Many industrial activities discharge sulphate- and metal-containing wastewaters, including the manufacture of pulp and paper, mining and mineral processing, and petrochemical industries. Acid mine drainage (AMD) is an example of such sulphate- and metal-containing waste streams. Formation of AMD is generally the result of uncontrolled oxidation of the sulphide minerals present in the terrain in which the drainage flows with concomitant leaching of the metals. Acid mine drainage (AMD) and other sulphate- and metal-containing waste streams are amenable to active biological treatment. Anaerobic reduction of sulphate, reaction of produced sulphide with metal ions present in the waste stream, and biooxidation of excess sulphide are three main sub-processes involved in the active biotreatment of AMD. Anaerobic reduction of sulphate can be achieved in continuous stirred tank bioreactors with freely suspended cells or in immobilized cell bioreactors. The application of freely suspended cells in a continuous system dictates a high residence time to prevent cell wash-out, unless a biomass recycle stream is used. In an immobilized cell system biomass residence time becomes uncoupled from the hydraulic residence time, thus operation of bioreactor at shorter residence times becomes possible. In the present work, kinetics of anaerobic sulphate reduction was studied in continuous immobilized cell packed-bed bioreactors. Effects of carrier matrix, concentration of sulphate in the feed and sulphate volumetric loading rate on the performance of the bioreactor were investigated. The bioreactor performance, in terms of sulphate reduction rate, was dependent on the nature of the carrier matrix, specifically the total surface area which was provided by the matrix for the establishment of biofilm. Among the three tested carrier matrices, sand displayed the superior performance and the maximum volumetric reduction rate of 1.7 g/L-h was achieved at the shortest residence time of 0.5 h. This volumetric reduction rate was 40 and 8 folds faster than the volumetric reduction rates obtained with glass beads (0.04 g/L-h; residence time: 28.6 h) and foam BSP (0.2 g/L-h; residence time: 5.3 h), respectively. Further kinetic studies with sand as a carrier matrix indicated that the extent of volumetric reduction rate was dependent on the feed sulphate concentration and volumetric loading rate. At a constant feed sulphate concentration, increases in volumetric loading rate caused the volumetric reduction rate to pass through a maximum, while increases in feed sulphate concentrations from 1.0 g/L to 5.0 g/L led to lower volumetric reduction rates. The maximum volumetric reduction rates achieved in the bioreactors fed with initial sulphate concentration of 1.0, 2.5 and 5.0 g/L were 1.71, 0.82 and 0.68 g/L-h, respectively. The coupling of lactate utilization to sulphate reduction was observed in all experimental runs and the rates calculated based on the experimental data were in close agreement with calculated theoretical rates, using the stoichiometry of the reactions involved. The maximum volumetric reduction rates achieved in the immobilized cell bioreactors were significantly faster than those reported for freely suspended cells employed in the stirred tank bioreactors.

Abstract Permeable reactive barrier technology is a cost effective means of treating near surface groundwater contaminant plumes. However, current reactive barrier technology lacks the capacity to manipulate flow rates and thus hydraulic retention time (HRT) within the barriers in order to maximize the effectiveness and longevity of the media. This study examines the effectiveness of tile drains as passive controls on the flow rate of ground-water through an existing wood particle media permeable reactive barrier treating agricultural nitrate. The use of upgradient and downgradient tile drains allowed HRT to be increased from 4.5 to 10 days in one trial and then to be decreased from 11.1 to 0.8 days in a second trial. Influent groundwater NO3-N concentrations of ~100 mg/L were attenuated to detection limit (0.02 mg/L) only 12% of the 4 m long barrier with HRTs of 4.5 to 10 days. During the second trial, HRT was decreased to 0.8 days and NO3-N penetrated to the downgradient edge of the PRB at 1.8 mg/L. The behaviour of SO4 in the PRB was also affected by flow rate. SO4 entered the PRB at 60 to 71 mg/L during the first trial. Under a HRT of 10 days it was depleted to detection limit after traveling through only 13% of the barrier. When HRT was decreased to 4.5 days, SO4 was able to penetrate the downgradient edge of the PRB at concentrations from 4 to 6 mg/L. With a 0.8 day HRT SO4 reduction was highly restricted as calculations showed 90% of available carbon in the PRB was being used to reduce NO3-N, compared to 7.5% being used for SO4 reduction at that time. In comparison, at the 10 day HRT, 61% of carbon being used for NO3-N reduction, 8.7% for SO4 reduction, 0.7 for dissolved oxygen and 29% was lost through DOC leaching. These calculations suggest that barrier efficiency can be greatly enhanced by manipulation of HRT through use of tile drains.

Abstract Permeable reactive barrier technology is a cost effective means of treating near surface groundwater contaminant plumes. However, current reactive barrier technology lacks the capacity to manipulate flow rates and thus hydraulic retention time (HRT) within the barriers in order to maximize the effectiveness and longevity of the media. This study examines the effectiveness of tile drains as passive controls on the flow rate of ground-water through an existing wood particle media permeable reactive barrier treating agricultural nitrate. The use of upgradient and downgradient tile drains allowed HRT to be increased from 4.5 to 10 days in one trial and then to be decreased from 11.1 to 0.8 days in a second trial. Influent groundwater NO3-N concentrations of ~100 mg/L were attenuated to detection limit (0.02 mg/L) only 12% of the 4 m long barrier with HRTs of 4.5 to 10 days. During the second trial, HRT was decreased to 0.8 days and NO3-N penetrated to the downgradient edge of the PRB at 1.8 mg/L. The behaviour of SO4 in the PRB was also affected by flow rate. SO4 entered the PRB at 60 to 71 mg/L during the first trial. Under a HRT of 10 days it was depleted to detection limit after traveling through only 13% of the barrier. When HRT was decreased to 4.5 days, SO4 was able to penetrate the downgradient edge of the PRB at concentrations from 4 to 6 mg/L. With a 0.8 day HRT SO4 reduction was highly restricted as calculations showed 90% of available carbon in the PRB was being used to reduce NO3-N, compared to 7.5% being used for SO4 reduction at that time. In comparison, at the 10 day HRT, 61% of carbon being used for NO3-N reduction, 8.7% for SO4 reduction, 0.7 for dissolved oxygen and 29% was lost through DOC leaching. These calculations suggest that barrier efficiency can be greatly enhanced by manipulation of HRT through use of tile drains.

Many industrial activities discharge sulphate- and metal-containing wastewaters, including the manufacture of pulp and paper, mining and mineral processing, and petrochemical industries. Acid mine drainage (AMD) is an example of such sulphate- and metal-containing waste streams. Formation of AMD is generally the result of uncontrolled oxidation of the sulphide minerals present in the terrain in which the drainage flows with concomitant leaching of the metals. Acid mine drainage (AMD) and other sulphate- and metal-containing waste streams are amenable to active biological treatment. Anaerobic reduction of sulphate, reaction of produced sulphide with metal ions present in the waste stream, and biooxidation of excess sulphide are three main sub-processes involved in the active biotreatment of AMD. Anaerobic reduction of sulphate can be achieved in continuous stirred tank bioreactors with freely suspended cells or in immobilized cell bioreactors. The application of freely suspended cells in a continuous system dictates a high residence time to prevent cell wash-out, unless a biomass recycle stream is used. In an immobilized cell system biomass residence time becomes uncoupled from the hydraulic residence time, thus operation of bioreactor at shorter residence times becomes possible. In the present work, kinetics of anaerobic sulphate reduction was studied in continuous immobilized cell packed-bed bioreactors. Effects of carrier matrix, concentration of sulphate in the feed and sulphate volumetric loading rate on the performance of the bioreactor were investigated. The bioreactor performance, in terms of sulphate reduction rate, was dependent on the nature of the carrier matrix, specifically the total surface area which was provided by the matrix for the establishment of biofilm. Among the three tested carrier matrices, sand displayed the superior performance and the maximum volumetric reduction rate of 1.7 g/L-h was achieved at the shortest residence time of 0.5 h. This volumetric reduction rate was 40 and 8 folds faster than the volumetric reduction rates obtained with glass beads (0.04 g/L-h; residence time: 28.6 h) and foam BSP (0.2 g/L-h; residence time: 5.3 h), respectively. Further kinetic studies with sand as a carrier matrix indicated that the extent of volumetric reduction rate was dependent on the feed sulphate concentration and volumetric loading rate. At a constant feed sulphate concentration, increases in volumetric loading rate caused the volumetric reduction rate to pass through a maximum, while increases in feed sulphate concentrations from 1.0 g/L to 5.0 g/L led to lower volumetric reduction rates. The maximum volumetric reduction rates achieved in the bioreactors fed with initial sulphate concentration of 1.0, 2.5 and 5.0 g/L were 1.71, 0.82 and 0.68 g/L-h, respectively. The coupling of lactate utilization to sulphate reduction was observed in all experimental runs and the rates calculated based on the experimental data were in close agreement with calculated theoretical rates, using the stoichiometry of the reactions involved. The maximum volumetric reduction rates achieved in the immobilized cell bioreactors were significantly faster than those reported for freely suspended cells employed in the stirred tank bioreactors.

Thermomechanical pulping (TMP) is a highly energy intensive process where most of the energy is used in therefining of chips to fibres. Various ways of reducing the energy consumption have earlier been studied, for examplechange of refiner pattern, addition of various chemicals, and also some biochemical implementation in the form of fungus and enzymes. This study includes pre-trials with the enzymes pectin lyase and pectin esterase,multipectinase, xylanase, and mannanase. The results are studied via a reducing sugar assay, an enzymatic assayusing spectrophotometry, and capillary zone electrophoresis. The study also includes results from a pilot scalerefining with multipectinase, xylanase, and mannanase, performed with a wing refiner at Helsinki University.Reductions of energy consumption in TMP by pre-treatment of Norwegian spruce chips are investigated and apotential reduction of energy consumption of 6 % is indicated.

No description available.

No description available.

The purpose of this study is to use vertical-flow constructed wetlands (VFCW) microcosm systems to investragte the removal efficiencies of sulfate. The system was located on the campus sewage treatment plant. nn National Sun Yat-sen University. In this study, two media, gravel and peat, were installed in four different systems. The two system with same media were separated into vegetated and non-vegetated (control) ones respectively. In the test runs, the operation methods included batch type filled with water, continuous flow and integrated vertical flow constructed wetland (IVCW) with continuous flow. In batch type test, it was run under an initial concentrations of SO42--S about 500 mg/L. The experimental results showed that the removal efficiencies were increased with increasing COD concentrations. Under the same conditions but with continuous flow operation, the removal efficiencies of SO42--S were lower than the batch type one, which 80% could be reached. The best system for operation was P1 (peat with vegetated), in which the removal effciency reached 90%. The experimental results also showed that the vegetated systems presented higher removal efficiencies of sulfate than the non-vegetated ones. In addition, this research were increased the concentrations of SO42--S and COD to about 1200 mg/L and 4000 mg/L respectively. The experimental results showed that the IVCW treatment system could achived greater efficiency than VFCW treatment system. The experimental in depth research test run indicated that the anaerobic condition did not affect the removal efficiencies of ammonia by using batch type. However, nitrification was the main reaction of ammonia to nitrate in the continuous flow type systems. When ORP values were found below the -300 mV, the sulfate began to be drcreased. It was believed that if the anaerobic condition were well be established, while the organic carbon could be contented in this system, the sulfate reducing bacteria (SRB) might live, and then sulfate could be removed. The effect of temperature on sulfate removal was generally established in this study. According to the experimental results, it was found that the activity of SRB motility was higher in higher temperature (35¢J) than that in lower temperature (25¢J).

In this study, Dyneema fiber can bear tension and not easy to react with the chemicals characteristics, to explore for the resistance to bending moment and compressive strength of concrete. To compare with different rate of Dyneema fiber added at different ratio of AE water-reducing in the condition of concrete slump test and slump flow test. We planning in different water-cement ratio 0.48(non AE water-reducing)¡B0.4(add AE water-reducing), to test for its fresh properties and hardened properties, and discussion the effect by AE water-reducing and Dyneema fiber on the marine engineering. According to this study, adding Dyneema fiber will make the slump and slump flow value dropped, and affecting the workability. Because of Dyneema fiber will tangle when add too much Dyneema fiber in concrete. So in mixing time, the Dyneema fiber and concrete will form clumps, in this study, we add the AE water-reducing to improve. After we add AE water-reducing, the slump, slump flow, compressive strength, are increase, but we still had to pay attention to the ratio between Dyneema fiber and AE water-reducing, the strength of structure perhaps decrease if added too much Dyneema fiber or AE water-reducing. This study can get the best positive effect when added 1.5% volume volume of Dyneema fiber.

After the promulgation of Financial Holding Company Law at the end of year 2001, the law has liberated the limitation of operations across banking, brokerage, and insurance. In order to cope with the future market competition, these institutions formed in total of 14 financial holding companies (FHCs) through self raising, merging, or acquisition. This research is aiming at the 14 FHCs and their subsidiary banks, security brokerages, and insurance companies, through applying financial ratio analysis to measure the synergy of FHCs¡¦ merging and acquisition. The sources of synergy are divided into three dimensions : operations, markets, and finance. A total of eight years of financial data is collected, including two parts: four years of pre-founding of FHCs from 1998 to 2001 and four years after founding the FHCs from 2002 to 2005. In-depth interview is conducted to look for the differences of operation performance and effect of increasing shareholder wealth after the FHCs merging and acquisition. The conclusions of this study are presented as following¡G 1.Market Synergy Dimension: The revenue increased after founding the FHCs shows that the market synergy exists and fits to expectation. FHCs could operate across fields including banking, brokerage, and insurance to provide cross selling chance for finance products. 2.Operational Synergy Dimension: The operating costs and operating costs ratio are increased after founding the FHCs. Because the FHCs do not reach the economy of scale, the unit operation cost is high and the organization of FHCs becomes large and needs more communication, which makes the decision making process inefficient, the management efficiency still needs to be improved. 3.Financial Synergy Dimension: The profit after tax and ROE are decreased after founding the FHCs, which are mainly contributed from inefficient use of financial resources and human resources as a whole group. 4.Synergy was hard to be seen within short term, which needed three to four years to make it possible. After merging or acquisition, FHCs need some time to reduce the conflicts between its subsidiaries and to conduct more efficient resource application to form FHCs synergy. 5.Market Evaluation: The market value of whole FHCs increases which increases the shareholder¡¦s wealth. This research provides the solution for increasing operation costs, including the following three points: 1.Converging the operation process. 2.Increasing economy of scale. 3.Enforcing the management efficiency.