摘要:

AbstractSorption of halogenated single carbon organic contaminants onto a sandy loam has been found to be controlled by the electrostatic attraction between a slightly negatively (δ−) charged clay particle and a positively (δ+) charged carbon atom within the solvent molecule. Adsorption isotherms for chloroform, bromodichloromethane and methylene chloride indicate that the extent of sorption appears to have a direct functional relationship to the molecular charge distribution within the solvent molecule, and to the atomic radii of the molecular substituents of the contaminant. When a carbon atom is saturated with highly electronegative substituents (e.g. carbon tetrachloride), an electron cloud surrounds the molecule and shields the slightly positive (δ+) carbon nuclei. This shielding effect limits the sorption that occurs. A study on carbon tetrachloride sorption resulted in no detectable sorption onto the sandy loam soil. This theory of adsorption is defined as Electrophysical Sorption (EPS) because it reflects the combination of electrostatic and physical contributions to sorp

ISSN:0278-4491    

DOI:10.1002/ep.3300080106

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.3300080102

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.3300080103

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.3300080104

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractToxic and hazardous compounds are often present in water at low concentrations, which can make their removal difficult and costly by conventional treatment processes. A promising method for destroying pollutants in water is ultraviolet (UV) catalyzed oxidation by hydrogen peroxide. The effectiveness of this process was determined for typical aromatic compounds including benzene, toluene, chlorobenzene, phenol, 2‐chlorophenol, 2,4‐dichlorophenol, 2,4,6‐trichlorophenol, dimethyl phthalate, and diethyl phthalate. The reactions were conducted in a quartz annular reactor equipped with a low‐pressure mercury lamp. Of the aromatics studied, reaction rates were fastest with 2,4,6‐trichlorophenol and slowest with the phthalates. Analyses of reacted samples by HPLC and GC/MS indicated that the aromatics formed many intermediates that could be destroyed by extending the treatment time. An empirical rate expression was developed to correlate th

ISSN:0278-4491    

DOI:10.1002/ep.3300080107

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractStudies were made on treating a leachate from New Lyme, Ohio. The leachate was transported to Cincinnati, where a pilot‐sized rotating biological contactor (RBC) was used for a treatment evaluation. Biomass was developed on the RBC discs with primary effluent from the City of Cincinnati's Mill Creek Sewage Treatment Facility. Experiments were then conducted to determine the effectiveness of treating a hazardous waste leachate and to provide information on: the rate of organics removal; the final effluent quality; the fate of priority pollutants and specific organic compounds; and the loss of volatiles via stripping in the RBC. The results of these experiments and the applicability of an RBC to treat a hazardous waste leachate from a Superfund site are reporte

ISSN:0278-4491    

DOI:10.1002/ep.3300080108

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractRemoval of sulfur compounds from hot coal gas is a necessary step during power generation operations. Zinc ferrite has been identified as a promising absorbent material. A mathematical model describing the kinetics of zinc ferrite during absorption and regeneration as it applies to a steady‐state moving‐bed concept, where the solids are continuously transferred between absorber and regenerator vessels has been developed. Model predictions, based on experimental data, are presented for various flow configurations and operating conditions, including multistage operation of regeneration, where the effect of diffusion mechanisms, temperature, gas concentrations, and flow rates on conversion are presen

ISSN:0278-4491    

DOI:10.1002/ep.3300080109

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractApplication of zinc ferrite, a regenerable mixed metal oxide, for the removal of H2S from hot coal derived gas streams is limited to a maximum temperature of about 1,250°F (677°C) and to a minimum H2S concentration of about 5 ppmv in the cleaned gas. Four novel sorbents that have shown potential for overcoming the limitations of zinc ferrite [1, 4] were selected for development and bench‐scale testing. Several variations of these mixed metal oxides were prepared, using different amounts of binders. They were tested in the presence of simulated coal gas using a thermogravimetric reactor (TGR) for selection of preparations possessing an adequate combination of reactivity, regenerability, capacity, and strength. Limited bench‐scale tests were conducted in the presence of simulated fluidized‐bed coal gasifier product gases at pressures from 1 to 2 MPa, temperatures from 525°C to 625°C and space velocities from 1,000 to 3000 Nm

ISSN:0278-4491    

DOI:10.1002/ep.3300080110

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractThe productivity of ion exchange processes is usually limited by the diffusional process. The use of very fine mesh resins (down to 10–25 microns diameter) in very thin (ca 3–9 mm) beds supported on a microfiltration membrane of three micron pore diameter is described. These systems were used to process a simulated wastewater containing 4000 ppm of NaCl, plus some calcium and magnesium chlorides, as well as 0.2 ppm each of the metal ions Cu, Ni, Pb, Zn, and Cr (III). Regeneration with dilute HCl produced a concentrate of 1/1000 the volume of the feedwater trea

ISSN:0278-4491    

DOI:10.1002/ep.3300080111

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper illustrates some of the principles that lead to a rational selection of a biological treatment process for industrial wastewaters.

ISSN:0278-4491    

DOI:10.1002/ep.3300080112

出版商:American Institute of Chemical Engineers    

年代:1989

数据来源: WILEY