Biomedical subjects

P J Longhurst

Publications and source records attributed to P J Longhurst.

3 recordsLinked to original sources

PubMed2006

Recent developments in the application of risk analysis to waste technologies.

The European waste sector is undergoing a period of unprecedented change driven by business consolidation, new legislation and heightened public and government scrutiny. One feature is the transition of the sector towards a process industry with increased pre-treatment of wastes prior to the disposal of residues and the co-location of technologies at single sites, often also for resource recovery and residuals management. Waste technologies such as in-vessel composting, the thermal treatment of clinical waste, the stabilisation of hazardous wastes, biomass gasification, sludge combustion and the use of wastes as fuel, present operators and regulators with new challenges as to their safe and environmentally responsible operation. A second feature of recent change is an increased regulatory emphasis on public and ecosystem health and the need for assessments of risk to and from waste installations. Public confidence in waste management, secured in part through enforcement of the planning and permitting regimes and sound operational performance, is central to establishing the infrastructure of new waste technologies. Well-informed risk management plays a critical role. We discuss recent developments in risk analysis within the sector and the future needs of risk analysis that are required to respond to the new waste and resource management agenda.

Environmental Health↗

PubMed2004

Odour management plans: a risk-based approach using stakeholder data.

Annoyance is a familiar reaction to odours arising from wastewater treatment sites, a reaction which can result in complaints and prosecutions. Odour management plans can be used to assess the extent of nuisance caused and prioritise mitigation measures. Often, these plans have been developed purely on the basis of technical assessments of emission and dispersion, with the general aim of limiting odour concentrations to a specific threshold at some distance from the works. They have often been prepared with inconsistent communication between the site staff and consultant during the development process, and may not directly refer to the affected population. This paper describes a risk-based approach to developing odour management plans, in which mitigation measures are assessed and prioritised on the basis of the likely frequency and intensity of odour exposure. A key element of the approach is the use of knowledge from data gained from key stakeholder groups: customers, staff, and regulators. Emphasis is placed on the development of clear communications between these groups, which helps both in terms of raising awareness amongst operators as to the significance of odour problems, and also in managing the expectations of customers and regulators. The practical application of this approach is demonstrated by the development of odour management plans for wastewater treatment sites by Yorkshire Water Services Ltd. These have used data from staff, customers and regulators to develop risk grids, which are then used to prioritise remediation measures. Involving staff in the data collection operations has been successful in raising awareness of the significance of odours, and has in turn led to low-cost emission reductions through improved housekeeping. Improved communications between operators, customers and regulators has led to more realistic expectations with regard to odour problems, a situation which can reduce conflict and prevent the imposition of stringent and sometimes unrealistic odour standards.

Communication↗

PubMed2004

Developing methods to evaluate odour control products.

An economical and practical alternative to the standard end-of-pipe odour control methods is the application of liquid odour control products. Currently, there are no established product-testing methods. The data that are available are often of questionable quality and may have limited relevance to waste management. Waste facilities receive differing streams of waste at varying loading volumes. Whilst in operation this exposes control products to a wide variety of environmental conditions, further increasing the difficulty of selecting an effective means of control. The current study initially identifies commercially available odour control products applicable for solid and liquid waste management operations. Bench-scale batch absorption tests have been carried out to investigate odorous gas abatement for a range of selected commercial products and water at a range of pH values. Hydrogen sulphide was the test odorous gas, as it is commonly associated with waste processes. Gas-phase volumetric mass-transfer coefficients (KGa) have been calculated to determine mass-transfer performance. The development of a pilot-scale spray tower is then presented as the testing apparatus for future work. This is an attempt to construct a repeatable testing method for evaluating abatement performance of odour control products, and control the problems encountered when applying odour control products to open sites. KGa values and data collected from tests in this study will be considered in future work as design parameters for the rig.

Absorption↗