Chih-Huang Weng | I-Shou University (original) (raw)

Papers by Chih-Huang Weng

Separation and Purification Technology, 2008

An electrochemical (EC) process was used to investigate the effectiveness of regeneration of fiel... more An electrochemical (EC) process was used to investigate the effectiveness of regeneration of field-spent granular activated carbon (SGAC) collected from a wastewater treatment plant. The influences of regeneration parameters such as processing time, voltage gradient, and processing fluid, were performed. The performance of EC regeneration was evaluated via batch methylene blue (MB) adsorption tests. Increasing voltage and prolonging the process

Journal of Environmental Engineering, 2002

... The model fittings for all kinetic data experiments under different ionic strengths, pHs, and... more ... The model fittings for all kinetic data experiments under different ionic strengths, pHs, and initial concentrations are presented as the solid lines in Figs. . ... Because the nickel hydroxide precipitates were found only at (see Fig. ...

Journal of Colloid and Interface Science, 2004

The adsorption of Pb(II) onto hydrous sandy loam soil was investigated with batch equilibrium ads... more The adsorption of Pb(II) onto hydrous sandy loam soil was investigated with batch equilibrium adsorption experiments. Results show that the amount of Pb(II) adsorbed increases with increasing pH and surface loading. It was demonstrated that the surface acidity of the soil could be determined using electrophoretic mobility measurements. The surface acidity constants, pK(a1)(int) and pK(a2)(int), were 1.57 and 3.43, respectively. A surface complex formation model (SCFM) was employed to describe the adsorption. The intrinsic stability constants, pK(i)(s), for the surface reaction between the Pb species and the ionized soil surface hydroxyl groups were determined from SCFM fitting. The adsorption free energy of Pb2+ and Pb(OH)+ ions ranges from -5.74 to -6.48 kcal/mol and from -9.68 to -10.00 kcal/mol, respectively, for surface loadings between 1.21 x 10(-5) and 2.41 x 10(-4) mol/g. The adsorption binding calculation indicated that the specific chemical interaction is the major mechanism responsible for the adsorption process.

Japan Geoscience Union, 2018

Chemical Engineering Journal, 2021

Sludge dewatering can be accomplished by freeze-thaw, centrifuge force, mechanical press and sun-... more Sludge dewatering can be accomplished by freeze-thaw, centrifuge force, mechanical press and sun-drying. The freeze thaw method is capable of decreasing the water content of sludge to 50~60%and even lower to 43% once added with polymer electrolytes under a low temperature condition. However, the consumption of energy and polymer electrolytes may become limiting factors for economical consideration. The technology by centrifuge force and mechanical press can not remove the bound water efficiently. Use of sunshine to remove water from sludge is an economical way, but it needs a large space and sufficient time (≥ 7 days). In Taiwan, mechanical press and sunshine are the two common sludge dewatering methods being used in wastewater treatment plants. The water content of sludge can be decreased to 65% ~ 85% and 60% ~70% for the above-mentioned methods, respectively. Electrokinetic (EK) process has been demonstrated to be a cost-effective remediation technology to extract heavy metals and...

Separation and Purification Technology, 2021

Abstract Four types of pathogens, namely, Staphylococcus aureus (S. aureus, gram-positive bacteri... more Abstract Four types of pathogens, namely, Staphylococcus aureus (S. aureus, gram-positive bacteria), Escherichia coli (E. coli, gram-negative bacteria), Mycobacterium avium (M. avium, mycobacteria), and Candida albicans (C. albicans, fungi), are common microorganisms that cause serious human health issues. However, searching for an efficient material for inactivating pathogens via visible light driven photocatalysts remains a challenge. An attempt was made to compare the photocatalytic performance using nano-sized nitrogen-doped titanium oxide (N-TiO2) and tourmaline-nitrogen-co-doped titanium oxide (T-N-TiO2) for inactivation of pathogens under visible light irradiation. S. aureus was used to compare the photocatalytic inactivation performance of N-TiO2 and T-N-TiO2. The findings showed that photocatalyst dosage, initial microbial concentration, and visible light intensity are the key factors affecting photocatalytic inactivation process for both photocatalysts. A 2-log-inactivation of S. aureus under 7.25 mW/cm2 visible light irradiation via T-N-TiO2 was achieved within 3 h, which is shorter than the inactivation via N-TiO2 (4 h). TEM observations had proved that both visible-light-induced photocatalysis could cause severe damage to the cell membrane. The results of electron paramagnetic resonance also indicated that more hydroxyl radicals generated in the T-N-TiO2 photo-inactivation system allowed a better inactivation performance of the visible-light-induced T-N-TiO2. This is the first work exploring that Light-responsive Modified Hom’s model (LHM) is able to simulate photocatalytic inactivation of S. aureus. T-N-TiO2 composite was firstly evaluated for its efficacy of photocatalytic inaction of S. aureus, E. coli, and M. avium, and an increasing order of time was required for complete inactivation as follows: S. aureus

Bioresource technology, 2017

The aim of this work was to study the effects of the presence of oxygen on the dechlorination of ... more The aim of this work was to study the effects of the presence of oxygen on the dechlorination of trichloroethene by a microbial consortium containing D. mccartyi. The 16S rRNA and reductive dechlorination genes of the functional bacteria and the non-dechlorinators were monitored. Exposing the consortium to oxygen altered the overall biotransformation rate of the dechlorination process, biotransformation processes prolonged with oxygen concentrations changing from 0 to 7.2mg/L, however, trichloroethylene was eventually dechlorinated to ethene. The qPCR analyses revealed that the D. mccartyi strains containing the tceA gene were less sensitive to exposure to oxygen than were the D. mccartyi strains containing the vcrA gene. High-throughput sequencing by Illumina MiSeq indicated that the non-dechlorinating organisms were probably crucial to scavenge the oxygen to protect D. mccartyi from being damaged.

Arabian Journal of Chemistry, 2016

Separation and Purification Technology, 2015

Water and Environment Journal, 2015

Environmental Geochemistry and Health - ENVIRON GEOCHEM HEALTH, 2001

The clay soil was taken from a depth of 0.7‐1.5 m at a location on the campus of I-Shou Universit... more The clay soil was taken from a depth of 0.7‐1.5 m at a location on the campus of I-Shou University, Kaohsiung, Taiwan. The properties of soil are as follows: average particle size 27.8 µm, organic matter content 1.79%, soil pH 7.0, pHzpc 2.3, BET-N2 specific surface area 29.6 m 2 g −1 . The EK experiments were conducted using Pyrex glass cylindrical cells (4.2 cm φ) consisting of three compartments: anode reservoir (5 cm-L), soil cell (12 cm-L), and cathode reservoir (5 cm-L). Each cell contained approximately 305 g of the artificially Cr(III)-contaminated clay soil (1950 mg kg −1 ) with a moisture content of 45 ± 3%. A fibreglass filter paper (0.45 µm, Gelman Sci.) was used to separate the soil from the processing fluid at each end of the cell. Two sets of graphite rod electrodes were installed at each side of the reservoirs. A constant electric gradient of 2.5 V cm −1 was applied to induce the movement of electrolyte solution within the soil cell for 7 days. Total

Separation and Purification Technology, 2007

Separation and Purification Technology, 2008

The removal of AB24 dye in aqueous solution by nano/micro-size zero-valent iron (ZVI) was investi... more The removal of AB24 dye in aqueous solution by nano/micro-size zero-valent iron (ZVI) was investigated. Results indicate that the degradation efficiency increases with increasing ZVI concentration and temperature but decreases with particle size of ZVI. Analysis of the results indicates that the reaction follows pseudo-first order kinetics. The rate constant increases linearly with ZVI concentration and decreases with particle size.

Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, 2006

The effectiveness of incorporating Fe(O) barrier into electrokinetic (EK) process to remediate Cr... more The effectiveness of incorporating Fe(O) barrier into electrokinetic (EK) process to remediate Cr(VI) contaminated clay (1,150 mg∕kg) was investigated. The EK experiments were conducted using a 12 cm long sample under a constant electric gradient of 2 V∕cm for 144 h . The barrier was installed in the cell and was filled with Fe(O) and silica sand (1:1 w∕w) . Experimental results showed the removal of Cr from clay was characterized by the high Cr(VI) concentration that occurred in the anode reservoir and the presence of Cr(III) precipitates in the cathode reservoir. The efficiencies of Cr(VI) reduction and total Cr removal for the EK process are 78 and 28%, respectively. As the barrier was installed in the process, a nearly 100% Cr(VI) reduction and 60–70% total Cr removal were achieved. The Cr removal mechanisms were mainly attributed to ion migration and electro-osmotic advection caused by electric gradient. Results indicated that the EK process was enhanced by the reduction of Cr(VI) to Cr(III) by Fe(O)...

Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, 2004

The effectiveness of the electrokinetic ~EK! process in treating soil enriched in chromite ore pr... more The effectiveness of the electrokinetic ~EK! process in treating soil enriched in chromite ore processing residue ~Cr-soil! was investigated. An electric gradient of 1.2 V/cm was applied to induce the movement of electrolyte solution in the soil cell for 17- 43 days. Simulated rainwater was used as EK processing fluid. Results show low removal efficiency of total Cr ~2-7%! because the insoluble form of chromite dominates in the Cr-soil. However, more than 95% of leachable Cr~VI! can be removed by controlling the pH of the processing fluid at 9.0 during experiments. The removal of Cr from Cr-soil was characterized by the high Cr ~VI! concentration collected at the anode, and the presence of Cr precipitates collected at cathode. The electric energy requirement under all experimental conditions varied from 1.3 to 5.8 kW h/m 3 . Results indicated that the EK is an effective process in mitigating the leaching of Cr ~VI! from Cr-soil.

Journal of Hazardous Materials, 2007

This paper investigated the effectiveness of incorporating zero-valent iron (ZVI) into electrokin... more This paper investigated the effectiveness of incorporating zero-valent iron (ZVI) into electrokinetic (EK) to remediate hyper-Cr(VI) contaminated clay (2497 mg/kg). A ZVI wall was installed in the center of the soil specimen and was filled with 1:1 (w/w) ratio of granular ZVI and sand. Results show that transport of H(+) is greatly retarded by the strong opposite migration of anionic chromate ions, whereupon a revered electroosmosis flow (EO) was resulted and alkaline zone across the specimen was developed promoting the release of Cr(VI) from the clay. Chromium removal was characterized by high Cr(VI) concentration occurred in the anolyte and the presence of Cr(III) precipitates in the catholyte. The Cr(VI) reduction efficiencies for the process without ZVI wall were 68.1 and 79.2% for 1 and 2V/cm, respectively. As ZVI wall was installed, the corresponding reduction efficiencies increased to 85.8 and 92.5%. The costs for energy and ZVI utilized in this process are US$ 41.0 and 57.5 per cubic meter for the system with electric gradient of 1 and 2V/cm, respectively. The role of ZVI wall effectively reducing Cr(VI) contamination and the operation simultaneous collection of Cr(VI) from the electrode reservoirs are two major advantages of this process.

Journal of Hazardous Materials, 2008

Advances in Environmental Research, 2003

Separation and Purification Technology, 2008

An electrochemical (EC) process was used to investigate the effectiveness of regeneration of fiel... more An electrochemical (EC) process was used to investigate the effectiveness of regeneration of field-spent granular activated carbon (SGAC) collected from a wastewater treatment plant. The influences of regeneration parameters such as processing time, voltage gradient, and processing fluid, were performed. The performance of EC regeneration was evaluated via batch methylene blue (MB) adsorption tests. Increasing voltage and prolonging the process

Journal of Environmental Engineering, 2002

... The model fittings for all kinetic data experiments under different ionic strengths, pHs, and... more ... The model fittings for all kinetic data experiments under different ionic strengths, pHs, and initial concentrations are presented as the solid lines in Figs. . ... Because the nickel hydroxide precipitates were found only at (see Fig. ...

Journal of Colloid and Interface Science, 2004

The adsorption of Pb(II) onto hydrous sandy loam soil was investigated with batch equilibrium ads... more The adsorption of Pb(II) onto hydrous sandy loam soil was investigated with batch equilibrium adsorption experiments. Results show that the amount of Pb(II) adsorbed increases with increasing pH and surface loading. It was demonstrated that the surface acidity of the soil could be determined using electrophoretic mobility measurements. The surface acidity constants, pK(a1)(int) and pK(a2)(int), were 1.57 and 3.43, respectively. A surface complex formation model (SCFM) was employed to describe the adsorption. The intrinsic stability constants, pK(i)(s), for the surface reaction between the Pb species and the ionized soil surface hydroxyl groups were determined from SCFM fitting. The adsorption free energy of Pb2+ and Pb(OH)+ ions ranges from -5.74 to -6.48 kcal/mol and from -9.68 to -10.00 kcal/mol, respectively, for surface loadings between 1.21 x 10(-5) and 2.41 x 10(-4) mol/g. The adsorption binding calculation indicated that the specific chemical interaction is the major mechanism responsible for the adsorption process.

Japan Geoscience Union, 2018

Chemical Engineering Journal, 2021

Sludge dewatering can be accomplished by freeze-thaw, centrifuge force, mechanical press and sun-... more Sludge dewatering can be accomplished by freeze-thaw, centrifuge force, mechanical press and sun-drying. The freeze thaw method is capable of decreasing the water content of sludge to 50~60%and even lower to 43% once added with polymer electrolytes under a low temperature condition. However, the consumption of energy and polymer electrolytes may become limiting factors for economical consideration. The technology by centrifuge force and mechanical press can not remove the bound water efficiently. Use of sunshine to remove water from sludge is an economical way, but it needs a large space and sufficient time (≥ 7 days). In Taiwan, mechanical press and sunshine are the two common sludge dewatering methods being used in wastewater treatment plants. The water content of sludge can be decreased to 65% ~ 85% and 60% ~70% for the above-mentioned methods, respectively. Electrokinetic (EK) process has been demonstrated to be a cost-effective remediation technology to extract heavy metals and...

Separation and Purification Technology, 2021

Abstract Four types of pathogens, namely, Staphylococcus aureus (S. aureus, gram-positive bacteri... more Abstract Four types of pathogens, namely, Staphylococcus aureus (S. aureus, gram-positive bacteria), Escherichia coli (E. coli, gram-negative bacteria), Mycobacterium avium (M. avium, mycobacteria), and Candida albicans (C. albicans, fungi), are common microorganisms that cause serious human health issues. However, searching for an efficient material for inactivating pathogens via visible light driven photocatalysts remains a challenge. An attempt was made to compare the photocatalytic performance using nano-sized nitrogen-doped titanium oxide (N-TiO2) and tourmaline-nitrogen-co-doped titanium oxide (T-N-TiO2) for inactivation of pathogens under visible light irradiation. S. aureus was used to compare the photocatalytic inactivation performance of N-TiO2 and T-N-TiO2. The findings showed that photocatalyst dosage, initial microbial concentration, and visible light intensity are the key factors affecting photocatalytic inactivation process for both photocatalysts. A 2-log-inactivation of S. aureus under 7.25 mW/cm2 visible light irradiation via T-N-TiO2 was achieved within 3 h, which is shorter than the inactivation via N-TiO2 (4 h). TEM observations had proved that both visible-light-induced photocatalysis could cause severe damage to the cell membrane. The results of electron paramagnetic resonance also indicated that more hydroxyl radicals generated in the T-N-TiO2 photo-inactivation system allowed a better inactivation performance of the visible-light-induced T-N-TiO2. This is the first work exploring that Light-responsive Modified Hom’s model (LHM) is able to simulate photocatalytic inactivation of S. aureus. T-N-TiO2 composite was firstly evaluated for its efficacy of photocatalytic inaction of S. aureus, E. coli, and M. avium, and an increasing order of time was required for complete inactivation as follows: S. aureus

Bioresource technology, 2017

The aim of this work was to study the effects of the presence of oxygen on the dechlorination of ... more The aim of this work was to study the effects of the presence of oxygen on the dechlorination of trichloroethene by a microbial consortium containing D. mccartyi. The 16S rRNA and reductive dechlorination genes of the functional bacteria and the non-dechlorinators were monitored. Exposing the consortium to oxygen altered the overall biotransformation rate of the dechlorination process, biotransformation processes prolonged with oxygen concentrations changing from 0 to 7.2mg/L, however, trichloroethylene was eventually dechlorinated to ethene. The qPCR analyses revealed that the D. mccartyi strains containing the tceA gene were less sensitive to exposure to oxygen than were the D. mccartyi strains containing the vcrA gene. High-throughput sequencing by Illumina MiSeq indicated that the non-dechlorinating organisms were probably crucial to scavenge the oxygen to protect D. mccartyi from being damaged.

Arabian Journal of Chemistry, 2016

Separation and Purification Technology, 2015

Water and Environment Journal, 2015

Environmental Geochemistry and Health - ENVIRON GEOCHEM HEALTH, 2001

The clay soil was taken from a depth of 0.7‐1.5 m at a location on the campus of I-Shou Universit... more The clay soil was taken from a depth of 0.7‐1.5 m at a location on the campus of I-Shou University, Kaohsiung, Taiwan. The properties of soil are as follows: average particle size 27.8 µm, organic matter content 1.79%, soil pH 7.0, pHzpc 2.3, BET-N2 specific surface area 29.6 m 2 g −1 . The EK experiments were conducted using Pyrex glass cylindrical cells (4.2 cm φ) consisting of three compartments: anode reservoir (5 cm-L), soil cell (12 cm-L), and cathode reservoir (5 cm-L). Each cell contained approximately 305 g of the artificially Cr(III)-contaminated clay soil (1950 mg kg −1 ) with a moisture content of 45 ± 3%. A fibreglass filter paper (0.45 µm, Gelman Sci.) was used to separate the soil from the processing fluid at each end of the cell. Two sets of graphite rod electrodes were installed at each side of the reservoirs. A constant electric gradient of 2.5 V cm −1 was applied to induce the movement of electrolyte solution within the soil cell for 7 days. Total

Separation and Purification Technology, 2007

Separation and Purification Technology, 2008

The removal of AB24 dye in aqueous solution by nano/micro-size zero-valent iron (ZVI) was investi... more The removal of AB24 dye in aqueous solution by nano/micro-size zero-valent iron (ZVI) was investigated. Results indicate that the degradation efficiency increases with increasing ZVI concentration and temperature but decreases with particle size of ZVI. Analysis of the results indicates that the reaction follows pseudo-first order kinetics. The rate constant increases linearly with ZVI concentration and decreases with particle size.

Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, 2006

The effectiveness of incorporating Fe(O) barrier into electrokinetic (EK) process to remediate Cr... more The effectiveness of incorporating Fe(O) barrier into electrokinetic (EK) process to remediate Cr(VI) contaminated clay (1,150 mg∕kg) was investigated. The EK experiments were conducted using a 12 cm long sample under a constant electric gradient of 2 V∕cm for 144 h . The barrier was installed in the cell and was filled with Fe(O) and silica sand (1:1 w∕w) . Experimental results showed the removal of Cr from clay was characterized by the high Cr(VI) concentration that occurred in the anode reservoir and the presence of Cr(III) precipitates in the cathode reservoir. The efficiencies of Cr(VI) reduction and total Cr removal for the EK process are 78 and 28%, respectively. As the barrier was installed in the process, a nearly 100% Cr(VI) reduction and 60–70% total Cr removal were achieved. The Cr removal mechanisms were mainly attributed to ion migration and electro-osmotic advection caused by electric gradient. Results indicated that the EK process was enhanced by the reduction of Cr(VI) to Cr(III) by Fe(O)...

Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, 2004

The effectiveness of the electrokinetic ~EK! process in treating soil enriched in chromite ore pr... more The effectiveness of the electrokinetic ~EK! process in treating soil enriched in chromite ore processing residue ~Cr-soil! was investigated. An electric gradient of 1.2 V/cm was applied to induce the movement of electrolyte solution in the soil cell for 17- 43 days. Simulated rainwater was used as EK processing fluid. Results show low removal efficiency of total Cr ~2-7%! because the insoluble form of chromite dominates in the Cr-soil. However, more than 95% of leachable Cr~VI! can be removed by controlling the pH of the processing fluid at 9.0 during experiments. The removal of Cr from Cr-soil was characterized by the high Cr ~VI! concentration collected at the anode, and the presence of Cr precipitates collected at cathode. The electric energy requirement under all experimental conditions varied from 1.3 to 5.8 kW h/m 3 . Results indicated that the EK is an effective process in mitigating the leaching of Cr ~VI! from Cr-soil.

Journal of Hazardous Materials, 2007

This paper investigated the effectiveness of incorporating zero-valent iron (ZVI) into electrokin... more This paper investigated the effectiveness of incorporating zero-valent iron (ZVI) into electrokinetic (EK) to remediate hyper-Cr(VI) contaminated clay (2497 mg/kg). A ZVI wall was installed in the center of the soil specimen and was filled with 1:1 (w/w) ratio of granular ZVI and sand. Results show that transport of H(+) is greatly retarded by the strong opposite migration of anionic chromate ions, whereupon a revered electroosmosis flow (EO) was resulted and alkaline zone across the specimen was developed promoting the release of Cr(VI) from the clay. Chromium removal was characterized by high Cr(VI) concentration occurred in the anolyte and the presence of Cr(III) precipitates in the catholyte. The Cr(VI) reduction efficiencies for the process without ZVI wall were 68.1 and 79.2% for 1 and 2V/cm, respectively. As ZVI wall was installed, the corresponding reduction efficiencies increased to 85.8 and 92.5%. The costs for energy and ZVI utilized in this process are US$ 41.0 and 57.5 per cubic meter for the system with electric gradient of 1 and 2V/cm, respectively. The role of ZVI wall effectively reducing Cr(VI) contamination and the operation simultaneous collection of Cr(VI) from the electrode reservoirs are two major advantages of this process.

Journal of Hazardous Materials, 2008

Advances in Environmental Research, 2003