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Articles 91 - 120 of 166
Full-Text Articles in Environmental Engineering
The Study Of Activated Sludge Settleability Using The Solids-Flux Analysis, Churng-Cherng Lin
The Study Of Activated Sludge Settleability Using The Solids-Flux Analysis, Churng-Cherng Lin
Theses
The activated sludge was cultivated in two pilot-scale activated sludge systems under three ratios of BOD to N, equal to 20:1, 70:1 and 300:1 in the influent wastewater. The aeration tank of the activated sludge system was constructed in two different configurations: one without compartments in the tank, the other consisting of six compartments. The activated sludge withdrawn from the last compartment of each system was tested in a one-liter graduate cylinder to measure its zone settling velocity. The solids-flux method was employed to analyze the sludge settling characteristic as a function of solids concentration. The results show that the …
Kinetic Measuremenmt Of Decomposition Of Aniline, 2,4-Dichlorophenol And 1,2,4-Trichlorophenol Using A Calorimetric Method, Ming-Chin Chang
Kinetic Measuremenmt Of Decomposition Of Aniline, 2,4-Dichlorophenol And 1,2,4-Trichlorophenol Using A Calorimetric Method, Ming-Chin Chang
Theses
Biological treatment techniques for detoxification of toxic organic compounds have been studied and applied for many years. There are many research and commercial applications proving that the biological method is more economic and efficient than the other treatment methods.
The traditional biomass measurements are time-consuming tasks. Researchers have intended to develop a simpler, faster, and also accurate method for determining the bioactivity. This study has tried to use the microcalorimetric method to monitor the energy productions from the degradation of aniline, 2,4-Dichlorophenol and 1,2,4-Trichlorobenzene. Thereafter, by utilizing the data obtained from the present study, it was possible to compute kinetic …
Disinfection Of Wastewater Using Ultraviolet Radiation, David L. Klemm
Disinfection Of Wastewater Using Ultraviolet Radiation, David L. Klemm
Theses
The disadvantages associated with the use of chlorine for disinfection, in conjunction with improvements in ultraviolet radiation disinfection technologies have led to the recent increased use of ultraviolet radiation to provide disinfection of effluents from wastewater treatment plants. The theory of ultraviolet radiation and the engineering design of the ultraviolet disinfection system are discussed in depth.
The operational history and records of two wastewater treatment plants that use ultraviolet radiation for disinfection were analyzed in an attempt to develop correlations on the factors that affect ultraviolet radiation disinfection efficiency and to investigate as to whether disinfection with ultraviolet radiation is …
Mathematic Models On Leaching Behavior Of Chemical Solidification And Stabilization Process For Heavy Metal Sludges, Sz-Hung Chen
Mathematic Models On Leaching Behavior Of Chemical Solidification And Stabilization Process For Heavy Metal Sludges, Sz-Hung Chen
Theses
Chemical Solidification and Stabilization of toxic metal-containing sludges is one of the most important problems for environmental protection. Although Chemical Solidification and Stabilization of hazardous wastes prior to disposal is increasing in importance, very little work has been done concerning the leaching mechanisms and kinetic models.
In this study, we apply Freundlich & Langmuir isotherms on Chemical Solidification and Stabilization process, and the theoretical results match with experimental data very well. In the same time, we develop a simple methematical kinetic model which relates leaching concentration of heavy metal to curing time. In this study kinetic model, what you need …
Influence Of Heavy Metal Concentration On Rotating Biological Contrator Performance, Huei-Sheng Cheng
Influence Of Heavy Metal Concentration On Rotating Biological Contrator Performance, Huei-Sheng Cheng
Theses
Seven heavy metals ( Fe+2, Mn+2, Zn+2, Ag+, Pb+2, Cu+2, Cd+2 ) at various concentrations were investigated in a Rotating Biological Contactor (RBC) system. The experimental data indicated that the degree of heavy metal toxicity in the biological system mainly depended on the ratio of inflow heavy metal concentration to organic loading. The optimal ratio of heavy metal to organic loading was determined on the basis of the maximum removal of chemical oxygen demand (COD) under different operating conditions. In addition, the effect of heavy metal on …
Biodegradation Of Tnt (2,4,6-Trinitrotoluene), Jin Lou
Biodegradation Of Tnt (2,4,6-Trinitrotoluene), Jin Lou
Theses
This study summaries the results of various methods treating 2,4,6-trinitrotoluene (TNT). Review of available literatures revealed that the most commonly used techniques in full-scale plant for TNT removal are chemical oxidation and carbon adsorption.
From economic point of view, the biological treatment system will be much more cost-effective. Various methods for improving the efficiency of biological system treating TNT wastewater were developed in the laboratory. Current laboratory results show that by isolating appropriate microorganisms under adequate conditions, TNT wastes can be degraded successfully.
At the some time, some pretreatment technologies are recommended in this study for improving the performance of …
Disc Size Scale-Up In Rotating Biological Contactor System, Chi-Sheng Chang
Disc Size Scale-Up In Rotating Biological Contactor System, Chi-Sheng Chang
Theses
Disc size scale-up of prototype and small-scale RBC plants are successfully developed by applying the 114 data sets obtained from 12 RBC plants to the evaluation of percent sBOD remaining. These data analyses are performed by the least square method, therefore, the scale-up factors of the prototype and the small-scale are determined at different hydraulic loading. Furthermore, the relationship between scale-up factor and the disc diameter are established under the given flow rate, the number of stages, and the number of discs. A group of Curves are obtained and can be utilized for the full-scale RBC plant preliminary design. The …
Stability Of Hot Mix Asphalt With Petroleum Contaminated Soils, De-Rong Lobo Huang
Stability Of Hot Mix Asphalt With Petroleum Contaminated Soils, De-Rong Lobo Huang
Theses
One of the most effective ways of reducing petroleum contaminated soil is to use it in the production of hot mix asphalt. Both asphalt cement and petroleum contaminates have similar chemical properties. Therefore, The contaminates will be locked within the asphalt matrix without potential leaching.
The six different petroleum contaminate soil samples from New Jersey were used in this research. Since those samples have different physical properties (such as moisture content, specific gravity, plastic limit, liquid limit, grain size distribution) and chemical properties( such as concentration of the contaminate, and type of contaminates) the maximum amount of petroleum contaminated soil …
Solidification/Stabilization Of Chromium Contaminated Soil Using Cement And Fly Ash, Arunkumar Sripathi
Solidification/Stabilization Of Chromium Contaminated Soil Using Cement And Fly Ash, Arunkumar Sripathi
Theses
Chromium, when present in the soil, can cause serious health hazards. Toxicity depends upon the concentration in the soil. Chromium in soil has become a major problem in some sites and a method must be developed so that it can be treated or disposed of in a safe manner.
In this research experiments are conducted to check whether the chromium contaminated soil can be solidified and landfilled in a safe way. To have a control over the amount of chromium present in the soil, pure soil (free from chromium contamination) was used and chromium was added in different proportion.
Another …
Centrifugal Modeling Of Leaking Underground Storage Tanks, Kuo-Neng George Chang
Centrifugal Modeling Of Leaking Underground Storage Tanks, Kuo-Neng George Chang
Theses
There are between 2 to 3.5 million Underground Storage Tanks (UST) located through this nation. Most of these tanks store gasoline and fuel oil. Many tanks in fact are or will soon be leaking, thus making them one of the major sources of groundwater contamination in USA. The fate and transport of chemicals from the leaking USTs is estimated from mathematical models. A major difficulty in these modeling efforts has been a crucial lack of information concerning the constitutive relationships governing multiphase contaminant movement.
Centrifugal modeling is an alternative to mathematical modeling, which may give an insight to the problem …
The Dewaterability Of Anaerobically-Digested Sludges, Hui-Ching Lee
The Dewaterability Of Anaerobically-Digested Sludges, Hui-Ching Lee
Theses
Vacuum filtration is the most common method used for sludge dewatering. Filtering or dewatering was operated to reduce the moisture content of the sludge after anaerobic digestion treatment.
The main purpose of this study is to determine the effect of the operating conditions of anaerobic digestion system on specific resistance in sludge filtration. The anaerobic sludges used for the present study were produced from the conventional single stage system and the multiple-stage system. From the experimental results, presently obtained that it is possible to compare the advantage and disadvantage of the two different digestion systems.
In addition, the effectiveness of …
Temperature Scale-Up On Rotating Biological Contactor Nitrification System, Kuanchun Lee
Temperature Scale-Up On Rotating Biological Contactor Nitrification System, Kuanchun Lee
Theses
The relationship between RBC scale-up factor (SUF) and wastewater temperature is successfully developed by using Dr. Wu's mathematical model as a basis and 114 sets of data from the operation of 8 full-scale and 5 pilot-scale RBC plants served for NH3-N removal. The SUF obtained from this study is put into practice to present the scale-up of hydraulic loading for basic full-scale RBC plant design when the pilot study results are known and the design efficiency is fixed. An additional study is made to investigate two different RBC products manufactured by Autotrol Inc. and Lyco Inc. in terms of the …
Demulsification And Separation Of Oil In A Water/Particulate System, Fong-Jung Tai
Demulsification And Separation Of Oil In A Water/Particulate System, Fong-Jung Tai
Theses
The wastewater generated from installation factories contains high suspended solids ( SS ) and oil. Effective removal of oil and clay particles in washrack wastewater can be achieved by using organic polymer TFL-398 alone or in conjunction with alum. The dissolved/emulsified oil concentration and suspended solids are used to represent the degree of oil demulsification and clay particles destabilization, respectively.
To improve the efficiency of oil demulsification and reduce the chemical consumption, pretreatment of the influent wastewater is essentially necessary. pH adjustment to 11-12 generally reduces chemical requirement. Total oil concentration was reduced significantly at pH = 11.7 without any …
A Study Of Methane Gas Production On Anaerobic Digestion System, Seng-Fung Su
A Study Of Methane Gas Production On Anaerobic Digestion System, Seng-Fung Su
Theses
The anaerobic sludge digestion process is not a recent development. At least 100 years ago in France,Louis H. Mouras designed and constructed fermenters to liquefy the sludge obtained from domestic wastes.
Since the turn of the century, the anaerobic fermentation process has been used extensively in the treatment of waste-water solids.
The necessity of preventing pollution of water resource, as a consequence of the rapid increase in human waste, demands adequate treatment of liquid wastes from domestic and industrial sources. For this purpose, the anaerobic digestion process can play an important role as a method for stabilizing and eliminating wastes …
Effect Of Inorganic Salts On Adsorption Process, Pai-Yuan Horng
Effect Of Inorganic Salts On Adsorption Process, Pai-Yuan Horng
Dissertations
`Small amounts (0.0 M-0.01 M) of inorganic salts (sodium chloride, calcium chloride, and aluminum chloride) added to bituminous coal fly ash and granular activated carbon in batch adsorption treatment experiments indicates the possibility of enhancing the extent and rate of adsorption process.
Experiments were conducted on aqueous solutions of highly toxic and hazardous chemicals, those include : phenol, benzene, toluene, isopropyl alcohol, and methyl-isobutyl ketone. Single and multiple solute systems were examined separately. Removal of organic pollutants was measured using a Flame Ionization Detector Gas Chromatograph.
This study investigated the role of inorganic salts during the sorption process. The results …
Application Research On Wastewater Reuse For Petrochemical Refining Industry In Taiwan, Lih-Shyan Lee
Application Research On Wastewater Reuse For Petrochemical Refining Industry In Taiwan, Lih-Shyan Lee
Theses
Nowadays water conservation and pollution abatement are needed to provide increasingly higher levels of treatment for industrial wastewaters.
Reducing treatment costs give us the incentive to minimize the volume of Wastewater effluent. Also, the national goal of zero discharge of pollutants to the waterways by 1985 provided further incentive -to minimize the flow of wastewaters.
A successful treatment of the wastewater discharged from the secondary effluent of the petroleum refinery plant to economically acceptable conditions offers a challenge to our technology.
Through this research, it is concluded that the excellent effluent water qualities produced from filtration and granular activated carbon …
Testing And Modelling Of The Cleaner Wick System For In-Situ Treatment Of Contaminated Groundwater Plumes, Sanjiv I. Shah
Testing And Modelling Of The Cleaner Wick System For In-Situ Treatment Of Contaminated Groundwater Plumes, Sanjiv I. Shah
Theses
The cleaner wick system, a modification of wick drains; a technology in recent use to consolidate low permeability soils, is proposed to treat contaminated groundwater plumes. Laboratory experiments on surrogate contaminants produce satisfactory results. Theoretical models are developed utilizing the cleaner wick system to treat volatile organic contaminants by air stripping and adsorption on granular activated carbon.
Treatment Of Trucking Station Wastewater By Two-Phase Anaerobic Digestion System And Rotating Biological Contactor, Tzu-Wen Uen
Treatment Of Trucking Station Wastewater By Two-Phase Anaerobic Digestion System And Rotating Biological Contactor, Tzu-Wen Uen
Theses
The wastewater produced as a result of trucking station activities has some major characteristics such as high COD (26,880 mg/1-42,925 mg/1) and BOD (12,278 mg/1-7,265 mg/1), high COD to BOD ratio (3.49-3.69), high pH range (3.72-11.7), and high grease content (480 mg/1-1,960 mg/1). Therefore, prior to any treatment, it is important to provide some sort of pre-treatment for pH adjustment and grease/oil removal.
The present laboratory investigation has indicated that successful treatment and purification of the subject wastewater is possible using two-phase anaerobic digestion system followed by rotating biological contactor. More than 90% of both COD and BOD was removed …
Anaerobic Biodegradation Of Trichloroethylene With The Addition Of Sugar Using Activated Carbon-Fluidized Beds, Suxan Huang
Anaerobic Biodegradation Of Trichloroethylene With The Addition Of Sugar Using Activated Carbon-Fluidized Beds, Suxan Huang
Dissertations
Anaerobic biodegradation of trichloroethylene (TCE) was carried out in a two-stage granular activated carbon fluidized bed bioreactor. The intermediate products were identified as: dichloroethylene (DCE), vinyl chloride (VC), 1,2-dichloroethane (DCA) and chloroethane (CA). Of the three geometric isomers of DCE, the trans-1,2 dichloroethylene (TDCE) was found to be the most predominant species, The production of DCA suggested a diverted reaction sequence from the conventional sequential reductive dechlorination pathway postulated in the past literature. CA was believed to be a product of VC and/or DCA. The co-substrate glucose was implicated for this reaction specificity. Based on our data and on other's …
Measurement Of Biodegradation Aniline, 2,4-Dichlorophenol, 1,2,4-Trichlorobenzene Using Microcalorimetric Method, Lung-Weng Yao
Measurement Of Biodegradation Aniline, 2,4-Dichlorophenol, 1,2,4-Trichlorobenzene Using Microcalorimetric Method, Lung-Weng Yao
Theses
Biodegradation of aniline, 2,4-dichloro-phenol, and 1,2,4-trichlorobenzene by using micro-calorimetric method under aerobic condition has been investigated. The rate of heat energy output during the course of log growth phase was kinetically expressed by inhibition equation. The constants of Um(the maximum energy production rate), Ks(saturation rate), Ki(inhibition constant), and n(degree of inhibition) has been of 8.764hr-1, 0.13mg/L, 0.136mg/L, and 4.6 for 2,4-DCP; 3.33hr-1, 0.315mg/L, 0.35mg/L, and 1.4 for 1,24-TCB; 3.639hr-1, 0.4485mg/L, 0.485mg/L, and 5 for aniline.
Surfactant Enhanced Scrubbing In An Ejector Venturi Scrubber Of Sulfur Dioxide From Air Exhaust Streams, Humberto Roman
Surfactant Enhanced Scrubbing In An Ejector Venturi Scrubber Of Sulfur Dioxide From Air Exhaust Streams, Humberto Roman
Theses
The objective of this work was to determine the feasibility of applying the Surfactant Enhanced Scrubbing technique to the removal of sulfur dioxide using an ejector venturi scrubber.
Surfactants were chosen according to information from manufacturers. Those surfactants which offered good behavior in the presence of acidic solutions ( low pH ), and anti-corrosion characteristics were tested.
In the first phase, experiments were performed to determine the behavior of the foams in the ejector venturi scrubber. A foam destruction system was used when foaming conditions required it. In the second phase dynamic runs were performed to determine the removal efficiencies …
Anaerobic Biodegradation Of Trichloroethylene By Activated Carbon Fluidized-Bed, Yeam-How Chin
Anaerobic Biodegradation Of Trichloroethylene By Activated Carbon Fluidized-Bed, Yeam-How Chin
Theses
Abstract - The biodegradation of Trichloroethylene by using anaerobic activated carbon fluidized bed has been investigated in the present study. High quality effluent was obtainable when the TCE influent concentration was up to 2.4 ppm in the first stage. Glucose was introduced as a cosubstrate to determine the effects of glucose/TCE ratio on the COD, Glucose and TCE removal. The experimental data indicates that the overall TCE removal efficiency was only slightly affected by TCE loading, but the first stage performance was significantly influenced by TCE loadings. It was also found that the microbial activities were affected by TCE loadings …
Variations Of Alkalinity, Ph, Oxidation Reduction Potential, And Conductivity In Single And Multi-Stage Sludge Digestion Systems, Nasser M. Kamazani
Variations Of Alkalinity, Ph, Oxidation Reduction Potential, And Conductivity In Single And Multi-Stage Sludge Digestion Systems, Nasser M. Kamazani
Theses
Anaerobic digestion is used at many municipal and industrial wastewater treatment plants. Recent increase in the cost of energy and search for an alternative source of energy for the future have prompted renewed interest in anaerobic digestion for energy recovery by production of methane from waste materials, including wastewater sludges and agricultural and municipal solid wastes. Accordingly, a large literature exist on the subject, most of it dealing with more physical aspects of different process design. Little or not enough attention has been paid to its highly complex biochemical characteristics.
The purpose of this study is a preliminary investigation regarding …
Removal Of Contaminants From Clay Soils By Thermal Desorption, Wen-Ming Mao
Removal Of Contaminants From Clay Soils By Thermal Desorption, Wen-Ming Mao
Theses
The objective of this study was to investigate the removal of contaminants from clay soils by thermal treatment. There were two phases involved in this project. The first was a study of equilibrium adsorption of clay - organics study, and the second was the determination of the thermal desorption characteristics.
Three organics, phenol, chlorophenol, and chlorobenzene and one clay soil, bentonite, were selected for these studies. The first phase, involved the simulation of the isothermal adsorption simulated the process of contaminants being sorbed onto bentonite. Three different isotherm models,viz, Linear isotherm, Freundlich isotherm, and Langmuir isotherm were evaluated with experimental …
Environmental Impact Assessment For Water Resources Projects : Planning Procedure And Analytical Methods, Mahadesh C. Tumkur
Environmental Impact Assessment For Water Resources Projects : Planning Procedure And Analytical Methods, Mahadesh C. Tumkur
Theses
This thesis presents a state of the art review of environmental impact assessment procedures utilised in the water resources projects which have evolved over the past two decades. The methodologies employed and some of their limitations which exist and are inherent in both the planning and assessment phases of analysis are identified. The above was supplemented by an investigation of the various views of professionals currently employing the above methodologies. The review effort summarizes the relevant information obtained from the literature which is rather dynamic because of the ever evolving nature of the field. One conclusion drawn from this study …
Durability Of Slurry Cut-Off Walls Around Hazardous Waste Sites, M. Khalid Umer
Durability Of Slurry Cut-Off Walls Around Hazardous Waste Sites, M. Khalid Umer
Theses
A study was undertaken in order to provide insight into the behavior of backfill materials when in contact with hazardous chemicals. It was found that the liquid limit is not a reliable parameter in assessing clay behavior when exposed to these chemicals. However, the expansion index provided a consistent correlation to permeability when all other conditions were kept constant. In addition, the use of fly ash mixed with clay showed an increase in the values of permeability even though its grain size is finer than that of sand. It is believed that this phenomenon was the result of the absence …
Anaerobic Biodegradation Of Trichloroethylene By Activated Carbon Fluidized-Bed, Jiunn-Horng Chern
Anaerobic Biodegradation Of Trichloroethylene By Activated Carbon Fluidized-Bed, Jiunn-Horng Chern
Theses
The synthetic wastewater containing trichloroethylene (TCE) was anaerobically degraded with glucose using activated carbon fluidized-bed.
The range of TCE concentration from 26 ppb to 10.8 ppm was examined. The ratio of glucose to TCE in the influent wastewater was ranged from 26 to 805, while the TCE loading ranged from 0.025 to 1.510 mg/hr-L.
The TCE removal efficiency under these treatment conditions was found to be of 99.4%. However, the reduction of chemical oxygen demand (COD) decreased when the TCE loadings was over 0.38 mg/hr-L.
Multiyear Drought Simulation With Periodic-Stochastic Hydrologic Processes, Lankeswara Hemal Wijayaratne
Multiyear Drought Simulation With Periodic-Stochastic Hydrologic Processes, Lankeswara Hemal Wijayaratne
Dissertations
Previous studies on multiyear droughts are often limited to the analysis of historic annual flow series. A major problem in these studies is the unavailability of long historic flow records, on which to perform the analysis. To overcome this difficulty, the present study has used synthetically generated mean annual flow series to suppliment the historic flows. For the purpose of generating flows, a general methodology was developed to propose a mathematical model based on the harmonic and stochastic analyses of the historic flow series. The main objective was to derive a large population of multiyear drought events from the generated …
Sorption And Desorption Of Organic Compounds By Flyash, Kashinath Banerjee
Sorption And Desorption Of Organic Compounds By Flyash, Kashinath Banerjee
Dissertations
A sorbent treatment process has been developed which uses flyash as sorbent in the treatment of highly toxic and hazardous chemicals; these include: Alcohols, Aldehydes, Ketones and Aromatics. Batch, as well as dynamic, studies were performed, in different phases, during the investigation. Single and multiple solute systems were examined separately. The samples were analyzed using a Flame Ionization Detector Gas Chromatograph.
The result of this study demonstrates that isolation/ immobilization of the organic pollutants is technologically feasible by adsorbing the contaminants onto flyash. The residual carbon content of the flyash plays a very significant role during the treatment process. The …
The Quantitative Determination Of Formaldehyde In Ambient Air (Analytical Method), Chitsan Lin
The Quantitative Determination Of Formaldehyde In Ambient Air (Analytical Method), Chitsan Lin
Theses
A procedure for coating in situ silica gel in prepacked cartridges with 2,4-dinitrophenylhvdrazine (DNPH) acidified with hydrochloric acid is described. The method was evaluated under practical field conditions in The Northern New Jersey-Staten Island Urban Air Toxics Project. The formaldehyde hydrazone formed is desorbed by acetonitrile and determined by high-performance liquid chromatography with UV det.ection. In this study, we have examined trap coaz)ng, trap efficiency, parallel ambient air and inaoor air sampLing, to find the best analysis method. Sampling traps aci:iifled .:ith hydrochloric acid perform better than those using percnicric acid or phosphoric acid. Trap sampling efficiency was significantly affected …