect of variables as fully discussed. The developed catalysts were found to be good for biodiesel production and have the ability of improved performance.