ANALYSIS AND SIMULATION OF ENERGY USE AND COST AT A MUNICIPAL WASTEWATER TREATMENT PLANT

The cost of electricity, a major operating cost of municipal wastewater treatment plants, is related to influent flow rate, power price, and power load. With knowledge of inflow and price patterns, plant operators can manage processes to reduce electricity costs. Records of influent flow, power price, and load are evaluated for Blue Plains Advanced Wastewater Treatment Plant. Diurnal and seasonal trends are analyzed. Power usage is broken down among treatment processes. A simulation model of influent pumping, a large power user, is developed. It predicts pump discharge and power usage based on wet-well level. Individual pump characteristics are tested in the plant. The model accurately simulates plant inflow and power use for two pumping stations [R2 = 0.68, 0.93 (inflow), R2 =0.94, 0.91(power)]. Wet-well stage-storage relationship is estimated from data. Time-varying wet-well level is added to the model. A synthetic example demonstrates application in managing pumps to reduce electricity cost.

A comprehensive life cycle water analysis framework for residential buildings

Most studies on the environmental performance of buildings focus on energy demand and associated greenhouse gas emissions. They often neglect to consider the range of other resource demands and environmental impacts associated with buildings, including water. Studies that assess water use in buildings typically consider only operational water, which excludes the embodied water in building materials or the water associated with the mobility of building occupants. A new framework is presented that quantifies water requirements at the building scale (i.e. the embodied and operational water of the building as well as its maintenance and refurbishment) and at the city scale (i.e. the embodied water of nearby infrastructures such as roads, gas distribution and others) and the transport-related indirect water use of building occupants. A case study house located in Melbourne, Australia, is analysed using the new framework. The results show that each of the embodied, operational and transport requirements is nearly equally important. By integrating these three water requirements, the developed framework provides architects, building designers, planners and decision-makers with a powerful means to understand and effectively reduce the overall water use and associated environmental impacts of residential buildings.

Destination municipal solid waste in the city of Buenos Aires : brief diagnosis and some alternatives

p.79-89

[Organiser of Stirling's Red Buildings Conference for the Twentieth Century Society]

The aim of the conference is to review the three 'Red Buildings' with experts who have studied their history and their performance, and to discuss their future. Work is due to take place on the Leicester and Oxford buildings in the relatively near future, and technical knowledge can be shared in a context of understanding the design intention. Also to celebrate Stirling and Gowan's careers from a broader perspective and to assert the value of looking after these special buildings as assets for the future. The speakers in the afternoon session are people who knew the two architects well, and in some cases worked for them. [From University of Leicester]

Municipal services: organisations, companies and alternatives

A review of the impact of international institutions and multinational companies on municipal services worldwide, and of campaigns for alternatives.

Current status and perspectives of accelerated carbonation processes on municipal waste combustion residues

The increasing volumes of municipal solid waste produced worldwide are encouraging the development of processes to reduce the environmental impact of this waste stream. Combustion technology can facilitate volume reduction of up to 90%, with the inorganic contaminants being captured in furnace bottom ash, and fly ash/APC residues. The disposal or reuse of these residues is however governed by the potential release of constituent contaminants into the environment. Accelerated carbonation has been shown to have a potential for improving the chemical stability and leaching behaviour of both bottom ash and fly ash/APC residues. However, the efficacy of carbonation depends on whether the method of gas application is direct or indirect. Also important are the mineralogy, chemistry and physical properties of the fresh ash, the carbonation reaction conditions such as temperature, contact time, CO2 partial pressure and relative humidity. This paper reviews the main issues pertaining to the application of accelerated carbonation to municipal waste combustion residues to elucidate the potential benefits on the stabilization of such residues and for reducing CO2 emissions. In particular, the modification of ash properties that occur upon carbonation and the CO2 sequestration potential possible under different conditions are discussed. Although accelerated carbonation is a developing technology, it could be introduced in new incinerator facilities as a "finishing step" for both ash treatment and reduction of CO2 emissions.

Three medieval buildings in the port of Ardglass, Co Down

Three buildings in what is now a small port in Ardglass, Co. Down are connected by their location on the ridge overlooking the harbour and quay. Because of the Irish vernacular style related to tower houses they have all been called castles, but analysis shows that they were originally more commercial in their purpose. The largest of the buildings is identified as a line of shops. The building adjacent to that was possibly used as a warehouse or communal hall, while the third building appears to have been used as a watch tower for the port. As such they relate to other commercial buildings found in late medieval Irish towns, notably Kilmallock, Co. Limerick.