Biomedical subjects

G De Gueldre

Publications and source records attributed to G De Gueldre.

6 recordsLinked to original sources

PubMed2006

Estimating costs and benefits of advanced control for wastewater treatment plants--the MAgIC methodology.

This paper discusses a methodology to estimate the costs and benefits of advanced control for wastewater treatment plants. The methodology has been applied to four wastewater treatment plants, representing four standard types of plants built in Flanders, Belgium. The paper outlines the methodology and illustrated results from one of the four design cases. General results are shown and contrasted with full-scale experience. The methodology appears to give realistic results and will be used for further refinement of default control algorithms for certain types of plants. A preliminary analysis indicates that on-line control can become cost-effective for plant sizes above 50,000 population equivalents.

Automation↗

PubMed2005

Experience with phosphorus removal and sludge handling and disposal in Flanders.

The way excess sludge must be disposed of is a key factor in the choice of the appropriate phosphorus removal technique at municipal wastewater treatment plants. In Europe the ongoing trend of tightening the sludge spreading rules called for a serious reduction of its agricultural utilisation and the expansion of the (co-)incineration disposal route, which led to a shift towards more sophisticated sludge handling techniques. This paper illustrates the impact of different sludge handling techniques on the performance of chemical and enhanced biological phosphorus removal at municipal WWTPs. The main conclusion is that although enhanced biological phosphorus removal is particularly sensitive to the problem of return liquors from sludge treatment processes indirect dewatering and anaerobic stabilisation cannot be discarded altogether when considering its implementation.

Bacteria, Anaerobic↗

PubMed2005

Technical-economical evaluation of the operation of oxidation ditches.

The optimisation of the economic performance is a central aspect in the management of wastewater treatment plants. A model-based procedure was developed that could provide a clearly enunciated and concise way of reporting to the stakeholders on how well the assets are performing and can perform, separating the firm inefficiency from the effect of the treatment. The applied modelling method is conventional considering current modelling research practice, but very good from practical point of view in that it is applicable utilising existing plant data, i.e. without the use of additional measuring campaigns. This paper illustrates the validity of the developed procedures through the evaluation of the performance of oxidation ditches.

Benchmarking↗

PubMed2004

Biological solution to storm water?

Standard practice in Flanders is to limit the hydraulic capacity of sewage treatment works to 6Q14 (Q14= 1.7 dry weather flow Q(DWF)). A maximum of 3Q14 is treated biologically, while the excess flow undergoes only physical treatment in storm tanks. This practice has been challenged by a new high-flow activated sludge operation concept, consisting of the treatment of the full storm sewage flow in the biological train and of the use of the storm tanks as additional secondary clarifiers. After successful testing in two installations, 56 works of different sizes and types were switched to high-flow activated sludge operation from 1999 to 2002. This paper reports on progress and experiences gained since then. The analysis focuses on the parameters subject to regulatory discharge (BOD, COD, suspended solids, total nitrogen and total phosphorus) plus ammonia. Special attention is paid to the performance of the clarification and of the nitrification processes. The results indicate that high-flow biological treatment provides a substantial reduction in wet weather discharges while maintaining acceptable process operating conditions.

Ammonia↗

PubMed2001

Key tools to accelerate fulfilment of the EU Urban waste water treatment directive in the Flemish region of Belgium.

The EU Urban Waste Water Treatment Directive (UWWTD) has been transposed in 1992. The whole area of the Flemish region was designated as a sensitive area. This implies nutrient removal for all works in agglomerations of more than 10,000 population equivalent (PE). Thanks to an accelerated investment programme, which is in a final phase now, the wastewater treatment plants (WWTPs) will fulfil treatment in 2005. Key tools for a quick and economic execution of the programme are standardisation for new WWTP's and increasing computerisation for retrofitting existing WWTPs. The UWWTD also stipulates the reuse of treated wastewater and sludge. Strategies are explained.

Belgium↗

PubMed1988

Quantitative electromyography of the masticatory muscles of Pteropus giganteus (Megachiroptera).

Mastication has been studied by cinematography and quantitative electromyography while flying foxes, Pteropus giganteus, were freely feeding on standardized pieces of apple, soaked raisin, and banana. The primarily orthal mandibular movements are caused by mainly bilaterally symmetrical firing of all the masticatory muscles. Asymmetric activity in the superficial and deep masseter and medial pterygoid causes slight protrusion early in opening. Slight lateral deviations at the end of opening and at the start of closing are caused by asymmetric and asynchronous activity in the pterygoids and digastrics, and by asynchronous firing of the deep temporalis and zygomaticomandibularis. Food consistency affects movement characteristics as well as characteristics of muscular activity. In this study electromyograms were digitized and the number of spikes and mean amplitude per interval (set by the filming rate) recorded. Although a significant correlation exists between descriptors, the product thereof appears to be the best predictor of certain kinematic variables (cycle length and maximum excursion of the mandible). On the other hand, the changes in magnitude of muscular activity as a function of the position of a cycle in the reduction sequence and as a function of food consistency are more translated in a variation of the mean amplitude than in a variation of the number of spikes per interval. Observed variation differs among muscles studied. It is most apparent in the superficial and deep masseter and least in the temporalis and zygomaticomandibularis. Late cycles of apple and raisin mastication are long and exhibit large gapes but almost no anterior movement. The adductor activity frequently shows a synchronized, pulsatile pattern leading to an unfused tetanus.

Animals↗