Browsing by Author "Busch, A. W."
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Item A study of carbon balances in mixed microbial populations(1964) Kambhu, Kawi; Busch, A. W.A study was made to define the validity of stoichiometric equations for the overall reaction of bacterial metabolism, using mixed microbial populations and soluble carbonaceous organics as substrates. In the study, simultaneous measurements of oxygen utilization, substrate removal, synthesized cell materials and COD of the mixed-liquor suspension were made. Oxygen uptake was measured by the Warburg manometric technique; substrate and mixed-liquor COD by the dichromate procedure; synthesized cell materials by the membrane filtration technique. During the reaction, multiple carbon balances, expressed in percent of the total biological oxygen demand, were carried out and are presented graphically. Within the experimental error of the determinations involved, the stoichiometric equations written for glucose, glutamic acid and sodium acetate metabolism are valid throughout the progression of bacterial growth. The experimental results illustrate the usefulness of the total biological oxygen demand concept in the field of environmental engineering. Carbon balances can be employed in the investigation of the biological degradability of complex compounds, and delineation of the kinetics involved in the system.Item Calcium carbonate precipitation inhibition in potable water and oil field brines(1972) Bradley, Bryant W., 1922-; Busch, A. W.Conditions that will cause calcium carbonate precipitation exist in most domestic hot water heaters and virtually all of the water injection wells used by the American oil producing industry. After discovery in 1936 of the precipitation inhibiting powers of sodium hexametaphosphate, at very low concentrations, its use exploded to many water handling applications where scale was troublesome. Very little research was undertaken to examine this phenomenon. Little research could be justified because treatment costs were so low and benefits were so great. The use of sodium hexametaphosphate, known as "threshold treatment", was originally intended to prevent internal scaling of water lines and valves. It certainly accomplished this job, but no one demonstrated whether calcium was mainly held in solution or precipitates were prevented from sticking. Bottle tests suggested that calcium remained in solution. However, the data were certainly sketchy for extrapolation to much more scale forming oil field brines held at higher temperatures under pressure. The research reported herein deals with the influence of all these variables. Also considered are the very important effects of pressure, surface roughness of the container, time, proprietary inhibitor brand (liquid organic phosphates) and concentration. To simulate a domestic hot water heater or oil field water injection well condition a new test apparatus was developed and patented. It consists of two chambers separated by a free piston fitted with an 0-ring. The test water is contained below the piston, and sealed from the pressuring gas above the piston by the 0-ring. Data are presented to show that a given water under field pressure conditions precipitates more calcium carbonate as the temperature is increased. If the test is run at atmospheric pressure, as done by all previous investigators, even more calcium carbonate precipitates. It is shown that 100 percent inhibition can be achieved. For the very scale-forming water used as our principal model only a few ppm of the chemicals provide complete inhibition under pressure in the test apparatus. At atmospheric pressure 500 ppm of inhibitor provide only 50 to 60 percent inhibition in one oil field brine. The empirical Stability Index, a measure of calcium carbonate precipitation tendency developed by previous investigators, appears to be a reliable measure of precipitation and thus inhibitor requirements. In addition, the data herein indicate a good possibility that a costeffective ranking of inhibitors would remain the same in many waters. The actual dosage of each chemical to achieve 100 percent inhibition would change, but cost rankings would remain the same.Item Effects of incubation temperature on the early period of oxygen uptake in mixed microbial systems(1963) LeGros, Paul Greig; Busch, A. W.Item Kinetic and regeneration aspects of the adsorption of phenol on activated carbon(1971) Cassidy, Edward King; Busch, A. W.Physical-chemical treatment of liquid wastes is becoming widespread. One promising physical treatment process is contaminant adsorption on activated carbon. Units are frequently operated with the inclusion of carbon reactivation or' regeneration. In order to design adsorption processes both the kinetics of removal and the effects of regeneration require quantification. This study was conducted to establish the kinetics of phenol removal in non-flow, well-mixed reactors where cocoanut charcoal was the adsorbent. The batch system consisted of a Phipps-Bird six place paddle stirrer run at 162 RPM. Reactor volumes were 1000 ml and fluid volumes were 900 ml. Reactors were buffered to pH of 6.8 to 7.0. Phenol was measured by light absorbance on a Beckman DBG spectrophotometer. Removal rate was found to follow a film diffusion limitation description, where concentration gradient across the proposed film was the driving force. Effective concentration at the surface of the particle was calculated by applying the isotherm equation of Weber and Morris, for which the parameters were established for the system studied. The proportionality between driving gradient and removal rate was determined. When the ratio of phenol to carbon was in excess of approximately 40 mg/gm intraparticle diffusion limitation was indicated. Regeneration effects on carbon were studied in four phases. The first phase established, for a single high temperature regeneration of carbon, initially loaded to 1 % by weight, that uptake rate was decreased upon redose, relative to virgin carbon. The second phase showed that virgin carbon at equilibrium with the atmosphere underwent mass loss and eventual destruction at regeneration temperatures of 550 °C and 950 °C, whereas, at 170 °C, mass loss stabilized at 3 %. The third phase separated, partially, the mechanisms operative in capacity change during regeneration at a single temperature (550 °C). The final phase of the regeneration study established, for the temperatures and loadings studied, the desirability of high temperature of regeneration and heavy loading of the carbon prior to regeneration. More capacity was recovered, and carbon destruction was retarded, when the carbon was initially heavily loaded and the regeneration temperature was the highest studied.Item Measurement of the total biological oxygen demand by mass culture aeration(1963) Hiser, Leland Ladd; Busch, A. W.Development of the field of environmental engineering has long been impeded by the lack of a quick, accurate method of measuring the biochemically oxidizable organic content of waste waters. Such a test is important to the detection and prevention of pollution of rivers, lakes, and other receiving waters. Proper operation of existing waste water treatment plants and the design of new waste treatment plants also depend on such a parameter. Rapid development of the chemical industry in recent years has further emphasized the need for such a test. A new test is presented which measures the disappearance of soluble organics from a substrate in contact with an active mass culture of mixed microbial organisms. Soluble organics in the system are measured by the Chemical Oxygen Demand (COD) test and reported in oxygen equivalents. The system substrate COD reaches a minimum when the soluble organics available to the mass culture for metabolism have been depleted. Substrate COD remains relatively constant from this point on. The difference between the initial substrate COD and the minimum substrate COD reached after aeration is then the Total Biological Oxygen Demand (TbOD) of the system. This TbOD test may be completed in 6 to 8 hours (approximately 4 to 6 hours laboratory time). In addition to measuring the TbOD, the test may be used, with modifications, to define process kinetics for design, to serve as a daily log of plant operation, or be used as a quick method of diagnosing plant operation difficulties. Delineation of plant cyclic load variations is another use for this test. This TbOD test will be particularly useful for the control of operating plants since an acclimated culture is available from the plant at all times.Item Some effects of DMSO in mixed culture bacterial systems(1966) Johnson, David Register; Busch, A. W.A study of the effects of the chemical dimethyl sulfoxide in an aerobic, mixed culture, single component substrate system was undertaken in the Environmental Engineering. Laboratories at Rice University. This study represents a portion of a broader project aimed at elucidation of the basic processes involved in substrate utilization by a biological system and the evaluation and significance of the concomitant oxygen demand exerted by such a system. By observation of changes induced in a well defined system by a biologically active substance such as DMSO, it was hoped to discover something about the mechanism of action of DMSO. The chemical's remarkable ability to increase permeability of living membranes is a quality that could help determine the influence of the bacterial membrane on the removal rate of organics from solution. The work showed that DMSO had effects on all systems Studied. Because additional effects were observed in systems operating under nitrogen limited conditions, it was necessary to define the effects of nitrogen limitation in all systems under consideration. The discovery was made that limiting the nitrogen in these systems resulted in a stimulation of oxidation with a concomitant increase in the oxygen uptake up to a point of approximately fifty percent of the required nitrogen. Past this point the synthesis of new organisms was inhibited to the extent that oxygen uptake was described by a straight line at a much reduced rate from the control. Thus, by the time the point was reached where a plateau would normally have occurred, secondary oxygen uptake by predators was well established, and the plateau phase of the oxygen uptake curve was obscured or eliminated. Introduction of DSO into a system operating under conditions of nitrogen limitation was observed to have several effects. There was an increase in the oxygen uptake value measured at 50 hours in those nitrogen limited systems. There was also an increase in rate of oxygen uptake in severely limited systems (40% or less of required nitrogen). In addition, DMSO was observed to have the following effects in both nitrogen limited and nitrogen sufficient systems. There was a lag time before onset of maximum oxygen uptake rate that increased as the concentration of DMS0 increased. An inhibition of predator activity as exhibited by the delay of the onset of secondary oxygen uptake past the plateau was observed. At a given degree of nitrogen limitation, no effect of increasing DMS0 concentration could be shown other than those effects observed in non-limited systems.Item Some effects of inorganic nitrogen metabolism in mixed microbial cultures(1964) Lewis, John Walter; Busch, A. W.Item Studies on cell synthesis in mixed microbial populations: cell recovery and total biological oxygen demand(1963) Grady, Leslie; Busch, A. W.A study was conducted in the Environmental Engineering Laboratory of Rice University on the cell recovery phase of the total biological oxygen demand, or TbOD, test, and further experiments were performed to confirm the validity of the total biological oxygen demand theory. Two general methods of cell recovery were investigated, a gravimetric technique and a chemical oxidation technique. TbOD was calculated using the results of each of these techniques as well as by a third method which was based on the chemical oxidation of the substrate itself. It was found that the gravimetric cell recovery technique gave the most accurate and precise results of the methods considered. Consequently, the method of calculating TbOD based on this technique proved to be the best of the methods studied. In general the results obtained were in good agreement with the theory. However, the validity of the assumption of a generalized formula for cell material should be investigated further.Item Studies on cell synthesis in mixed microbial populations; log phase innocula and total oxygen demand(1962) Shivajirao, Tipirneni; Busch, A. W.; Hellums, J. David; Read, Clark P.A study of the effects of a log-phase seeding technique and of the oxidative assimilation relations, in soluble substrates, of mixed cultures of bacteria and protozoa, as found in a typical domestic waste water, was conducted in the Environmental Engineering Laboratory of the Rice University during the 1961-1962 academic year. These studies were part of a broad investigation of the study of the Biochemical Oxygen Demand Progression in soluble substrates. This is believed to be the first work using the log-phase seeding technique in shortening the time to the plateau in oxygen utilization and in the formulation of oxidative assimilation relationships in mixed microbial populations. Previous work on the effects of log-phase seeding and microbial assimilations generally utilized pure cultures and heavy innocula of bacteria with short incubation periods. Substrates studied in this investigation were glucose, glutamic acid, a (1:1) mixture of glucose and glutamic acid, aspartic acid, acetic acid, propionic acid, and lactose. Both Warburg and dilution techniques were utilized. The log-phase seeding technique produced a marked reduction in lag for all of the substrates and a reduction in time to reach the plateau for lactose, glutamic acid, aspartic acid, and propionic acid. The general pattern of the progression of biochemical degradation of soluble substrates in shown in graph form. The plateau in oxygen utilization was highly reproducible and was characteristic for a specific substrate. Based on the data obtained, oxidative assimilation equations were developed for the substrates under study. Theoretical plateaus occurred at 41, 40, 39, 44, 50, 52, and 41 per cent of the theoretical oxygen demand in the case of glucose, a (1:1) mixture of glucose and glutamic acid, glutamic acid, aspartic acid, acetic acid, propionic acid, and lactose, respectively. The nitrogqp supplied by the standard dilution technique for B.O.D. analysis is adequate for glucose and lactose concentrations only up to 8mg/l. At the concentrations of 12.1 mg/10 utilized in this study, the resulting nitrogen deficiency yielded low values for the plateau in oxygen uptake normally representing completion of synthesis.Item Summary and Closure(Rice University, 1966-04) Busch, A. W.; Electronic version made possible with funding from the Rice Historical Society and Thomas R. Williams, Ph.D., class of 2000.Item Table of contents for the Rice University Studies, Volume Fifty-two, No. 2, Spring 1966: Water Technology, A Multidisciplinary Perspective(Rice University, 1966-04) Busch, A. W.; Electronic version made possible with funding from the Rice Historical Society and Thomas R. Williams, Ph.D., class of 2000.Item The selective stimulation of respiration in mixed cultures of bacteria and protozoa(1959) Myrick, Henry Nugent; Busch, A. W.A study of the selective stimulation of respiration in the cultures of bacteria and protozoa, as found in a typical domestic waste water, was conducted in the Sanitary Engineering and Science Laboratory of The Rice Institute during the 1958-59 academic year. These studies were part of a broad investigation of the study of the progression of the biochemical oxygen demand of soluble organic compounds in order to determine the validity of a short-term B. O. D. determination. The progression in soluble substrates of the B. O. D. exerted by a mixed culture of micro-organisms was found to be a multi-stage reaction. This is believed to be the first work using this biochemical technique of studying intermediary metabolism to define the progression of the biochemical oxygen demand of soluble organic compounds. Previous work on the inhibition of assimilation utilized pure cultures and heavy inoculums of bacteria for short incubation periods. Sodium azide, 2, 4-dinitrophenol, and sodium fluoride were used for the selective stimulation of respiration or inhibition of assimilation processes. Sodium azide was the only agent which produced a marked degree of stimulation of respiration for either glucose, glutamic acid or a 1:1 mixture of these substrates. The general pattern of oxidation due to these agents is shown in graph form. The progression of the oxidation of these soluble compounds can be altered considerably and yet produce 120-hour incubation period (five-day) B. 0. D. values which are within the accepted standard deviations for these substrates using the bottle dilution technique. Similar results were obtained from manometric experiments. A critical concentration of the inhibitory agent significantly prevented synthesis and forced the reaction in the direction of complete oxidation to carbon dioxide and water, as shown by increased plateau values. Low concentrations of sodium azide initially retarded respiration slightly and simultaneously the synthesis processes were partially inhibited. Relatively high concentrations of this agent reduced the rate of respiration considerably. No increase in the extent of oxidation of fresh settled sewage was observed in the presence of sodium azide or 2, 4- dinitrophenol.