No description available.

The anaerobic biodegradability of food waste (FW), meat waste and FOG (fats, oils and greases) with municipal primary sewage sludge was assessed using a laboratory scale anaerobic digester and by ultimate sludge digestibility, at mesophilic conditions by varying the inoculum to feedstock ratio (1:2-1:10) and solids retention time (SRT). Preliminary analysis assessed the anaerobic digestion of food waste and meat at a biogas production over 30 days at 1000 mL and 1400 mL, respectively. The maximum methane yield was 0.18 m3/kg VS and 0.50 m3/kg VS for 1:10 in meat and FOG, respectively in 28 days with 56-61% volatile solids of destruction and first order methane generation rate of 0.15 d-1 for both meat and FOG. The optimal ratio for meat and FOG was determined to be beyond highest ratio tested (1:10), and longer SRT should be considered to investigate the impact of feedstock on methane yield. Preliminary modeling suggests that for one 1.74 MG digester, diverting just 0.6% of the food waste generated in one-third of Palm Beach County could produce enough methane to power 130-360 homes for one full month. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

No description available.

This thesis aimed at investigating a process based on anaerobic mixed culture fermentation (AMCF) of organic waste to produce carboxylates, molecular hydrogen and ethanol. The novelty of this study was to estimate the potential production of these bulk chemicals from selected renewable feedstocks and to experimentally investigate their production from the AMCF of three distinct types of feedstock without physicochemical pre-treatment: grass, a lignocellulosic substrate; cheese whey, a lactose-rich residue; and fish processing wastewater, a complex effluent containing proteins and fats. The estimation showed that AMCF of a small fraction (less than 1.6%) of the selected feedstock would be required to suffice the current production of carboxylates from oil-based feedstock, whilst up to 51% of the feedstock would be needed to satisfy the current production of ethanol and molecular hydrogen. In the experiments with AMCF of grass, low organic loading rates and long solids retention times were required to increase the substrate conversion because of the hard-biodegradability found in the substrate without any physicochemical pre-treatment. For the AMCF of cheese whey, the production of carboxylates decreased the pH to low levels and consequently inhibited the fermentation. For the AMCF of fish processing wastewater, the feedstock showed high biodegradability with production of biogas under batch condition and stable production of carboxylates under semi-continuous condition. The release of ammonium during the degradation of proteins was considered one of the main factors to avoid the pH drop when carboxylates were produced throughout the fermentation. In conclusion, the study showed that the feedstock nature and the operating condition play a key role in how to drive the AMCF to the production of these chemicals and avoid methanogenesis. Whilst hydrolysis limits the fermentation for hardly biodegradable feedstock, volatile fatty acids formation and pH inhibit the AMCF of more easily biodegradable feedstock.

The most cost effective treatment scheme for effluent from Midfield Meats, an abattoir in Warrnambool, Australia, was evaluated via a series of laboratory and commercial scale experiments. Effectiveness was measured in terms of suspended solids (SS) and biological oxygen demand (BOD) reduction. Economic assessment was based on predicted reduction in trade waste charges versus infrastructure and running costs. From the range of potential treatment technologies, those deemed most appropriate for trialling included pre-screening, sedimentation, coagulation and flocculation treatment and dissolved air floatation (DAF). Prior to evaluation of treatment types, flow, loads and contaminant characterisation of the waste streams was conducted to aid in selection of treatment type and capacity. Prescreening was found to be the most cost effective, followed by sedimentation, coagulation and flocculation treatment and finally DAF. The most economical treatment scheme that satisfied the requirements of Midfield Meats included a combination of prescreening and sedimentation. DAF and coagulation and flocculation treatment satisfactorily treated the wastewater, however were not cost effective under the current trade waste agreement.

The phenomenon of selective retention of cations from aqueous solutions by microbial biomass has been termed biosorption. Samples of waste microbial biomass, originating from industrial fermentations and biological waste water treatment plants, have been tested for their uranium and thorium biosorption potential. Optimum biosorption conditions have been identified. Rhizopus arrhizus was identified as the biomass presenting the highest U or Th uptake capacity, in excess of 170 mg/g. The effect of solution co-ions (namely Fe('+2), Zn('+2)) on the equilibrium biosorptive uptake capacity of Rhizopus arrhizus has been examined. The study of the rapid kinetics of U and Th biosorption has been initiated. Accumulated experimental and theoretical information led to the formulation of a biosorption mechanism hypothesis for the systems U or Th - Rhizopus arrhizus. Biosorption of both U and Th by Rhizopus arrhizus occurs mainly in the cell wall of the mycelium. Complexation by the cell wall chitin, adsorption, and hydrolysis of the complex are the processes participating in the proposed mechanism hypotheses.

Thesis (M. Phil.)--University of Hong Kong, 1995. / Includes bibliographical references (leaves 117-127).

Thesis (Ph. D., Environmental Science)--University of Idaho, June 2009. / Major professor: J.D. Wulfhorst. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.

Thesis (Ph. D., Plant Science)--University of Idaho, December 2007. / Major professor: John E. Lloyd. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.

Thesis (M.Phil.) - University of Queensland, 2006. / Includes bibliography.