ISSN:0006-3592    

DOI:10.1002/bit.260180902

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractA heat and caustic pretreatment process has been tested to determine the increase in gas yield that can be obtained from fermentation of organic municipal refuse. A treatment temperature of 130°C and a NaOH concentration of 3 g/100 g of dry solids resulted in the highest gas yield for the conditions tested. The probable increase in gas yield was 20% for the best conditions tested. The treatment procedure also substantially increased the rates of gas production. A high conversion efficiency is possible at much shorter reactor retention times with pretreatment than without pretreatment

ISSN:0006-3592    

DOI:10.1002/bit.260180903

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractA conceptual model of aerobic microbial growth in semisolid matrices was developed as a first step in the prediction of the rate of breakdown of semisolid cellulosic material. The conceptual model was described by a series of equations simplified by the assumption of steady‐state microbial activity, and heat and mass transfer limitation. Temperature and oxygen distribution in compost piles were measured experimentally at the Butler County Mushroom Farm, Butler County, Pennsylvania, to test the validity of these assumptions. The compost piles consisted of ground corn husks, straw, and race horse manure. The data fit with the model was excellent with deviations between model predictions (as solved by an analog computer) and actual temperature measurements never exceeding 3°C. The effects of compost pile geometry, external temperature, compost density, external oxygen concentration, and insulation at the bottom of the pile were then predicted using a digital computer to solve the model. The predictions show that the maximum breakdown rate occurs for an optimum height (which depends upon the system), insulating the base increases the breakdown rate, increasing the external temperature increases the initial breakdown rate but decreases the pseudo‐steady‐state breakdown rate and the uniformity, and any increase in the external oxygen concentration increases the breakdown rate but decreases the unif

ISSN:0006-3592    

DOI:10.1002/bit.260180904

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractShellfish processing wastewaters were characterized and subjected to laboratory‐scale treatability investigations using continuous flow chemostats operated under both aerobic and anaerobic conditions with and without biological solids recycle. System operation and evaluation employed hydraulic retention time as the controlled variable with substrate removal and biomass production as dependent variables. Additional variables specific to anaerobic operation included total and methane gas production rate and volatile acids generation. Application of a kinetic model incorporating the Monod substrate concentration– growth rate function allowed estimation of kinetic coefficients μmax,kd,Y, andKs.Aerobic treatment of the wastewaters could be adequately described by the kinetic model presented. However, total efficiencies were notably affected by the inherent morphological differences induced by changing hydraulic flows as reflected by poor solids separation at lower and higher retention times. Anaerobic treatment, although not amenable to kinetic description by the model and data presented, exhibited a limited potential for wastewater stabilization in that soluble substrate removals and methane production occurred at all retention times. Difficulties in successfully describing the system kinetically stemmed from an inability to quantify influent solids liquifaction rates. Moreover, evidence of some substrate associated inhibition of methanogenesis was apparent. Solids recycle tended to reduce the inhibitory influences and to increase treatment efficiencies in both the aerobic and anaerobic proce

ISSN:0006-3592    

DOI:10.1002/bit.260180905

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractA mathematical model was developed for percent removal of a pure, non‐adsorbable, biodegradable substrate in a submerged biological filter using the nonlinear Monod expression for the substrate utilization rate. Analytical solutions were obtained using zero and first order linearizations of the Monod expression and were compared to the numerical solution of the nonlinear system. The relevant dimensionless parameter groups describing the system were identified and their effects on substrate flux into the biolayer, effectiveness factor, and percent removal were also examined. Criteria were established for determining the relative accuracy of the two biokinetic approximations and for determining values of “limiting” biolayer thickness.There are two major results of engineering significance. (1) The approximation of the nonlinear Monod expression by a first order rate expression yields accurate results for a much wider range of bulk concentrations than might be expected from inspection of the Monod half‐velocity coefficient for a given substrate. (2) Percent removal of substrate is a weak function of biolayer thickness (and thus total cell mass) when the thickness is greater than a rather small limiting value but is a strong function of particle radius (and thus biolayer surface area) for a wide range of parameter values including those of common i

ISSN:0006-3592    

DOI:10.1002/bit.260180906

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractA completely mixed anaerobic filter, in which the influent organic matter concentration is diluted with recirculated effluent, was found to effectively remove organic matter concentrations in high strength acidic wastewater, at a range of organic loadings and shock loads. Increases in organic loading had a substantial effect on the relative organic matter composition of the effluent and the magnitude of the fatty acid fraction showed a pattern inverse to that of the nitrogenous organics. A fixed film model was formulated which indicated that at high substrate concentrations the substrate removal rate is proportional to the square root of the substrate concentration and the specific area of the filter medium. A comparison of the biofilm model and the measured effluent concentrations tended to indicate that the substrate removal rate is primarily affected by substrate concentration, specific surface area, flow rate, and temperature of the unit.

ISSN:0006-3592    

DOI:10.1002/bit.260180907

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractEthanol fermentation studies were conducted withSaccharomyces cerevisiaeATCC #4126, to determine the optimal conditions of oxygen tension and feed sugar concentration. In long‐term continuous culture maximum ethanol production was found to occur at 0.07 mmHg oxygen tension and 10% glucose feed concentration. Preliminary process design and cost studies are developed for industrial scale fermentations to produce ethanol and torula yeast from sugars obtained by enzymatic hydrolysis of newsprin

ISSN:0006-3592    

DOI:10.1002/bit.260180908

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

摘要:

AbstractAn integrated processing scheme is described for the conversion of a cellulosic waste (newsprint) to sugars by enzymatic hydrolysis and then to ethanol and yeast by fermentation. The unconverted solids are burned to produce process energy requirements and surplus electrical power. Preliminary designs and cost studies are developed to provide a rough perspective on the potential economic feasibility of this method of cellulose utilization.

ISSN:0006-3592    

DOI:10.1002/bit.260180909

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260180910

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260180911

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1976

数据来源: WILEY