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Current trends in regulation have produced the inclination in industry towards the use of solvents which are not regulated under the Resource Conservation and Recovery Act. Many of these non-regulated replacement solvents are nonhalogenated. There is, however, a genuine concern that regulated, halogenated byproducts may be formed upon the chlorination of these solvents. Waste streams containing these solvents face a probability of chlorination in disinfection and in cyanide oxidation. The goal of this research was to determine what regulated compounds might be formed under the conditions which might prevail in the chlorination of these solvent laden waste streams. A survey of chemical vendors was completed in the Fall of 1989 to identify non-halogenated solvents on the market which are potential substitutes for regulated products. Four products were selected for experimental evaluation: 1. Monoterpene. 2. Alkaline Cleaner. 3. Glycol Ether. 4. N-methyl-2-pyrrolidone. The products were determined to be biodegradable. Chlorination by-products were identified to include regulated compounds (Total Toxic Organics, TTO) in a concentration range of several hundred parts per billion. Chloroform, methylene chloride, and bromodichloromethane were the most common chlorination by products. The disinfection experiments generated a large number of other unidentified by-products which are not currently included on the TTO list. Further study is recommended for full characterization of these additional chlorination by-products.

Described is the design specification for an Artificial Neural Network (ANN) communication controller. The communication controller will provide efficient data exchange between individual ANN units in a large parallel system. Interconnections are dynamic in nature, and can be configured to implement any arbitrary feedback path. A nexus topology is used to interconnect the communication controllers in a system. Because the recursive nature of the communication protocol, the communication controllers function identically regardless of position in the hierarchy, providing scalability and simplifying VLSI design. The protocol and the communication controller's modes of operation are presented in detail.

Surface coating and drying operations typically exhaust large air volumes containing low concentrations of volatile organic compounds (VOC) with potential adverse environmental impacts. Operating on the principle of catalytic incineration, the SUNKISS Thermoreactor produces infra-red heat for paint drying and curing. Reported benefits include reduced drying time, improved surface coating finish, smaller exhaust air/solvent volumes. and greater energy and economic efficiency. In addition. the SUNKISS Thermoreactor has been reported to reduce VOC emissions due to oxidation of the solvent vapors. This claim was investigated under laboratory conditions at the University of Central Florida (UCF). Primary system components developed as a part of this study included the VOC-in-air flow system, a completely mixed test chamber, and a sampling train which resulted in the generation of data exhibiting a high degree of precision. Design and calibration studies necessary to maintain that accuracy and precision constituted major components of the work performed. Our study showed that an 18 to 48 percent reduction in VOC emissions may be expected from the SUNKISS Thermoreactor. VOC destruction was found to be a function of detention time within the test chamber and not inlet concentrations. Very little difference was observed during experimental runs involving both Hexane and Methyl Ethyl Ketone. Relationships among destruction efficiency, air flow rate, the generation of carbon monoxide and incomplete combustion of the a uxiliary fuel supply were also determined.

The purpose of this study was to identify the effects of ultraviolet (UV) catalyzed ozone oxidation of trihalomethane (THM) precursors for a groundwater source. The scope of this research was to define an empirical model to predict THM precursor destruction rates and to establish the product water quality attainable by UV/Ozone processes. The experimental design consisted of a full factorial experiment for 3 applied ozone dose rates (2, 3, and 4 grams/hour (gms/hr)), 3 UV dose rates (3.11, 1.33, and 0.728 watts/liter (W/L)), and 3 pH adjustments (ambient pH, ambient pH+0.5 standard units (SU), and ambient pH-0.5 SU), resulting in a total of 27 UV/Ozone experiments. Also included were 5 half factorial experiments for ozone alone and 5 experiments for UV alone. Also included were 2 aeration control experiments. The effects of pH and temperature on THM precursor destruction rates were not shown to be significant within the levels tested (6.2-8.7 SU and 7-40°c respectively). The effects of pH may not have been significant due to the narrow pH range tested and the rapid equalization (15 minutes) of pH to approximately 8 SU for all pH adjustments. Temperature effects may have been confounded by the uv dose rate used since the temperature increased as the UV dose rate increased. UV dose rate was shown to be a significant factor for the UV/Ozone experiments. The effect of UV dose rate was, however, small when compared to applied ozone dose rate, and THM formation potential concentration (THMFP) effects. The influence of UV dose rate was, however, large when compared to ozone (no UV) experiments. Thus the influence of UV was shown to be mostly catalytic. UV/Ozone oxidation reduced THMFP concentration to levels ranging from 15 ppb too ppb for all experiments tested after a 3 hr reaction time (initial 7 day THMFP ranged from 252 ppb to 118 ppb). These reductions are sufficient to meet anticipated maximum contaminant levels (MCLs) that may drop as low as 20 ppb (1990 MCL for total THMs is 100 ppb). Ozone (no UV), UV (no ozone), and aeration were not effective processes for reducing THMFP to anticipated MCLs.

Full-scale and bench-scale tests were performed on an operating wastewater treatment facility to define kinetics for nitrogen removal. The facility uses a bionutrient removal system designed to remove nitrogen and phosphorus. This research report investigates full-scale biokinetic data to determine actual nitrification and denitrification rates and bench-scale biokinetic data to estimate the kinetic parameters associated with documented kinetic models. Furthermore, the tests were performed at two solids retention times (SRTs) to compare baseline operating conditions with those designed to simulate a greater overall flowrate through the facility. This report includes independent evaluation of nitrification and denitrification rates from full-scale operating data specific to the process basins, of kinetic relationships for continuous flow bench-scale tests and of kinetic relationships for batch bench-scale tests. Also included in this report is an evaluation of the limitations of bench-scale and full-scale testing procedures.

Bottom sediment was collected from wet detention ponds receiving highway runoff, and extracted using EP A's (1990) Toxicity Characteristic Leaching Procedure (TCLP). The extract fluid was analyzed for 68 semi-volatile and 36 volatile organic priority pollutants. Most compounds were non-existent, and the remaining were detected at insignificant levels. The sediments cannot be considered toxic according to regulations established for TCLP extracts. Additionally, more aggressive extraction procedures applied to the sediments produced no detectable levels of the organic compounds. The TCLP was unable to release certain organics from sediments spiked with known amounts. Overall, there appears to be a minimal threat to groundwater due to leaching from the ponds of the organic pollutants examined. Phenol was further studied through batch experiments. Rapid removal, using relatively high initial solution concentrations (1 to 200 ppm phenol) was detected using oven-dried sediment. A first order equation best-described the removal, with calculated rate constants dependent upon initial solution concentrations. Fresh sediment removed phenol faster than oven-dried sediment, while autoclaving destroyed the removal capability. As solution pH was increased from 5 to 10, a decline in removal occurred. Results suggest that biodegradation is the mechanism responsible for removal of phenol in contact with detention pond bottom sediments.