Engineering Commons^™

Methods To Improve The Remediation Of Polycyclic Aromatic Hydrocarbons (Pahs) In Aerobic And Anaerobic Environments, Brian Wartell

Dissertations

Oil spills occur regularly in terrestrial environments and crude oil can contain many compounds that are highly resistant to degradation. Among these compounds are high levels of polycyclic aromatic hydrocarbons (PAHs) which are not only toxic but can also be carcinogenic and/or mutagenic. The first chapter of this dissertation includes an extensive review chapter on the variables affecting the anaerobic degradation of hydrocarbons, with a particular focus on PAHs. Electron acceptors, electron donors, temperature, salinity, pH all play key roles in determining the possibility effective of effective degradation occurring. Thus, by addressing solutions, such as biostimulation, improving environmental variables for …

Modeling Biodegradation Settlement Of Municipal Solid Waste (Msw) Based On Measurement Of Landfill Gas And Degradable Solids In Leachate Recirculated Bioreactors, Vatsal Atulkumar Shah

Dissertations

The purpose of this work is two-fold: 1) to understand the phenomenon of the biodegradation process of municipal solid waste (MSW) in leachate recirculated bioreactors, and 2) to create a realistic predictive model based on this understanding which is capable of supporting a laboratory-to-field relationship for bioreactor landfills. Biodegradation is best described by loss of mass; however, primary researchers have assumed the phenomenon to be purely volume loss and modeled best by mechanical processes using a conservation of energy approach. It is suggested that the phenomenon requires a fundamental understanding of biodegradation process which results in a loss of mass, …

Mechanics Of Biocell Landfill Settlements, Chamil Hiroshan Hettiarachchi

Dissertations

Prediction of landfill gas generation and settlements are of concerns in design and maintenance of biocell landfills. Accurate settlement prediction is essential for design of piping systems used for the delivery of re-circulated leachate and recovery of landfill gas. Landfill settlement is the result of change in overburden stresses and biodegradation of waste. Biodegradation-induced settlement results from the re-arrangement of waste skeleton in response to the decomposition of waste mass.

Current practice of landfill settlement modeling is predominantly empirical, thus most of the available techniques make no attempt to simulate the real mechanisms of waste settlement. Traditionally compressibility index is …

Biodegradation And Landfill Settlement, Shailesh Pisolkar

Theses

The most widely used method for the final disposal of solid waste is landfilling, which is also economical and simpler than most other disposal systems. Long term settlement in a landfill occurs mainly due to biodegradation of the refuse which is a very slow microbiological process. However, if the rate of biodegradation is enhanced, it may be possible to achieve early stabilization, faster settlement, consequently more capacity of the landfill to handle waste.

The objective of this research is to study the effects of enhanced biodegradation on settlement and to compare these results to other models used for predicting landfill …

A Study Of Settlement In Landfills Due To Biodegradation, Michael Guasconi

Theses

Finding new space for landfills is difficult due to land availability, stringent environmental regulations, and public sentiment. So other means of waste disposal, such as hauling it to a distant landfill, or incinerating it, will have to be resorted to. These methods may be unpopular with the public involved. By studying settlement due to biodegradation, ways to increase settlement can be found, allowing for additional waste disposal capacity in operating, and closed landfills.

Existing theoretical models are based on rheological concepts, not on biodegradation. So, they do not realistically model settlement. In this study, a model to determine the rate, …

Biodegradation Of Multiple Substrates In A Batch Reactor, Nilesh Naik

Theses

The biological degradation of multiple substrates was studied at room temperature in aerated 5-liter batch reactors using mixed liquor from the Passaic Valley Sewerage Commissioners wastewater treatment plant (Newark, New Jersey).

Two substrate mixtures were used (with initial concentration indicated in parenthesis): (1) phenol(100ppm) + nitrobenzene(10ppm) + 2,6-dichiorophenol(10ppm); (2) 2-chlorphenol(20ppm) + nitrobenzene(10ppm) + 2,6-dichlorphenol(10ppm). From concentration versus time data, kinetic rate constants for zero-order, first-order, and Monod models were determined. Most of the data were best fit by either the Monod or zero-order model. For all compounds tested biodegradation was the primary removal mechanism, and in many cases the rate …

Biodegradation Of Mixed Phenolic Substrates, Prasad Gonnabathula

Theses

The biological degradation of phenol, with either 2-chlorophenol, 2,6-dichlorophenol, or nitrobenzene as cosubstrates was studied in aerated five - liter batch reactors using mixed liquor from the Passaic Valley Sewarage Commissioners wastewater treatment plant (Newark, NJ). The initial substrate concentrations were: 100 – 150 ppm phenol, 10 - 20 ppm 2-cp, 10 ppm 2,3 dcp, and 10 - 20 ppm nitrobenzene. The concentration vs. time data were fit to three kinetic models: zero-order, first-order, and Monod(assuming constant biomass). Most of the data were best fit by either the Monod or zero-order model. For all compounds tested, biodegradation was the primary …

Biodegradation Of Phenol And 2-Chlorophenol Using A Fill-And-Draw-Reactor, Chi-Chun Tsai

Theses

The biological degradation of phenol and 2-chlorophenol was studied at room temperature in a microprocesser controlled fill-and-draw reactor using activated sludge from the Passaic Valley Sewerage Commissioners wastewater treatment plant (Newark, New Jersey). The reactor was cycled through four unit processes: fill, react, settle, and draw. Different cycle times were tested, and the system response was characterized by dissolved oxygen measurements and substrate analysis (by gas chromatography).

With inhibitory substrates, such as those tested, this reactor had much more flexibility, and was therefore much easier to operate, than a standard continuous flow reactor.

A Comparison Of The Biodegradation Of Nitrobenzene, 1-Butanol, And 2,4-Dichlorphenoxyacetic Acid Using A Municipal Mixed Liquor And Three Commercial Bacterial Preparations, Salvatore P. Salerno

Theses

The biological degradation of nitrobenzene, 1-butanol, and 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in aerated 6 liter batch reactors using activated sludge from the Livingston, NJ wastewater treatment plant-- by itself and in a 10:1 by volume mixture with each of three commercial bacterial preparations: Hydrobac, BI-CHEM DC-1006/7, and Liquid Live Microorganisms (LLMO). Air stripping and adsorption were determined to be insignificant removal mechanisms for the three compounds studied. None of the bacterial mixtures were able to degrade 10 ppm nitrobenzene to any significant extent. A small but noticeable improvement in degradation rates occurred when the Livingston sludge was mixed with …

Kinetics Of Biodegradation Of Phenol And 2,6-Dichlorophenol, Samir Shrikant Desai

Theses

Biological removal of phenol up to 600 ppm and 2,6-dichlorophenol up to 20 ppm was studied in a well aerated fill-and-draw reactor of 41 capacity at 26 C using an activated sludge obtained from the municipal treatment plant in Livingston, N.J. Experimental evaluation of kinetic parameters showed that biodegradation of both phenol and 2,6-DCP followed zero-order kinetics. As expected, the lag time for both compounds was considerably reduced when acclimated sludge was used. However, the metabolism of 2,6-DCP was very slow even for preacclimated sludge, requiring about 36 hours to degrade only 15 ppm.. This was markedly improved by the …

Growth Patterns Of Bacteria In Pressurized Sewage, Dennis Mazzei

Theses

Primary sewage was pressurized at 100 psi for one hour. The effects of this pressure on the growth patterns of general and nitrifying bacteria were examined daily for eighteen consecutive days using Standard Plate Counts and Most Probable Number (MPN) estimates. In conjunction with these tests, the degree of biodegradability was also determined by measuring both daily biochemical oxygen demands (BOD's) and dissolved oxygen levels.

Graphical analysis of experimental data compare the BOD's exterted [sic] by microorganisms to their respective numbers of colonies as determined by plate counts of both pressurized and non-pressurized sanitary sewage diluted to 3. 00%. The …

The Effects Of Pressure On The Biodegradability Of Sanitary Sewage In A Model Activated Sludge Reactor, Nicholas A. Mezei

Theses

Based on existing information concerning the effects of pressure on the biodegradability of sanitary sewage, a model activated sludge reactor was used in conjunction with pressurization to determine the viability of pressurization as a primary sewage treatment process.

Municipal sewage samples were pressurized at 40 psig for one hour with an excess of oxygen. An air compressor and a steel drum were used for sample pressurization. A non-pressurized control sample was maintained. After pressurization, the samples were fed into separate model activated sludge reactors. Biodegradability of both types of effluent was measured by determining their five day biochemical oxygen demands …

Biocatalytic Oxidation Of Nitrilotriacetate, Saul Hammerman

Theses

The specific scope of this work is to study the biological and chemical effects of a single genetic strain of bacteria, Bacillus subtilis #9524, on the specific destruction to innocuous products of sodium nitrilotriacetate (NTA) and sodium tripolyphosphate (STPP). Insofar as the same strain of bacteria was used each time, under limited variability and sterile conditions, the side effects of multiple bacterial strains and their inter-relationships among themselves and the organic substrates are eliminated. This has allowed for excellent replication of results.

This is a generalized technique for the evaluation of the biodegradability of a compound. Whereas tests with activated …