Advanced Materials Research Vols. 931-932

Abstract: In this research, the effect of diammoniumphosphate (DAP) as fire retardant additive during thermal degradation of wood samples from shorea obtuse (Dipterocarpaceae) has been investigated. Thermal properties of wood samples impregnated with DAP ranging from 0-40 %wt were characterized by thermogravimetric analysis (TGA) and limiting oxygen index (LOI). Leachability of DAP from impregnated samples kept under running water was also investigated. The results indicated that the rate of weight loss obtained from TGA reveal that impregnation of DAP reduced the degradation rate from 0.95%/°C to 0.56%/°C. Furthermore, LOI of woods specimens trended to be increase from 24.8 to 30.6 when they were treated with DAP having a range of 0-30 %wt. Based on the results of this study, wood samples impregnated with 30%wt of DAP can be classified as self-extinguishing materials and cloud meet the requirement for non-flammability in construction. The leachability test indicated that only trace amount of unreacted DAP leached from the samples.

Abstract: Bismuth vanadate (BiVO₄) powder was synthesized via the solvothermal method at 100200 °C for 26h by using acetic acid as solvent without calcination steps. The phase transition of BiVO₄ powder was studied by Xray diffraction (XRD). The morphology and chemical composition of BiVO₄ powder were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional groups of BiVO₄ powder was identified by Fourier transform infrared spectroscopy (FTIR).

Abstract: It founded that crude palm oil, CPO, could be changed to Bio-hydrogenated Diesel, BHD, which has a potential to replace the petroleum-derived diesel. Therefore, techno-economic feasibility of BHD production for Thailand was studied with a capacity of 1 million liters per day (MLD) of BHD. In this work, a conceptual design of BHD process was developed by using process simulator, ASPEN Plus. Calculation of mass and energy balance, equipment sizing and cost estimation in five major unit operations were performed. The total capital investment was calculated and used for economic analysis to estimate the return on investment, price value and payback period. The results showed that total capital investment cost was 174.34 millions USD with 1 MLD of BHD, PBP was 5 years with 17.02% ROI. BHD price of 1.16 USD/L.

Abstract: It is well known that membrane with hydrophobic property is a fouling membrane. Polysulfone (PSf) membrane has hydrophobic characteristic was blended with a hydrophilic polymer, cellulose acetate phthalate (CAP) in order to increase hydrophilicity property of pure PSf membrane. In this study, membrane casting solutions containing 17 wt% of polymer was prepared via wet phase inversion process. The pure PSf membrane was coded as PC-0. PSf/CAP blend membranes with blend composition of 95/5, 90/10, 85/15 and 80/20 wt% of total polymer concentration in the membrane casting solutions were marked as PC-5, PC-10, PC-15 and PC-20 respectively. All of the membranes were characterized in terms of pure water flux and permeability coefficient in order to study their hydrophilicity properties. The investigated results shows that increased of CAP composition in PSf blend membranes has increased pure water flux, permeability coefficient and porosity of the blend membrane which in turn formed membrane with anti-fouling property.

Abstract: The objective of this work is to study the removal of acetate from succinate in an aqueous solution by dead-end nanofiltration. The effect of applied pressure under 40, 50 and 60 psi on the separation between both solutes was investigated. Experiments with a HL4040FM membrane were evaluated using various synthetic solutions, i.e. single-solute solutions of potassium acetate and potassium succinate and mixed-solute solutions containing both solutes. In single-solute solution, the retentions of acetate and succinate salts increase with increasing in applied pressures. At each applied pressure the retention of acetate salt decreases with time while the retention of succinate salt declines to a constant. In mixed-solute solutions, in presence of succinate anion, the retention of acetate anion is significantly lower than those observed in single-solute solution even showing negative value. The lower retention of acetate can be well described by the facilitated transport of the monovalent anion due to pumping effect and electroneutrality in the presence of a divalent anion. It was expected that removal of acetate by-product from succinate solution with HL4040FM in dead end filtration was possible.

Abstract: The adsorption efficiency of As (V) ions from an aqueous solution was investigated. The adsorption experiments were carried out in a batch reactor. The effects of operating parameters; i.e. the absorbent dose (g/L), the pH, the adsorption temperature (°C), the As (V) initial concentration (ppb), and type of adsorbents, on the adsorption efficiencies were studied. A PlackettBurman experimental design was used to screen for the important factors that influence As (V) adsorption. It has been found that the most important effect on the As (V) adsorption capacity was the type of adsorbent. The factor importance could be written in descending order as follows: the type of adsorbents, the adsorbent dose, the As (V) initial concentration, the adsorption temperature, and the pH.

Abstract: Oily wastewater is a potential source for biohydrogen production due to its high organic content. Incorporation of surfactant could enhance the solubilization of oil in water, and thus increase its biodegradability. The first part of this work studied the influence of surfactant concentrations (0-240 CMC) and temperatures (28-70 °C) on oil solubilization in aqueous solution. Results from batch tests showed that the oil solubilization improved as the surfactant concentration increased up to 100 CMC. As high as 0.002 mg/L oil concentration could be solubilized at 1 CMC and 55 °C, which was 90 times higher than that obtained without surfactant application. Moreover, the time to reach oil-in-liquid equilibrium could be shortened by increasing the temperature. In the second part, the effect of surfactant addition on hydrogen production was investigated at pH 5.5 and 55 °C. In 148 h batch assays, the highest hydrogen production observed was 19.3 mL at 1 CMC while it was 8.7 mL at no surfactant. Further investigation at 1 CMC revealed that surfactant degradation to H₂ was 2.36 mL, thus the effect of surfactant to enhance oil degradability was 0.24 L H₂ per liter of aqueous solution under excess oil condition.

Abstract: In previous work, Saccharomycescerevisiae TISTR 5596 could produce bioethanol in the strength condition. Thus, this work was examined to understand effect of sulfuric acid on hydrolysis of synthetic cellulose and sorghum straw. The ethanol fermentation of S.cerevisiae TISTR 5596 of the products from the hydrolysis was also determined. The results showed the maximum amount of sugar from hydrolysis reaction of synthetic cellulose in 5%v/v sulfuric acid which are analyzed by high performance liquid chromatography which has yield 28 g/L and 25.46 g/L for the maximum amount of sugar form hydrolysis of sorghum straw in 3%v/v sulfuric acid. Furthermore, the ethanol fermentation at 30°C for 25 hrs with hydrolysis of the synthetic cellulose and sorghum straw was determined by gas chromatography. S.cerevisiae TISTR 5596 can produce 9.021 g/L of ethanol or 32.89% of initial sugar concentration at 28 g/L for fermented at 30°C for 25 hrs. and 1.8 g/L or 22.52% of initial sugar concentration at 25.46 g/L at 30°C for 40 hrs, for extracted samples from synthetic cellulose and sorghum straw, respectively.

Abstract: The sugarcane is the one of economic agricultural product in Thailand. The sugarcane leaf is a residual waste from post-harvest process. Conversion of the residual waste to a value material is quite a challenge. The aim of this research work is to extract sugar from the sugarcane leaf by the acid hydrolysis reaction. The hydrolysis conditions were varied in terms of sulfuric acid (H₂SO₄) concentration (04%, v/v), reaction time (15180 minutes), amount of sugar cane leaves (50-125g/l) with constant incubation temperature at 122 °C. The identification and quantitation analysis of hydrolysed sample was performed by high performance liquid chromatography (HPLC). The result was shown the best hydrolysis condition was at 1% v/v of H₂SO₄, reaction time 60 min and the sugarcane leaves 100 g / L with ca 17 g/L of xylose, ca 3 g/L of glucose and ca 2 g/L of arabinose. Also, the Scanning Electron Microscopy (SEM) was analysed the morphology of untreated and treated sugarcane leaf which the surface of treated sample showed the broken fibril.

Abstract: Microspheres have been widely used for tissue engineering scaffolds. Microspheres have many advantages over the macrostructure such as high surface area for cell adhesion and proliferation and low mass transfer limits. In this study, we fabricated microspheres from gelatin and silk fibroin using water-in-oil (w/o) emulsion technique and glutaraldehyde crosslinking. Gelatin (G) and silk fibroin (SF) were blended at different G/SF weight blending ratios of 100/0, 90/10, 70/30, and 50/50. Physical and chemical properties of the microspheres including size and morphology were characterized. The Average size of microspheres obtained were at 858.42±41.93, 832.97± 9.44 , 785.24±17.66 and 735.83 ±13.19 μm, respectively. Morphology of G/SF microspheres was observed under a scanning electron microscope. Blending of silk fibroin increased the crosslinking degrees and water absorption. It also reduced degradation rate, comparing to the gelatin microspheres. The in vitro attachment and proliferation of rat bone marrow derived mesenchymal stem cells (MSC) cultured on G/SF microspheres were evaluated. G/SF 50/50 microspheres promoted the highest attachment of MSC on microspheres (46.0±5.8% of initial seeding at 6 hr). The G/SF 70/30 microspheres promoted the higher cell proliferation of MSC compared the others. Specific growth rate of the cells on the microspheres was at 9.85x10^-3 h^-1.