IRANICA JOURNAL OF ENERGY AND ENVIRONMENT
Year:2017 | Volume:8 | Issue:4|Papers Count:10

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Leachate contents from the landfill that infiltrate the liner may contaminate nearby groundwater and river. Hence, the liner material must be chosen properly so that pollutants can be retained as much as possible at the liner thus reducing the contamination risk. This study studied the characteristics of earthenware clay and pressmud, and their suitability in reducing heavy metals content in leachate. Their suitability to fit as candidate for a landfill liner was tested using batch equilibrium study at 24 and 48 hours reaction times. The mixture of clay and pressmud were labelled PM0, PM10, PM30, PM50, PM80 and PM100 based on their pressmud content. Both reaction time, in any mixtures, manganese easily removed from leachate. 97% zinc was reduced in PM80 after 48 hours reaction time. No significant removal detected for lead in PM0, PM50 and PM80 although the experiment was prolonged from 24 to 48 hours. In a nutshell, for overall contaminants, the longer the reaction time, the higher removal percentage. The clay-pressmud mixtures have the potential to be applied as a landfill liner, however, the removal percentage of metal ions depends on mixture’ s physicochemical characteristic.

Rice field is one of the agriculture areas in Malaysia that is exposed to the usage of pesticide before the paddy planting phase, during vegetative phase and the post-harvesting phase. The study was to determine the water quality and also degradation of isoprothiolane in paddy field water samples. Isoprothiolane is one of the fungicides that is used during the vegetative phase to kill the fungi on the paddies. This study of isoprothiolane degradation in water samples was conducted in four different conditions, namely autoclaved water sample exposed to sunlight, autoclaved water sample kept in dark, non-autoclave water sample exposed to sunlight and non-autoclaved water sample kept in dark via laboratory batch experiment in a course of 30 days. The extraction and determination of the isoprothiolane in the water samples were done by solid phase extraction method (SPE) and analyzed by Gas Chromatography– Mass Spectrometry (GC-MS). The study revealed that isoprothiolane degraded very slowly in all four conditions within 30 days of observation, and the degradation rates ranged from 0. 0003 to 0. 0037 day-1. The study also proved that the residue of isoprothiolane remained at least a month after its application.

Silicon dioxide (SiO2) in nanoscale had been detected as waste product in river water for the past two decades and it is recently proven to have adverse effects toward human and animal health, the ecosystem and water treatment system. The removal of SiO2 nanoparticles (NPs) from water still remains a challenge due to its small size and unknown interactions within the water body. In this study, dynamic light scattering (DLS) technique was applied to characterize SiO2 in terms of surface charge and particle size as a function of pH within the range of 2 to 11 to analyze the aggregation behavior and significance of the intermolacular interactions in deionized (DI) water and tap water. DLS analysis identified both pH values of the point of zero charge (pHPZC) of SiO2 NPs in DI water and tap water at pH 3. 2 and pH 2. 8 respectively. The initial pH was discovered at 7. 1 in tap water with a mean particle size of 346 nm and an average surface charge value of-27 mV compared to initial pH of DI water which was 5. 4 with mean particle size of 295 nm and an average surface charge value of-33 mV. It was found that both in DI water and tap water, SiO2 NPs aggregated and increased in particle size but reduced in surface charge when pH slowly decreased towards their respective pHPZC from the initial pH by adding 0. 25M of hydrochloric acid. The mean particle size at pHPZC in DI water is measured at 1750 nm larger compared to the mean particle size in tap water indicating that the presence of other ions in tap water suppressed the aggregation process. In conclusion, results suggests that pH does influence the surface charge of SiO2 NPs and affect the stability behavior and its interaction processes in aqueous suspensions.

The main objectives of this study were to evaluate the biodegradation behaviour of experimental particleboard bonded with modified 30 % of PVOH, 70 % of Oil palm starch and 3 % of nano silicon dioxide (SiO2). Boric acid at 2 % was also added as a cross-linker to PVOH in modified oil palm starch to enhance decay resistant for the samples. All the particleboards were evaluated by soil burial, borer and fungal strains tests. The samples were then compared with particleboard bonded with native oil palm starch and commercial urea formaldehyde (UF). The results indicated that particleboards bonded with modified PVOH/Oil palm starch were more resistant than particleboard bonded with their native starch and thus can be used as a potential binder for green particleboard in future. The SiO2 also showed a significant effect towards modified oil palm starch as compared to their native oil palm starch and commercial binder.

Phantom materials are important tools for quality control and dosimetry works in medical physics. The tannin-bonded Rhizophora spp. particleboards in were fabricated as phantom and the dosimetric properties at high energy photons and electrons were evaluated. The particleboards were fabricated at dimensions of 30 x 30 x 1 cm3 and target density of 1. 0 g/cm3 based on the commonly used solid water phantoms in radiotherapy. The effective atomic number of the particleboard was determined based on the elemental compositions measured using energy dispersive x-ray analysis (EDXA). The mass attenuation coefficients at high energy photon were measured at 16. 59-25. 26 keV photons and 60Co and 137Cs gamma energies. The percentage depth dose and beam parameters of the particleboards were measured at 6 MV photons and 6 MeV electrons using Gafchromic EBT2 film and treatment planning system (TPS) software. The results showed that the effective atomic number and electron density of the particleboards were close to the value of water. The mass attenuation coefficient at high energy photons were close to the XCOM value of water. The percentage depth dose at high energy photons and electrons showed an agreement to the value in water and solid water phantom within 10% at all measured depths. The overall results indicated the suitability of tanninbonded Rhizophora spp. as phantom material for high energy photons and electrons.

Phytoremediation is a process which utilizes plants to remove contaminants from the environment. It is the latest alternative to treatment technique, phytoremediation needs to identify these plants and its ability to resist toxicity of contaminants before a full scale system can be installed to ensure that the remedy is effective by selected plants. The aim of this study is to evaluate the ability of two native plants in in Malaysia, Ludwigia octovolvis and Phragmites karka, to survive when exposed to real crude oil sludge. The experiment was performed in a greenhouse for 15 days. The observation was made three times a week. The plants were also watered using tap water to ensure the plants could grow. After 15 days of observation, the two plant species had shown that they could grow and survive in pots with 100% of crude oil sludge. From this preliminary test, L. octovolvis and P. karka showed its initial ability to treat sand contaminated with crude oil sludge. As a conclusion, both native plants have the potential in the phytoremediation process of hydrocarbon and will be used in future prolonged phytoremediation of crude oil sludge.

In this study, physical, mechanical and flame retardant properties of oil palm trunk particleboards were evaluated. The properties of oil palm trunk particleboards were compared with polylactic acid (PLA) added board, where PLA was added as a function of natural binder, and PLA added board with calcium sulfate (CaSO4) and magnesium oxide (MgO), where CaSO4 and MgO was added as a function of flame retardant additives. The thickness swelling, modulus of rupture and internal bond strength properties improved as addition of PLA. In comparison to addition of additives, PLA added board with CaSO4 exhibited higher physical and mechanical properties than PLA added boards. The flame retardant properties of PLA added oil palm trunk board with CaSO4 showed higher value of LOI compared to others. Overall results revealed addition PLA improved the physical and mechanical properties of oil palm trunk particleboard and the flame retardant properties increased with addition of additives namely MgO and CaSO4.

This study has simulated climate change impacts on the runoff processes of the Karnali River Basin of Nepal. Estimation of the variation of snowmelt contribution to streamflow in increased temperatures has been done. The semi-distributed HBV rainfall-runoff model has been calibrated using hydrometeorological data available from 1986 to 1997. The model simulates runoff based on precipitation, air temperature and potential evapotranspiration. The calibrated model is fed with the climatic projections developed using the PRECIS Regional Climate Model to estimate future (2040s) streamflow. The study indicates that the growing temperatures will generally result in wetter flow regime in the future.

Nanoporous heterogeneous AlSBA-15 (x) type aluminosilicate catalyst with different nSi/nAl ratios (x = 41, 129, and 210) was synthesized using hydrothermal method. AlSBA-15 catalysts were characterized by XRD, N2 sorption, TPD-NH3, FT-IR, SEM and TEM. XRD analyses of AlSBA-15 catalysts confirmed the presence of wellordered crystalline structure with p6mm symmetry. N2 isotherm of AlSBA-15 catalyst materials showed a type IV adsorption isotherm with H1 hysteresis loops. The specific surface area and specific pore volume of the AlSBA-15 catalysts are in the rage from 480 to 757 m2/g and from 0. 65 to 0. 95 cm3/g, respectively. SEM analysis of AlSBA-15 (41) revealed a worm-like particle morphology comprising particles in a size range of 3 μ m with the co-existence of smaller particles of ca. 1 μ m size. A distinct approach adopted for the synthesis of α-aminonitriles using heterogeneous nanoporous AlSBA-15 catalyst via Strecker reaction. This one-pot, three component system of amines (primary/secondary), carbonyl compounds (aldehydes/ketone) and TMSCN compounds proceed excellently in the presence of AlSBA-15 catalyst in water medium at room temperature (RT). The major advantages are excellent yield, short reaction time, high chemo-selectivity, simple experimental procedure, recyclability of the catalyst, easy work up procedure. This one-pot synthesis consists of two consecutive steps: (1) imine formation from amine and aldehyde/ketone and (2) cyano addition to imine. The findings suggest that catalyst is recyclable and can be reused up to six cycles.