摘要:

Bacteria indigenous to a trichloroethylene (TCE) contaminated site were exposed to 0.56 and 6.7 mg L‐1TCE. Under the aerobic, oligotrophic conditions of the microcosms, the populations were able to degrade TCE and to increase their numbers by two orders of magnitude within one week. No other substrate was added. The average TCE disappearances were 47 percent and 33 percent for initial TCE concentrations of 0.56 and 6.7 mg L‐1, respectively. No TCE disappearance was observed in controls. Results of individual microcosms suggest that bacteria degraded TCE to levels as low as 1–2 percent of the initial concentration. Lag times of 14 and 18 days were observed for the 0.56 and 6.7 mg L‐1concentration microcosms, respectively. Bacterial population shifts were noted throughout the experiment. None of the isomers of a dehalogenation reaction were found.

ISSN:0360-1226    

DOI:10.1080/10934528909375502

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Much attention has been given to groundwater contamination due to the release of hazardous constituents from treatment and disposal facilities. Since some of the constituents entered groundwater aquifers in much shorter times than had been calculated, regulatory agencies have become concerned that hazardous constituents may be escaping from units not currently regulated under hazardous waste management programs. One of the major concerns of regulators is that unlined earthen surface impoundments in industrial wastewater treatment trains may be leaking heavy metals such as chromium and other hazardous constituents into the groundwater. The Environmental Protection Agency has moved toward bringing such impoundments under the Resource Conservation and Recovery Act (RCRA) regulations. In addition, EPA is now proposing to list hexavalent chromium as a hazardous air pollutant due to its possible release from the mist of cooling towers, citing hexavalent chromium's potent carcinogenicity as the primary concern. While such a listing would primarily affect worker exposure, leakage of chromium from surface impoundments could enter groundwater sources and carry exposures far beyond industrial facilities.

ISSN:0360-1226    

DOI:10.1080/10934528909375503

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Type I Portland cement samples containing the soluble nitrates of the priority pollutant metals chromium, lead, barium, mercury, cadmium and zinc have been investigated using thermogravimetric and fourier—transform infrared techniques (including diffuse reflectance). The major vibrational bands and thermal stability of the carbonate, sulfate, silicate, water and nitrate species are tabulated and discussed in comparison to uncontaminated Portland cement. The solubility and volatility of mercury in cement and the effect of metal nitrate concentration on the silicate condensation process is discussed. Although results suggest that retardation of cement setting by Zn and Pb salts occurs by limiting hydration, the chemistry of the two processes is distinctly different.

ISSN:0360-1226    

DOI:10.1080/10934528909375504

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Low Temperature Carbonization Wastes contain high concentrations of various phenols, organic bases, ammonia, cyanide, thiocyanate and several other constituents of environmental concern. Fresh waste water is colourless to straw‐yellow in colour but changes to red or brownish red due to oxidative coupling of phenols resulting in quinone structures with C‐O‐C linkages.

ISSN:0360-1226    

DOI:10.1080/10934528909375505

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Low temperature carbonization (LTC) is a process in which coal is heated (500–800°C), in absence of oxygen, yielding products like coke, tar, oil, liquor and gases. The liquor contains several pollutants like phenols, ammonia, cyanide, thiocyanate. Therefore, the characteristic of the liquor are of significant importance, with reference to environmental pollution. The quality and quantity of liquor is dependent on the nature of the coal and process of carbonization. In the present study, the strength of the liquor has been correlated with the temperature of carbonization and the volatile matter content of coal, using Gray‐King Assay apparatus for the carbonization. Present study indicates that the pollution load of liquor is directly proportional to the volatile matter content of coal. The temperature of carbonization also influences the concentration of the pollutants in the waste liquor.

ISSN:0360-1226    

DOI:10.1080/10934528909375506

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A mathematical model of compressive thickening is developed which is based on Kos’ model yet can be calibrated from measurements of concentration, concentration gradient, and bulk underflow velocity in continuous thickening experiments. The need for sensitivity and difficult measurements such as interparticle pressure or volumetric solids concentration is eliminated. Numerical programs to simulate the model are described. The model was calibrated and tested using steady state continuous thickening experiments. Unsteady state continuous thickening was studied by use of computer simulation of the model. Programs are described for nonlinear regression of the models to continuous thickening column data, and for steady state and unsteady state simulation.

ISSN:0360-1226    

DOI:10.1080/10934528909375507

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Information Resources in Toxicology, 2nd Edition by Philip Wexler, 1988. Hard Back 510 pages plus XXIV, Elsevier, New York ($?).

ISSN:0360-1226    

DOI:10.1080/10934528909375508

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528909375501

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor