Browsing by Author "Chung, YC"

Now showing 1 - 20 of 24

Adsorption of Cu(II) and Ni(II) by pelletized biopolymer
(1996-02-01)
Huang, CP
;
Chung, YC
;
Liou, MR
;
交大名義發表
;
環境工程研究所
Chitosan and Ca-alginate, derivatives of biopolymer, were separately prepared from crab chitin and algin in pellet form for adsorption of Cu(II) and Ni(II) from aqueous solutions. The capability of these biopolymers was also investigated to remove copper and nickel from aqueous solutions in an immobilization system, along with a comparison made of these biopolymers with other adsorbents. Additionally, the feasibility of alginate/chitosan in pellets to remove nickel ion and nickel cyanide complex from polluted water was investigated. Stabilizing chitosan physically in an alginate support medium was deemed possible, by means of which both free metal and metal cyanide ions could be removed from aqueous solutions in an engineering system. However, the crosslinking reaction during immobilization would result in blocking of some adsorption sites.
Biodegradation of hydrogen sulfide by a laboratory-scale immobilized Pseudomonas putida CH11 biofilter
(1996-11-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
A heterotrophic Pseudomonas putida CH11 was isolated from livestock farming wastewater and applied for the treatment of H2S-containing gas. Extensive tests including removal characteristics, metabolic products, and removal efficiencies of H2S by P. putida CH11 were examined in batch and continuous systems. The optimum pH required to remove hydrogen sulfide was found in the range of 6-8. The maximum removal rate and the saturation constant were calculated to be V-m=1.36 g S/day . kg dry bead and K-s=45.9 ppm, respectively. The main metabolic product of H2S oxidation was determined to be elemental sulfur. When P. putida CH11 was immobilized within Ca alginate, the cells exhibited high H2S removal efficiency, in excess of 96%, at concentrations of hydrogen sulfide from 10 to 150 ppm (now rates of 36 and 72 L/h). These results suggest that P. putida CH11 immobilized within Ca alginate has the potential to be used as a H2S removal agent.
Biological elimination of H2S and NH3 from wastegases by biofilter packed with immobilized heterotrophic bacteria
(2001-06-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
Biotreatment of various ratios of H2S and NH3 gas mixtures was studied using the biofilters, packed with co-immobilized cells (Arthrobacter oxydans CH8 for NH3 and Pseudomonas putida CH11 for H2S). Extensive tests to determine removal characteristics, removal efficiency, removal kinetics, and pressure drops of the biofilters were performed. To estimate the largest allowable inlet concentration, a prediction model was also employed. Greater than 95% and 90% removal efficiencies were observed for NH3 and H2S, respectively, irrespective of the ratios of H2S and NH3 gas mixtures. The results showed that H2S removal of the biofilter was significantly affected by high inlet concentrations of H2S and NH3. As high H2S concentration was an inhibitory substrate for the growth of heterotrophic sulfur-oxidizing bacteria, the activity of H2S oxidation was thus inhibited. In the case of high NH3 concentration, the poor H2S removal efficiency might be attributed to the acidification of the biofilter. The phenomenon was caused by acidic metabolite accumulation of NH3. Through kinetic analysis, the presence of NH3 did not hinder the NH3 removal, but a high H2S concentration would result in low removal efficiency, Conversely, H2S of adequate concentrations would favor the removal of incoming NH3. The results also indicated that maximum inlet concentrations (model-estimated) agreed well with the experimental values for space velocities of 50-150 h(-1). Hence, the results would be used as the guideline for the design and operation of biofilters. (C) 2001 Elsevier Science Ltd. All rights reserved.
Biotreatment of ammonia from air by an immobilized Arthrobacter oxydans CH8 biofilter
(1997-11-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
A heterotrophic Arthrobacter oxydans CH8 that was capable of removing NH3 from NH3 containing gas was isolated from livestock farming wastewater. The A. oxydans CH8 was immobilized with calcium alginate packed into filter column. Metered NH3-containing gas was partially humidified and passed through the glass column. Extensive tests including the removal characteristics, the removal efficiencies, and the metabolic products of NH3 by A. oxydans CH8 were conducted. Additionally, the operation criteria for the biofilter was also established. NH3 removal capacities were elevated by the immobilized-cell (biological conversion) method and the BDST (bed depth service time) method (physical adsorption), respectively. The optimum temperature for removing NH3 was 30 degrees C, while the nitrification ability remained 80% at 40 degrees C. The high efficiency (>97%) in the removal of NH3 was attained at 36 L/h with pH control and was not decreased because of high NH3 inlet concentration. In addition, the high maximum removal rate (1.22 g of N/day.(kg of bead)) enhanced the use of the biofilter in industrial-scale NH3(g) pollution control. The ability to remove NH3 at high inlet concentration and temperature suggested that the immobilized A. oxydans CH8 biofilter has potential in processing NH3 gas.
Biotreatment of ammonia from air by an immobilized Arthrobacter oxydans CH8 biofilter
(1997-11-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
A heterotrophic Arthrobacter oxydans CH8 that was capable of removing NH3 from NH3 containing gas was isolated from livestock farming wastewater. The A. oxydans CH8 was immobilized with calcium alginate packed into filter column. Metered NH3-containing gas was partially humidified and passed through the glass column. Extensive tests including the removal characteristics, the removal efficiencies, and the metabolic products of NH3 by A. oxydans CH8 were conducted. Additionally, the operation criteria for the biofilter was also established. NH3 removal capacities were elevated by the immobilized-cell (biological conversion) method and the BDST (bed depth service time) method (physical adsorption), respectively. The optimum temperature for removing NH3 was 30 degrees C, while the nitrification ability remained 80% at 40 degrees C. The high efficiency (>97%) in the removal of NH3 was attained at 36 L/h with pH control and was not decreased because of high NH3 inlet concentration. In addition, the high maximum removal rate (1.22 g of N/day.(kg of bead)) enhanced the use of the biofilter in industrial-scale NH3(g) pollution control. The ability to remove NH3 at high inlet concentration and temperature suggested that the immobilized A. oxydans CH8 biofilter has potential in processing NH3 gas.
Biotreatment of ammonia in air by an immobilized Nitrosomonas europaea biofilter
(1998-06-01)
Chung, YC
;
Huang, CP
;
環境工程研究所
;
Institute of Environmental Engineering
The chemoautotrophic microorganism Nitrosomonas europaea has been utilized to remove gaseous ammonia in a continuous reactor Extensive tests including removal characteristics, metabolic products, and removal efficiencies of ammonia by N. europaea were conducted. The operational principles governing the biofilter and the question of the heterotroph contamination were also studied. The optimum pH value and operating temperature required to effectively remove ammonia were-found to be pH 7.5 and 30 degrees C, respectively. When the diluted inlet ammonia concentration was 10 or 20 ppm, the biofilter achieved a 99% removal efficiency after 4 days of operation. However, higher ammonia inlet concentrations and heterotroph contamination resulted in a lower removal efficiency. The results showed that the maximum removal rate and apparent saturation constant were 1.11 g-N/day/kg-bead and 63.67 ppm, respectively. The mainly metabolic product of ammonia oxidation was determined to be nitrite, but the conversion ratio was dependent on whether the contaminations by hererotrophic bacteria were present. A om an operating perspective, if the ammonia emission limit (i.e., 1 ppm) was to be achieved the maximum inlet concentration could not exceed 75 ppm. These results suggest that the immobilized Nitrosomonas europaea biofilter provides a significant potential for treating ammonia In the gaseous phase.
Biotreatment of H2S- and NH3-containing waste gases by co-immobilized cells biofilter
(2000-08-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
Pan, JR
;
環境工程研究所
Gas mixture of H2S and NH3 in this study has been the focus in the research area concerning gases generated from the animal husbandry and the anaerobic wastewater lagoons used for their treatment. A specific microflora (mixture of Thiobacillus thioparus CH11 for H2S and Nitrosomonas europaea for NH3) was immobilized with Ca-alginate and packed inside a glass column to decompose H2S and NH3. The biofilter packed with co-immobilized cells was continuously supplied with H2S and NH3 gas mixtures of various ratios, and the removal efficiency, removal kinetics, and pressure drop in the biofilter was monitored. The results showed that the efficiency remained above 95% regardless of the ratios of H2S and NH3 used. The NH3 concentration has little effect on H2S removal efficiency, however, both high NH3 and H2S concentrations significantly suppress the NH3 removal. Through product analysis, we found that controlling the inlet ratio of the H2S/NH3 could prevent the biofilter from acidification, and, therefore, enhance the operational stability. Conclusions from bioaerosol analysis and pressure drop in the biofilter suggest that the immobilized cell technique creates less environmental impact and improves pure culture operational stability. The criteria for the biofilter operation to meet the current H2S and NH3 emission standards were also established. To reach Taiwan's current ambient air standards of H2S and NH3 (0.1 and 1 ppm, respectively), the maximum inlet concentrations should not exceed 58 ppm for H2S and 164 ppm for NH3, and the residence time be kept at 72 s. (C) 2000 Elsevier Science Ltd. All rights reserved.
Biotreatment of hydrogen sulfide- and ammonia-containing waste gases by fluidized bed bioreactor
(2001-02-01)
Chung, YC
;
Huang, CP
;
Liu, CH
;
Bai, HL
;
環境工程研究所
Gas mixtures of H2S and NH3 are the focus of this study of research concerning gases generated from animal husbandry and treatments of anaerobic wastewater lagoons. A heterotrophic microflora (a mixture of Pseudomonas putida for H2S and Arthrobacter oxydans for NH3) was immobilized with Ca-alginate and packed into a fluidized bed reactor to simultaneously decompose H2S and NH3. This bioreactor was continuously supplied with H2S and NH3 separately or together at various ratios. The removal efficiency, removal rate, and metabolic product of the bioreactor were studied. The results showed that the efficiency remained above 95% when the inlet H2S concentration was below 30 ppm at 36 L/hr. Furthermore, the apparent maximum removal and the apparent half-saturation constant were 7.0 x 10(-8) gS/cell/day and 76.2 ppm, respectively, in this study. The element sulfur as a main product prevented acidification of the biofilter, which maintained the stability of the operation. As for NH3, the greater than 90% removal rate was achieved as long as the inlet concentration was controlled below 100 ppm at a flow rate of 27 L/hr. In the NH3 inlet, the apparent maximum removal and the apparent half-saturation constant were 1.88 x 10(-6) g-N/cell/day and 30.5 ppm, respectively. Kinetic analysis showed that 60 ppm of NH3 significantly suppressed the H2S removal by Pseudomonas putida, but H2S in the range of 5-60 ppm did not affect NH3 removal by Arthrobacter oxydans. Results from bioaerosol analysis in the bioreactor suggest that the co-immobilized cell technique applied for gas removal creates less environmental impact.
Comparison of autotrophic and mixotrophic biofilters for H2S removal
(1998-04-01)
Chung, YC
;
Huang, CP
;
Pan, JR
;
Tseng, CP
;
環境工程研究所
We demonstrate that the facultative chemoautotroph Thiobacillus novellus CH3 removes hydrogen sulfide (H2S) gas in continuous reactors under nutrient-limiting conditions. Extensive tests including removal characteristics, metabolic products, and removal efficiencies of H2S by T. novellus CH3 were conducted in autotrophic and mixotrophic environments. The optimal pH value and temperature required to remove hydrogen sulfide are found to be pH 7 and 26 degrees C. The biofilter had an H2S removal efficiency greater than 99.5% under the mixotrophic condition after l0-day operation. The results show that the maximum removal rate and saturation constant were 1.9 g S/d per kg bead and 69.2 ppm, respectively. The main metabolic product of H2S oxidation was determined to be sulfate, but the conversion ratio was dependent on the growth environment. These results suggest that the mixotrophic potential of T. novellus CH3 biofilter provides a significant advantage in HS removal over autotrophic biofilters.
Control of H2S waste gas emissions with a biological activated carbon filter
(2004-06-01)
Chung, YC
;
Lin, YY
;
Tseng, CP
;
生物科技學系
;
Department of Biological Science and Technology
The removal of high concentrations of H2S from waste gases containing mixtures of H2S and NH3 was studied using the pilot-scale biofilter. Granular activated carbon (GAC), selected as support material in this study, demonstrated its high adsorption capacity for H2S and good gas distribution. Extensive tests to determine removal characteristics, removal efficiency, and removal capacity of high H2S levels and coexisting NH3 in the system were performed. In seeking the appropriate operating conditions, the response surface methodology (RSM) was employed. H2S removal capacities were evaluated by the inoculated bacteria (biological conversion) and BDST (Bed Depth Service Time) methods (physical adsorption). An average 98% removal efficiency for 0.083-0.167 mg dm(-3) of H2S and 0.004-0.021 mg dm(-3) of NH3 gases was achieved during the operational period because of rapid physical adsorption by GAC and subsequently an effective biological regeneration of GAC by inoculated Pseudomonas putida CH11 and Arthrobacter oxydans CH8. The results showed that H2S removal efficiency for the system was not affected by inlet NH3 concentrations. In addition, no acidification was observed in the BAC biofilter. High buffer capacity and low moisture demand were also advantages of this system. The maximal inlet loading and critical loading for the system were 18.9 and 7.7 g-H2S m(-3) h(-1), respectively. The results of this study could be used as a guide for the further design and operation of industrial-scale systems. (C) 2004 Society of Chemical Industry.
Evaluation of a modified chitosan biopolymer for coagulation of colloidal particles
(1999-02-15)
Pan, JRS
;
Huang, CP
;
Chen, SC
;
Chung, YC
;
環境工程研究所
Chitosan, a deacetylated derivative of chitin, is a biodegradable cationic polymer. Chitosan can be a potential substitute for aluminum salts and synthetic polyelectrolytes in water treatment because it can: (1) avoid the health effects from residual aluminum (III) and synthetic polymers; (2) produce biodegradable sludge; and (3) reuse the crab shell. Chitosan can be modified with various pretreatments including dissolution in acid solution and various deacetylation conditions to improve its coagulation efficiency. In this study, coagulations of synthetic and real water with the modified chitosan, mixed coagulant of chitosan and PACl at various ratios, and PACl were compared. The efficiency was evaluated by the factors of settling rate, hoc diameter, and residual turbidity. Coagulation with chitosan alone required least dosage. Chitosan coagulants also produced larger flee with higher settling velocity. Satisfactory results were obtained from the mixed coagulant of chitosan/PACl = 4:1. Although low pH decreased the optimal dosage, the flocs produced were smaller with slower settling rate. Increasing the rapid mixing strength improved the coagulation only when the applied dosage was less than the optimum dosage. Studies using other particles such as kaolinite and clay indicate that the properties of particles have a significant effect on the chitosan coagulation efficiency. (C) 1999 Elsevier Science B.V. All rights reserved.
Evaluation of immunomagnetic separation method for detection of Giardia for different reaction times and reaction volumes
(2001-06-01)
Hsu, BM
;
Huang, CP
;
Lai, YC
;
Tai, HS
;
Chung, YC
Immunomagnetic separation (IMS) has been specified as a standard method for the measurement of Giardia. In this study, Dynal IMS was evaluated on the basis of recovery efficiencies of Giardia cysts for various IMS operational conditions. The average recoveries for Giardia in deionized, treated and raw water samples were 82.6 +/- 12.2% (n = 6), 75.6 +/- 15.2% (n=3), and 70.6 +/- 18.2% (n = 3), respectively. Significant changes in recovery were observed by altering the debris ratio and the debris components of water samples. Changing the reaction volume within the same vessel had no significant effect on cyst recovery efficiencies. However, prolonging the reaction time did increase recovery efficiencies.
Feasibility of fluidized-bed bioreactor for remediating waste gas containing H2S or NH3
(2001)
Chung, YC
;
Liu, CH
;
Huang, CP
;
環境工程研究所
;
Institute of Environmental Engineering
Pseudomonas putida for H2S and Arthrobacter oxydans for NH3 were immobilized with Ca-alginate and packed inside glass columns to form fluidized-bed bioreactors. The feasibility of the lab-scale bioreactor for the treatment of H2S or NH3 was examined. Phosphate salt, being added to the nutrient solution as buffer solution, may chelate with Ca2+ in the Ca-alginate beads, resulting in the disintegration of gel structure. When the buffer capacity of the phosphate solution was over the critical point of 33.5 mM/pH, all calcium ions in the bead were released and beads were broken. Increasing liquid flowrate and inlet gas concentration favored to H2S and NH3 removal. Carbon source addition was essential and Facilitated malodorous removal for this system. Removal capacity increased with inlet concentration. However, increasing pattern was dependent of H2S or NH3. The result clearly indicated that bioreactor was suitable to be applied for the industry of livestock farm for removing wastegas containing H2S or NH3.
Hydrogen sulfide gas treatment by a chemical-biological process: Chemical absorption and biological oxidation steps
(2003)
Chung, YC
;
Ho, KL
;
Tseng, CP
;
生物科技學系
;
Department of Biological Science and Technology
In order to remove high concentrations of hydrogen sulfide (H2S) gas from anaerobic wastewater treatments in livestock farming, a novel process was evaluated for H2S gas abatement involving the combination of chemical absorption and biological oxidation processes. In this study, the extensive experiments evaluating the removal efficiency, capacity, and removal characteristics, of H2S gas by the chemical absorption reactor were conducted in a continuous operation. In addition, the effects of initial Fe2+, concentrations, pH, and glucose concentrations on Fe2+ oxidation by Thiobacillus ferrooxidans CP9 were also examined. The results showed that the chemical process exhibited high removal efficiencies with H2S concentrations up to 300 ppm, and nearly no acclimation time was required. The limitation of mass-transfer was verified as the rate-determining step in the chemical reaction through model validation. The Fe2+ production rate was clearly affected by the inlet gas concentration as well as flow rate and a prediction equation of ferrous production was established. The optimal operating conditions for the biological oxidation process were below pH 2.3 and 35degreesC in which more than 90% Fe3+ formation ratio was achieved. Interestingly, the optimal glucose concentration in the medium was 0.1%, which favored Fe2+ oxidation and the growth of T ferrooxidans CP9.
Hydrogen sulfide removal by immobilized autotrophic and heterotrophic bacteria in the bioreactors
(1996-08-01)
Huang, CP
;
Chung, YC
;
Hsu, BM
;
交大名義發表
;
環境工程研究所
Autotrophic Thiobacillus sp. CH11 and heterotrophic Pseudomonas putida CH11 were isolated from piggery waste water. Extensive tests, including removal action, removal efficiency, removal capacity, and adaptability to perturbed conditions were conducted on autotrophic and heterotrophic biofilters. The results clearly demonstrate the application potential of autotrophic and heterotrophic biofilters for the continuous H2S removal under different perturbed conditions.
Kinetics of hydrogen sulfide oxidation by immobilized autotrophic and heterotrophic bacteria in bioreactors
(1996-10-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
The kinetics of H2S oxidation in bioreactors with separately packed autotrophic Thiobacillus thioparus CH11 and heterotrophic Pseudomonas putida CH11 were evaluated. The reaction rates were determined to be first-order below 20 ppm, zero-order above 60 ppm, and fractional-order in the intermediate concentration ranges for the Thiobacillus thioparus CH11 bioreactor, the first-order below 35 ppm, zero-order above 80 ppm, and fractional-order in the intermediate concentration ranges for the Pseudomonas putida CH11 bioreactor. The saturation constants for H2S by Thiobacillus thioparus CH11 and Pseudomonas putida CH11 were calculated to be 30.3 ppm and 44.2 ppm, respectively.
Kinetics of hydrogen sulfide oxidation by immobilized autotrophic and heterotrophic bacteria in bioreactors
(1996-10-01)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
The kinetics of H2S oxidation in bioreactors with separately packed autotrophic Thiobacillus thioparus CH11 and heterotrophic Pseudomonas putida CH11 were evaluated. The reaction rates were determined to be first-order below 20 ppm, zero-order above 60 ppm, and fractional-order in the intermediate concentration ranges for the Thiobacillus thioparus CH11 bioreactor, the first-order below 35 ppm, zero-order above 80 ppm, and fractional-order in the intermediate concentration ranges for the Pseudomonas putida CH11 bioreactor. The saturation constants for H2S by Thiobacillus thioparus CH11 and Pseudomonas putida CH11 were calculated to be 30.3 ppm and 44.2 ppm, respectively.
Microbial oxidation of hydrogen sulfide with biofilter
(1996)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
A heterotrophic Pseudomonas putida CH11, isolated from the pig feces and wastewater, was immobilized with Ca-alginate to provide as a packing material in a novel and practical biofilter system for the control of hydrogen sulfide. Extensive tests have been conducted to evaluate the effect of the operating parameters such as temperature, retention time, and gas concentration on the removal efficiency of hydrogen sulfide. The criterion for a scale-up design of biofilter was established. The high removal efficiencies of hydrogen sulfide were observed in the initial hours from the history of removal efficiency and a satisfactory level of removal efficiency could maintain for one week at least. The maximum inlet loading in the linear region was found to be 1.9 g-S/d . kg dry bead. At economically viable retention time of 28 seconds, the biofilter could reduce over 97% hydrogen sulfide. The results suggested that the Pseudomonas putida CH11 immobilized with Ca-alginate could be a potential method to remove hydrogen sulfide.
Operation optimization of Thiobacillus thioparus CH11 biofilter for hydrogen sulfide removal
(1996-11-29)
Chung, YC
;
Huang, CP
;
Tseng, CP
;
環境工程研究所
;
生物科技學系
Members of the autotrophic species, Thiobacillus thioparus CH11, were isolated from swine wastewater and immobilized with Ca-alginate to produce pellet packing materials for a novel biofilter system that controls hydrogen sulfide emission. The effect of operating parameters, including retention time, temperature, and inlet gas concentration, on the removal efficiency and capacity was evaluated. Criteria necessary for a scale-up design of the biofilter were established and the sulfur balances at various loadings were tabulated. High and satisfactory H2S removal efficiency levels were maintained during operation and the optimal retention time was found to be 28 a corresponding to a H2S removal efficiency greater than 98%. The pH drop was insignificant in this biofilter. The optimal inlet S-loading can be noted as 25 g m(-3) h(-1) that is at the upper end of linear correlation between inlet loading and removal capacity. We suggest that the Thiobacillus thioparus CH11 immobilized with Ca-alginate is a potent method to control hydrogen sulfide emissions. Copyright (C) 1996 Elsevier Science B.V.
Operational characteristics of effective removal of H2S and NH3 waste gases by activated carbon biofilter
(2004-04-01)
Chung, YC
;
Lin, YY
;
Tseng, CP
;
生物科技學系
;
Department of Biological Science and Technology
Simultaneous removal of hydrogen sulfide (H,S) and ammonia (NH3) gases from gaseous streams was studied in a biofilter packed with granule activated carbon. Extensive studies, including the effects of carbon (C) source on the growth of inoculated microorganisms and gas removal efficiency, product analysis, bioaerosol emission, pressure drop, and cost evaluation, were conducted. The results indicated that molasses was a potential C source for inoculated cell growth that resulted in removal efficiencies of 99.5% for H2S and 99.2% for NH3. Microbial community observation by scanning electron microscopy indicated that granule activated carbon was an excellent support for microorganism attachment for long-term waste gas treatment. No disintegration or breakdown of biofilm was found when the system was operated for 140 days. The low bioaerosol concentration emitted from the biofilter showed that the system effectively avoided the environmental risk of bioaerosol emission. Also, the system is suitable to apply in the field because of its low pressure drop and treatment cost. Because NH3 gas was mainly converted to organic nitrogen, and H2S gas was converted to elemental sulfur, no acidification or alkalinity phenomena were found because of the metabolite products. Thus, the results of this study demonstrate that the biofilter is a feasible bioreactor in the removal of waste gases.