Chih-Huang Weng - Profile on Academia.edu (original) (raw)
Papers by Chih-Huang Weng
Nano‐adsorbents for the removal of metallic pollutants from water and wastewater
Environmental Technology, 2009
Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbo... more Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbon has been the most popular. A number of minerals, clays and waste materials have been regularly used for the removal of metallic pollutants from water and industrial effluents. Recently there has been emphasis on the application of nanoparticles and nanostructured materials as efficient and viable alternatives to activated carbon. Carbon nanotubes also have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions. Because of their importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu. Separation of the used nanoparticles from aqueous solutions and the health aspects of the separated nanoparticles have also been discussed. A significant number of the latest articles have been critically scanned for the present review to give a vivid picture of these exotic materials for water remediation.
Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi-221 0... more Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi-221 005, Uttar Pradesh, India Department of Civil and Ecological Engineering, I Shou University, Kaohsiung County, 84001, Taiwan, ROC <em>Manuscript received online 17 July 2012, accepted 20 August 2012</em> The present study was undertaken to investigate the efficiency of nano-Fe3O<sub>4</sub> (<em>n</em>-Fe3O<sub>4</sub>) for the removal of nickel from their aqueous solutions. Removal process of Ni(II) was carried out by using batch adsorption experiments. Various important process parameters such as concentration of metal solution, contact time, pH and temperature were investigated. It was observed that removal decreases from 90.48 to 87.94% by increasing concentration from 1.9 x 10<sup>-2</sup> to 5.7 x 10<sup>-2</sup> mol/L. pH studies revealed that basic ranges favour Ni(II) removal. Removal of Ni(II) by adsorption ...
CATENA, 2013
The objective of this study is to investigate the removal of Cr(VI) from aqueous solutions by usi... more The objective of this study is to investigate the removal of Cr(VI) from aqueous solutions by using modified sand as adsorbent. The modified sand was characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and FTIR. pH zpc of the raw and modified sands was found to be 6.98 and 6.66, respectively. Removal efficiency of the modified sand was investigated by using batch adsorption experiments. The effect of important parameters such as initial concentration, contact time, adsorbent dosage, pH and temperature on removal of Cr(VI) was investigated. It was demonstrated that the removal efficiency increased from 67.24% to 80.40% by the decreasing initial metal concentration from 15 to 5 mg L −1. Effect of pH was investigated by varying the solution pH from 2.0 to 8.0. The optimum pH for adsorption of Cr(VI) on modified sand was found to be 2.5 with a maximum removal of~80.40%. Extent of removal decreases by increasing the temperature from 25°C to 35°C confirming exothermic nature. Kinetics of removal process was studied by applying pseudo-first order and pseudo-second order models. Pseudo-first order rate constant was found to be 0.037 min −1 while the rate constant for pseudo-second order reaction was found to be 0.0236 g mg −1 min −1 at 25°C. Values of thermodynamic parameters viz. ΔG°, ΔH°and ΔS°were calculated and found to be −3.67 kJ mol −1 , −68.74 kJ mol −1 and −0.243 kJ mol −1 K −1 , respectively at 25°C. The values of ΔG°were found to be negative at all temperatures indicating the spontaneity of the removal process. A negative value of ΔH°further confirms the exothermic nature of removal process. The experimental data were fitted to Langmuir as well as Freundlich adsorption isotherm equations. The results obtained in the present study show the modified sand to be a better adsorbent for removal of Cr(VI).
Application of a Thermally Modified Agrowaste Material for an Economically Viable Removal of Cr(VI) from Aqueous Solutions
Journal of Hazardous, Toxic, and Radioactive Waste, 2013
ABSTRACT
Journal of Chemical & Engineering Data, 2011
The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern ... more The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern because of its toxic and nonbiodegradable nature. Its removal from water and wastewater is mandatory. Though activated carbon has been effective in removing metallic species including nickel from water and effluents, its high cost limits its large scale application to developing nations. The present paper addresses the removal of nickel from aqueous solutions by alumina nano particles. The adsorbent, nano alumina powder, was synthesized in the laboratory and was characterized by X-ray diffractometry (XRD), Fourier transformation infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The BET surface area and porosity of nanosized alumina powder were found to be 78.79 m 2 g À1 and 0.51, respectively. The initial concentration of nickel, agitation speed, and contact time were found to affect the removal of nickel from aqueous solutions. Kinetic studies were performed and pseudofirst order, second order, intraparticle diffusion, and mass transfer studies were carried out. The equilibrium data were analyzed by various isotherms viz. Langmuir, Freundlich, DubininÀRadushkevich, and Temkin and Pyzhev isotherms. Results of the present study revealed that nano particles of alumina powder can be used for a large scale treatment of water containing Ni(II) in particular and that of pollutant species in general.
PJCT, 2011
Economically viable synthesis of Fe3O4 nanoparticles and their characterization Nano iron oxide p... more Economically viable synthesis of Fe3O4 nanoparticles and their characterization Nano iron oxide particles (Fe3O4) were synthesized by coprecipitation of Fe2+ and Fe3+ by ammonia solution in the aqueous phase. Various instrumentation methods such as X ray Diffractometry (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Vibrating Sample Magnetometery (VSM) were used to characterize the properties of nanoparticles. The size of the nanoparticles was measured and was found to be between 10 to 15 nm. The value of saturation magnetization of the nanoparticles was found to be 55.26 emu/g. The BET surface area of nano iron oxide particles measured to be 86.55 m2/g.
Advances in Environmental Research, May 1, 2003
Bricks manufactured from dried sludge collected from an industrial wastewater treatment plant wer... more Bricks manufactured from dried sludge collected from an industrial wastewater treatment plant were investigated. Results of tests indicated that the sludge proportion and the firing temperature were the two key factors determining the brick quality. Increasing the sludge content results in a decrease of brick shrinkage, water absorption, and compressive strength. Results also showed that the brick weight loss on ignition was mainly attributed to the organic matter content in the sludge being burnt off during the firing process. With up to 20% sludge added to the bricks, the strength measured at temperatures 960 and 1000 8C met the requirements of the Chinese National Standards. Toxic characteristic leaching procedure (TCLP) tests of brick also showed that the metal leaching level is low. The conditions for manufacturing good quality bricks is 10% sludge with 24% of moisture content prepared in the molded mixtures and fired at 880-960 8C.
Environment Protection Engineering, 2017
Factors contributing to nitrogen removal in a biological aerated filter (BAF) using oyster shell ... more Factors contributing to nitrogen removal in a biological aerated filter (BAF) using oyster shell medium have been investigated. The system was operated in parallel with a bio-ball filter. Both filters were fed with a synthetic domestic wastewater containing approximately 25 mg N/dm 3 of total nitrogen (TN). The COD of wastewater was 200 mg O2/dm 3 . The sizes and dissolved oxygen (DO) of the voids within both filters were measured. Results indicated that the oyster shell system performed better with a nitrogen removal of 64.3%. The two systems exhibited a similar COD removal efficiency of approximated 80%. The oyster shell filter showed higher degree of variability in both sizes and DO levels of its void spaces. The condition provided a favorable environment for nitrogen removal through simultaneous nitrification and denitrification (SND). The release of carbonates from oyster shells were minimal, as judged from mass balance analysis of the system using calcium. It is concluded that the function of a SND reactor can be enhanced by using non-uniform filter media such as oyster shells. On the other hand, alkalinity is not a major concern when treating wastewaters with moderate ammonia concentration, such as that of domestic wastewaters.
Sustainability, Jan 12, 2017
4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major poly... more 4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam-washed black tea, green tea, and coconut palm leaf powders were 21.85 mg•L -1 , 14.56 mg•L -1 and 22.47 mg•L -1 , respectively. The results also showed that the adsorption equilibrium (q e ) was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k 2 ) of all pressure steam-washed adsorbents ranged from 8.16 × 10 -3 to 6.61 × 10 -2 g•(mg•L -1 ) -1 •s -1 , and the amount adsorbed at q e by all pressure steam-washed adsorbents ranged from 4.21 to 4.78 mg•L -1 . Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg•L -1 , respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.
Separation and Purification Technology, Sep 1, 2016
Carbonate ions in wastewater can interfere with the reactions in advanced oxidation processes. In... more Carbonate ions in wastewater can interfere with the reactions in advanced oxidation processes. In the present study, the effects of carbonate ions on the degradation of a polyazo direct dye, the Sirius Ò Red F3B (SRF3B), using persulfate (PS) oxidation catalyzed by Fe 0 aggregates (PS/Fe 0 ) was investigated. Results of this study indicated that the oxidation power of the PS/Fe 0 process was inhibited in the dye solutions containing carbonates, and the efficiency of SRF3B decolorization decreased with increasing concentration of Na 2 CO 3 . A short period of ultrasound (US) irradiation can significantly enhance the destruction of dye molecules. Complete decolorization of a 25 mg/L SRF3B solution containing 1 Â 10 À3 M carbonate, 5 Â 10 À3 M PS, and 1.5 g/L Fe 0 was achieved within 5 min in a PS/Fe 0 /US system augmented with 5 min of US irradiation (60 kHz, 106 W/cm 2 ). The operating cost to complete removal of the dye was estimated at 2.79 USD/m 3 . Higher PS dosage and US power further minimized the interference from carbonate ions. A two-step reaction model, including a slow surface heterogeneous and a fast homogeneous aqueous reactions was proposed for the system. The presence of Fe 2+ and Fe 3+ ions identified using X-ray photoelectron spectroscopy, suggests a direct oxidation of the dye on the surface of the Fe 0 aggregates.
Environmental Science and Pollution Research, Aug 31, 2019
Environmental Engineering and Management Journal, 2015
This study investigated the use of tea waste to decolorize refractory dyestuff from textile waste... more This study investigated the use of tea waste to decolorize refractory dyestuff from textile wastewater. The influence of the solution pH and the contacting time were examined for various adsorbents, namely green tea-leaf powder (GTP), black tea-leaf powder (BTP), and powdered activated carbon (PAC). Results from batch experiments revealed that the reduction in true color (ADMI) increases with decreasing pH. The ADMI reduced from 1106 to 150 with 0.8 g/L of GTP at pH 2. The results also showed following ADMI removal efficiency order: GTP > PAC >> BTP. The active functional groups of the tea wastes involved in the adsorptive decoloration of tea waste were the hydroxyl, amine, carboxyl stretching, and C-O groups. The work carried out has revealed that green tea waste has a high potential to be used as an economically viable adsorbent to remove true color from textile effluents.
Electrokinetic (EK) remediation coupled with activated carbon barrier was evaluated to remove nic... more Electrokinetic (EK) remediation coupled with activated carbon barrier was evaluated to remove nickel (500 mg/kg) from kaolinite. Laboratory experiments were performed by applying a constant voltage to create electric field strength of 1 or 1.25 V/cm for 3 days. Findings showed that the barrier filled with activated carbon could prevent the formation of reverse electro-osmotic flow, which had an adverse effect on the Ni(II) removal. Application of activated carbon barrier into EK process resulted in an increase of Ni migration from 11 to 47%.
Sustainability, 2017
4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major poly... more 4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam-washed black tea, green tea, and coconut palm leaf powders were 21.85 mg•L -1 , 14.56 mg•L -1 and 22.47 mg•L -1 , respectively. The results also showed that the adsorption equilibrium (q e ) was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k 2 ) of all pressure steam-washed adsorbents ranged from 8.16 × 10 -3 to 6.61 × 10 -2 g•(mg•L -1 ) -1 •s -1 , and the amount adsorbed at q e by all pressure steam-washed adsorbents ranged from 4.21 to 4.78 mg•L -1 . Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg•L -1 , respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.
Journal of Chemical & Engineering Data, 2011
The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern ... more The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern because of its toxic and nonbiodegradable nature. Its removal from water and wastewater is mandatory. Though activated carbon has been effective in removing metallic species including nickel from water and effluents, its high cost limits its large scale application to developing nations. The present paper addresses the removal of nickel from aqueous solutions by alumina nano particles. The adsorbent, nano alumina powder, was synthesized in the laboratory and was characterized by X-ray diffractometry (XRD), Fourier transformation infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The BET surface area and porosity of nanosized alumina powder were found to be 78.79 m 2 g À1 and 0.51, respectively. The initial concentration of nickel, agitation speed, and contact time were found to affect the removal of nickel from aqueous solutions. Kinetic studies were performed and pseudofirst order, second order, intraparticle diffusion, and mass transfer studies were carried out. The equilibrium data were analyzed by various isotherms viz. Langmuir, Freundlich, DubininÀRadushkevich, and Temkin and Pyzhev isotherms. Results of the present study revealed that nano particles of alumina powder can be used for a large scale treatment of water containing Ni(II) in particular and that of pollutant species in general.
Adsorption of a cationic dye, methylene blue, on to chitosan hydrogel beads generated by anionic surfactant gelation
Environmental Technology, 2011
Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the ... more Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the removal of a cationic dye, methylene blue (MB), from aqueous solutions. The adsorption capacity of chitosan beads (CB) formed by alkali gelation was low because of charge repulsions between the chitosan (CS) and the MB. The adsorption capacity of CSB (4 g/L SDS gelation) for MB (100 mg/L) was 129.44 mg/g, and it decreased significantly with increasing SDS concentration during gelation. This decrease was a result of increased density of the CSB membrane materials. The CSB membrane materials formed with the 4 g/L SDS gelation showed the highest volumetric adsorption capacity. The MB adsorption on to CB and CSB increased with increasing values for the initial pH of solution. Data from both CB and CSB showed good fit to Sips isotherm models, and the maximum adsorption capacity of CSB (226.24 mg/g) was higher than that of CB (99.01 mg/g).
Environmental Science and Pollution Research, Nov 16, 2021
This special issue (SI) of Environmental Science and Pollution Research (ESPR) entitled "Water En... more This special issue (SI) of Environmental Science and Pollution Research (ESPR) entitled "Water Environment and Recent Advances in Pollution Control Technologies" collected the best papers that were formally presented at "The 6 th International Conference on Water Resource and Environment (WRE2020)" from August 23rd to 26th, 2020. The WRE2020 conference was a great success with 137 participants from 27 countries; three keynote speeches delivered by Prof. Jun Xia, Prof. Zhongbo Yu, and Prof. Chih-Huang Weng; 53 oral presentation papers; and 9 poster presentation papers. The conference themes covered various aspects of water environment, environmental science, and pollution control technologies, including, but not limited to, water resources, water quality, pollution control, groundwater issues, water and wastewater treatment technologies, wetland system, climate changes adaptation and mitigation strategies, ecological environments, waste utilization, and flood risk management and impact assessment. The WRE conference aims to provide a forum for scientific professionals and specialists to exchange the up-to-date knowledge relating to water resources and environmental issues, specifically focusing on understanding the issue of indispensable water resources in achieving a sustainable manner and targeting advanced vital technologies to protect the fragile water environments under the growing concern of intensive water usage that we are facing today (Weng 2020). Due to the outbreak of the COVID-19 pandemic, the WRE 2020 stopped being held in Tokyo as initially scheduled and transitioned online via virtual presentations.
Adsorption Characteristics of Cu(II) Onto Spent Pineapple Leaves
Regeneration of granular activated carbon by an electrochemical process
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
Removal of Nickel(II) from Dilute Aqueous Solution by Sludge-Ash
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. ...
Nano‐adsorbents for the removal of metallic pollutants from water and wastewater
Environmental Technology, 2009
Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbo... more Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbon has been the most popular. A number of minerals, clays and waste materials have been regularly used for the removal of metallic pollutants from water and industrial effluents. Recently there has been emphasis on the application of nanoparticles and nanostructured materials as efficient and viable alternatives to activated carbon. Carbon nanotubes also have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions. Because of their importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu. Separation of the used nanoparticles from aqueous solutions and the health aspects of the separated nanoparticles have also been discussed. A significant number of the latest articles have been critically scanned for the present review to give a vivid picture of these exotic materials for water remediation.
Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi-221 0... more Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi-221 005, Uttar Pradesh, India Department of Civil and Ecological Engineering, I Shou University, Kaohsiung County, 84001, Taiwan, ROC <em>Manuscript received online 17 July 2012, accepted 20 August 2012</em> The present study was undertaken to investigate the efficiency of nano-Fe3O<sub>4</sub> (<em>n</em>-Fe3O<sub>4</sub>) for the removal of nickel from their aqueous solutions. Removal process of Ni(II) was carried out by using batch adsorption experiments. Various important process parameters such as concentration of metal solution, contact time, pH and temperature were investigated. It was observed that removal decreases from 90.48 to 87.94% by increasing concentration from 1.9 x 10<sup>-2</sup> to 5.7 x 10<sup>-2</sup> mol/L. pH studies revealed that basic ranges favour Ni(II) removal. Removal of Ni(II) by adsorption ...
CATENA, 2013
The objective of this study is to investigate the removal of Cr(VI) from aqueous solutions by usi... more The objective of this study is to investigate the removal of Cr(VI) from aqueous solutions by using modified sand as adsorbent. The modified sand was characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and FTIR. pH zpc of the raw and modified sands was found to be 6.98 and 6.66, respectively. Removal efficiency of the modified sand was investigated by using batch adsorption experiments. The effect of important parameters such as initial concentration, contact time, adsorbent dosage, pH and temperature on removal of Cr(VI) was investigated. It was demonstrated that the removal efficiency increased from 67.24% to 80.40% by the decreasing initial metal concentration from 15 to 5 mg L −1. Effect of pH was investigated by varying the solution pH from 2.0 to 8.0. The optimum pH for adsorption of Cr(VI) on modified sand was found to be 2.5 with a maximum removal of~80.40%. Extent of removal decreases by increasing the temperature from 25°C to 35°C confirming exothermic nature. Kinetics of removal process was studied by applying pseudo-first order and pseudo-second order models. Pseudo-first order rate constant was found to be 0.037 min −1 while the rate constant for pseudo-second order reaction was found to be 0.0236 g mg −1 min −1 at 25°C. Values of thermodynamic parameters viz. ΔG°, ΔH°and ΔS°were calculated and found to be −3.67 kJ mol −1 , −68.74 kJ mol −1 and −0.243 kJ mol −1 K −1 , respectively at 25°C. The values of ΔG°were found to be negative at all temperatures indicating the spontaneity of the removal process. A negative value of ΔH°further confirms the exothermic nature of removal process. The experimental data were fitted to Langmuir as well as Freundlich adsorption isotherm equations. The results obtained in the present study show the modified sand to be a better adsorbent for removal of Cr(VI).
Application of a Thermally Modified Agrowaste Material for an Economically Viable Removal of Cr(VI) from Aqueous Solutions
Journal of Hazardous, Toxic, and Radioactive Waste, 2013
ABSTRACT
Journal of Chemical & Engineering Data, 2011
The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern ... more The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern because of its toxic and nonbiodegradable nature. Its removal from water and wastewater is mandatory. Though activated carbon has been effective in removing metallic species including nickel from water and effluents, its high cost limits its large scale application to developing nations. The present paper addresses the removal of nickel from aqueous solutions by alumina nano particles. The adsorbent, nano alumina powder, was synthesized in the laboratory and was characterized by X-ray diffractometry (XRD), Fourier transformation infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The BET surface area and porosity of nanosized alumina powder were found to be 78.79 m 2 g À1 and 0.51, respectively. The initial concentration of nickel, agitation speed, and contact time were found to affect the removal of nickel from aqueous solutions. Kinetic studies were performed and pseudofirst order, second order, intraparticle diffusion, and mass transfer studies were carried out. The equilibrium data were analyzed by various isotherms viz. Langmuir, Freundlich, DubininÀRadushkevich, and Temkin and Pyzhev isotherms. Results of the present study revealed that nano particles of alumina powder can be used for a large scale treatment of water containing Ni(II) in particular and that of pollutant species in general.
PJCT, 2011
Economically viable synthesis of Fe3O4 nanoparticles and their characterization Nano iron oxide p... more Economically viable synthesis of Fe3O4 nanoparticles and their characterization Nano iron oxide particles (Fe3O4) were synthesized by coprecipitation of Fe2+ and Fe3+ by ammonia solution in the aqueous phase. Various instrumentation methods such as X ray Diffractometry (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Vibrating Sample Magnetometery (VSM) were used to characterize the properties of nanoparticles. The size of the nanoparticles was measured and was found to be between 10 to 15 nm. The value of saturation magnetization of the nanoparticles was found to be 55.26 emu/g. The BET surface area of nano iron oxide particles measured to be 86.55 m2/g.
Advances in Environmental Research, May 1, 2003
Bricks manufactured from dried sludge collected from an industrial wastewater treatment plant wer... more Bricks manufactured from dried sludge collected from an industrial wastewater treatment plant were investigated. Results of tests indicated that the sludge proportion and the firing temperature were the two key factors determining the brick quality. Increasing the sludge content results in a decrease of brick shrinkage, water absorption, and compressive strength. Results also showed that the brick weight loss on ignition was mainly attributed to the organic matter content in the sludge being burnt off during the firing process. With up to 20% sludge added to the bricks, the strength measured at temperatures 960 and 1000 8C met the requirements of the Chinese National Standards. Toxic characteristic leaching procedure (TCLP) tests of brick also showed that the metal leaching level is low. The conditions for manufacturing good quality bricks is 10% sludge with 24% of moisture content prepared in the molded mixtures and fired at 880-960 8C.
Environment Protection Engineering, 2017
Factors contributing to nitrogen removal in a biological aerated filter (BAF) using oyster shell ... more Factors contributing to nitrogen removal in a biological aerated filter (BAF) using oyster shell medium have been investigated. The system was operated in parallel with a bio-ball filter. Both filters were fed with a synthetic domestic wastewater containing approximately 25 mg N/dm 3 of total nitrogen (TN). The COD of wastewater was 200 mg O2/dm 3 . The sizes and dissolved oxygen (DO) of the voids within both filters were measured. Results indicated that the oyster shell system performed better with a nitrogen removal of 64.3%. The two systems exhibited a similar COD removal efficiency of approximated 80%. The oyster shell filter showed higher degree of variability in both sizes and DO levels of its void spaces. The condition provided a favorable environment for nitrogen removal through simultaneous nitrification and denitrification (SND). The release of carbonates from oyster shells were minimal, as judged from mass balance analysis of the system using calcium. It is concluded that the function of a SND reactor can be enhanced by using non-uniform filter media such as oyster shells. On the other hand, alkalinity is not a major concern when treating wastewaters with moderate ammonia concentration, such as that of domestic wastewaters.
Sustainability, Jan 12, 2017
4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major poly... more 4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam-washed black tea, green tea, and coconut palm leaf powders were 21.85 mg•L -1 , 14.56 mg•L -1 and 22.47 mg•L -1 , respectively. The results also showed that the adsorption equilibrium (q e ) was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k 2 ) of all pressure steam-washed adsorbents ranged from 8.16 × 10 -3 to 6.61 × 10 -2 g•(mg•L -1 ) -1 •s -1 , and the amount adsorbed at q e by all pressure steam-washed adsorbents ranged from 4.21 to 4.78 mg•L -1 . Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg•L -1 , respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.
Separation and Purification Technology, Sep 1, 2016
Carbonate ions in wastewater can interfere with the reactions in advanced oxidation processes. In... more Carbonate ions in wastewater can interfere with the reactions in advanced oxidation processes. In the present study, the effects of carbonate ions on the degradation of a polyazo direct dye, the Sirius Ò Red F3B (SRF3B), using persulfate (PS) oxidation catalyzed by Fe 0 aggregates (PS/Fe 0 ) was investigated. Results of this study indicated that the oxidation power of the PS/Fe 0 process was inhibited in the dye solutions containing carbonates, and the efficiency of SRF3B decolorization decreased with increasing concentration of Na 2 CO 3 . A short period of ultrasound (US) irradiation can significantly enhance the destruction of dye molecules. Complete decolorization of a 25 mg/L SRF3B solution containing 1 Â 10 À3 M carbonate, 5 Â 10 À3 M PS, and 1.5 g/L Fe 0 was achieved within 5 min in a PS/Fe 0 /US system augmented with 5 min of US irradiation (60 kHz, 106 W/cm 2 ). The operating cost to complete removal of the dye was estimated at 2.79 USD/m 3 . Higher PS dosage and US power further minimized the interference from carbonate ions. A two-step reaction model, including a slow surface heterogeneous and a fast homogeneous aqueous reactions was proposed for the system. The presence of Fe 2+ and Fe 3+ ions identified using X-ray photoelectron spectroscopy, suggests a direct oxidation of the dye on the surface of the Fe 0 aggregates.
Environmental Science and Pollution Research, Aug 31, 2019
Environmental Engineering and Management Journal, 2015
This study investigated the use of tea waste to decolorize refractory dyestuff from textile waste... more This study investigated the use of tea waste to decolorize refractory dyestuff from textile wastewater. The influence of the solution pH and the contacting time were examined for various adsorbents, namely green tea-leaf powder (GTP), black tea-leaf powder (BTP), and powdered activated carbon (PAC). Results from batch experiments revealed that the reduction in true color (ADMI) increases with decreasing pH. The ADMI reduced from 1106 to 150 with 0.8 g/L of GTP at pH 2. The results also showed following ADMI removal efficiency order: GTP > PAC >> BTP. The active functional groups of the tea wastes involved in the adsorptive decoloration of tea waste were the hydroxyl, amine, carboxyl stretching, and C-O groups. The work carried out has revealed that green tea waste has a high potential to be used as an economically viable adsorbent to remove true color from textile effluents.
Electrokinetic (EK) remediation coupled with activated carbon barrier was evaluated to remove nic... more Electrokinetic (EK) remediation coupled with activated carbon barrier was evaluated to remove nickel (500 mg/kg) from kaolinite. Laboratory experiments were performed by applying a constant voltage to create electric field strength of 1 or 1.25 V/cm for 3 days. Findings showed that the barrier filled with activated carbon could prevent the formation of reverse electro-osmotic flow, which had an adverse effect on the Ni(II) removal. Application of activated carbon barrier into EK process resulted in an increase of Ni migration from 11 to 47%.
Sustainability, 2017
4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major poly... more 4-Dibromodiphenyl ether (BDE-3) and 4,4 -dibromodiphenyl ether (BDE-15) are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam-washed black tea, green tea, and coconut palm leaf powders were 21.85 mg•L -1 , 14.56 mg•L -1 and 22.47 mg•L -1 , respectively. The results also showed that the adsorption equilibrium (q e ) was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k 2 ) of all pressure steam-washed adsorbents ranged from 8.16 × 10 -3 to 6.61 × 10 -2 g•(mg•L -1 ) -1 •s -1 , and the amount adsorbed at q e by all pressure steam-washed adsorbents ranged from 4.21 to 4.78 mg•L -1 . Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg•L -1 , respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.
Journal of Chemical & Engineering Data, 2011
The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern ... more The presence of nickel in aquatic systems due to discharge of industrial effluents is of concern because of its toxic and nonbiodegradable nature. Its removal from water and wastewater is mandatory. Though activated carbon has been effective in removing metallic species including nickel from water and effluents, its high cost limits its large scale application to developing nations. The present paper addresses the removal of nickel from aqueous solutions by alumina nano particles. The adsorbent, nano alumina powder, was synthesized in the laboratory and was characterized by X-ray diffractometry (XRD), Fourier transformation infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The BET surface area and porosity of nanosized alumina powder were found to be 78.79 m 2 g À1 and 0.51, respectively. The initial concentration of nickel, agitation speed, and contact time were found to affect the removal of nickel from aqueous solutions. Kinetic studies were performed and pseudofirst order, second order, intraparticle diffusion, and mass transfer studies were carried out. The equilibrium data were analyzed by various isotherms viz. Langmuir, Freundlich, DubininÀRadushkevich, and Temkin and Pyzhev isotherms. Results of the present study revealed that nano particles of alumina powder can be used for a large scale treatment of water containing Ni(II) in particular and that of pollutant species in general.
Adsorption of a cationic dye, methylene blue, on to chitosan hydrogel beads generated by anionic surfactant gelation
Environmental Technology, 2011
Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the ... more Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the removal of a cationic dye, methylene blue (MB), from aqueous solutions. The adsorption capacity of chitosan beads (CB) formed by alkali gelation was low because of charge repulsions between the chitosan (CS) and the MB. The adsorption capacity of CSB (4 g/L SDS gelation) for MB (100 mg/L) was 129.44 mg/g, and it decreased significantly with increasing SDS concentration during gelation. This decrease was a result of increased density of the CSB membrane materials. The CSB membrane materials formed with the 4 g/L SDS gelation showed the highest volumetric adsorption capacity. The MB adsorption on to CB and CSB increased with increasing values for the initial pH of solution. Data from both CB and CSB showed good fit to Sips isotherm models, and the maximum adsorption capacity of CSB (226.24 mg/g) was higher than that of CB (99.01 mg/g).
Environmental Science and Pollution Research, Nov 16, 2021
This special issue (SI) of Environmental Science and Pollution Research (ESPR) entitled "Water En... more This special issue (SI) of Environmental Science and Pollution Research (ESPR) entitled "Water Environment and Recent Advances in Pollution Control Technologies" collected the best papers that were formally presented at "The 6 th International Conference on Water Resource and Environment (WRE2020)" from August 23rd to 26th, 2020. The WRE2020 conference was a great success with 137 participants from 27 countries; three keynote speeches delivered by Prof. Jun Xia, Prof. Zhongbo Yu, and Prof. Chih-Huang Weng; 53 oral presentation papers; and 9 poster presentation papers. The conference themes covered various aspects of water environment, environmental science, and pollution control technologies, including, but not limited to, water resources, water quality, pollution control, groundwater issues, water and wastewater treatment technologies, wetland system, climate changes adaptation and mitigation strategies, ecological environments, waste utilization, and flood risk management and impact assessment. The WRE conference aims to provide a forum for scientific professionals and specialists to exchange the up-to-date knowledge relating to water resources and environmental issues, specifically focusing on understanding the issue of indispensable water resources in achieving a sustainable manner and targeting advanced vital technologies to protect the fragile water environments under the growing concern of intensive water usage that we are facing today (Weng 2020). Due to the outbreak of the COVID-19 pandemic, the WRE 2020 stopped being held in Tokyo as initially scheduled and transitioned online via virtual presentations.
Adsorption Characteristics of Cu(II) Onto Spent Pineapple Leaves
Regeneration of granular activated carbon by an electrochemical process
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
Removal of Nickel(II) from Dilute Aqueous Solution by Sludge-Ash
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. ...