The oxochlorates, such as ClO4-, ClO3- and ClO2- are toxic compounds and therefore they must be removed from effluents. In general they are synthetic compounds from industries and naturally also presents in Chilean caliche. Salts of these compounds are used in many purposes for examples, NH4 ClO4 uses as a solid propellant in rocket, explosive and fireworks. It is difficult to removing this salt from environmental pollutions because it is soluble in water. Today, bioremediation process which is most used method to removing these toxic compounds in wastewater treatment from industries. There are many species which have capability to using perchlorate and/or chlorate as a sole electron acceptor in respiration pathway under anaerobic conditions, for examples, Ideonella dechloratans, strain GR-1, CKB and perc1ace. However, besides a perchlorate and chlorate, nitrate can also be used as an electron acceptor by PRB. The using of nitrate instead ammonia is saving both cost and energy, but nitrate may be interfere with the chlorate reduction. The reduction of (per) chlorate is catalyzed by two enzymes, (per)chlorate reductase and chlorite dismutase(Cld). Chlorite dismutase (Cld) is a heme based enzyme and has an important function in the pathway of reduction of (per)chlorate, which converted chlorite into oxygen and chloride (ClO2 -            Cl-+O2).   The main object of this work was to investigate and develop a method to measuring the potential effect of nitrate on chlorate reduction in activated sludge from the paper and mill industry. The result of this work is that no effect of nitrate concentration on chlorate reduction from the sludge was found.

Biodiesel is a renewable fuel that can supplement petroleum fuel supply. A major deterrent to commercial biodiesel production from traditional feedstock like soybean, canola or rapeseed oils is the high cost of feedstock: 70 - 95% of total biodiesel production cost. Therefore, a relatively cheaper feedstock is needed to make the price of biodiesel cost-competitive with petroleum diesel. Activated sludge from wastewater treatment plants is a relatively cheaper feedstock and relatively easy to obtain. However, drying of this sludge prior to oil extraction is a major operating cost of this process, as high as 50% of biodiesel production cost. The goal of this research is to address this challenge by investigating the feasibility of using activated sludge from municipal wastewater for cost-efficient biodiesel production with little or no drying of the feedstock. First, the use of water-tolerant catalysts for biodiesel production was investigated to determine the level of water tolerance of these catalysts for the case where the sludge could be dried to an extent. The study investigated porous metal oxide and zeolite catalysts with tunable basicities, acidities and hydrophobicities and proposed a reaction mechanism for the most active catalyst. Next, the alternative where the catalysts were not very tolerant of moisture was considered, and the feasibility of a non-catalytic means of producing biodiesel from wet microbial media using supercritical methanol was also investigated. A model system of oleaginous yeast, Rhodotorula glutinis, was used to evaluate the production of biodiesel in a system similar to sludge. Since the non-catalytic method showed the highest tolerance for water at 90% moisture content, the optimum reaction conditions for highest FAME yields were determined. Two methods of the non-catalytic process, 1-step and 2-step processes, that could produce high FAME yields were studied and compared in terms of FAME yields and kinetic rate constants. With these results, an economic analysis was performed to investigate the cost efficiency of both methods of the non-catalytic process and recommend one with great potential for producing biodiesel from activated sludge at a cost-competitive price.

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Steven K. Dentel, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

No description available.

Thesis (M.S.)--University of Tennessee, 2007. / Title from title page screen (viewed on Apr. 02, 2008). Thesis advisor: Paul R. Bienkowski. Vita. Includes bibliographical references.

Thesis (M.Sc. (Hons)) - University of Western Sydney, Hawkesbury. / "A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Hons.) (Environmental Science" --tp.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 101-103). Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1947. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [107]-113).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 78-88).

Thesis (M.S.)--University of Wisconsin--Madison, 1983. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.