This study investigated the effect of excess carbon loading in the anoxic reactor on the nitrogen removal capacity of a biological pre-denitrification system for the treatment of a high ammonia leachate. The influent leachate was low in degradable organic carbon, thus an external carbon source was needed for denitrification requirements. Four different carbon sources were studied: methanol, glucose, acetate, and a waste brewer's yeast. The carbon loading was increased over the duration of the experimental period. The COD:NOx added to the anoxic reactor reached more than three times the carbon loading required to just achieve complete denitrification. All four carbon sources were found to support denitrification, but the glucose system showed erratic behaviour and ultimately failed after reaching a CODrNOx loading of about 23:1. The system using acetate appeared to require the least amount of COD:NOx (5.9:1) for complete denitrification, followed closely by methanol (6.2:1), then the yeast waste (8.5:1), and finally by glucose (9:1). Carbon breakthrough, the bleeding of carbon from the anoxic reactor into the aerobic reactor, was observed to occur just after complete denitrification was reached. The excess carbon did not appear to have any effect on denitrification, except in the case of the glucose system. The unit nitrification was found to decrease as the CODrNOx was increased, even though the ammonia removal remained at 100%. The decrease in nitrification, with respect to the COD:NOx, was most pronounced in the system that used methanol, and about equal in the other three systems. The cause of the decrease in nitrification is suspected to be due to increased ammonia assimilation by the heterotrophs rather than an inhibition of the nitrifiers. Nitrification ceased in the glucose system, but was restored within 12 days after the glucose addition was halted. The cause of the failure of the nitrogen removal process in the glucose system was not determined. Nitrite accumulation was observed in all the systems except the methanol system. The yeast waste system had nitrite accumulation in the aerobic reactor at C0D:N0x loadings over 25:1. Free ammonia inhibition of Nitrobacter is suspected to be the cause of aerobic nitrite buildup. The glucose and acetate systems had nitrite buildup in the anoxic reactor until complete denitrification was achieved. Facultative anaerobic bacteria are suspected of causing this nitrite accumulation. This theory was supported by observations in the glucose system, such as low anoxic pH; this may have been due to volatile fatty acids produced from fermentation. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Peeled or whole-pack tomatoes, herring roe and oysters are processed at a Virginia Cannery. Wastewater from each food processing effluent was characterized. Treatment alternatives were investigated for tomato and herring roe wastewaters. For herring roe processing wastewater, the discharge requirement for BOD was nearly met through plain settling, while the TSS limitation was easily achieved by settling out the roe particles" Oyster processing wastewater was found to meet effluent guidelines without treatment. Bench-scale treatability studies were performed using sequencing batch reactors (SBRs) to treat the segregated wastewater from the caustic tomato peeling operation. This isolated 98% of sodium present in the wastewater. Previously, all wastewater was land applied and the high sodium content damaged soil structure. Sodium levels in monitoring wells below the irrigation field have risen, approaching regulated values. Results indicated that SBRs can be effective in reducing BOD and TSS to discharge requirements. BOD and TSS removals were well in excess of 90%. Initial values for BOD and TSS were 21,400 mg/l and 14,000 mg/l, respectively. Although conventional food to microorganism ratios were used, relatively long hydraulic retention times of 8 to 20 days were required to accomplish adequate BOD removal. Screening was found to be an effective form of pretreatment to remove large quantities of TSS. It appears practical to treat the tomato peeling wastewater by means of sludge drying beds. Approximately 0.5 acre of land would be required for bed construction. Final disposal costs associated with landfilling the dried sludge may govern whether sludge drying beds or an SBR should be used. In an effort to eliminate wastewater problems associated with the caustic peeling operation, an enzyme peeling study was performed using pectinase. Peeling ability of the enzyme was not as good as that of caustic, however, further investigation into alternative peeling operations is warranted due to the adverse effects of caustic materials on wastewater treatment alternatives. / Master of Science

Although the East Central Florida area is not heavily industrialized, its dependence on groundwater resources makes it especially vulnerable to contamination by poor waste disposal practices. The East Central Florida area was studied to discover the nature and disposal of hazardous wastes generated. It was found that a large portion of hazardous wastes in the region were from very small industries, distributors, and even consumers. Three of the most toxic and/or voluminous waste problems in the area--metal plating wastes, pesticide wastes, and hospital wastes--were studied to determine available alternatives for disposal and their costs.

A legislative authority empowered to protect Srilanka's environment, operating similarly to the Environmental Protection Agency of the U.S., is needed, along with wastewater treatment. Wastewater parameters of importance in treatment are BOD, COD, total suspended solids, settleable solids, pH, colour, turbidity, ammonia or nitrate nitrogen, heavy metals, sulfides, phosphates, and phenols. Methods of industrial waste treatment vary depending on the climatic conditions, the industry, raw materials, and process adopted. Textile and pulp and paper industries exist in Srilanka and have very high pollution potential. Methods of treatment to finally generate reasonably good quality effluent are available. Processing of effluents from these type industries together with municipal sewage is feasible and economical. Due to the complex nature of the composition of industrial wastes, a final decision could only be made after a thorough investigation of the industrial complexes, the methodology used, and pilot plant studies.

Safe disposal of contaminated dredged material has become a significant issue especially as public environmental awareness and concerns increase. Solidification/ stabilization technology potentially may provide for a safer, more effective and more economical means of disposal. This research investigated the technical feasibility of applying solidification/stabilization technology to contaminated sediment from Indiana Harbor Canal, Indiana. Specifically, physical strength and reduction of chemical leachability resulting from solidification/stabilization A with various cement based, pozzolanic, and proprietary additives were analyzed. Also investigated was the immobilization capability of a proprietary polymer for selected organic contaminants when used in conjunction with solidification/stabilization processes. Physical strength is an important parameter in determining the ultimate bearing capacity, stability of embankments and pressure against retaining walls. Physical stabilization of contaminated dredged material is a viable treatment option. Application of cement-based and pozzolanic—based processes uses the sediment moisture to form hydration products, therefore dewaterimg is not required. All process formulations produced a solidified sediment. / Master of Science

The possibility that the biological phosphorus removal mechanism can be inhibited in a continuous flow process by acetic acid passing through into the anoxic and aerobic zones of the reactor was investigated. The objectives of the research were to determine the amenability of a wastewater from the Hoescht Celanese Celco Plant in Narrows, Virginia to the biological phosphorus removal process. The wastewater from the Celco plant is very high in both phosphorus and acetic acid, which is the volatile fatty acid known to be a preferred substrate for the biological phosphorus removal process. However, past research indicated that the wastewater was not amenable to the biological phosphorus removal process; therefore, studies were established to determine at what point and for what reason the biological phosphorus removal process fails. In particular the occurrence of acetic acid “breakthrough" was investigated by operating a parallel control reactor treating a municipal sewage and acetate combination. Results of the research project indicated that the Celco wastewater caused the biological phosphorus removal process to fail at acetic acid and COD concentrations lower than those causing failure in the wastewater consisting of municipal sewage and acetate only. This led to the conclusion that the Celco wastewater contains a biologically inhibitory constituent which causes the biological phosphorus removal mechanism to fail. In addition, the reactor treating a combination of municipal sewage and acetate failed to remove phosphorus biologically at acetate concentrations of 800 mg/L. At this point, the acetate began to pass through into the anoxic and aerobic zones, respectively, causing the biological phosphorus removal mechanism to fail. / Master of Science

This study was a full-scale investigation of SBR for the treatment of oily wastewater with determination of the effects of different operating conditions on process performance. It was demonstrated that under a rather complex situation, the performance of the SBR could be significantly improved, compared to the results prior to the study. In contrast to the low COD reduction, significantly higher BOD5 removals were achieved. When the waste was only composed of wasted oils, the BOD, in the effluent averaged 179 mg/I for an average removal of 87%. Also good reductions of phenols and oil & grease were attained during the study. Based on a thorough evaluation of the results the following specific conclusions are made. / Master of Science

The Upflow Anaerobic Sludge Bed reactor (UASB) has been used successfully by the food processing, pulp and paper and municipal wastewater industries. High organic strength wastewater, limited space, extended down times and sludge handling and disposal have been critical factors in waste treatment system selection. This study investigated the performance of a laboratory-scale UASB reactor for treating clam-processing wastewater. Virginia state effluent regulations for BOD₅:TSS ranged from 0:0 to 90:90 to as high as 500:500 depending on the facility location. It was found that at a volumetric organic loading rate of 13.8 g COD/L/d the BOD₅ removal efficiency averaged 87% and TSS removal efficiency averaged 83%. The average effluent values for BOD₅ and TSS were 200 ppm and 90ppm, respectively. The conversion efficiency of COD to methane gas was 81%. At an organic loading rate of 4.8 g COD/L/d the effluent values averaged 77 and 66 mg/L for BOD₅ and TSS, respectively. Methane production was inhibited at Na⁺ concentrations above 5,000 ppm in batch experiments. At Na⁺ concentrations above 12,500 ppm inhibition was essentially 100%. Nutrient enrichment did not affect methane production. / Master of Science

Pretreatment is a common approach for removing color and reducing the organic load of textile dyeing and finishing wastewater. Subsequent aerobic treatment is often employed to complete organic removal as well as remove toxicity and metals. The wastewater from the textile dyeing and finishing industry studied was not treated efficiently and often failed effluent toxicity and metals tests. In this research project, various pretreatment alternatives were studied in an attempt to identify the most efficient and economical method(s). Also, aerobic, biological treatment was performed in bench-scale reactors to determine the biological kinetic coefficients of the wastewater so that the overall efficiency and performance of the biological treatment system might be improved. Effluent toxicity of the wastewater was also evaluated in hopes that improved treatment efficiency would yield subsequent improved effluent toxicity. The performance of a sequencing batch reactor was compared to that of the continuous-flow reactors. In regard to pretreatment with various polymers, coagulation with a blend of inorganic aluminum and a polyamine (AL220, Polymer Systems, Inc.) produced the most economical and efficient results. Subsequent addition of an anionic polymer improved the settling characteristics of the chemical flocs. Color removal ranged from 71-90% and DOC removal averaged 25% with AL220 doses between 400-600 mg/L. Increased sludge ages (θ_c) of the continuous-flow reactors produced improved removal efficiencies. Sludge ages of 8-30 days resulted in an average of 55-68% COD removal. Kinetic analysis produced values of 0.032 d⁻¹ and 0.619 for k_d, and Y, respectively. K_s and k could not be determined accurately. This difficulty was attributed to possible inhibitory effects and a residual, biorefractory COD that was not quantified in this study. The SBR, operated with a cycle time of one day and an average MLSS concentration of 4,266 mg/L, achieved an average 69% COD removal and 59% color removal. Addition of nutrients did not appear to improve these efficiencies. Settling characteristics of the sludge were excellent. Preliminary acute toxicity testing of the SBR effluent and effluent from the 8 day θ_c reactor produced encouraging results. Subsequent chronic toxicity testing of the 15, 20 and 30 day θ_c reactors yielded a maximum No Observed Effect Concentration of 50-75%. / Master of Science

The purpose of this investigation was to use the manometric method to determine the effect of the following variables on the B.O.D. values of a neutralized acid industrial waste: pH, type of seed, age of seed, adapted seed, dilution water, and dilution. In order to determine the effect of each variable on the B.O.D. of the waste, the temperature and agitation of the Warburg apparatus were kept at fixed values. While the optimum condition for one variable was being determined, the remaining factors were kept constant. As the optimum condition of each variable was found, it was used as a reaction constant, and this process was continued until the list of variable factors was completed. Since only a limited number of tests were run for each variable, no definite conclusions can be drawn. However, the following trends were indicated from the data obtained: A pH of 4.1 depressed the B.O.D. values and they were exerted only after long lag periods; the waste exerted a higher B.O.D. with much shorter lag periods when the pH was raised to 7.1. River water seed caused the waste to exert higher B.O.D. values than did garden soil seed, fresh sewage seed, and settled sewage seed. This indicated that the river water contained a microbiological population adapted to the utilization of the waste under study. The age of seed made little difference in the B.O.D. values exerted for the seeds studied. The waste gave higher B.O.D. values when adapted seeds of river water, adapted soil seed, end activated sludge were used than when regular garden soil seed was used. It is believed that the bacterial organisms in the river water below the waste outfall had become adapted to the waste material. The presence of mineral nutrients as found in river water or the addition of mineral nutrients as recommended by Standard Methods for the Examination of Water and Sewage (1) are necessary for the waste to exert a normal B.O.D. The presence of a substance toxic to the B.0.D. test is indicated because the B.0.D. values increased with increasing dilution. The bottle B.O.D. values, obtained from another investigator, were not given for all of the tests; therefore, no conclusions were drawn except that the bottle B.O.D. values vere in the same general range as the corresponding manometric B.O.D. values. / Master of Science