In North America, the activated sludge process is commonly used in wastewater treatment. However, there are many aspects of the process that elude researchers, in particular, those that will ensure a successful control and optimization of the process. Because of the biological nature of the activated sludge process, its characteristics are highly dependent on environmental factors and hence can be very difficult to control and manage successfully. A very important factor contributing to an optimized activated sludge plant is the experience of its operators with the activated sludge process. This is achieved through the use of a variety of tools including traditional classroom training, computer based training, expert systems and simulation tools. Some of the tools aim to help the new operators acquire this experience quicker while others aim to enhance the experience of seasoned operators. This project presents a premise that an integration of these tools will be an effective and innovative way to help the operators achieve their goals. Hence, a design of an Integrated Training and Decision Support System (IT-DSS) has been proposed, and parts of the prototype system have been built. Preliminary results showed that such an integrated solution is feasible and realisable although a fully functional system has yet to be realised due to the scope limit. The results of this project provided solid and valuable starting points for the completion of such a step, and they also further support the value of the integration approach that has been put forth.

The main objective of this study was to compare the total suspended solids (TSS) removal efficiency of a modified sedimentation tank to that of a conventional tank The experimental tank was designed for flow to pass over a series of inclined plates. It had a much shallower flow through zone and the inclined plates were situated just below this zone. The inclined plates were added to provide a quiescent settling zone for the falling particles and to act as a barrier to prevent scour of settled particles. A conventional horizontal flow sedimentation tank was also used in this study. The two designs were run in parallel and a highly concentrated clay suspension was passed through both tanks. The TSS concentrations of both the influence and effluent streams were measured. The response of both designs to different parameters such as sampling time, depth over the inclined plates, flowrate, inclined plates spacing and inlet TSS concentration was observed. The tank with the inclined plates (at the smallest spacing) proved to have an equal to slightly high removal efficiency and a slightly better reaction to the change of parameters. This tank also proved to have less dead volume than the control tank. Since the reduction in flow through volume proved to be as good and slightly better than the control tank the concept deserves further research. It has the potential to permit considerable tank depth reductions while retaining efficiency.

A dynamic model describing the simultaneous degradation of easily degradable substrates (sucrose and acetic acid (HAc)) and 2,4-dichlorophenol (2,4-DCP) in upflow anaerobic sludge blanket reactors (UASB) was developed. Two critical factors considered in the multiple substrate degradation processes were sorption and substrate interaction during degradation. Experimental investigations on the sorption of chlorinated phenols under dynamic situations as well as the degradation kinetics of cosubstrates and 2,4-DCP considering sorption and substrate interaction were conducted first. It was found that partitioning was the dominant mechanism in sorption of chlorophenols to anaerobic granules and that metabolically mediated diffusion during sorption was negligible. Under a dynamic situation, anaerobic sorption of chlorophenols which follow sorption linearity and sorption-desorption singulanty in isotherms, can be described by a dynamic model incorporating linear sorption equation. Nonequilibrium sorption caused by diffusion limitations in anaerobic reactors was found to be negligible because of the strong hydrodynamic dispersion that prevails in anaerobic reactors and the high porosity of anaerobic granules. However, rmnor nonideal sorption phenomena were observed for 3,4-dichlorophenol (3,4-DCP) and pentachlorophenol (PCP), both of which showed sorption-desorption isotherm hysteresis. Substrate interaction during degradation of cosubstrates and 2,4-DCP resulted in the inhibition of acetogenesis and methanogenesis by 2,4-DCP. The effect of electron donors on 2,4-DCP degradation was found to be minimal. A modified Haldane type inhibition function was proposed to described the degradation of 2,4-DCP. On the basis of model discrimination results, the degradation kinetics of HAc and propionic acid (HPr) were defined by the uncompetitive inhibition and Haldane type inhibition functions, respectively, with 2,4-DCP as inhibitor. Acidogenesis of sucrose to HAc or HPr followed the Monod equation since no inhibiting factor was found for this degradation process. Knowledge obtained from the above investigations was used to develop a dynamic model for UASB reactors. Data that were obtained from experimental investigations on multiple substrate degradation in continuous UASB reactors were used to validate and veritjl the dynamic model. The model predicts the system responses for 2,4-DCP, 4-monochlorophenol (4-MCP), HAc, HPr and chemical oxygen demand (COD) concentration in the effluent. Based on model fitting results, it was found that the degradation rates of 2,4-DCP and cosubstrates, HAc and HPr, changed inversely as a function ofthe specific organic loading rate ofthe UASB reactors. The implication ofthis finding was fully discussed.

Water, flowing through beds of refuse in a sanitary landfill, will leach organic and inorganic substances from the fill. These leached substances may be a source of pollution for receiving surface or ground waters. The leachate, before it is diluted by the receiving water, can usually be classed as a very strong waste water; that is, the levels of the waste water parameters COD, Suspended Solids, low dissolved oxygen and turbidity are many times those found in normal, municipal waste water. Added to these foregoing parameters are possible high levels of toxic chemicals and metals. It is now generally recognized that the leachate from refuse landfills should be controlled, and in some recently designed landfills, leachate collection is incorporated into the overall design. Toxic chemicals and metals are not adequately removed from waste waters by the standard biological sewage treatment processes; thus, the collected landfill leachate often requires pretreatment before it can be discharged to a municipal sewer system. If it is to be discharged to a natural receiving water, it requires more complete treatment. It was the purpose of this research to attempt to develop a physical-chemical treatment system for landfill leachate, such that the effluent might be safely discharged to a biological treatment plant or a natural receiving water. To deal with the extremely large number of possible chemical reagents, and to a lesser extent, physical methods available-, it was first necessary to select a number of primary candidates from prior information and theory available in the literature; secondly, it was advantageous to use a statistically designed experimental programme for screening those candidates chosen. In the screening process, no changes in the physical parameters screened, such as duration and speed of mixing or duration of settling, were found to be significant, if normal minimum times and usual speeds were used. Four chemical reagents, lime, ozone, ferric sulfate, and alum were indicated as having a potentially significant effect on the leachate-contained Total Solids (TS), Total Carbon (TC), Turbidity (Turb), Cadmium (Cd), Copper (Cu), Iron (Fe), Zinc (Zn), Potassium (K), Calcium (Ca), Sodium (Na), Phosphorus and the acid-base relationship as expressed by the term pH. The follow-up experiments determined that only two of the above four reagents were significantly effective in removal of the afore-named pollutants, as well as Manganese (Mn), Lead (Pb), Colour, Chemical Oxygen Demand (COD), the components of Total Carbon (TC) Total Inorganic Carbon (TIC) and Total Organic Carbon (TOC), and the components of Total Solids (TS)—Suspended Solids (SS) and Dissolved Solids (DS). All of the multivalent metals, except Calcium, were significantly removed from this wastewater by pH adjustment with lime, with additional minor removals by oxidation with ozone. Dissolved organic materials were not removed by pH adjustment and only removed in approximate stoichiometric amounts by reaction with ozone. In these experiments, the polymers tested were not effective in the removal of the named pollutants. Ozone is indicated to be an effective disinfectant, but highly sensitive to the COD of the leachate. An ozone-COD ratio, which determines the quantity of applied ozone necessary for the oxidation of some of the dissolved metals and for disinfection, as a function of the contained COD, is proposed for this leachate. The possibility of the application of this ozone-COD ratio is put forth, subject to further investigation. / Applied Science, Faculty of / Civil Engineering, Department of / Unknown

Thesis (B.S.) Massachusetts Institute of Technology. Dept. of Civil and Sanitary Engineering, 1949. / Bibliography: leaf 24. / by Thomas J. Lamphier. / Thesis (B.S.) Massachusetts Institute of Technology. Dept. of Civil and Sanitary Engineering, 1949.

Thesis (B.S.) Massachusetts Institute of Technology. Dept. of Civil and Sanitary Engineering, 1949. / Bibliography: leaf 41. / by Emmert M. Lowry, Jr. and Frederick W. Reusswig. / Thesis (B.S.) Massachusetts Institute of Technology. Dept. of Civil and Sanitary Engineering, 1949.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959. / by Arthur Tilden Prentiss, III. / Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959. / by Herbert M. Priluck. / Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959. / Includes bibliographical references (leaf 110). / by J. Antonio Rodriguez-Andrade. / Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959. / Includes bibliographical references (leaves 66-68). / by Edwin C. Rossow. / Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959.