摘要:

AbstractThe Dow patented Stretford Chemical Recovery Process reclaims the two key chemicals while purging undesirable by‐products from Stretford gas sweetening plants. Recovery of these chemicals can reduce costs in terms of chemical loss and solution disposal. The process involves filtration, charcoal adsorption and ion exchang

ISSN:0278-4491    

DOI:10.1002/ep.670050106

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.670050102

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractThe crystal growth rate of CaSO3· 1/2H2O was measured by a pH‐stat method in aqueous solution with pH 3.5 to 6.5, 1 to 25 mM dissolved sulfite, 0.01 to 0.3 M Ca++, and 0 to 25 mM sulfate. The growth rate was a strong function of relative supersaturation and was strongly inhibited by dissolved sulfate. The growth rate per unit BET surface area, R' (mole/cm2‐min), is given by: 9.7 × 10−4exp (−10250/RT) × (RSCaSO3−1)2× RSCaSO4−1, where RSCaSO3and RSCaSO4are the relative saturations with respect to calcium sulfite and gypsum, respectively. Scanning electron microscopy and IR spectroscopy demonstrated that solids generated in the presence of dissolved sulfate contained solid solution sulfate and crystallized as agglomerates of very thin platelets. In the absence of solid or dissolved sulfate the solids were agglomerates of well‐informed columnar, h

ISSN:0278-4491    

DOI:10.1002/ep.670050107

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.670050104

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.670050105

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractQuantitative data from actual field tests show that the carbonic‐acid content of the landfill area is critica

ISSN:0278-4491    

DOI:10.1002/ep.670050108

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractAn up‐to‐date review of the present situat

ISSN:0278-4491    

DOI:10.1002/ep.670050109

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractA model has been developed to describe the transport of low volatility organic chemicals in a column of soil. The mathematical model calculates the rate of movement through the soil by solving the dynamic material and energy balances around the soil column. The model is used to make predictions on the transport of 2,3,7,8‐tetrachlorodibenzop‐dioxin (TCDD) at the Eglin Air Force Base Agent Orange biodegradation test plots. The model predicts a vertical movement of TCDD, buried in 1972, through the soil column. Soil column profile data confirm the vertical movement of T

ISSN:0278-4491    

DOI:10.1002/ep.670050110

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractThe rate of calcium sulfite dissolution in slurry scrubbers and hold tanks for flue gas desulfurization affects SO2absorption, limestone utilization and sulfite oxidation. The dissolution rates of calcium sulfite were measured by the pH‐state method. A mass transfer model was developed assuming that calcium sulfite particles behave as spheres in an infinite stagnant solution. The model combined with the Bechtel‐modified Radian solution equilibrium program successfully predicts calcium sulfite dissolution rates at pH 3.5 – 5.5, 23 and 55°C, 0.001 – 0.3 M Ca++and 2 – 25 mM dissolved sulfite. The effects of sulfate content in solids and liquids and particle size/shape were also studied.At conditions typical of flue gas desulfurization processes calcium sulfite dissolution was controlled by mass transfer, not surface reaction kinetics. Dissolution was fast at low pH and slowed near the equilibrium pH determined by dissolved Ca++and SO3=concentrations in the aqueous solutions, Kspof the CaSO3· 1/2H2O solids, and temperature. The presence of dissolved Mg++increased the equilibrium pH and enhanced the disolution rate. The presence of dissolved sulfate reduced the dissolution rate and the equilibrium pH. The effect of sulfate was not adequately described by the mass tra

ISSN:0278-4491    

DOI:10.1002/ep.670050111

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractA landfill leachate is treated, after mixing with chemical manufacturing wastewaters, by activated carbon adsorption. Biotreatment of the combined wastewater in sequencing batch reactors (SBRs) reduced the carbon requirement by 90%. Excellent treatment efficiency was consistently achieved under a variety of operating conditions: wastewater TOC, feed rate, hydraulic retention time, MLSS, organic loading, temperature, and cycle time. The SBR performance was unaffected when wastewater feeding was suspended during weekends and holidays. Results obtained in 1‐L SBRs were reproduced in 12‐L and 500‐L units. The experimental data served as the basis for design of a full‐scale SBR‐adsorption system. The integrated wastewater treatment system would produce a better quality effluent at a lower overall cost. Biodegradation rates for some of the more persistent wastewater constituents were enhanced in batch bioreactors which were supplemented with strains of bacteria isolated from the land

ISSN:0278-4491    

DOI:10.1002/ep.670050112

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY