作者：
张悦王建龙李花子施汉昌竺建荣tate Key Joint Laboratory of Environment Simulation and Pollution Control
Department of Environmental Science and Engineering Tsinghua University Beijing 100084 tate Key Joint Laboratory of Environment Simulation and Pollution Control
Department of Environmental Science and Engineering Tsinghua University Beijing 100084 strain of yeast which can endure high osmotic pressure is employed for the sensitive material of the microbial BOD sensor. Two immobilization methods are used i.e. calcium alginate gel beads and PVA gel beads. The results show that the PVA gel beads is better. The influences of osmosis and heavy metal ions on the yeast entrapped in the PVA gel beads are also studied in the experiment.
A strain of yeast, which can endure high osmotic pressure, is employed for the sensitive material of the microbial BOD sensor. Two immobilization methods are used, I.e. Calcium alginate gel be ads and PV A gel beads. ...
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A strain of yeast, which can endure high osmotic pressure, is employed for the sensitive material of the microbial BOD sensor. Two immobilization methods are used, I.e. Calcium alginate gel be ads and PV A gel beads. The results show that the PVA gel beads is better. The influences of osmosis and heavy metal ions on the yeast entrapped in the PVA gel beads are also studied in the experiment.
In the present research, a submerged membrane bioreactor was tested to treat domestic wastewater. Three experimental runs were conducted all with a hydraulic retention time of 5h and sludge retention times (SRTs) of 5...
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In the present research, a submerged membrane bioreactor was tested to treat domestic wastewater. Three experimental runs were conducted all with a hydraulic retention time of 5h and sludge retention times (SRTs) of 5, 10, and 20 d. The pollutant removal performance of the membrane bioreactor, the membrane effluent quality, and a kinetic model for sludge growth in the bioreactor were investigated. The combined process was capable of removing over 90% of both COD (chemical oxygen demand) and NH 3 N on the average. The total removal for COD was almost independent of SRT, but that for NH 3 N improved with increasing SRT. Membrane effluent quality meets the water quality standard for reuse issued by the Ministry of Construction of China. Increasing SRT causes the concentrations of suspended solids (SS) and volatile suspended solids (VSS) in the bioreactor to increase. However, the ratio of VSS/SS did not change much. Kinetic analysis showed that the sludge yield coefficient (kg VSS·kg COD -1 ) and the endogenous coefficient of microorganisms were 0.25 and 0.04d -1 , which are similar to those of the conventional activated sludge process.
The adsorption behaviour of 4 chlorophenol from aqueous solution to activated sludge was quantitatively characterized in this paper. The effects of the initial pH values, initial chlorophenol concentration and adsorb...
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The adsorption behaviour of 4 chlorophenol from aqueous solution to activated sludge was quantitatively characterized in this paper. The effects of the initial pH values, initial chlorophenol concentration and adsorbent dosage on bioadsorption were investigated. The maximum adsorption capacity was found to be 110.5 mg/g at 100 mg/L initial concentration. The Freundlich and Langmuir adsorption isotherms were applied to describe the biosorption processes and the isotherm constants were evaluated.
With a review of advances in the high-order-accurate finite difference methods for fluid flow and heat transfer, the practical limitations of the existing methods are analyzed and the key evolution trends are noted. E...
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With a review of advances in the high-order-accurate finite difference methods for fluid flow and heat transfer, the practical limitations of the existing methods are analyzed and the key evolution trends are noted. Emphasis is put on the compact finite difference methods such as the optimal difference methods and perturbational difference methods developed recently. Some conclusions are finally given.
Microorganisms capable of degrading di-n-butyl phthalate (DBP) were immobilized by polyvinyl alcohol (PVA) and used for DBP degradation. The characteristics of DBP degradation by immobilized and free cells were invest...
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Microorganisms capable of degrading di-n-butyl phthalate (DBP) were immobilized by polyvinyl alcohol (PVA) and used for DBP degradation. The characteristics of DBP degradation by immobilized and free cells were investigated. The experimental results showed that the degradation rate of immobilized cells was higher than that of free cells. The optimal pH and temperature for DBP degradation were determined to be 7.0 and 25 degrees C, respectively. The semi-continuous degradation test demonstrated that high-frequency feeding of low concentration (50 mg/L) was more favourable than low-frequency feeding of high concentration (150 mg/L) for DBP degradation. The main intermediates of DBP degradation by immobilized cells were identified using a gas chromatography/mass spectrometry method. The results revealed the presence of monobutyl phthalate, phthalic acid, and protocatechuate. A tentative pathway for DBP degradation was proposed, which demonstrated that the metabolic mechanism of immobilized cells remained the same as that of the free cells. (C) 1997 Elsevier Science Ltd.
The biodegradation of di-n-butyl phthalate (DBP) in soil microcosoms by indigenous microbial population and a DBP degrading inoculum as well as DBP adsorption by soil was investigated. The results demonstrated that th...
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The biodegradation of di-n-butyl phthalate (DBP) in soil microcosoms by indigenous microbial population and a DBP degrading inoculum as well as DBP adsorption by soil was investigated. The results demonstrated that the adsorption of DBP by soil conformed to Freundlich equation. The indigenous bacteria were capable of degrading phthalate in soil. The innoculation of the soil with DBP degrader enhanced the DBP degradation rate. The enumeration of microorganisms indicated a good correlation between phthalate degradation and microbial counts. (C) 1997 Elsevier Science Ltd.
Activated sludge obtained from a coke-plant wastewater treatment plant was acclimated and used as seeding microbes to investigate the kinetics of biodegradation of di-n-butyl phthalate (DBP), one of the most frequentl...
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Activated sludge obtained from a coke-plant wastewater treatment plant was acclimated and used as seeding microbes to investigate the kinetics of biodegradation of di-n-butyl phthalate (DBP), one of the most frequently identified phthalic acid esters in diverse environments and the most widely used plasticizer in China. DBP biodegradation conformed to the first-order model with respect to its concentration and the rate constant was independent of the initial concentration when the initial DBP concentration was less than 200 mg/litre. (C) 1997 Elsevier Science Ltd.
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