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Elimination Capacity (elimination + capacity)
Selected AbstractsA novel reactor for exploring the effect of water content on biofilter degradation ratesENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2003Milinda A. Ranasinghe A novel batch recycle reactor was developed to investigate the effect of water content changes on the biological degradation rate of gas phase contaminants in low water content systems, such as biofilters. The reactor tightly controlled the water content of the unsaturated packing material using the principle of a suction cell. Matric potential in the compost was controlled between ,6 and ,36 cm H2O. A soil water retention curve relating matric potential to gravimetric water content was generated for the compost. Periodic dry weight analyses of reactor samples, together with the water retention curve, verified moisture content control. Runs were performed with toluene as the contaminant using unamended compost at a constant temperature of 30°C. Degradation results indicated a linear, biologically limited degradation region, followed by a non-linear region at lower concentrations. Elimination capacities were calculated for the linear region for different matric potentials along both the wetting and drying curves, and both changes in the water content and direction of approach affected the removal rates in the linear region. The elimination capacity ranged from 155 g/m3 hr to 24 g/m3 hr for toluene over the matric potential range investigated. Repeatability studies indicated that moisture content was most likely the parameter that influenced changes in performance. [source] Removal of TEX vapours from air in a peat biofilter: influence of inlet concentration and inlet loadJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2006Carmen Gabaldón Abstract This paper presents the results of the study of the removal of toluene, ethylbenzene, and o -xylene (TEX) by biofiltration using a commercial peat as filter-bed material. Runs with a single organic compound in air, and with the mixture of TEX in air, were carried out for at least 55 days in laboratory-scale reactors inoculated with a conditioned culture. The influence of organic compound inlet load and of gas flow rate on the biofilter's performance was studied, including relatively high values of pollutant inlet concentration (up to 4.3 gC m,3 for ethylbenzene, 3.2 gC m,3 for toluene, and 2.7 gC m,3 for o -xylene). Results obtained show maximum elimination capacities of 65 gC m,3 h,1 for o-xylene, 90 gC m,3 h,1 for toluene, and 100 gC m,3 h,1 for ethylbenzene, and high removal efficiency (>90%) even for moderately elevated concentrations: 3.0, 2.5 and 1.8 gC m,3 for ethylbenzene, toluene and o -xylene, respectively. The behaviour of the TEX mixture was in good agreement with the results obtained for the runs in which only one organic compound was present. Ethylbenzene and toluene are degraded easier than o -xylene, and inhibitory effects due to the presence of multiple substrates were not observed. Copyright © 2005 Society of Chemical Industry [source] Influence of nitrogen on the degradation of toluene in a compost-based biofilterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2001Marie-Caroline Delhoménie Abstract Two identical laboratory-scale bioreactors were operated simultaneously, each treating an input air flow rate of 1,m3,h,1. The biofilters consisted of multi-stage columns, each stage packed with a compost-based filtering material, which was not previously inoculated. The toluene inlet concentration was fixed at 1.5,g,m,3 of air. Apart from the necessary carbon, the elements nitrogen, phosphorus, sulfur, potassium and other micro-elements are also essential for microbial metabolism. These were distributed throughout the filter bed material by periodic ,irrigations' with various test nutrient solutions. The performance of each biofilter was quantified by determining its toluene removal efficiency, and elimination capacity. Nutrient solution nitrogen levels were varied from 0 to 6.0,g,dm,3, which led to elimination capacities of up to 50,g,m,3,h,1 being obtained for a toluene inlet load of 80,g,m,3,h,1. A theoretical analysis also confirmed that the optimum nitrogen solution concentration lays in the range 4.0,6.0,g,dm,3. Validation of the irrigation mode was achieved by watering each biofilter stage individually. Vertical stage-by-stage stratification of the biofilter performance was not detected, ie each filter bed section removed the same amount of pollutant, the elimination capacity per stage being about 16,g,m,3,h,1 per section of column. © 2001 Society of Chemical Industry [source] Functional significance of hepatic arterial flow reserve in patients with cirrhosisHEPATOLOGY, Issue 2 2003Alexander Zipprich In cirrhosis, hepatic arterial vasodilatation occurs in response to reduced portal venous blood flow. However, although the hepatic arterial flow reserve is high in patients with cirrhosis, its impact on hepatic function is unknown. This study investigated the effect of adenosine-induced hepatic arterial vasodilatation on different markers of liver function. In 20 patients with cirrhosis (Child-Pugh class A/B/C: n = 2/7/11) adenosine (2-30 ,g · min,1 · kg body wt,1) was infused into the hepatic artery and hepatic arterial average peak flow velocities (APV), pulsatility indices (PI), and blood flow volumes (HABF) were measured using digital angiography and intravascular Doppler sonography. Indocyanine green (ICG), lidocaine, and galactose were administered intravenously in doses of 0.5, 1.0, and 500 mg/kg body weight in the presence of adenosine-induced hepatic arterial vasodilatation and, on a separate study day, without adenosine. ICG disappearance, galactose elimination capacity (GEC), and formation of the lidocaine metabolite monoethylglycinxylidide (MEGX) were assessed. Adenosine markedly increased APV and HABF and markedly decreased PI. Serum MEGX concentrations were 63.7 ± 18.2 (median, 62; range, 36-107) and 99.0 ± 46.3 (82.5; 49-198) ng/mL in the absence and presence of adenosine infusion, respectively (P = .001). Adenosine-induced changes in MEGX concentrations were correlated inversely to changes in APV (r = ,0.5, P = .02) and PI (r = ,0.55, P = .01) and were more marked in Child-Pugh class C compared with Child-Pugh class A patients (57.4 ± 49.9 [44; ,14 to 140] vs. 8.4 ± 16.5 [13; ,11 to 35] ng/mL, P < .01). In conclusion, hepatic arterial vasodilatation provides substantial functional benefit in patients with cirrhosis. The effect does not depend directly on hepatic arterial macroperfusion and is observed preferentially in patients with decompensated disease. [source] Influence of nitrogen on the degradation of toluene in a compost-based biofilterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2001Marie-Caroline Delhoménie Abstract Two identical laboratory-scale bioreactors were operated simultaneously, each treating an input air flow rate of 1,m3,h,1. The biofilters consisted of multi-stage columns, each stage packed with a compost-based filtering material, which was not previously inoculated. The toluene inlet concentration was fixed at 1.5,g,m,3 of air. Apart from the necessary carbon, the elements nitrogen, phosphorus, sulfur, potassium and other micro-elements are also essential for microbial metabolism. These were distributed throughout the filter bed material by periodic ,irrigations' with various test nutrient solutions. The performance of each biofilter was quantified by determining its toluene removal efficiency, and elimination capacity. Nutrient solution nitrogen levels were varied from 0 to 6.0,g,dm,3, which led to elimination capacities of up to 50,g,m,3,h,1 being obtained for a toluene inlet load of 80,g,m,3,h,1. A theoretical analysis also confirmed that the optimum nitrogen solution concentration lays in the range 4.0,6.0,g,dm,3. Validation of the irrigation mode was achieved by watering each biofilter stage individually. Vertical stage-by-stage stratification of the biofilter performance was not detected, ie each filter bed section removed the same amount of pollutant, the elimination capacity per stage being about 16,g,m,3,h,1 per section of column. © 2001 Society of Chemical Industry [source] Quantitative liver function tests in donors and recipients of living donor liver transplantationLIVER TRANSPLANTATION, Issue 4 2006Christoph Jochum The unique ability of the liver to regenerate quickly after resection makes living donor liver transplantation (LDLT) possible. This technique uses the unique ability of the liver to regenerate to full size after partial resection. However, the quality and course of this regeneration process in humans are still widely unexplored. In the present study we investigated the quantitative liver function tests galactose elimination capacity (GEC), indocyanine green half-life (ICG), and lidocaine half-life as markers for the quality of the liver regeneration in the first 3 months after LDLT. In this study, 22 consecutive living liver donors and their corresponding recipients were analyzed at baseline and at 10 and 90 days after LDLT. Six recipients lost their grafts during the study period. We compared donors and recipients at the different time points. After LDLT, GEC decreased (,42.6%) and ICG increased (+50.6%) significantly in donors. ICG and GEC remained significantly altered over 3 months in donors with an improvement between days 10 and 90 (GEC, +59.3%; ICG, ,9.1%). ICG and GEC improved significantly in recipients between days 10 and 90 (ICG, ,63.7%; GEC, +16.3%). The lidocaine half-life showed no significant changes. The donors had better test results and recovered faster than the recipients. In conclusion, after LDLT the parameters for liver capacity and flow remain altered in donors and recipients despite rapid volume growth. Liver Transpl 12:544,549, 2006. © 2006 AASLD. [source] | ||||||||||