• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 604
  • 587
  • 68
  • 61
  • 59
  • 46
  • 19
  • 15
  • 14
  • 12
  • 10
  • 10
  • 10
  • 10
  • 10
  • Tagged with
  • 1723
  • 814
  • 456
  • 451
  • 389
  • 250
  • 240
  • 235
  • 215
  • 196
  • 196
  • 196
  • 185
  • 177
  • 173
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An investigation for a method for measuring microbial degradation for oxochlorates in waste water sludge

Najem, Hoger January 2015 (has links)
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.
2

Evaluation of Catalytic and Non-Catalytic Production of Biodiesel from Wet Microbial Media and Reaction Schemes

Coker, Adebola Titilope 14 December 2013 (has links)
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.
3

Gel-like behavior of biosolids in conditioning and dewatering processes

Dursun, Derya. January 2007 (has links)
Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Steven K. Dentel, Dept. of Civil & Environmental Engineering. Includes bibliographical references.
4

Chemical and mechanical effects on the rheology of concentrated wastewater flocs

Keown, J. January 2002 (has links)
No description available.
5

Investigation in applications of hydrolyzed industrial activated sludge operation of Unit BX, Kingsport, TN /

Hutton, Jacob Eli, January 2007 (has links) (PDF)
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.
6

Salmonella regrowth potential of two sewage sludge products /

Mann, C. M. January 1997 (has links)
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.
7

Laboratory evaluation of conditioning requirements for sludge dewatering using belt filter press /

Burgos, William David, January 1990 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 101-103). Also available via the Internet.
8

Physical and chemical transformations in activated sludge-sewage mixtures

Dietz, Jess Clay. January 1947 (has links)
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).
9

Comparison of batch and continuous-flow laboratory studies for the determination of substrate removal rates by mixed microbial cultures

Rollins, Richard M. January 1979 (has links)
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).
10

Preparation of plant and sewage sludge samples for multi-element anaysis by inductively coupled plasma (ICP) emission spectrometry

Huang, Joyce Chao-Yong Luh. January 1983 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1983. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Page generated in 0.0282 seconds