A pilot study on anaerobic treatment of the foul condensate from an ammonia based spent sulfite liquor evaporator has recently been conducted at the Proctor & Gamble Paper Products Plant in Mehoopany, Pennsylvania...
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ISBN:
(纸本)0250406403
A pilot study on anaerobic treatment of the foul condensate from an ammonia based spent sulfite liquor evaporator has recently been conducted at the Proctor & Gamble Paper Products Plant in Mehoopany, Pennsylvania. The study involved construction of pilot plants representative of three technologies commercially available with a seven month (January to July 1983) pilot plant program to compare their performance. The three pilot systems studied were the anaerobic filter, the anaerobic upflow sludge blanket (contact) bed, and the anaerobic fluidized bed. This paper presents the development and results of the kinetic analysis on the anaerobic fluidized bed reactor along with a brief summary of the removals obtained on the three systems studied.
An input-output model was developed to predict changes in Salton Sea salinity and water level until the year 2000 due to proposed water conservation efforts and geothermal and solar pond energy developments. The model...
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An input-output model was developed to predict changes in Salton Sea salinity and water level until the year 2000 due to proposed water conservation efforts and geothermal and solar pond energy developments. The model SALINP provided good agreement with the observed salinities for 1960-80. A change in the historical means of the Imperial Valley runoff and evaporative loss inputs produced a significant effect on future predictions. The proposed water conservation measures caused the predicted Salton Sea salinity for 2000 to greatly exceed 40,000 ppm, the level at which adverse effects to wildlife are believed to occur. The possible geothermal development also produced predicted salinities considerably above 40,000 ppm. The salinity predictions for solar ponds by themselves and in conjunction with geothermal development were below 45,000 ppm for 2000.
The activation process near cloud base for submicrometer, soluble atmospheric aerosols is described and special attention is focused on the fraction, ε, of the total aerosol mass concentration that form cloud droplet...
The activation process near cloud base for submicrometer, soluble atmospheric aerosols is described and special attention is focused on the fraction, ε, of the total aerosol mass concentration that form cloud droplets. The variation of ε with updraft speed for various aerosol size distributions is calculated by means of an adiabatic, one-dimensional Lagrangian cloud model. Calculations are made for aerosol particles consisting of pure ammonium bisulphate, (NH4)HSO4and the results show that for a clean continental background aerosol population. ε should be very near unity for all updraft speeds. For an average urban aerosol population, ε is close to unity for convective clouds. but for stratiform cases ε decreases rapidly as the updraft velocity is lowered.
Batch bioassays have been conducted to characterize the response of methanogenic bacteria to several constituents of sulfite evaporator condensate. The results can be grouped into three ranges with increasingly severe...
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Batch bioassays have been conducted to characterize the response of methanogenic bacteria to several constituents of sulfite evaporator condensate. The results can be grouped into three ranges with increasingly severe consequences to anaerobic reactors: a low concentration, no effect range; a medium concentration range where methanogenesis is temporarily interrupted or slowed down, but may return to normal; and a high concentration range where methanogenesis is permanently inhibited. In some cases the toxicant was metabolized when present in the lower concentration ranges. There was also evidence that mechanisms other than fermentation to methane were significant in accounting for removal of the toxicants from solution. Organisms acclimated to low concentrations of a toxicant are better able to withstand a shock load of that toxicant than are unacclimated organisms.
Biofilm processes are potentially important for transformation of organic micropollutants in ground water. Some theoretical hypotheses and empirical observations suggest that a concentration threshold exists for some ...
Biofilm processes are potentially important for transformation of organic micropollutants in ground water. Some theoretical hypotheses and empirical observations suggest that a concentration threshold exists for some compounds below which the concentration cannot be reduced by bacterial action. In the presence of 1 compound at a relatively high concentration, termed the primary substrate, another compound present at trace concentrations, termed the secondary substrate, can be biotransformed as well. These concepts were evaluated through laboratory column studies with several halogenated organic compounds of importance in ground water. A biofilm model successfully described utilization of trace substrates, and application to modeling the subsurface was discussed. A simplified batch model with 1st order kinetics may have been adequate for describing subsurface microbial processes when low active organism and pollutant concentrations existed over a large scale.
A basic framework for the modeling of the fate of chemicals in natural water systems is presented. Both the physical/chemical and ecological fate of the substance are considered. The fully time variable equations do n...
A basic framework for the modeling of the fate of chemicals in natural water systems is presented. Both the physical/chemical and ecological fate of the substance are considered. The fully time variable equations do not present any significant insight into the general behavior of chemical fate. However, under a steady state assumption and including bottom sediment interactions, relatively simple formulations result that permit rapid calculation of the maximum concentrations that might be expected. It is shown that for a completely mixed lake the ratio of the areal loading rate of the toxicant to the water column concentration is determined by the hydraulic overflow rate and the net loss rate of the toxicant from the water column. Thus, c T = W Ta /q + w T for c T as the total toxicant concentration, W Ta as the areal loading rate of the chemical, q as the hydraulic overflow rate, and w T the net loss of the chemical. The net loss rate w T is a function of all water column and sediment decay rates and interactions. The steady state food chain model of the accumulation of a toxic chemical from both water and food sources is shown to be a means for estimating the parameters of loss and sediment interaction for a lake. The steady state case of the discharge of a chemical into a stream provides a simple means for estimating net loss rates under some reasonable assumptions. Also coupling the food chain model to the physio-chemical model permits the use of chemical concentrations in the fish to estimate the net loss of toxicant in a stream. Application is made to metals concentrations in Lakes Ontario and Michigan and to 1,4 dichlorobenzene in Lake Zurich. The theory indicates that under zero decay of the chemical in the sediment and equal partition coefficients in the sediment and the water column that the chemical in particulates form in the sediment should equal that in the water column. Metals data for Lake Ontario appears to confirm this result at least to order of ma
Light absorption by carbon particles has been clearly demonstrated to be important to urban and regional scale radiative processes, with questions remaining about the global scale. Measurements of the light absorption...
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Light absorption by carbon particles has been clearly demonstrated to be important to urban and regional scale radiative processes, with questions remaining about the global scale. Measurements of the light absorption coefficient of size-classified samples of aerosol particles from a wide variety of locations reveal a nearly ubiquitous presence of optically effective carbonaceous particles concentrated in the submicron sizes. Light absorption coefficients at 0.5 μm wavelength for urban areas range from 10 −5 m −1 or less to well over 10 −3 m −1 . Remote marine and stratospheric locations exhibit values as low as a few times 10 −8 m −1 (referenced to sea level) with rural areas in between. Both chemical analysis (in urban/rural cases) and mass absorptivities (in remote cases) indicate that the light absorption is largely due to an elemental carbon component. Since this material probably is produced exclusively by combustion of carbon-based materials and since this occurs primarily on land, the elemental carbon in remote locations may be a residue which has undergone long-distance transport. This hypothesis can be used as the basis for a simple flow diagram which portrays the urban/industrial regions as the source, dispersion carrying carbon aerosol through rural to remote areas with removal occurring continuously or periodically over the lifetime. Via this model the data allow a crude estimation of the regional and hemispheric influence of sources. Collected data will be summarized with ancillary estimates heating rate, demonstrating the range of expected radiative effects.
The majority of data were collected in the central Pacific ocean between 30 degree N and 30 degree S and 130 degree W and 155 degree W. During the KOROLEV cruise, a general symmetry in several aerosol optical and phys...
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ISBN:
(纸本)0444009477
The majority of data were collected in the central Pacific ocean between 30 degree N and 30 degree S and 130 degree W and 155 degree W. During the KOROLEV cruise, a general symmetry in several aerosol optical and physical parameters was observed for both Northern and Southern hemispheres centered on the Intertropical Convergence Zone, while a minima in aerosol mass concentration was observed for this region. An exception was observed for the fine particle size distribution as measured by an active scattering aerosol spectrometer probe.
In a search for the chemical and meteorological factors controlling rainwater composition the authors have demonstrated the performance of these techniques in the analysis of data consisting of rainwater samples colle...
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In a search for the chemical and meteorological factors controlling rainwater composition the authors have demonstrated the performance of these techniques in the analysis of data consisting of rainwater samples collected weekly at four sites in Western Washington State in 1982-83. The approach we have undertaken involves the identification of the underlying factors governing precipitation composition at individual sites supplemented by identification of the factors which link the local composition at different sites within a region. Major steps in this type of analysis include initial data scaling and transformation, outlier detection, determination of the underlying factors, and evaluation of the effect that experimental procedures may have on the variance of the results. Most of the calculations were performed with the ARTHUR software package.
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