Pag-Asa Gaspillo - Academia.edu (original) (raw)
Papers by Pag-Asa Gaspillo
ASEAN Journal of Chemical Engineering
The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol p... more The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol production. The optimization of alkali (sodium hydroxide) pretreatment parameters such as concentration and residence time was carried out by the Taguchi method using L16 orthogonal array with two factors and four levels. Sugarcane bagasse powder was mixed with sodium hydroxide (NaOH) solution (0.5-2 wt.%) and heated in an autoclave at 121°C and at varied times (30-120 min). From the statistical analysis of data, it was observed that delignification and glucan increased with the increased concentration and short time. The optimum parameters of NaOH pretreatment were 2 wt.% of NaOH concentration and 30 minutes of residence time. At the optimum conditions, 86.8% delignification and 46.6% glucan content of SCB were obtained. Thus, alkali pretreatment optimized by Taguchi design is the effective method to remove lignin and to increase cellulose or glucan content in sugarcane bagasse for facil...
Applied Science and Engineering Progress
Sustainable biofuel feedstock could become a critical issue in the light of the recent fuel crisi... more Sustainable biofuel feedstock could become a critical issue in the light of the recent fuel crisis. The use of mixed biomass could reinforce to overcome this issue. The present work examined the parallel use of agricultural residue sugarcane bagasse (SCB) and natural invasive marine seaweed Sargassum sp. (SSP) as a single feedstock and its mixture in two-step concentrated acid hydrolysis followed by yeast fermentation in order to produce reducing sugar with minimal formation of furfural, and bioethanol. In this work, alkali pretreated SCB and SSP were used as feedstock in acid hydrolysis. To investigate the influenced parameters of acid hydrolysis, biomass type (SCB, mixed biomass MB (SCB and SSP in 1:1 ratio by weight) and SSP), initial acid concentration (64–80 wt%), reaction time (30–90 min) and solid loading (10–20%w/w) were optimized by using Taguchi method. The optimized conditions were obtained with mixed biomass type, the initial acid concentration of 64 wt%, reaction time o...
Microwave-assisted extraction (MAE) of phenolic compounds from the processed dry leaves of Moring... more Microwave-assisted extraction (MAE) of phenolic compounds from the processed dry leaves of Moringa oleifera Lam. was optimized by applying response surface methodology. The phenolic profile and antioxidant activities of the extract obtained under optimum conditions were also evaluated. Optimum conditions for the extraction of phenolic compounds were achieved at 5 min of extraction time, 65 °C of extraction temperature, 0.015 g mL-1 of sample/solvent ratio and 35% of aqueous ethanol concentration. The yield of total phenolic content under optimum conditions was 16.5 ± 0.2 mg gallic acid equivalent (GAE) per g of dry leaf. The extraction yield was comparable with yield obtained by the conventional extraction technique. However, the technique was time efficient. The antioxidant activities were relatively high compared with those of some plants reported in the literature. Interestingly, the presence of vanillic acid, a new compound which had not been reported in M. oleifera in prior lit...
Chemical Engineering Transactions, 2017
Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioet... more Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioethanol production from lignocellulosic materials, it is necessary to remove lignin due to its recalcitrant nature. The present work aimed to study the effect of alkali pretreatment on removal of lignin from sugarcane bagasse using sodium hydroxide. Two solid loading conditions (20 %w/v and 10 %w/v) were used in this study. For 20 % loading condition, base concentrations were varied at four levels and autoclaving time was varied at 3 levels, and the experiments were performed in 12 runs for this loading rate. For 20 % w/v solid loading, the concentrations of sodium hydroxide were 0.5 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt% at 121 °C for 10 min, 30 min and 60 min. For 10 % loading condition, the levels of each factor were increased. The base concentrations were varied at six levels and autoclaving time was varied at 5 levels, and the experiments were also performed, resulting in 30 runs for this...
ASEAN Journal of Chemical Engineering, 2021
The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol p... more The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol production. The optimization of alkali (sodium hydroxide) pretreatment parameters such as concentration and residence time was carried out by the Taguchi method using L16 orthogonal array with two factors and four levels. Sugarcane bagasse powder was mixed with sodium hydroxide (NaOH) solution (0.5-2 wt.%) and heated in an autoclave at 121°C and at varied times (30-120 min). From the statistical analysis of data, it was observed that delignification and glucan increased with the increased concentration and short time. The optimum parameters of NaOH pretreatment were 2 wt.% of NaOH concentration and 30 minutes of residence time. At the optimum conditions, 86.8% delignification and 46.6% glucan content of SCB were obtained. Thus, alkali pretreatment optimized by Taguchi design is the effective method to remove lignin and to increase cellulose or glucan content in sugarcane bagasse for facil...
Co 0.5 Ni 0.5 Fe 2 O 4 nanoparticles have been synthesized by a stearic acid method. Core/shell C... more Co 0.5 Ni 0.5 Fe 2 O 4 nanoparticles have been synthesized by a stearic acid method. Core/shell Co 0.5 Ni 0.5 Fe 2 O 4 /SiO 2 nanomaterials at varying amount of SiO 2 are prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) precursor. The composition phase and average crystallite size have been characterized by means of X-ray diffraction. The particle structure and morphology of the core-shell nanoparticles are determined using transmission electron microscopy (TEM). The presence of Si-O-Si bonds for both coated samples is confirmed through Fourier transform infrared spectroscopic. Results show a decreasing saturation magnetization (M s) when amount of TEOS is increased. The addition of SiO 2 at first instance enhance the coercivity (H c), and maximum H c is observed when 0.4 mL TEOS is added. However, adding more SiO 2 decrease the coercivity because the domain wall motion on the surface of nanoparticles is limited.
![Research paper thumbnail of An Investigation on the Removal of Arsenic from Simulated Groundwater by Adsorption Using Iron and Iron Oxide[III]](https://attachments.academia-assets.com/90110253/thumbnails/1.jpg)
](Journal of Environmental Science for Sustainable Society, 2009
This work aims to investigate the removal of arsenic from the simulated groundwater by batch adso... more This work aims to investigate the removal of arsenic from the simulated groundwater by batch adsorption using Iron (ZVI) and Iron[III] Oxide (IO). The effect of initial arsenic concentration, adsorbent dose and pH were investigated. Adsorption equilibrium and its kinetics were also studied. The results showed that both ZVI and IO have a high efficiency for adsorption of arsenic from groundwater. Langmuir isotherm described well the adsorption equilibrium and the pseudo-second order kinetic model gave the best fit with the experimental kinetic data for both ZVI and IO.
Journal of Water and Environment Technology, 2008
Groundwater is one of the most important sources for drinking water. Arsenic (As) contamination o... more Groundwater is one of the most important sources for drinking water. Arsenic (As) contamination of groundwater is a serious problem worldwide, especially in Bangladesh, India and South East Asia. Adsorption using appropriate and readily available adsorbents is a promising method for the removal of arsenic with applicability in rural areas. This work aims to study the removal of arsenic from synthetic groundwater using an adsorption column by sequential combination of laterite (LA) and iron-modified activated carbon (AC-Fe) as adsorbents. The effect of ratio LA/AC-Fe, flow rate, initial arsenic concentration and pH to the breakthrough time were investigated. Adsorption equilibrium and adsorption kinetics were also studied through batch experiment. The result was found to be an efficient and feasible approach for arsenic treatment from groundwater for ready applicability in rural areas.
The Philippine …, 2009
This study compares the composition of essential oil extracted from lemongrass leaves and stems u... more This study compares the composition of essential oil extracted from lemongrass leaves and stems using supercritical CO2 (SC CO2) and steam distillation. In the process using SC CO2 extraction in a Supercritical Fluid Extraction System (SFE), the temperature ...
Desalination, 2008
Zero-valent iron (ZVI) immobilized in cationic exchange membrane (CEM) was investigated for the d... more Zero-valent iron (ZVI) immobilized in cationic exchange membrane (CEM) was investigated for the degradation of trichloroethylene (TCE). Using a commercial CEM as a support, it was possible to immobilize ZVI conveniently. According to the surface analysis, the nanoparticles were formed on the surface of CEM after immobilization and the size of them was 30-40 nm. The ZVI-immobilized CEM (Fe(0)-CEM) contained 75 mg Fe/m 2 membrane. The removal of TCE was accomplished by sorption on the membrane matrix and degradation by the immobilized ZVI. About 36.2 mg/L of TCE was removed within initial 2 h and the observed rate constant (k obs) was 0.44 h −1. The value of surface area normalized rate constant (k SA) of Fe(0)-CEM was 35.77 L h −1 m −2. The obtained k SA was higher than other studies on the nanoparticles or the membrane-immobilized nanoparticles by 1-3 orders of magnitudes. The higher k SA resulted from low metal loading (ca. 6.5 mg/L) in this test. Moreover the released iron concentration to aqueous phase was very low (0.1-0.3 mg/L), In conclusion, the Fe(0)-CEM proposed in this study was effective in the TCE removal. And it would be possible to reuse the Fe(0)-CEM repeatedly after re-reducing it.
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 1998
Chemical Engineering Transactions, 2017
Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioet... more Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioethanol production from lignocellulosic materials, it is necessary to remove lignin due to its recalcitrant nature. The present work aimed to study the effect of alkali pretreatment on removal of lignin from sugarcane bagasse using sodium hydroxide. Two solid loading conditions (20 %w/v and 10 %w/v) were used in this study. For 20 % loading condition, base concentrations were varied at four levels and autoclaving time was varied at 3 levels, and the experiments were performed in 12 runs for this loading rate. For 20 % w/v solid loading, the concentrations of sodium hydroxide were 0.5 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt% at 121 °C for 10 min, 30 min and 60 min. For 10 % loading condition, the levels of each factor were increased. The base concentrations were varied at six levels and autoclaving time was varied at 5 levels, and the experiments were also performed, resulting in 30 runs for this...
Journal of Water Resource and Protection, 2009
A preliminary study on nitrogen and organic removal efficiency of a lab-scale system using aerobi... more A preliminary study on nitrogen and organic removal efficiency of a lab-scale system using aerobic and anaerobic reactors was performed. A simulated wastewater containing elevated levels of nitrogen was used. This paper aims to compare the efficiency of aerobic and anaerobic reactors in achieving nitrogen and chemical oxygen demand (COD) removal of nutrient-rich wastewater. It also presents the start-up experimentation conducted on simulated wastewater using two different reactors configured as aerobic and anaerobic. Start-up experiments were carried out using a 5-liter acrylic aerobic reactor and a 4-liter flask anaerobic reactor containing activated sludge taken from De La Salle University (DLSU) wastewater treatment plant as a source of inoculum. Simulated wastewater was continuously fed to the two reactors and the time course of biomass growth was monitored by measuring the biomass concentration represented by mixed liquor volatile solids (MLVS). The time course of organic pollutant reduction by measuring the chemical oxygen demand (COD) was conducted until steady state condition was reached. On the other hand, COD and nitrogen tests such as Ammonia nitrogen (NH 3-N), Nitrite nitrogen (NO 2-N), Nitrate nitrogen (NO 3-N) were also performed using 5 batch aerobic reactors containing different concentrations of wastewater and a single batch anaerobic reactor to see the effect of different feed concentrations in the removal of nitrogen. Preliminary results showed that 98% reduction in COD was obtained in aerobic reactor, as supported by increasing concentration of MLVS, with a hydraulic retention time (HRT) of 5 hours after 11 days while 34% reduction in COD was obtained in anaerobic reactor with the same HRT after 14 days.
Vietnam Journal of Science, Technology and Engineering, Mar 25, 2020
CuO-ZnO nanoparticles were successfully synthesized by the sol-gel method. Characteristic propert... more CuO-ZnO nanoparticles were successfully synthesized by the sol-gel method. Characteristic properties of the synthesized nanoparticles were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), N 2 adsorption/desorption isotherms, and BJH pore diameter distributions. The formation of highly crystalline CuO and ZnO was confirmed by XRD. FT-IR confirmed that Zn-O and Cu-O bonds were formed in the material. SEM and TEM images showed that the obtained CuO-ZnO nanoparticles were nearly spherical in shape and had a uniform size distribution with sizes ranging between 5-20 nm for the CuO-containing phase and 50-100 nm for the ZnO-containing phase. The CuO-ZnO sample showed effective antifungal activities against four strains. Aspergillus and Penicillium were completely inhibited with a concentration of 5 mg/ml of CuO-ZnO. For the Magnaporthe and Neoscytalidium strains, the minimum inhibitory concentration was 10 mg/ml.
Materials
This study deals with the impact of calcination, alkalinity, and curing time parameters on the hy... more This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 500 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing ti...
Materials
This study deals with the impact of calcination, alkalinity, and curing time parameters on the hy... more This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 500 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing ti...
ASEAN Journal of Chemical Engineering
Untreated wastewater from textile industries when discharged to nearby waterways would cause cons... more Untreated wastewater from textile industries when discharged to nearby waterways would cause considerable health concerns to humans and animal life and to the host environment. They contain various chemicals such as dyes, detergents and surfactants, some of which are recalcitrant to biodegradation. Such wastewater can be better remediated by chemical treatment. The treatment of a textile bleaching and dyeing industrial wastewater was done by Coagulation and Flocculation Method using a jar test apparatus. Alum, polyaluminum chloride (PAC), and ferrous sulfate were used in separate runs as coagulants, while excelfloc 264 (a polyacrylamide copolymer) was used as flocculant. Preliminary tests were first conducted to determine the appropriate coagulation and flocculation agitation rates and settling time. The initial pH of the sample effluent was varied from 5 to 8 for alum coagulation, 5 to 8.5 for PAC coagulation and 9 to 11 for ferrous sulfate coagulation. The dosages of each coagulan...
ASEAN Journal of Chemical Engineering
The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol p... more The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol production. The optimization of alkali (sodium hydroxide) pretreatment parameters such as concentration and residence time was carried out by the Taguchi method using L16 orthogonal array with two factors and four levels. Sugarcane bagasse powder was mixed with sodium hydroxide (NaOH) solution (0.5-2 wt.%) and heated in an autoclave at 121°C and at varied times (30-120 min). From the statistical analysis of data, it was observed that delignification and glucan increased with the increased concentration and short time. The optimum parameters of NaOH pretreatment were 2 wt.% of NaOH concentration and 30 minutes of residence time. At the optimum conditions, 86.8% delignification and 46.6% glucan content of SCB were obtained. Thus, alkali pretreatment optimized by Taguchi design is the effective method to remove lignin and to increase cellulose or glucan content in sugarcane bagasse for facil...
Applied Science and Engineering Progress
Sustainable biofuel feedstock could become a critical issue in the light of the recent fuel crisi... more Sustainable biofuel feedstock could become a critical issue in the light of the recent fuel crisis. The use of mixed biomass could reinforce to overcome this issue. The present work examined the parallel use of agricultural residue sugarcane bagasse (SCB) and natural invasive marine seaweed Sargassum sp. (SSP) as a single feedstock and its mixture in two-step concentrated acid hydrolysis followed by yeast fermentation in order to produce reducing sugar with minimal formation of furfural, and bioethanol. In this work, alkali pretreated SCB and SSP were used as feedstock in acid hydrolysis. To investigate the influenced parameters of acid hydrolysis, biomass type (SCB, mixed biomass MB (SCB and SSP in 1:1 ratio by weight) and SSP), initial acid concentration (64–80 wt%), reaction time (30–90 min) and solid loading (10–20%w/w) were optimized by using Taguchi method. The optimized conditions were obtained with mixed biomass type, the initial acid concentration of 64 wt%, reaction time o...
Microwave-assisted extraction (MAE) of phenolic compounds from the processed dry leaves of Moring... more Microwave-assisted extraction (MAE) of phenolic compounds from the processed dry leaves of Moringa oleifera Lam. was optimized by applying response surface methodology. The phenolic profile and antioxidant activities of the extract obtained under optimum conditions were also evaluated. Optimum conditions for the extraction of phenolic compounds were achieved at 5 min of extraction time, 65 °C of extraction temperature, 0.015 g mL-1 of sample/solvent ratio and 35% of aqueous ethanol concentration. The yield of total phenolic content under optimum conditions was 16.5 ± 0.2 mg gallic acid equivalent (GAE) per g of dry leaf. The extraction yield was comparable with yield obtained by the conventional extraction technique. However, the technique was time efficient. The antioxidant activities were relatively high compared with those of some plants reported in the literature. Interestingly, the presence of vanillic acid, a new compound which had not been reported in M. oleifera in prior lit...
Chemical Engineering Transactions, 2017
Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioet... more Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioethanol production from lignocellulosic materials, it is necessary to remove lignin due to its recalcitrant nature. The present work aimed to study the effect of alkali pretreatment on removal of lignin from sugarcane bagasse using sodium hydroxide. Two solid loading conditions (20 %w/v and 10 %w/v) were used in this study. For 20 % loading condition, base concentrations were varied at four levels and autoclaving time was varied at 3 levels, and the experiments were performed in 12 runs for this loading rate. For 20 % w/v solid loading, the concentrations of sodium hydroxide were 0.5 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt% at 121 °C for 10 min, 30 min and 60 min. For 10 % loading condition, the levels of each factor were increased. The base concentrations were varied at six levels and autoclaving time was varied at 5 levels, and the experiments were also performed, resulting in 30 runs for this...
ASEAN Journal of Chemical Engineering, 2021
The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol p... more The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol production. The optimization of alkali (sodium hydroxide) pretreatment parameters such as concentration and residence time was carried out by the Taguchi method using L16 orthogonal array with two factors and four levels. Sugarcane bagasse powder was mixed with sodium hydroxide (NaOH) solution (0.5-2 wt.%) and heated in an autoclave at 121°C and at varied times (30-120 min). From the statistical analysis of data, it was observed that delignification and glucan increased with the increased concentration and short time. The optimum parameters of NaOH pretreatment were 2 wt.% of NaOH concentration and 30 minutes of residence time. At the optimum conditions, 86.8% delignification and 46.6% glucan content of SCB were obtained. Thus, alkali pretreatment optimized by Taguchi design is the effective method to remove lignin and to increase cellulose or glucan content in sugarcane bagasse for facil...
Co 0.5 Ni 0.5 Fe 2 O 4 nanoparticles have been synthesized by a stearic acid method. Core/shell C... more Co 0.5 Ni 0.5 Fe 2 O 4 nanoparticles have been synthesized by a stearic acid method. Core/shell Co 0.5 Ni 0.5 Fe 2 O 4 /SiO 2 nanomaterials at varying amount of SiO 2 are prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) precursor. The composition phase and average crystallite size have been characterized by means of X-ray diffraction. The particle structure and morphology of the core-shell nanoparticles are determined using transmission electron microscopy (TEM). The presence of Si-O-Si bonds for both coated samples is confirmed through Fourier transform infrared spectroscopic. Results show a decreasing saturation magnetization (M s) when amount of TEOS is increased. The addition of SiO 2 at first instance enhance the coercivity (H c), and maximum H c is observed when 0.4 mL TEOS is added. However, adding more SiO 2 decrease the coercivity because the domain wall motion on the surface of nanoparticles is limited.
Journal of Environmental Science for Sustainable Society, 2009
This work aims to investigate the removal of arsenic from the simulated groundwater by batch adso... more This work aims to investigate the removal of arsenic from the simulated groundwater by batch adsorption using Iron (ZVI) and Iron[III] Oxide (IO). The effect of initial arsenic concentration, adsorbent dose and pH were investigated. Adsorption equilibrium and its kinetics were also studied. The results showed that both ZVI and IO have a high efficiency for adsorption of arsenic from groundwater. Langmuir isotherm described well the adsorption equilibrium and the pseudo-second order kinetic model gave the best fit with the experimental kinetic data for both ZVI and IO.
Journal of Water and Environment Technology, 2008
Groundwater is one of the most important sources for drinking water. Arsenic (As) contamination o... more Groundwater is one of the most important sources for drinking water. Arsenic (As) contamination of groundwater is a serious problem worldwide, especially in Bangladesh, India and South East Asia. Adsorption using appropriate and readily available adsorbents is a promising method for the removal of arsenic with applicability in rural areas. This work aims to study the removal of arsenic from synthetic groundwater using an adsorption column by sequential combination of laterite (LA) and iron-modified activated carbon (AC-Fe) as adsorbents. The effect of ratio LA/AC-Fe, flow rate, initial arsenic concentration and pH to the breakthrough time were investigated. Adsorption equilibrium and adsorption kinetics were also studied through batch experiment. The result was found to be an efficient and feasible approach for arsenic treatment from groundwater for ready applicability in rural areas.
The Philippine …, 2009
This study compares the composition of essential oil extracted from lemongrass leaves and stems u... more This study compares the composition of essential oil extracted from lemongrass leaves and stems using supercritical CO2 (SC CO2) and steam distillation. In the process using SC CO2 extraction in a Supercritical Fluid Extraction System (SFE), the temperature ...
Desalination, 2008
Zero-valent iron (ZVI) immobilized in cationic exchange membrane (CEM) was investigated for the d... more Zero-valent iron (ZVI) immobilized in cationic exchange membrane (CEM) was investigated for the degradation of trichloroethylene (TCE). Using a commercial CEM as a support, it was possible to immobilize ZVI conveniently. According to the surface analysis, the nanoparticles were formed on the surface of CEM after immobilization and the size of them was 30-40 nm. The ZVI-immobilized CEM (Fe(0)-CEM) contained 75 mg Fe/m 2 membrane. The removal of TCE was accomplished by sorption on the membrane matrix and degradation by the immobilized ZVI. About 36.2 mg/L of TCE was removed within initial 2 h and the observed rate constant (k obs) was 0.44 h −1. The value of surface area normalized rate constant (k SA) of Fe(0)-CEM was 35.77 L h −1 m −2. The obtained k SA was higher than other studies on the nanoparticles or the membrane-immobilized nanoparticles by 1-3 orders of magnitudes. The higher k SA resulted from low metal loading (ca. 6.5 mg/L) in this test. Moreover the released iron concentration to aqueous phase was very low (0.1-0.3 mg/L), In conclusion, the Fe(0)-CEM proposed in this study was effective in the TCE removal. And it would be possible to reuse the Fe(0)-CEM repeatedly after re-reducing it.
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 1998
Chemical Engineering Transactions, 2017
Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioet... more Lignin is complex polymer compound contained in woody plant tissue. In sugar extraction and bioethanol production from lignocellulosic materials, it is necessary to remove lignin due to its recalcitrant nature. The present work aimed to study the effect of alkali pretreatment on removal of lignin from sugarcane bagasse using sodium hydroxide. Two solid loading conditions (20 %w/v and 10 %w/v) were used in this study. For 20 % loading condition, base concentrations were varied at four levels and autoclaving time was varied at 3 levels, and the experiments were performed in 12 runs for this loading rate. For 20 % w/v solid loading, the concentrations of sodium hydroxide were 0.5 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt% at 121 °C for 10 min, 30 min and 60 min. For 10 % loading condition, the levels of each factor were increased. The base concentrations were varied at six levels and autoclaving time was varied at 5 levels, and the experiments were also performed, resulting in 30 runs for this...
Journal of Water Resource and Protection, 2009
A preliminary study on nitrogen and organic removal efficiency of a lab-scale system using aerobi... more A preliminary study on nitrogen and organic removal efficiency of a lab-scale system using aerobic and anaerobic reactors was performed. A simulated wastewater containing elevated levels of nitrogen was used. This paper aims to compare the efficiency of aerobic and anaerobic reactors in achieving nitrogen and chemical oxygen demand (COD) removal of nutrient-rich wastewater. It also presents the start-up experimentation conducted on simulated wastewater using two different reactors configured as aerobic and anaerobic. Start-up experiments were carried out using a 5-liter acrylic aerobic reactor and a 4-liter flask anaerobic reactor containing activated sludge taken from De La Salle University (DLSU) wastewater treatment plant as a source of inoculum. Simulated wastewater was continuously fed to the two reactors and the time course of biomass growth was monitored by measuring the biomass concentration represented by mixed liquor volatile solids (MLVS). The time course of organic pollutant reduction by measuring the chemical oxygen demand (COD) was conducted until steady state condition was reached. On the other hand, COD and nitrogen tests such as Ammonia nitrogen (NH 3-N), Nitrite nitrogen (NO 2-N), Nitrate nitrogen (NO 3-N) were also performed using 5 batch aerobic reactors containing different concentrations of wastewater and a single batch anaerobic reactor to see the effect of different feed concentrations in the removal of nitrogen. Preliminary results showed that 98% reduction in COD was obtained in aerobic reactor, as supported by increasing concentration of MLVS, with a hydraulic retention time (HRT) of 5 hours after 11 days while 34% reduction in COD was obtained in anaerobic reactor with the same HRT after 14 days.
Vietnam Journal of Science, Technology and Engineering, Mar 25, 2020
CuO-ZnO nanoparticles were successfully synthesized by the sol-gel method. Characteristic propert... more CuO-ZnO nanoparticles were successfully synthesized by the sol-gel method. Characteristic properties of the synthesized nanoparticles were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), N 2 adsorption/desorption isotherms, and BJH pore diameter distributions. The formation of highly crystalline CuO and ZnO was confirmed by XRD. FT-IR confirmed that Zn-O and Cu-O bonds were formed in the material. SEM and TEM images showed that the obtained CuO-ZnO nanoparticles were nearly spherical in shape and had a uniform size distribution with sizes ranging between 5-20 nm for the CuO-containing phase and 50-100 nm for the ZnO-containing phase. The CuO-ZnO sample showed effective antifungal activities against four strains. Aspergillus and Penicillium were completely inhibited with a concentration of 5 mg/ml of CuO-ZnO. For the Magnaporthe and Neoscytalidium strains, the minimum inhibitory concentration was 10 mg/ml.
Materials
This study deals with the impact of calcination, alkalinity, and curing time parameters on the hy... more This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 500 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing ti...
Materials
This study deals with the impact of calcination, alkalinity, and curing time parameters on the hy... more This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 500 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing ti...
ASEAN Journal of Chemical Engineering
Untreated wastewater from textile industries when discharged to nearby waterways would cause cons... more Untreated wastewater from textile industries when discharged to nearby waterways would cause considerable health concerns to humans and animal life and to the host environment. They contain various chemicals such as dyes, detergents and surfactants, some of which are recalcitrant to biodegradation. Such wastewater can be better remediated by chemical treatment. The treatment of a textile bleaching and dyeing industrial wastewater was done by Coagulation and Flocculation Method using a jar test apparatus. Alum, polyaluminum chloride (PAC), and ferrous sulfate were used in separate runs as coagulants, while excelfloc 264 (a polyacrylamide copolymer) was used as flocculant. Preliminary tests were first conducted to determine the appropriate coagulation and flocculation agitation rates and settling time. The initial pH of the sample effluent was varied from 5 to 8 for alum coagulation, 5 to 8.5 for PAC coagulation and 9 to 11 for ferrous sulfate coagulation. The dosages of each coagulan...