Scholarly Work - Center for Biofilm Engineering
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/9335
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Item Nitrification and Autotrophic Denitrification in Calcium Alginate Beads(1987-01) Lewandowski, Zbigniew; Bakke, Rune; Characklis, William G.Immobilization of nitrifiers and autotrophic denitrifiers (Thiobacillus denitrificans) within calcium alginate gel was demonstrated. Calcium carbonate reagent was immobilized along with bacteria as the stabilizing agent. Protons released as a result of microbial respiration reacted with calcium carbonate producing calcium ions which internally stabilized the calcium alginate gel. The microbially active gel beads were mechanically stable and active for three months in a continuous flow system without addition of calcium.Item Dissolved oxygen and pH microelectrode measurements at water-immersed metal surfaces(1989-02) Lewandowski, Zbigniew; Lee, Whonchee; Characklis, William G.; Little, Brenda J.Dissolved oxygen (DO) and pH were measured at metal/artificial seawater interfaces using microelectrodes in biotic and abiotic systems. Measurements in a closed system proved that presence of electrochemical and/or biological reaction products substantially influence the conditions at the metal surface. For long-term studies, only open (e.g., continuous flow) reactors should be used. An open channel flow reactor suitable both for microbiological and electrochemical measurements has been constructed and successfully tested.Item Nitrification process in a packed bed reactor with a chemically active bed(1983-01) Kowalski, Eligiusz; Lewandowski, ZbigniewA laboratory scale submerged filter filled with crushed marble was used for the nitrification process investigation. The resttlts obtained showed that the alkaline reactor filling material react with the hydrogen ions released during the process course which enables reactor exploitation without any pH value or alkalinity control.Item Temperature dependency of biological denitrification with organic materials addition(1982-01) Lewandowski, ZbigniewThe rate of a waste water dentification process depends amongst others upon the temperature and the kind of compound used as electron donor. The results of measurements of denitrification kinetics using methanol, acetone and acetic acid have been presented.Item Biological denitrification in the presence of cyanide(1984-01) Lewandowski, ZbigniewThe influence of cyanide presence on the denitrification process using methanol, propanol, sodium acetate, glucose and acetone as the energy and carbon sources were described. It was shown that during denitrification the carbonyl compounds used as the sole energy and carbon sources for denitrifiers can form cyanohydrins with the cyanide ion. The product of cyanohydrin hydrolysis is biodegradable serving as electron donors for denitrifying bacteria. The simultaneous denitrifieation and cyanide removal was proved.Item Inhibition of nitrification in the packed bed reactors by selected organic compounds(1985-01) Oslislo, Andrzej; Lewandowski, ZbigniewThe effect of methanol, acetone, formalin and glucose on the nitrification process in the packed bed reactors has been investigated. For the utilized compounds the inhibition constant K, was determined according to Dixon's method. The determined values were as follows: methanol K, = 116.0 mgl-1: acetone K1 = 804.2 mgl-1; formalin K1 = 61.5 mgl-1. The value of K1 for glucose has not been determined because glucose in applied concentration up to 11.325 mgl-1 had no effect on the nitrification course.Item Inhibition coefficient (k1) determination in activated sludge(1985-01) Lewandowski, Zbigniew; Janta, Krystyna; Mazierski, JerzyA method of measurement of the inhibition coefficient, K1 of chemicals within the activated sludge has been proposed. It makes possible the objective determination of the influence of noncompetitive inhibitors on the reaction rate by means of simple respiration rate measurements with the application of a dissolved oxygen meter. The values of K1 for chromium Cr6-, for cyanide CN- and for two pesticides--DDVP and des-methyl DDVP was determined.Item Nitrification process in activated sludge with suspended marble particles(1985-01) Lewandowski, ZbigniewThe process of nitrification in activated sludge was investigated. As the solid support for nitrifiers' growth a suspension of marble particles has been used. The results proved the possibility of successful nitrification of 100 mgl-1 NH4-N simultaneously with the removal of 600 mgl-1 COD.Item Denitrification by packed bed reactors in the presence of chromium(VI)(1985-01) Lewandowski, ZbigniewThe effect of chromium Cr6+ on bacterial denitrification was investigated. The long-term influence of chromium presence was observed in packed bed reactors using methanol, ethanol, n-propanol, n-butanol, sec-butanol, tert-butanol, iso-butanol and n-pentanol as the carbon and energy sources for denitrifiers. Short-term influence was investigated by the inhibition coefficient Ki determination within activated sludge under anoxic conditions. The measured inhibition constant K, was equal to 84.2 mgl -1 Cr6-. independently of the kind of organic compound utilized as the electron donor for the bacterial system. The concepts of the reactor resistance to inhibition (RRI) and the resistance to inhibition (RI) have been evaluated.Item Biological reactor resistance to inhibition(1986-07) Lewandowski, ZbigniewThe phenomenon of complete substrate conversion within biological reactors in the presence of toxic compounds, called the Reactor Resistance to Inhibition (RRI), has been investigated. It was theoretically demonstrated that the RRI value, which means the highest concentration of inhibitor by which complete substrate conversion is possible, depends on liquid detention time. The excess detention time over that required for complete conversion, imply the existence of a "reserve" reaction potential. The value of this "reserve" can be reduced by inhibitor action with no influence on the observed substrate conversion rate. The influence of detention time on biological denitrification in Packed Bed Reactors in the presence of chromium Cr6+ was investigated. The RRI value for 1 h detention time was 1.5 mg l-1 Cr6+ . For 3 h detention time the RRI value was 22 mg I-1 Cr6+ . The relationship between the RRI value and detention time was linear.