Type II methanotrophic bacteria are superior to Type I methanotrophs in accumulating polyhydroxybutyrate (PHB), a biodegradable alternative to polypropylene and other petro-chemical plastics, under nutrient limiting conditions. We evaluated the growth of Type I and Type II methanotrophs in a 15.2-liter bench-scale fluidized bed reactor (FBR) over a 270-day period. The aim was to identify operational characteristics and selection pressures that would favor Type II over Type I methanotrophs. The results indicate that Type II methanotrophs can be grown in an FBR under the appropriate conditions and that such a method may be a viable means of producing large quantities of biomass for PHB production.

Type II methanotrophic bacteria are superior to Type I methanotrophs in accumulating polyhydroxybutyrate (PHB), a biodegradable alternative to polypropylene and other petro-chemical plastics, under nutrient limiting conditions. We evaluated the growth of Type I and Type II methanotrophs in a 15.2-liter bench-scale fluidized bed reactor (FBR) over a 270-day period. The aim was to identify operational characteristics and selection pressures that would favor Type II over Type I methanotrophs. The results indicate that Type II methanotrophs can be grown in an FBR under the appropriate conditions and that such a method may be a viable means of producing large quantities of biomass for PHB production.

This work investigated two different approaches to optimize biological sulphate reduction in order to develop a process control strategy to optimize the input of an electron donor and to study how to increase the feasibility of using a cheap carbon source. Feast/famine regimes, applied to design the control strategy, were shown to induce the accumulation of storage compounds in the sulphate reducing biomass. This study showed that delays in the response time and a high control gain can be considered as the most critical factors affecting a sulphide control strategy in bioreactors. The delays are caused by the induction of different metabolic pathways in the anaerobic sludge, including the accumulation of storage products. On this basis, a mathematical model was developed and validated. This can be used to develop optimal control strategies. In order to understand the microbial pathways in the anaerobic oxidation of methane coupled to sulphate reduction (AOM-SR), diverse potential electron donors and acceptors were added to in vitro incubations of an AOM-SR enrichment at high pressure. Acetate was formed in the control group, probably resulting from the reduction of CO2. These results support the hypothesis that acetate may serve as an intermediate in the AOM-SR process.

Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.

Wastewater treatment management, alongside many other industries, is seeking to attain a higher degree of sustainability for its processes by focusing on new technologies which minimise the consumption of resources or even recover them from the wastewater. Conventional removal of ammonium requires usually large amounts of energy for aeration and organic carbon for denitrification. This report focuses on making the nitrogen-removal process more sustainable. This can be achieved by a partial oxidation of ammonium to nitrite, after which the nitrate produced can be converted into nitrogen gas with the rest of ammonium under anoxic conditions. The treatment of nitrogen-rich water can be carried out beneficially by a combination of the Sharon process with the Anammox process. In this combined process less than 50% of the aeration energy is needed, no COD is required and an insignificant amount of sludge is produced. In this Report the potential of using this technology for the treatment of water arising from sludge treatment at a municipal wastewater treatment plant (WWTP) is evaluated and the results of the operation of the system are described in detail. This reject water contains a significant fraction of the N-load towards the wastewater treatment plant. The results are used in an economic evaluation of a potential full scale installation. The Combined Sharon/Anammox Process Report will provide an invaluable source of information for all those concerned with the efficient and sustainable treatment of wastewater including plant managers, process designers, consultants and researchers.

The latest Methods for Wastewater Treatment Using Fixed-Film Processes This Water Environment Federation resource provides complete coverage of pure fixed-film and hybrid treatment systems, along with details on their design, performance, and operational issues. Biofilm Reactors discusses factors that affect the design of the various processes, appropriate design criteria and procedures, modeling techniques, equipment requirements, and construction methods. Operational issues associated with each type of process are presented, including potential problems and corrective actions. Real-world case studies illustrate the application of the technologies presented in this authoritative volume. Biofilm Reactors covers: Biology of fixed-film processes Trickling filter and combined trickling filter suspended-growth process design and operation Rotating biological contactors Moving-bed biofilm reactors Hybrid processes Biological filters New and emerging fixed-film technologies Clarification Effluent filtration Development and application of models for integrated fixed-film activated sludge, moving-bed reactors, biological aerated filters, and trickling filters