Environmental Engineering Commons^™

Conditioning Films Formed By Algal Biopolymers In Seawater Reverse Osmosis Desalination, David Ladner, John Jurevis, Mark Clark

David A Ladner

No abstract provided.

Navigating The Academic Job Search For Environmental Engineers: Guidance For Job Seekers And Mentors, David Ladner, Stephanie Bolyard, Defne Apul, Andrew Whelton

David A Ladner

Students and postdoctoral associates interested in tenure-track environmental engineering positions have limited resources to aid them. The Student Services Committee (SSC) of the Association of Environmental Engineering and Science Professors (AEESP) organized a workshop to fill some of the need. Newly hired faculty and experienced search committee and department chairs shared information on how to create competitive applications. Students and postdoctoral associates were also provided with individualized feedback on their faculty application packages. Survey data were collected for all participants, and these data are presented in this paper along with tips shared during the workshop and information collected from the …

Characterization Of Reverse Osmosis Membrane Foulants In Seawater Desalination, David Ladner

David A Ladner

No abstract provided.

Photocatalytic Processes For The Removal Of Toxic Metal Ions, Pankaj Chowdhury, Ali Elkamel, Ajay Ray

PC

No abstract provided.

Evaluation Of Chlorine Emission Potential At The New Deer Island Wastewater Treatment Plant, Somnath Basu, Kenneth Shilinsky, Irvine Wei

Irvine W. Wei

The Massachusetts Water Resources Authority (MWRA) is currently constructing a 1,200 million gallon per day secondary wastewater treatment facility on Deer Island, in Boston Harbor. Chlorine, in the form of sodium hypochlorite solution, is purchased and barged to Deer Island for use in both effluent disinfection and odor scrubbing. The Process Engineering Department of Deer Island, as part of its on-going cost effectiveness program, is currently evaluating on-site generation of sodium hypochlorite. The technical analysis includes a thorough examination of the chemistry of production and storage, including potential losses to atmosphere. This paper presents an overview of that examination, defines …

Reuse Of Municipal Wastewater As Makeup To Circulating Cooling Systems, D. Goldstein, Irvine Wei, R. Hicks

Irvine W. Wei

The reuse of municipal wastewater for industrial cooling is an excellent way of preserving clean waters for other uses. Details have been collected from several countries and there is no doubt that this is a thoroughly practical reuse option.

Makeup waters successfully used fall in the range 10-30 mg/l BOD, 30-50 mg/l o-PO₄, 1000-1500 mg/l TDS and 30-70 mg/l NH₃. The major problems are phosphate scale and biological fouling. Usual treatments are lime clarification and chlorination.

Most of the industrial users are power plants, which use high alloy metals to avoid corrosion, but industries using carbon-steel heat exchangers have not …

Analysis Of The Fate Of Chlorine Species As Part Of On-Site Generation Evaluation Of Sodium Hypochlorite At Deer Island, Somnath Basu, Kenneth Shilinsky, Irvine Wei

Irvine W. Wei

No abstract provided.

Effects Of Nitrogen Deposition And Empirical Nitrogen Critical Loads For Ecoregions Of The United States, Linda Pardo, Mike Fenn, Christine Goodale, Linda. Geiser, Charles Driscoll, Edith Allen, Jill Baron, Roland Bobbink, Williams Bowman, Christopher Clark, Bridget Emmett, Frank Gilliam, Tara Greaver, Sharon Hall, Erik Lilleskov, Lingli Liu, Jason Lynch, Knute Nadelhoffer, Steven Perakis, Molly Robin-Abbott, John Stoddard, Kathleen Weathers, Robin Dennis

Frank S. Gilliam

Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the deposition of pollution that would be harmful to ecosystems is the determination of critical loads. A critical load is defined as the input of a pollutant below which no detrimental ecological effects occur over the long-term according to present knowledge.

The objectives of this project were to synthesize …

Sacrificial Hydrogen Generation From Formaldehyde With Pt/Tio2 Photocatalyst In Solar Radiation, Pankaj Chowdhury, Ghodsieh Malekshoar, Madhumita Ray, Jesse Zhu, Ajay Ray

P

In this work, solar TiO2 photocatalysis was used for sacrificial hydrogen generation from formaldehyde. Platinum was loaded onto a TiO2 photocatalyst by a solar photodeposition method to suppress the electron/hole recombination process. The photocatalyst inside the reactor was irradiated from the top with a solar simulator. Photocatalytic hydrogen generation from formaldehyde was influenced by the solution pH, platinum loading (wt %) on TiO2, catalyst concentration, light intensity, and initial formaldehyde concentration. A Langmuir-type model fitted well with the experimental data, and the values of surface reaction rate constant, k, and the adsorption equilibrium constant, K, are 2.3598 × 10–6 mol …

Proteomic Analysis Of 17Β-Estradiol Degradation By Stenotrophomonas Maltophilia, Zhongtian Li

Z Li

Microbial degradation plays a critical role in determining the environmental fate of steroid hormones, such as 17β-estradiol (E2). The molecular mechanisms governing the microbial transformation of E2 and its primary degradation intermediate, estrone (E1), are largely unknown. The objective of this study was to identify metabolism pathways that might be involved in microbial estrogen degradation. To achieve the objective, Stenotrophomonas maltophilia strain ZL1 was used as a model estrogen degrading bacterium and its protein expression level during E2/E1 degradation was studied using quantitative proteomics. During an E2 degradation experiment, strain ZL1 first converted E2 to E1 stoichiometrically. At 16 h …

Removing 17Β-Estradiol From Drinking Water In A Biologically Active Carbon (Bac) Reactor Modified From A Granular Activated Carbon (Gac) Reactor, Zhongtian Li

Z Li

Estrogenic compounds in drinking water sources pose potential threats to human health. Treatment technologies are needed to effectively remove these compounds for the production of safe drinking water. In this study, GAC adsorption was first tested for its ability to remove a model estrogenic compound, 17β-estradiol (E2). Although GAC showed a relatively high adsorption capacity for E2 in isotherm experiments, it appeared to have a long mass transfer zone in a GAC column reactor, causing an early leakage of E2 in the effluent. With an influent E2 concentration of 20 μg/L, the GAC reactor was able to bring down effluent …

Mechanism And Kinetics Of Oxidation Of 2,4,6-Trichlorophenol By Fenton's Reagent, Somnath Basu, Irvine Wei

Irvine W. Wei

Fenton's reagent is an effective oxidant for pretreatment and toxicity reduction in wastewater contaminated with 2,4,6-trichlorophenol (TCP). The reaction, and its dependence on various parameters (e.g., molar ratios of the reacting chemicals, pH, temperature, etc.) have been reported elsewhere. In this paper a mechanistic interpretation of the reaction pathway, with identity of the intermediate reaction products, has been presented. An empirical expression for the rate of reaction has also been proposed in terms of the disappearance of TCP in water, as a function of the concentrations of the TCP itself and of the oxidant, hydrogen peroxide.

Oxidation Of 2,4-Dinitrotoluene Using Fenton's Reagent: Reaction Mechanisms And Their Practical Applications, Nihar Moriarty, Irvine Wei

Irvine W. Wei

With the strict regulations of present times, chemical oxidation holds tremendous potential for destructive treatment of hazardous wastes which are resistant to biological oxidation. Fenton's reagent has proved to be an inexpensive and powerful oxidant which has been shown to oxidize a wide variety of organics. In this paper, 2,4 dinitrotoluene (2,4 DNT) was chosen as a model compound following previous work where 2,4 DNT was subjected to oxidation by hydrogen peroxide in the presence of medium power UV source. Various factors that are important to optimize the oxidation of organics were studied. The effect of aeration, step dosing and …

Comparison Of Theory And Experiments For Dispersion In Homogeneous Porous Media, Mark Porter, Francisco Valdes-Parada, Brian Wood

Francisco J. Valdes-Parada

Modeling dispersion in homogeneous porous media with the convection–dispersion equation commonly requires computing effective transport coefficients. In this work, we investigate longitudinal and transverse dispersion coefficients arising from the method of volume averaging, for a variety of periodic, homogeneous porous media over a range of particle Péclet (Pep) numbers. Our objective is to validate the upscaled transverse dispersion coefficients and concentration profiles by comparison to experimental data reported in the literature, and to compare the upscaling approach to the more common approach of inverse modeling, which relies on fitting the dispersion coefficients to measured data. This work is unique in …

Biological Treatment Processes For Fish Processing Wastewater–A Review, Pankaj Chowdhury, T. Viraraghavan, A. Srinivasan

PC

Water consumption in a fish-processing industry and high-strength wastewater from such an industry are of great concern world-wide. Liquid effluent regulations are becoming more stringent day by day. Biological treatment is the best option for such a wastewater. Anaerobic processes such as upflow anaerobic sludge blanket (UASB) reactor, anaerobic filter (AF) and anaerobic fluidized bed (AFB) reactor can achieve high (80–90%) organics removal and produce biogas. Aerobic processes such as activated sludge, rotating biological contactor, trickling filter and lagoons are also suitable for organics removal. Anaerobic digestion followed by an aerobic process is an optimal process option for fish processing …

Sonochemical Degradation Of Chlorinated Organic Compounds, Phenolic Compounds And Organic Dyes–A Review, Pankaj Chowdhury, T. Viraraghavan

PC

Sonochemical processes have been widely used in chemistry and chemical engineering field. Recently, these processes have found new applications in the environmental field, because of advantages in terms of operational simplicity, secondary pollutant formation and safety. Several studies have reported on sonochemical degradation of organic compounds that are toxic in nature. The objective of this review was to identify and examine some of the studies on sonochmical degradation of chlorinated organic compounds, phenolic compounds and organic dyes. This review also examines the basic theory of sonochemical reactions and the use of sonochemical reactors for environmental applications.