Showing papers in "Journal of the Environmental Engineering Division in 1982"
TL;DR: In this paper, the credibility of water quality models is examined by several quantitative measures of model performance: regression analysis between observed and computed values, relative and root mean square errors and comparison of means.
Abstract: The basic concepts of water quality models are reviewed and the need to recognize calibration and verification of models with observed data is stressed. Post auditing of models after environmental control procedures are implemented is necessary to determine true model prediction ability. The direct questions in the decision-making arena related to model credibility are examined by several quantitative measures of model performance: regression analysis between observed and computed values, relative and root mean square errors and comparison of means. An analysis of 15 DO water quality models indicated median relative error of 10%. For a eutrophication model of Lake Ontario, application of quantitative verification measures indicated the credibility of the calculations decreased as the model was applied to smaller scale phenomena. Inclusion of more complex kinetics reduced median relative error across five variables and over a 10 year modeling framework from 32% to 22%. It is suggested that quantitative measures of water quality model credibility be integrated into the modeling analysis whenever possible.
172 citations
TL;DR: An activated-sludge anaerobic digestion model is proposed which includes a first-order rate mechanism for preliminary conversion of viable activated sludge biomass into available anaer aerobic substrate.
Abstract: The purpose of this laboratory study was to evaluate, and model the effect of solids retention time in the activated sludge process (θ\N\dc\uA\uS) on the performance of anaerobic digesters fed the resulting waste sludges. Activated sludge systems were operated over a range of θ\N\dc\uA\uS values, with the waste sludges used as feed sources for batch and semi-continuous anaerobic digestion studies. Previous models for aerobic biodegradability of activated sludges were found to accurately predict ultimate anaerobic digestibility. However, conventional kinetic models of digestion over-estimated actual performance with this substrate. An activated-sludge anaerobic digestion model is proposed which includes a first-order rate mechanism for preliminary conversion of viable activated sludge biomass into available anaerobic substrate. Decreasing θ\N\dc\uA\uS results in increased sludge solids for digestion. However, the solids are of sufficiently greater digestibility that both the quantity of digested solids for ultimate disposal, as well as the cost of digestion, are virtually independent of θ\N\dc\uA\uS.
164 citations
TL;DR: In this paper, the impact of temperature variations on the rate of methane generation from solid waste was investigated, and the results showed that the temperature of 41°C was the optimum for methane generation on a short term basis.
Abstract: The objective of this investigation was to study the impact of temperature variations on the rate of methane generation from solid waste. The temperatures investigated ranged from 21°C to 48°C. Two approaches were applied. These were short term residence at seven different temperatures and intermediate term residence at two different temperatures. For the short term studies, samples were obtained from the Freshkills landfill (M.Y.) and the Operating Industries landfill (Calif.). Three samples were used in the intermediate term studies, and were from Palos Verdes landfill and Menlo Park landfill, both in California. From the short term results, energy of activation values of 22.4 kilo calories per mole to 23.7 kilo calories per mole were calculated. The intermediate term results produced values ranging from 18.7 to 21.8 kilo calories per mole. From the results it was concluded that some minor population shifts occurred with minor temperature changes but all of the energy of activation values were higher than any previous reportings. In addition, the temperature of 41°C was found to be the optimum for methane generation on a short term basis.
105 citations
TL;DR: In this article, a method for the analysis of refuse stability has been developed and tested by analyzing refuse obtained directly from test lysimeters and actual landfills across the United States.
Abstract: A method for the analysis of refuse stability has been developed and tested by analyzing refuse obtained directly from test lysimeters and actual landfills across the United States. Refuse samples from test lysimeters are analyzed to develop the procedures and to test the concepts involved. Results obtained from actual landfill situations are compared to those obtained from the test lysimeters of known refuse age in order to determine the degree of refuse stability in each landfill in relation to depth and location. Each landfill was analyzed as to how environmental conditions such as pH, moisture content, and remaining organic content are affected by location and depth. Also, the results obtained from landfills of different geographical locations, different climatic situations, and different configurations are compared. Because the ultimate use of a sanitary landfill site is of prime concern, the rate of refuse stabilization is important to know from the standpoints of future leachate production, methane gas generation, and differential settlement.
103 citations
TL;DR: In this article, mathematical models are applied to the movement and inorganic contamination of moisture in sanitary landfills situated above the water table, based on simple well-mixed reactor concepts, and on unsaturated flow and transport in porous media.
Abstract: Mathematical models are applied to the movement and inorganic contamination of moisture in sanitary landfills situated above the water table. The models are based on simple well-mixed reactor concepts, and on unsaturated flow and transport in porous media. Computer simulations are obtained for laboratory-scale experimental landfills reported by others. General agreement between simulated and observed results indicates that leachate behavior is explainable in terms of fundamental transport processes. The roles of moisture retention in the landfill and dilution by infiltrating water are shown to be of primary importance in understanding and predicting leachate quantity and quality.
92 citations
TL;DR: In this article, eight test lysimeters containing 100-200 tons of refuse each were monitored for seven years for leachate and runoff rates, leachates and gas composition, refuse temperature, and surface settlement.
Abstract: Eight test lysimeters containing 100-200 tons of refuse each were monitored for seven years for leachate and runoff rates, leachate and gas composition, refuse temperature, and surface settlement The lysimeters were designed to indicate the effects of refuse shredding soil cover, and lift thickness on the monitored parameters More runoff but less evapotranspiration was obtained with soil cover, with the result that leachate rates were approximately the same with or without soil cover Shredded refuse produced higher peak concentrations of matter in leachate than unprocessed refuse when landfilled under similar conditions The absence of soil cover resulted in leachate strengths declining rapidly after peak concentrations were produced, with the result that shredded refuse without cover produced less COD than either shredded or unprocessed refuse which was covered Doubling the depth approximately doubled the leachate COD levels, but greatly increased the stabilization time required to low COD levels to be attained Placing a second lift of refuse over a relatively stabilized first lift resulted in 75 to 99% reduction in COD produced by the second lift
83 citations
TL;DR: Alkaline heat treatment was evaluated as a pretreatment process for increasing the anaerobic digestibility of municipal refuse, with the goal was an increased methane yield from refuse lignocellulose as discussed by the authors.
Abstract: Alkaline heat treatment was evaluated as a pretreatment process for increasing the anaerobic digestibility of municipal refuse. The goal was an increased methane yield from refuse lignocellulose. Batch digestibility assays were employed to ascertain the separate effects of solids concentration (0.79 - 10.0 percent), sodium hydroxide concentration (75 - 300 meq/l), and temperature (25 - 250°C) on the methane yield from refuse. Consumption of added alkali was observed and found to be relatively constant per unit mass of refuse solids. Various semi-continuous reactor configurations were evaluated. These studies resulted in investigation of a two-stage digestion system, with the second digester fed alkaline-heat-treated (180 meq/l NaOH, 200°C, 2.1 percent solids, 1 hour) effluent from the first. Such a system operated on newsprint was capable of increasing the methane yield by 80 percent, compared with the yield from a single-stage digester fed raw newsprint. A major limitation appears to be digester inhibition noticeable whenever the concentration of heat-treated lignin products exceeds 1 g/l.
68 citations
TL;DR: In this paper, first-order uncertainty analysis was applied to 258 stream segments to determine the relative contributions to scatter, or uncertainty, in dissolved oxygen predictions by each of the parameters of the Streeter-Phelps equation.
Abstract: First-order uncertainty analysis was applied to 258 stream segments to determine the relative contributions to scatter, or uncertainty, in dissolved oxygen predictions by each of the parameters of the Streeter-Phelps equation. For very sluggish streams with reaeration rates less than about 0.1 per day (base e), the most important parameters for dissolved oxygen predictions were the initial deficit and the deoxygenation rate constant. For streams having reaeration coefficients greater than 0.1 per day the most important parameter corresponded to the predominant aspect of the oxygen balancing mechanism for the stream segment. On the depletion portion of the dissolved oxygen sag curve, where deoxygenation exceeds reaeration, the deoxygenation rate constant contributed most of the uncertainty in D. O. predictions. However, on the recovery portion of the D. O. sag curve, where reaeration exceeds deoxygenation, the reaeration rate constant contributed most of the uncertainty in D. O. predictions. Application of the uncertainty analysis to identify critical water quality parameters for a given stream would lead to more efficient data collection efforts.
59 citations
TL;DR: In this paper, three models describing toxicity phenomena are given to help engineers develop more rational design and operational strategies for wastewater treatment using anaerobic methane fermentation, which is considered unreliable when treating wastewaters containing toxicants.
Abstract: Wastewater treatment using anaerobic methane fermentation offers several significant advantages over aerobic methods, but is considered unreliable when treating wastewaters containing toxicants. Three models describing toxicity phenomena are given to help engineers develop more rational design and operational strategies. The first model describes the recovery pattern of methane fermentation systems from slug addition of toxicants as a function of toxicant type and concentration, and time. This model allows for prediction of periods of zero gas production and threshold toxicant concentrations. The second two models incorporate the effect of toxicity on the fundamental Monod-type expressions. Unsteady-state behavior is effectively described by both models and the importance of providing proper biological solids retention time is emphasized. The primary effect of toxicant addition is to alter process kinetics by temporarily or permanently increasing bacterial washout time. Therefore, to minimize the severity of both transient and chronic toxicity, a sufficiently large solids retention time is required.
56 citations
TL;DR: In this paper, a stormwater runoff pollutant loading model was developed on the basis of results from composite sampling of approximately 500 storms at nine locations in Washington State, and the model as presently constructed is capable of predicting loadings over a time span encompassing a number of storms (monthly or annually), but has little precision when applied to individual storms.
Abstract: A stormwater runoff pollutant loading model has been developed on the basis of results from composite sampling of approximately 500 storms at nine locations in Washington State. One component of the model is an expression for total suspended solids (TSS) load in relation to traffic, runoff coefficient, and surrounding land use contributions. Other contaminants are estimated from TSS load using ratios derived from the data. These ratios may be taken as constants at any Washington State location for some pollutants or as linear functions of traffic for other pollutants. The model as presently constructed is capable of predicting loadings over a time span encompassing a number of storms (monthly or annually), but has little precision when applied to individual storms.
50 citations
TL;DR: In this paper, the authors apply linear programming techniques to investigate the relative costs of regional and state-wide hazardous waste management schemes and identify a cost effective configuration of transportation routes, transfer stations, processing facilities and secure long-term storage impoundments.
Abstract: Linear programming techniques are applied to investigate the relative costs of regional and state-wide hazardous waste management schemes. The focus is the identification of a cost effective configuration of transportation routes, transfer stations, processing facilities and secure long-term storage impoundments. Wastes generated in North Carolina are studied as a useful example of linear programming applications in general and options available within a given state in particular. The value of the techniques are highlighted as are their limitations. The usefulness in developing relative costs of alternatives is stressed, particularly in the ability of the techniques to conduct sensitivity analyses in a topic area where data may not be generally available. Suggestions are made for overcoming data shortcomings. In the case study, the options are seen to revolve around the state of North Carolina's expressed desire to locate one large centralized storage landfill. From a pure cost standpoint, other management facilities like transfer stations and incinerators appear to be precluded even with optimal routing to and from the facilities. From other viewpoints, including risk aversion to spills while the waste is in transit, the inclusion of these facilities in the states program can be supported.
TL;DR: The acid rain model has been developed to simulate lake-watershed acidification processes as mentioned in this paper, which provides a quantitative linkage between atmospheric deposition and lake water chemistry. But the model is limited to the Panther and Woods Lake basins in the Adirondack mountains.
Abstract: The acid rain model has been developed to simulate lake-watershed acidification processes. It provides a quantitative linkage between atmospheric deposition and lake water chemistry. The continuous simulation model is comprised of several modules including watershed hydrology, stream and lake hydraulics, canopy, snow, soil, stream and lake chemistry. The hydrology module simulates the processes of interception, throughfall, evapotranspiration, freezing and thawing of soil, and snow accumulation and melting. The model segregates the watershed horizontally into subcatchments and vertically into soil layers. Flows are routed through a layered soil profile to the streams and ultimately to the lake. Incoming precipitation and deep groundwater flow. Application of the model to Panther and Woods Lake basins in the Adirondack mountains of New York indicates the importance of flowpaths in determining lake water acidity.
TL;DR: In this paper, equal-sized activated carbon and anthracite coal were compared when used as packing media in completely mixed anaerobic filters, and the granular activated carbon packed filter resulted in better chemical oxygen demand conversion, higher rates of methane production, and lower biomass production than the anthricite packed filter for all the conditions tested.
Abstract: Equal-sized activated carbon and anthracite coal were compared when used as packing media in completely mixed anaerobic filters. Synthetic glucose and phenol bearing solutions and a diluted paint stripping bath wastewater were used as the test substrated. Each wastewater was fed to the two anaerobic filters until stable operating conditions were reached. The granular activated carbon packed filter resulted in better chemical oxygen demand conversion, higher rates of methane production, and lower biomass production than the anthracite packed filter for all the conditions tested.
TL;DR: The Safe Drinking Water Act of 1974 emphasizes the need to take costs into consideration when promulgating regulations and as mentioned in this paper presents cost equations that can be used for water treatment unit process cost estimating The need for pre-design estimates is discussed, and the factors affecting the reliability of cost estimates are examined.
Abstract: The Safe Drinking Water Act of 1974 emphasizes the need to take costs into consideration when promulgating regulations This paper presents cost equations that can be used for water treatment unit process cost estimating The need for pre-design estimates is discussed, and the factors affecting the reliability of cost estimates is examined These factors include availability of basic data, stage of development, definition of scope, the time expended on analysis, and experience of the analyst Data for these equations were derived from a carefully designed study to establish water supply unit process costs on a consistent and understandable basis The basis for derivation of these curves is presented Examples of the application of these equations are developed based on a standard layout for a water supply treatment plant and assumed standard values for the input factors for the cost equations
TL;DR: In this paper, the Dynamic Estuary model (DEM) was applied to both the Delaware and Potomac Estuaries by the Environmental Protection Agency during the 1970s and evaluated for its usefulness to investigations of wastewater management alternatives in tidal rivers and the upper reaches of estuaries.
Abstract: Applications of the Dynamic Estuary model (DEM) to both the Delaware and Potomac Estuaries by the Environmental Protection Agency during the 1970s are summarized and evaluated. Methods for calibrating, refining, and validating this model, and statistics for evaluating its performance are discussed. Following a brief description of DEM, observed and predicted hydrodynamic, mass transport, and water quality variables are statistically analyzed for the Delaware and Potomac applicatins. Weaknesses in the model and in these applications are identified. Model performance is evaluated for its usefulness to investigations of wastewater management alternatives in tidal rivers and the upper reaches of estuaries. Results indicate that the DEM can describe real-time longitudinal tidal hydraulics with good accuracy for relatively steady flow periods and can predict longitudinal mass circulation with sufficient accuracy for well-mixed, far-field conditions. The DEM can adequately predict relative differences in water quality to be expected from incremental wastewater management alternatives, but more realistic kinetic structures are needed to predict water quality response to large changes in waste load characteristics.
TL;DR: The results indicate that aerobic activity is negligible over the leaching life of a landfill, and that anerobic activity is significantly inhibited from that observed in coventional municipal wastewater treatment.
Abstract: Mathematical models are applied to the dissolution, transport, and decay of organic materials in unsaturated sanitary landfills. The models are based on cascaded reactor concepts and on unsaturated moisture and contaminant transport in porous media. The roles of aerobic and anaerobic bacteria are simulated using conventional kinetic formulations. Computer simulations are obtained for landfill experiments reported by others, and good agreement with observed behavior is demonstrated. The results indicate that aerobic activity is negligible over the leaching life of a landfill, and that anerobic activity is significantly inhibited from that observed in coventional municipal wastewater treatment. Further, the processes of dilution of landfill moisture by infiltration of rainwater, and convection of materials from the landfill via leaching, are significant and in some cases the predominant influences on overall organic behavior. The retention of cells within the landfill system during leachate recycling can be a significant contributor to accelerated rates of biostabilization. The landfill models are useful in the analysis of empirical data and in the identification of important leaching processes.
TL;DR: In this article, the adsorption characteristics of CdII from Cd(II)-BF 4 plating solution on both granular and powdered activated carbons were investigated. And the results indicated that at all pH values, powdered activated carbon such as Nuchar SA and Nuchara SN, exhibited greater Cd II removal capacity than the granular ones such as Darco HD 3000 and Filtrasorb 400.
Abstract: The use of activated carbon for heavy metal removal was exemplified by studying the adsorption characteristics of Cd(II) from Cd(II)-BF 4 plating solution on both granular and powdered activated carbons. The results indicated that at all pH values, powdered activated carbons such as Nuchar SA and Nuchar SN, exhibited greater Cd(II) removal capacity than the granular ones such as Darco HD 3000 and Filtrasorb 400. The powdered activated carbon was bound to spheres (0.6 mm-1 mm) using a suspension-polymerization technique. The adsorption capacity of the aggregated carbons was 85% - 90% of the unbound ones. The rate of Cd(II) removal at pH 7 is proportional to the cadmium concentration, the carbon dose, and the available surface sites. Used activated carbons were regenerated chemically with strong acids such as HCl, HClO 4 , and H 2 SO 4 . Two treatment schemes are proposed with economical analysis for comparison with other common treatment processes.
TL;DR: In this paper, the basic model for both surface and subsurface aeration systems is the exponential form of the first order mass transfer equation, and a nonlinear least squares regression procedure is recommended for estimating the oxygen transfer coefficient and equilibrium saturation concentration.
Abstract: Recommendations for modeling, parameter estimation, and experimental design in unsteady state clean water aeration tests are presented. The basic model for both surface and subsurface aeration systems is the exponential form of the first order mass transfer equation. A nonlinear least squares regression procedure is recommended for estimating the oxygen transfer coefficient and equilibrium saturation concentration. Techniques for selecting the number and spacing of data values and for assessing model adequacy are suggested. Methods for applying clean water test results to field water conditions are described and an example problem is presented.
TL;DR: Using a variety of sludges from thirteen municipal wastewater treatment plants in southeastern Wisconsin, an excellent correlation was established between the calorific value and chemical oxygen demand of the sludge as mentioned in this paper.
Abstract: Calorific values of wastewater plant sludges are best determined using an oxygen bomb calorimeter, an apparatus which is not readily available in many plants. Using a variety of sludges from thirteen municipal wastewater treatment plants in southeastern Wisconsin, an excellent correlation is established between the calorific value and chemical oxygen demand of the sludges. A well-tested recommended procedure for conducting the chemical oxygen demand of wet sludges and semi-dry cakes is also presented.
TL;DR: In this article, the first year of full-time operation of ten highway runoff monitoring sites in the State of Washington, a total of 241 storms were sampled with a composite sampling system developed by Clark and found that vehicle traffic during the storm was the principal factor influencing the mass of suspended solids in the runoff.
Abstract: During the first year of full-time operation of ten highway runoff monitoring sites in the State of Washington, a total of 241 storms were sampled with a composite sampling system developed by Clark. Vehicle traffic during the storm was found to be the principal factor influencing the mass of suspended solids in the runoff. During winter ice conditions a major fraction of solids loadings in runoff can be traced to sand used. A predictive model for total suspended solids loadings was derived as a function of cumulative traffic during storms. Traffic during the dry periods appeared to remove pollutants from the highways and is not significant in predicting pollutant loadings in the State of Washington.
TL;DR: In this paper, the phytoplankton mass and available phosphorus during a destratification experiment, at Lake Calhoun, Minnesota, in 1972, were simulated by a numerical, multilayered, unsteady numerical model.
Abstract: The phytoplankton mass and available phosphorus during a destratification experiment, at Lake Calhoun, Minnesota, in 1972, are simulated by a numerical, multilayered, unsteady numerical model. A timescale of one day is used. The effects of surface mixed layer dynamics, PO\d4-P inflows from surface runoff, recycling of PO\d4-P from the sediments available light, temperature, and mixing in the hypolimnion on phytoplankton productivity are analyzed. The model is used to hindcast the events of 1972, and explore the effects of other lake management alternatives such as the reduction of PO\d4-P from runoff, the elimination of phosphorus recycling, and the maintenance of an artifical deepened surface layer.
TL;DR: In this paper, six different mathematical formulations are evaluated for the photosynthesis-light relationship, based on their ability to describe experimental data collected from nutrient saturated, hypereutrophic Onandaga Lake in New York State.
Abstract: Photosynthesis-light curves for photoplankton describe the characteristic dependence of the instantaneous rate of photosynthesis on incident light. Six different mathematical formulations are evaluated for the photosynthesis-light relationship, based on their ability to describe experimental data collected from nutrient saturated, hypereutrophic Onandaga Lake in New York State. The data are comprised of measurements of in situ gross primary productivity, and the available light from 115 experiments.
TL;DR: In this paper, a field study on the effectiveness of perforated baffles in an existing cross-baffled serpentine flow chlorine contact chamber was reported to increase hydraulic efficiency and lower the required chlorine dose.
Abstract: A field study on the effectiveness of perforated baffles in an existing cross-baffled serpentine flow chlorine contact chamber is reported. The object of the method studied was to increase the hydraulic efficiency and lower the required chlorine dose. A cross-baffled serpentine flow chamber was chosen because it is a common design. Tracer curves and disinfection efficiency were monitored on a modified and unmodified chlorine contact chamber simultaneously operating under equal conditions. Data generated from these field tests and batch reactor experiments were used to determine the efficiency increase achieved from these baffles, and to project the expected benefit of these modifications as an interim solution at municipal treatment plants.
TL;DR: In this article, the authors used both wet weather and dry weather sampling to monitor densities of coliform bacteria in waters draining residential areas of coastal North Carolina and found that septic tank drainfields installed in unsuitable soils are a major source of contamination of these shellfish waters.
Abstract: Wet weather and dry weather sampling is utilized to monitor densities of coliform bacteria in waters draining residential areas of coastal North Carolina. The bacterial levels are compared to different densities of unsewered residences in each watershed and the limitations of the developed soils for assimilating septic tank effluent. An analysis of the data implicates septic tank drainfields installed in unsuitable soils as a major source of contamination of these shellfish waters. In order to reduce the threat to public health and the multimillion dollar economic loss to the fishing industry, several options are presented for rehabilitating concentrations of failing septic tank systems and for modifying overdesigned drainage systems that carry the contamination directly to shellfish waters. In addition, several common sense management practices that minimize the delivery of bacterial contamination to estuarine waters are suggested for use in siting future coastal residential development.
TL;DR: In this paper, the mass transfer coefficients for the volatilization of ethylene and propane were correlated with the hydraulic and geometric properties of seven streams, and predictive equations were developed.
Abstract: Mass-transfer coefficients for the volatilization of ethylene and propane were correlated with the hydraulic and geometric properties of seven streams, and predictive equations were developed. The equations were evaluated using a normalized root-mean-square error as the criterion of comparison. The two best equations were a two-variable equation containing the energy dissipated per unit mass per unit time and the average depth of flow and a three-variable equation containing the average velocity, the average depth of flow, and the slope of the stream. Procedures for adjusting the ethylene and propane coefficients for other organic compounds were evaluated. These procedures are based on molecular diffusivity, molecular diameter, or molecular weight. Because of limited data, none of these procedures have been extensively verified. Therefore, until additional data become available, it is suggested that the mass-transfer coefficient be assumed to be inversely proportional to the square root of the molecular weight.
TL;DR: Theoretical calculations based on aqueous base neutralizing capacity underestimated the CaCO\d3 dose required to achieve lake neutralization (pH 6.5) for a year.
Abstract: Calcium carbonate was utilized to neutralize an acidic lake and stream in the Adirondack Region of New York state. Theoretical calculations based on aqueous base neutralizing capacity underestimated the CaCO\d3 dose required to achieve lake neutralization (pH 6.5) for a year. It would appear that lake sediments have a profound influence on base dose requirements. Calcium carbonate neutralization altered water column pH, calcium, acid neutralizing capacity, dissolved inorganic carbon, dissolved organic carbon, free fluoride, aluminum, manganese, zinc, and copper levels. Chemical equilibrium models appear to be a useful tool in predicting changes in aqueous aluminum chemistry. While calcium carbonate appears to be an effective means of accomplishing lake neutralization, there are potentially deleterious consequences associated with its use.
TL;DR: In this paper, Wu's model for the prediction of soluble BOD removal in RBC systems is discussed extensively for various operating conditions and the model is tested by the use of more than 80 data sets obtained from the operation of six full-scale RBC plants.
Abstract: Practical application of Wu’s model for the prediction of soluble BOD removal in RBC systems is discussed extensively for various operating conditions. The model was tested by the use of more than 80 data sets obtained from the operation of six full-scale RBC plants. Also, nomograms were constructed to demonstrate a method for selecting the design surface hydraulic loadings. More importantly, the hydraulic loading rates predicted/calculated on the basis of the criteria employed for four full-scale RBC plant designs were compared with the actual design hydraulic loadings. No significant difference between the predicted and the designed hydraulic loading was found.
TL;DR: In this paper, anaerobic filter has been used on a laboratory scale to treat a variety of industrial wastewaters, which is known to be effective at treating fermentation pharmaceutical wastes but synthesized organic chemical wastes were considered to be less amenable to treatment.
Abstract: The anaerobic filter has been used on a laboratory scale to treat a variety of industrial wastewaters. The process was known to be effective at treating fermentation pharmaceutical wastes but synthesized organic chemical wastes were considered to be less amenable to treatment. Preliminary studies did indicate that the raw waste exhibited toxicity to both aerobic and anerobic organisms. This investigation dealt with analyzing the physical and chemical variations in the constituents of the pharmaceutical waste. By using laboratory scale models under conditions of controlled temperature, hydraulic loading and organic strength and using a waste feed composed of varying percentages of methanol and waste at a constant COD, it was possible to investigate the toxic effects of the waste on anaerobic digestion. The waste was found to be toxic but the filter could acclimate to it. Final results indicate that the anaerobic filter would treat the waste faster than the existing aerobic extended aeration system producing an effluent as good or better, and because of the methane generated would be an energy producer rather than a consumer.
TL;DR: In this article, a lignocellulosic material (prune pits) was prepared by pyrolysis to 900°C, and then activated in CO 2 at 900°c for activation times ranging from 15 to 60 minutes.
Abstract: Activated carbons were prepared from a lignocellulosic material (prune pits) by pyrolysis to 900°C, and then activation in CO 2 at 900°C for activation times ranging from 15 to 60 minutes. These were compared with each other and to Filtrasorb 400 and Aquanuchar A with regard to specific surface area (N 2 , 77K), pore volume distribution, and the rate and extent of adsorption of dissolved organic carbon (DOC) from filtered wastewater secondary effluent. It was found that the magnitudes of the above variables increased with increased time of activation, and that the magnitudes were greater for extensively activated fruit pits than for Filtrasorb 400 and Aquanuchar A. Moreover, the uptake of DOC onto these powdered activated carbons in batch reactors behaved according to a model based on linear equilibrium and rate controlled by pore diffusion. The apparent diffusivities estimated by this model were in the range of 1 x 10 - ¹ 0 to 3 x 10 - ¹ 0 m²/s, which conform to expected values.