Engineering Commons^™

Optimizing The Methanotrophic Production Of Polyhydroxyalkanoates Using Mixed Microbial Bacteria Cultures, Kai Cheng

Civil and Environmental Engineering Theses and Dissertations

The use of petroleum-based plastics has caused serious economic and environmental problems. It is imperative to develop sustainable ways to produce valuable and environmentally-friendly materials. Methanotrophic bacteria are known for assimilating methane while generating polyhydroxybutyrate (PHB) biopolymers, which are potential substitutes for conventional plastics. Additionally, biologically generated methane and volatile fatty acids (VFAs) are abundant and readily accessible through anaerobic digestion of organic wastes. Thus, optimizing the methanotrophic production will bring significant economic and environmental benefits.

In section one, a feast-famine based cultivation system was adopted to produce PHAs using Hyphomicrobium, and Methylocysits dominated bacterial culture. The mixed bacterial culture …

Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton

Civil and Environmental Engineering Theses and Dissertations

Access to safe potable water is a necessity for all. Groundwater is a commonly relied upon drinking water source for many areas around the world. This is especially true for communities in high density, rural settings. Such is the case for populations near Cox’s Bazaar, Bangladesh, and in the Bugesera region of Rwanda. Sediment and groundwater contamination, through toxic dissolved species, represents a significant public health risk to exposed populations. Tropical soils, such as the soil profiles in Bangladesh and Rwanda, often contain higher concentrations of heavy metals (Rieuwerts, 2007). Additionally, nitrate from fertilizers, are widely used on the soils …