The basic objectives of this study were to determine: (1) the extent of water pollution contributed by our communities in the form of municipal and industrial wastes, (2) an investigation of the extent of use, performance characteristics, and costs or the sewage lagoon, (3) the planning aspects of the sewage lagoon, (4) the extent of anti-pollution law enforcement, and (5) the existing financial aid available to communities tor the construction of' sewage lagoons. The findings of this study indicate that: 1. The extensive contribution to the water pollution problem by municipalities and industry is serious. The projection of future water use based upon present standards of use and recovery indicates a very serious water problem in the near future. A need exists for an inexpensive method or sewage treatment. 2. Sewage lagoons are relatively new but are widely used. They have proved to be relatively inexpensive and are achieving a high standard of purification. 3. Possible secondary benefits resulting from the use of sewage lagoons may prove to be of substantial value to municipalities in terms of efficient land use and the preservation of open land for alternate future uses. 4. The enforcement of the existing anti-pollution laws have been ineffectively enforced; however, new emphasis is being placed upon legal proceedings I rather than the voluntary compliance that has been practiced in the past. 5. With proper planning, a community can conceivably use several governmental programs for financial assistance both in grants-in-aid and long term loans for the construction or a sewage lagoon. / Master of Science

A microcomputer simulation model was developed to compare sludge disposal alternatives for an urban region. The model calculates both capital and operation costs for sludge treatment and disposal operations. For a study of an urban region with an equilibrium wastewater generation rate of 44.74 million m³/yr, the optimum sludge disposal alternative was dedicated land disposal for a baseline analysis of wastewater sludge treated by gravity thickening and anaerobic digestion. The capital cost at system equilibrium is $6.09 million and the total cumulative operation and maintenance cost over 100 years is $103.2 million. The operation and maintenance cost is 94% of the total capital and cumulative operation and maintenance cost. A description of the investigation and the criteria used for selection of this sludge disposal alternative ls included / Master of Science

Research was undertaken in order to simulate and optimize an Aquatair Model P-3 package sewage treatment plant for which operating data from the National Sanitation Foundation was available. The treatment plant consists essentially of a plastic medium trickling filter mounted overtop of a complete-mix activated sludge (CMAS) tank; the unit also has a primary sludge holding tank and a secondary clarifier. From consideration of reaction kinetics, reactor type, and geometry, a mechanistic model was developed to explain the phenomena of substrate removal in the Aquatair Model P-3. The two-factor SIMPLEX optimization procedure was used to determine the best set of biological reaction constants K1 and K2 which would characterize the substrate removal behavior of the Aquatair biological oxidation tower and recirculation chamber, respectively, based on actual plant data. Once the behavior of the plant was accurately simulated, cost functions were developed in order to relate the various design variables to cost. An n-factor PERPLEX optimization routine was then used to optimize the various plant variables for a given flow, organic load, and efficiency. PERPLEX, a modification of the Box COMPLEX method, was shown to be a useful tool for evaluating the factor space defined by a set of mathematical assumptions. The cost benefit of aerobic digestion occurring in the Aquatair bio-oxidation tower was predicted by the model and confirmed by nitrification data and sludge production calculations. / Master of Science

no abstract provided by author / Master of Science

Previous research relating to alum sludge land application has primarily been restricted to laboratory studies of short-term environmental effects. In general, most research has concluded that the environmental effects of alum sludge constituents can be easily controlled. This study investigated the fate of land-applied alum sludge constituents nearly three years after incorporation into a Slagle soil. An existing field site was used. The site had been used for a pilot study examining the land application of alum sludge from the Harwood's Mill Water Treatment Plant in Newport News, Virginia. Alum sludge and lime were applied to the site in November, 1989. Soil, soilwater, groundwater and pine needle tissue media were sampled during the summer of 1992. It was determined that the alum sludge posed no observable long-term threat to groundwater quality or vegetative productivity. Migration of alum sludge constituents through the soil profile could not be confirmed in this research. However, acid precipitation may have destroyed the alkalinity added to the soil. Thus, long-term management of alum sludge land application to acid soils may require additional increments of alkalinity. / Master of Science

The current Environmental Protection Agency (EPA) method utilized for analysis of trace organic chemicals and heavy metals leached from solid waste is the Extraction Procedure (EP) Toxicity Test. Because of various operational problems and limitations of the EP, the EPA has developed and plans to implement the Toxicity Characteristic Leaching Procedure (TCLP), which is an expanded version of the EP capable of analyzing more organic components, in particular volatile organic chemicals. The purpose of this research was to investigate and compare the ability of the EP and TCLP test procedures to quantitatively recover added surrogate standards (1,2-dibromoethane, bromoform, 1â chlorooctane, fusarex, heptachlor, and DDT) and also qualitatively identify and evaluate unknown trace organic chemicals in domestic wastewater sludges. In order to meet the research objectives established, three small (approximately 1 MGD or less) municipal wastewater treatment plants that land applied their sludges were analyzed. / Master of Science

Master of Science

The objectives of this study were to investigate the effects of the crystal seeding technique on certain handling characteristics of nickel hydroxide sludge and to investigate the changes in sludge particle properties that mediated any changes in those characteristics. A continuous-flow nickel hydroxide precipitation reactor was operated with and without solids recycle to produce sludge for analysis. The concentration of solids produced in the reactor clarifier was monitored and the specific resistance of the sludge was measured. Batch settling tests were also conducted on the sludge samples. The particle size distribution of the sludge produced was measured by an electronic particle counter and the density of the sludge flocs were measured. After the initiation of solids recycle in experiment I, the concentration of sludge solids increased from a range of 9,510-13,720 mg/l to 27,500-76,000 mg/l. Specific resistance values decreased an order of magnitude from an average of 4.01 x 10¹² m/kg before recycle to an average of 2.73 x 10¹¹m/kg during recycle in experiment I. Also, batch settling tests indicated an improvement in solids settling velocity. Similar results were obtained in the second experimental run. The improvement in these sludge handling parameters was attributed to an increase in particle size and particle density. Mean sludge particle diameter increased from an average of 2.9 microns before solids recycle to an average of 3.9 microns during recycle. Sludge particle density also increased during the recycling of sludge. These changes in sludge particle size and density were produced by an alteration of the crystal growth process. / Master of Science

Odorous gases such as hydrogen sulfide have long been associated with wastewater treatment plants, especially those with long forced mains which allow septic conditions to develop. With the encroachment of urban and suburban populations, many wastewater treatment plants are no longer located far enough from residential areas to prevent odor problems. This has lead to renewed efforts to develop odor control techniques. The application of high energy coronas as a means to oxidize odorous gases has been limited by the relatively small size of the corona region around a given charged wire, approximately 1 centimeter at an applied voltage of 35 kilovolts. Attempts to enlarge the effective corona region by spacing wires such that their coronas would overlap have failed due to corona extinction, the destructive interference of the electric fields surrounding adjacent charged wires. This study demonstrates that corona extinction can be avoided in a system of closely spaced wires flanked by grounded plates if the wires are energized individually instead of' simultaneously. By employing a rapid load-switching technique an essentially continuous corona sheet can be produced. A bench-scale device utilizing the rapid switching principle was constructed and its ability to remove odorous gases, including hydrogen sulfide, was demonstrated. The influence of parameters such as flowrate, inlet concentration, switching frequency, temperature, and humidity on removal efficiency was evaluated. / Ph. D. / incomplete_metadata

Nearly 700,000 Virginians depend on septic tanks and other wastewater treatment systems for treatment of household wastes. The Joint Subcommittee Report HJR 7 1987 reported that sixty percent of Virginia's residential septic “systems and drainfields are operating improperly. With the demand for rural and suburban development increasing, a viable alternative to septic systems and drainfields is needed. One proposed alternative is single family package treatment systems. One vital concern is that a majority of these systems discharge directly into surface waters. Thus, the objective of this study was to evaluate the performance of aerated package treatment systems (APTS). Five APTS located in southwest Virginia were chosen. Each site was visited three times during 1990 and 1991, and various parameters were monitored from the primary settling chamber, aeration chamber, and effluent. Systems were sampled in the morning, afternoon, and night. Also, two dye studies were conducted to evaluate hydraulic displacement. The results indicated that overall field performance was poor due to unreliable maintenance by homeowners, an ineffective chlorinator/dechlorinator system, inadequate biological treatment, and mechanical malfunctions. Eighty-one percent and 62% of the effluent samples were found to have five day Biochemical Oxygen Demand (BOD,) and total suspended solid (SS) concentrations exceeding 30 mg/L, respectively. Effluent dissolved oxygen values were less than 5 mg/L, the state's standard for small package treatment systems. Sixty-four percent of the effluent samples were found to contain more than 200 fecal coliforms/100 mL. In five instances where disinfection was evident, chlorine residuals were detected in the effluent, which also violates state standards. / Master of Science