Browsing by Author "Ma, YS"

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Alkaline hydrolysis of the sludge generated from a high-strength, nitrogenous-wastewater biological-treatment process
(1998-07-01)
Lin, JG
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Ma, YS
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Huang, CC
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環境工程研究所
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Institute of Environmental Engineering
The production of acrylonitrile butadiene styrene (ABS, a petrochemical product) in Taiwan is one of the biggest manufactoring processes in the world. The large amount of ABS sludge generated in the wastewater treatment plant from the highly nitrogenous-wastewater contains significant amount of complex and biorefractory organic substances. Resource recovery is the optimal conception of the traditional sludge treatment for the purpose of organic matters removal. An alkaline pretreatment method is used to enhance the efficiency of biological hydrolysis of industrial wastewater sludge in the present study. The operating conditions for the alkaline pretreatment of the ABS sludge were maintained at room temperature (25+/-3 degrees C), reaction time of 24h, total solids in the feed of 0.5-2%, and NaOH dosages of 10-50 mg l(-1). Considering the increasing concentrations of soluble chemical oxygen demand and biochemical oxygen demand, the experimental results indicated that the alkaline pretreatment method was useful in biodegradability enhancement. (C) 1998 Elsevier Science I;tn. All rights reserved.
BMP test on chemically pretreated sludge
(1999-05-01)
Lin, JG
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Ma, YS
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Chao, AC
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Huang, CL
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環境工程研究所
Municipal waste activated sludge (WAS) was treated with NaOH to solubilize the particulate organic matter in order to improve its digestibility when the sludge was stabilized in an anaerobic digestion process. For the WAS of 1% TS treated with 20 and 40 meq/l NaOH at ambient temperature for 24 h, the SCOD/TCOD values increased from 3.5 to 39 and 55%, respectively. Results of the BMP (biochemical methane potential) test showed that recoveries of carbon and nitrogen reached 94-105% and the methane produced was 349 ml (at 1 atm and 35 degrees C) for 1 g of COD removed. The improvement in VS removal for sludge treated with 40 meq/l of NaOH was as high as 41% over the control sludge sample, with COD removal and gas production improved by 30 and 34%, respectively, over the control. Results of the cumulative COD removal appeared to follow first-order reaction kinetics. Parameters of the first-order model such as ultimate biodegradable COD (L-u), reaction rate coefficient (k) and ultimate biodegradability (mu), were calculated using the Thomas method. The BMP test can be used as a valuable tool to study the kinetics and efficiency of anaerobic digestion processes. (C) 1998 Elsevier Science Ltd. All rights reserved.
Degradation of 4-nitrophenol using the Fenton process
(2000)
Ma, YS
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Huang, ST
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Lin, JG
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環境工程研究所
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Institute of Environmental Engineering
In this study, The Fenton process was applied as a pretreatment method to treat industrial wastewater containing 4-nitrophenol (4-NP). The effect of oxidant dosages on the decomposition of 4-NP and the reaction kinetics were investigated. More than 99% of 4-NP was readily decomposed when the reaction was carried out at oxidant concentrations of 5 mM H2O2 and 5 mg/L Fe2+ for 2 hours. The total nitrogenous compounds and the nitrogen gas evolved, accounted for 88% of the initial nitrogen concentration. However, the maximum DOC removal efficiency was 30.6%; and only 1/3 of 4-NP was mineralized to carbon dioxide by the Fenton process. 4-NP degradation profiles fitted well into a pseudo first-order kinetic equation; degradation rate constant (min(-1)) of 4-NP increased from 4.3x10(-3) to 66.1x10(-3) With increasing dosages of H2O2 and Fe2+. In addition, the t value was calculated for studying the significance of simulation by the t-test. It was found that the t value was greater than the value for 99% confidence. This result suggested that the 4-NP decomposition profile could be described by the pseudo first-order kinetic equation. Biodegradability of 4-NP before and after the reaction was 0.018 and 0.594, respectively.
Effect of pre-sonication on removal of organic matters resulting from chlorinated humic acids
(1998)
Ma, YS
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Lin, JG
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環境工程研究所
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Institute of Environmental Engineering
Humic acids are amorphous organic macromolecules that are responsible for the color of natural water. They play an important role in the formation of disinfection by-products, the stabilization of wastewater sludge, and the treatment of wastewater. An ultrasonic process is applied as a pretreatment method for the purpose of reducing the risk of chlorinated by-products. Experimental results indicate that the initial pH, ionic strength, and chlorine demand affect the amount of total organic carbon removal and Cl-2 consumption significantly. The formation of chlorinated by-products depends on both the initial pH and ionic strength. Experimental results also propose a good agreement that the humic acid can be removed efficiently by ultrasonic pretreatment under aerobic conditions. In this study, when the ultrasound/O-2 process is used as a pretreatment method, the biodegradability which is defined as the formation bf BOD5 increases with sonication time. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
Efficiency evaluation of PTA wastewater treatment with the ultrasound/H2O2 process
(1997)
Liu, CH
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Ma, YS
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Lin, JG
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交大名義發表
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環境工程研究所
In this study, we used the ultrasound/hydrogen peroxide (H2O2) process to treat the pure terephaltic acid (PTA) industrial wastewater. The BOD5 and TOC of raw PTA wastewater were 13,200 and 6,390 mg/L, respectively. Several semi-and non-volatile organics, such as benzoic acid, 4-methyl benzaldehyde, phenyl acetic acid, and 4-ethyl benzoic acid were detected in PTA wastewater by GCD (HP GCD 1800A). In the present paper, we discussed the effect of ultrasound/H2O2 process with various concentrations of H2O2 and pH values on mineralization and biodegradability of PTA wastewater. Mineralization of PTA wastewater was evaluated by the ratio of TOC removal and biodegradability by real residual BOD5 over theoretical residual BOD5. The results show that the lower the initial pH value and the higher the concentration of H2O2, the higher ratio of mineralization was found. During the reaction time, the ORP value at pH 3 was greater than at pH 7 and 11. The pH value affected ORP value more significantly than H2O2 dosage in this work. The biodegradability increased with the amount of TOC removal by ultrasound/H2O2 process but decreased with the amount of TOC removal by ultrasound only. The optimum condition to pretreat PTA wastewater with ultrasound/H2O2 process before biological treatment was pH 3 and H2O2 200 mg/L. However, when ultrasound/H2O2 process was used as a sole treatment without biological treatment, the optimum pH value was also controlled at 3, but the concentration of H2O2 must increase upto 500 mg/L. Under such conditions, the ratio of mineralization was 70%.
Enhancement of decomposition of 2-chlorophenol with ultrasound/H2O2 process
(1996)
Lin, JG
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Chang, CN
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Wu, JR
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Ma, YS
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環境工程研究所
We investigated the effects of pH, ionic strength, catalyst, and initial concentration on both decomposition of 2-chlorophenol (2-cp) and removal of total organic carbon (TOC) in aqueous solution with ultrasonic amplitude 120 mu m and H2O2 (200 mg/l). When the initial concentrations of 2-cp was 100 mg/l and the pH was controlled at 3, the rate of 2-cp decomposition was enhanced up to 6.6-fold and TOC removal up td 9.8-fold over pH controlled at 11. At pH 3, the efficiency of decomposition of 2-cp was 99% but the removal of TOC was only 63%; a similar situation applied at pH 7 and 11. Hence intermediate compounds were produced and 2-cp was not completely mineralized. When the concentration of ionic strength was increased from 0.001 to 0.1 M, the rate of 2-cp decomposition was enhanced only 0.3-fold, whereas the TOC removal was not enhanced. In comparison of the effects of pH and ionic strength, pH had greater influence on both 2-cp decomposition and TOC removal than ionic strength. The effect of a catalyst (FeSO4) on decomposition of 2-cp was insignificant comparing with direct addition of H2O2 The reaction rate at a smaller initial concentration of 2-cp (10 mg/l) was more rapid than at a greater one (100 mg/l). The rate of 2-cp decomposition and TOC removal appeared to follow pseudo-first-order reaction kinetics. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.
Magnitude of effect of reaction parameters on 2-chlorophenol decomposition by ultrasonic process
(1999-05-14)
Lin, JG
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Ma, YS
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環境工程研究所
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Institute of Environmental Engineering
In the present work, decomposition of o-chlorophenol (2-cp) was carried out using an ultrasonic process. The extent of 2-cp decomposition depends on several parameters such as ultrasound wave energy (ultrasonic amplitude), addition of hydrogen peroxide (H2O2), pH value (H+ concentration), ionic strength, and initial concentration of 2-cp. The experimental results showed that the decomposition of 2-cp was affected by the various reaction conditions. The profiles of 2-cp decomposition fitted well with the first-order kinetic equation. A linear relationship was obtained between the rate constants of 2-cp decomposition and the varying reaction parameters. The magnitude of effect of reaction parameters such as ultrasonic amplitude, H+ concentration, ionic strength, H2O2 and 2-cp initial concentration on 2-cp decomposition were 0.60, 0,48, 0.19, 0.09 and -0.06, respectively. (C) 1999 Elsevier Science B.V. All rights reserved.
Oxidation of 2-chlorophenol in water by ultrasound/Fenton method
(2000-02-01)
Lin, JG
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Ma, YS
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環境工程研究所
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Institute of Environmental Engineering
One of the toxic and refractory pollutants formed during the color removal of fertilizer, chemical, and petroleum industrial effluents by chlorine is 2-chlorophenol (2-cp). The objective of this study is to investigate the effect of H2O2 and Fe2+ dosages on the decomposition of 2-cp using a coupled ultrasound/Fe2+/H2O2 process. The extent of 2-cp decomposition and mineralization depends on the dosages of H2O2 and Fe2+. More than 99% of 2-cp was decomposed and 86% of 2-cp was mineralized using the ultrasound/Fe2+/H2O2 process at Fe2+ of 10 mg/L and H2O2 of 500 mg/L. Oxidation-reduction potential (ORP) monitoring is a useful method for determining the decomposition efficiency of the target compound. There was a slight increase in the ORP values with increasing Fe2+ dosages, and an apparent increase with increasing H2O2 dosages was observed. The major intermediate formed during the decomposition of 2-cp was 2-chloro-p-benzoquinone. It was also readily decomposed using the coupled ultrasound/Fe2+/H2O2 process.