bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant experience using hydrogen peroxide for enhanced fat flotation and bod removal
Authors: Steiner Norbert , Gec Robert 
Published: February 2007

AbstractHydrogen peroxide (H2O2), is known in the food processing industry to reduce COD, BOD, to prevent anaerobic conditions in pipes, tanks and lagoons and to remove malodorous sulfides in effluents from anaerobic wastewater treatment. It has recently been shown to also provide effective solids removal from food processing wastewater. The wastewater of food processing plants often contains a very high loading of organic material consisting of fat, oil and grease (FOG), resulting in unacceptable BOD and COD levels. Since many wastewater treatment systems are being pushed to the limit of their capacity or are already overloaded, the high FOG loading cannot be removed well by the conventional means of treating the wastewater with dissolved air flotation or grease traps. As a result, many food processors are paying surcharges for not being in compliance with the tight discharge limits. To overcome these problems, a process has been developed using H2O2 for enhanced FOG recovery and BOD removal. The process is based on the formation of microbubles which attach themselves to the FOG particles and float them to the surface where they can be easily skimmed off. In addition to meeting effluent standards, the process has been able to yield a material that is very renderable and suitable for reuse. Technical and operational data of several industrial applications in the U.S. and Canada are presented, together with process costs. H2O2 treatment will generally be most applicable when improvement of solids removal is required without major investment costs, e.g. emergency situations, during seasonal peaks or increased production.
Removal of creosote from soil by bioslurry reactors
Authors: Lauch Richard P. , Herrmann Jonathan G. , Mahaffey William R. , Jones Alan B. , Dosani Majid , Hessling Judy 
Published: February 2007

AbstractBiological slurry reactors were tested for removal of polynuclear aromatic hydrocarbons (PAHs) from creosote contaminated soil. Five bioslurry reactors, operated in parallel, kept the soil aerated, partially suspended and well mixed.The reactors were inoculated with indigenous microbes of the Genus Pseudomonas. Nutrients were added to maintain the optimum ratio of carbon, nitrogen, and phosphorus. Temperature within the reactors was approximately 25°C. The slurry consisted of approximately 30% contaminated soil.Results of pilot studies showed that approximately 90% of the total PAHs were removed in the first two weeks. Total PAH concentration in the soil was reduced from approximately 10,973 mg/kg to 1,097 mg/kg. Two and three ring PAHs, such as naphthalene, fluorene, and phenanthrene were approximately 96% removed in the first two weeks and higher ring compounds such as chrysene, benzo‐a‐pyrene, and benzo(b) fluoranthene were approximately 83% removed in the first two weeks.
NOx removal on a coal‐fired utility boiler by selective non‐catalytic reduction
Authors: Jødal Morten , Lauridsen Tove Linding , Dam‐Johansen Kim 
Published: February 2007

AbstractA plant for Selective Non‐catalytic Reduction (SNR) of NOx emissions by NH3 (ammonia) injection has been designed, installed and successfully tested on a 135 MWe coal‐fired utility boiler. The final 2000 hours test was performed with the plant automatically controlled.The NOx level in the untreated flue gas is typically 400–700 ppm, and NH3 is injected at a molar ratio to NO between 0.6 and 1.8. Through most of the load range 50–70% reduction of the NOx emission was achieved.The temperature window for the process is 850–1050°C, with an optimum at 950°C.In order to minimize the emission of unburnt NH3, natural gas was added in a molar ratio to NOx of about 1 in part of the load range. The plant met a demand of no more than 15 ppm NH3 in the flue gas.The research and development work needed for adoption of the SNR‐process to coal‐firing has been in progress through five years in a cooperation between Alborg Ciserv International, The Technical University of Denmark, and the Danish power plant association ELSAM. The research program included basic laboratory research on the chemical kinetics of the process, pilot scale research on the reducing capacity and emissions of ammonia and urea, testing in laboratory scale and pilot scale of several additives for widening the temperature window and minimizing the NH3 emission, and development of nozzles for good mixing of NH3 into the flue gas.The resulting concept is applicable for NOx‐removal on several types of boilers.
Anaerobic/aerobic biological activated carbon (BAC) treatment of a high strength phenolic wastewater
Authors: Weber A. Scott , Lai Ming‐Shen , Lin Wei , Goeddertz John G. , Ying Wei‐Chi , Duffy James J. 
Published: February 2007

AbstractAs a result of manufacturing operations at the Durez Division of Occidental Chemical Corporation (OCC) located in North Tonawanda, New York, a highly phenolic wastestream is produced. At the time of this study, average phenols and total COD concentrations of the wastestream averaged 35,000 and 10,000 mg/L. Studies were conducted at the Durez Facility to assess sequenced anaerobic/aerobic biological activated carbon (BAC) process treatment of this wastestream. The first stage anaerobic BAC process achieved significant organic conversion with minimal solids production, and near stoichiometric methane production. Excellent polishing of the AnBAC process effluent was achieved in the aerobic BAC unit even under variable influent conditions. Effluent filterable COD from the aerobic BAC process averaged 165 mg/L and was speculated to be primarily non‐biodegradable soluble metabolic endproducts. Effluent phenols from the process typically were below 0.01 mg/L and averaged 0.04 mg/L. Overall process efficiency for total COD, filterable COD, and phenols were > 97, > 99, and approximately 100 percent, respectively.
Effects of fine powder addition on the sludge unit of a chemical wastewater
Authors: Kwelle C. Hart 
Published: February 2007

AbstractEquilibrium powdered activated carbon (PAC) concentrations of 20, 160, and 280 mg/L in bench‐scale activated sludge units treating cellulose acetate processing wastewater were found to enhance substrate removal. The mean improved COD removal was 20 percent. The apparent mechanism of enhanced substrate removal was the stimulation of greater biomass growth.PAC addition increased the oxygen uptake rate (OUR), the observed cell yield coefficient (Yobs) and the pseudo‐first order substrate removal coefficient (Kb), of the activated sludge system, which was operated at a temperature of 18° C and at a mean cell residence time (MCRT) of 14 days. The addition of PAC also improved the sludge settleability, but this resulted in higher effluent SS concentration because zone settling velocity (ZSV) was the primary factor affecting effluent SS.
Biocatalytic desulfurization of petroleum and middle distillates
Authors: Monticello D. J. 
Published: February 2007

AbstractBiocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst‐based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations.This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. Feasibility studies with various crude oils and middle distillates achieved unoptimized desulfurization levels of 40–80%. Sensitivity analyses indicate that total desulfurization costs of about $3.00 per barrel for crude oil and less than $2.00 per barrel for diesel are possible. Key criteria for commercial success of the process include the cost and half‐life of the biocatalyst, residence time in the reactor, oil/water ratios required to extract the sulfur and the disposition of the separated sulfur products.
Fluorescence monitoring of polycyclic aromatic hydrocarbon biodegradation and effect of surfactants
Authors: Putcha Rajesh V. , Domach Michael M. 
Published: February 2007

AbstractPolycyclic Aromatic Hydrocarbons (PAH) are ubiquitous environmental pollutants that are suspected to be carcinogenic. Because some PAHs can undergo metabolic degradation, an interest has emerged in bioremediating contaminated sites and incorporating surfactants into treatment processes because the release of slowing desorbing, soil‐bound PAH may be promoted. We employed fluorescence spectroscopy and quenching experiments to investigate micelle‐naphthalene interaction and the dynamics of biodegradation in the presence and absence of micelles. These experiments were envisioned to provide some molecular‐level insights as well as constitute the basis for subsequent work where realistic model systems will be investigated in a noninvasive manner. In the absence of micelles, naphthalene was observed to be degraded within three days and intermediates were detected. Micelles protected naphthalene against copper quenching and also suppressed biodegradation. Additionally, the emission spectrum of the naphthalene associated with the micelles changed over the course of days. Based on prior quenching and polarization studies, this finding suggests that micelle maturation may occur over the time scale of the days resulting in increased sequestering of naphthalene in the micellar phase.
A screening protocol for bioremediation of contaminated soil
Authors: Rogers Jean A. , Tedaldi Dante J. , Kavanaugh Michael C. 
Published: February 2007

AbstractA bioremediation treatability protocol for soil is presented which can provide feasibility study and remedial action engineers maximum information with respect to the viability and efficiency of bioremediation. The protocol, divided into two main phases, progressively evaluates the viability of biodegradation and the requirements for optimization of the process once implemented. Chemical and microbiological baseline conditions and the potential for contaminant degradation are assessed during Phase I screening. During Phase II the endpoint achievable and kinetics of the biodegradation reactions can be established with pan and slurry reactor tests for ex‐situ systems or column tests for in‐situ systems. Models are reviewed which can predict the rate of removal of organic constituents, and these data in conjunction with the Phase I and II may be used to estimate the potential time required to achieve cleanup standards, assess the relative importance of biological versus chemical removal mechanisms, and compare expected performance of alternative bioremediation methods.
Removal of arsenic from groundwater using reagent binding/membrane separation
Authors: Legault Anne S. , Volchek Konstantin , Tremblay André Y. , Whittaker Harry 
Published: February 2007

AbstractA hybrid method incorporating selective polymeric binding and membrane separation was used for the removal of arsenic from contaminated groundwater. Two types of polymers, polyethylenimine (PEI) and poly‐diallyl dimethyl ammonium chloride (DADMAC) and an ultrafiltration membrane were used at various concentrations and pH. Bench‐scale tests demonstrated a high degree of arsenic removal. The retention of arsenic was also determined in the presence of various background salts such as NaCl, NaNO3, Na2SO4, Na2CO3. Retention was found to depend on the concentration and type of anion present in solution.
MX‐2500 thermal processor for the treatment of petroleum refining wastes and contaminated soils
Authors: Swanberg Christopher 
Published: February 2007

AbstractSeparation and Recovery Systems, Inc. (SRS) of Irvine, California is the market leader in supplying hazardous waste and secondary material dewatering and drying services to the petroleum refining industry. In late 1991, SRS introduced the new generation of dryer technology, the MX‐2500. The MX‐2500 is an electrically heated dryer system that recovers virtually all of the hydrocarbon value of refinery wastes and secondary materials, while producing a solid residue meeting EPA Land Disposal Restriction (LDR) treatment levels which allows the refinery to land dispose of the solids, thereby realizing two objectives: waste minimization and oil recovery/recycling.
Chemical barriers for controlling groundwater contamination
Authors: Morrison S. J. , Spangler R. R. 
Published: February 2007

AbstractChemical barriers are being explored as a low‐cost means of controlling groundwater contamination. The barrier can intercept a contaminant plume and prevent migration by transferring contaminants from the groundwater to immobile solids. A chemical barrier can be emplaced in a landfill liner or in an aquifer cutoff wall or can be injected into a contaminant plume. Chemical barriers can be classified as either precipitation barriers or sorption barriers depending upon the dominant mode of contaminant extraction. In a precipitation barrier, contaminants are bound in the structures of newly formed phases; whereas, in a sorption barrier, contaminants attach to the surfaces of preexisting solids by adsorption or some other surface mechanism. Sorption of contaminants is pH dependent. A precipitation barrier can control the pH of the system, but alkaline groundwater may dominate the pH in a sorption barrier. A comparison is made of the characteristics of precipitation and sorption barriers. Experimental data on the extraction of uranium and molybdenum from simulated groundwater are used to demonstrate these concepts.
Field testing solar photocatalytic detoxification on TCE‐contaminated groundwater
Authors: Mehos Mark S. , Turchi Craig S. 
Published: February 2007

AbstractThe Solar Detoxification Field Experiment was designed to investigate the photocatalytic decomposition of organic contaminants in groundwater at a Superfund site at Lawrence Livermore National Laboratory. The process uses ultraviolet (UV) energy available in sunlight in conjunction with a photocatalyst, titanium dioxide, to decompose organic chemicals into nontoxic compounds. The destruction mechanism, as in many other advanced oxidation processes, involves hydroxyl radicals. The field experiment was developed by three federal laboratories: the National Renewable Energy Laboratory, Sandia National Laboratory, and Lawrence Livermore National Laboratory. The United States Department of Energy funded the experiment. Groundwater at the test site was contaminated with trichloroethylene (TCE). A factorial test series examined four separate process variables: pH, catalyst loading, flow velocity, and solar intensity. Lowering the pH from pH 7 to pH 5 had the largest single effect, presumably by minimizing interference by bicarbonate. The catalyst was found to operate more efficiently at low, e.g. ambient sunlight, UV light levels. Information from these field tests suggest that treatment costs for the solar process would be similar to those for more conventional technologies.
Rate controlling model for bioremediation of oil contaminated soil
Authors: Li K. Y. , Annamalai S. N. , Hopper J. R. 
Published: February 2007

AbstractA mathematical model of bio‐remediation of hydrocarbons in a soil matrix has been developed to predict the rate controlling step and the remediation rate during the bioremediation of a contaminated soil. The model is based on mass transfer of oxygen and oil into the aqueous solution in the soil matrix and the biodegradation of the hydrocarbons in the aqueous solution. Monod's equation was used to describe the biodegradation rate in aqueous solution while the mass transfer equations were used to describe the mass transfer rates of oxygen and oil in the soil matrix. Results from model calculations indicate that the bio‐remediation rate increases and approaches a limiting value when one of the rates becomes controlling. When the parameters of the site soil samples are measured and the solubilities of oxygen and oil in aqueous solution are obtained, the bioremediation rate can be predicted by this model. The rate controlling step of the bioremediation site may be identified quickly and steps to improve the bioremediation rate can be recommended.
Simultaneous NOx–SOx removal by ammonia using methanol injection and partial flue gas condensation
Authors: Hjuler Klaus , Dam‐Johansen Kim 
Published: February 2007

AbstractThe feasibility of combining selective reduction of nitric oxide by ammonia, or nitric oxide oxidation by methanol, with partial flue gas condensation has been studied in the laboratory. It was demonstrated that both combinations may result in high removal efficiencies for nitric oxide and sulfur dioxide.High‐temperature reactors (600–900°C) and low‐temperature (20–40°C) tubular condensers were applied in series, and each one was tested individually. The flow of simulated flue gas ranged from 1 to 5 Nl/min. In the condenser simultaneous absorption of ammonia, sulfur dioxide, oxygen, and nitrogen dioxide took place. At certain conditions large quantities of aerosols were formed, particularly when NO2 was present.
Adsorption and desorption studies in the aqueous phase for the toluene/activated carbon system
Authors: Chatzopoulos Dimitrios , Varma Arvind , Irvine Robert L. 
Published: February 2007

AbstractThe activated carbon adsorption and desorption of toluene in single‐component aqueous solutions were investigated. Adsorption equilibrium and batch rate studies were conducted to measure the capacity of Filtasorb‐300 (F‐300) for toluene and to determine the effects of the initial toluene concentration, the F‐300 particle size, and the hydrodynamic conditions in the liquid phase on the rate of toluene adsorption on F‐300. The results of the adsorption rate experiments were successfully fitted with the homogeneous surface diffusion (HSD) model and a surface diffusion coefficient which varies exponentially with surface coverage. The model also accounted for the dependence of the external toluene mass transfer coefficient on the hydrodynamic conditions in the liquid phase. The reversibility of toluene adsorption on F‐300 was addressed in desorption equilibrium experiments which indicated that only about five percent of the toluene molecules adsorb irreversibly on the surface of F‐300. Batch desorption rate studies were conducted for different initial toluene surface concentrations, F‐300 particle sizes, and liquid/solid ratios. Use of the previously determined toluene transport parameters in the HSD model allowed for successful prediction of the experimental desorption rates.
Experimental and modeled results describing the adsorption of acetone and benzene onto activated carbon fibers
Authors: Cal Mark P. , Larson Susan M. , Rood Mark J. 
Published: February 2007

AbstractActivated carbon fibers (ACF) were used to adsorb ppmv concentrations of volatile organic compounds (VOCs) from laboratory generated gas streams. VOCs considered were benzene and acetone because the VOC are commonly found in indoor air and have potential to increase health risks to humans. ACF were used as the adsorbent because they typically exhibit higher adsorption capacities and faster adsorption kinetics than commercially available granular activated carbons (GAC) and show potential as an adsorbent to effectively remove VOCs from indoor air.Adsorption models by Dubinin and coworkers (Dubinin, 1975), based on the theory of volume filling of micropores, and an empirical model by Freundlich were used to fit the measured adsorption isotherms. Agreement between the modeled and experimental results for acetone and benzene using the Dubinin‐Radushkevich equation generally improved with increasing BET surface area and produced reasonable fits of the adsorption isotherms for both acetone and benzene. The Freundlich equation produced values for correlation coefficients (R) between modeled and experimental data from 0.980 to 0.997, indicating the validity of using the Freundlich equation to model the adsorption isotherms over the concentration range of interest.These results indicate that ACF show potential as an adsorbent for removing low concentrations of VOCs from indoor air.
Comparison of adsorption characteristics for VOCs on activated carbon and oxidized activated carbon
Authors: You J. H. , Chiang H. L. , Chiang P. C. 
Published: February 2007

AbstractIn this investigation, the selected activated carbon is treated in NaOH solution or gas fluid with ozone from an ozone generator. FTIR, BET specific surface area and element analysis instruments were used to identify the difference in the chemical and physical characteristics between the activated carbon and oxidized activated carbon. The system of adsorption apparatus consists of a fixed adsorption column, quartz pan, electronic balance, and data acquisition system to measure the adsorption capacities and adsorption rates for VOCs under various operating conditions. VOCs, n‐hexane, methyl‐ethyl‐ketone, and benzene were selected to evaluate the effect of adsorption characteristics on the activated carbon and oxidized activated carbon.The results of chemical analysis with the FTIR instrument indicate the absorption bands and peaks measured at 1632 cm−1 on the oxidized activated carbons (AOHO3 and AO3) are much stronger than on the activated carbon (AC). This shows that carbonyl (conjugated CO) of the functional group is predominantly found to increase on the oxidized activated carbons (AO3 and AOHO3). Significant changes were observed for BET‐specific areas for AOHO3 and AO3 but the carbon contents of AOHO3 decreased slightly. Moreover, the oxidized activated carbons showed greater affinity for polar adsorbate than did AC, and the overall effective mass transfer coefficients, kD, of AO3 for various VOC adsorption were larger than those of AC and AOHO3.
Supercritical extraction of organic contaminants from soil combined with adsorption onto activated carbon
Authors: Madras Giridhar , Erkey Can , Akgerman Aydin 
Published: February 2007

AbstractA novel process is proposed for remediation of soils contaminated with heavy molecular weight organic compounds. In this process, the organics are continuously extracted using supercritical carbon dioxide and then deposited on activated carbon. The feasibility of this process is investigated on a laboratory scale for remediation of soils contaminated with naphthalene, phenanthrene, hexachlorobenzene, and pentachlorophenol. The desorption profiles of the organics from soil and the adsorption isotherms of these organics on activated carbon were determined in presence of supercritical carbon dioxide using an experimental technique based on frontal analysis chromatography. The desorption profiles from soil indicated that the organics can be completely extracted from soil in a short time. The adsorption isotherms of the organics on carbon indicated that the adsorptive capacity of carbon was very high and approached monolayer coverage. An economic analysis using these results indicated that the proposed process is feasible for soils contaminated with low levels of these organics.