Engineering passive bioreactive barriers: risk-managing the legacy of industrial soil and groundwater pollution

Permeable reactive barriers are a technology that is one decade old, with most full-scale applications based on abiotic mechanisms. Though there is extensive literature on engineered bioreactors, natural biodegradation potential, and in situ remediation, it is only recently that engineered passive bioreactive barrier technology is being considered at the commercial scale to manage contaminated soil and groundwater risks. Recent full-scale studies are providing the scientific confidence in our understanding of coupled microbial (and genetic), hydrogeologic, and geochemical processes in this approach and have highlighted the need to further integrate engineering and science tools.

Complexity and Conundrums in Pollution Control:Improving Effectiveness in Regulatory Compliance

The last century has witnessed a dramatic increase in the wealth of European nations and the well being of their inhabitants. The focus has, however, largely been upon economic growth to the detriment of people and the environment. It is only in recent years that governments have taken cognisance of the impacts of our actions and there is a growing realisation that the causal factors must be identified and addressed as a matter of urgency. One of the key problem areas is pollution and as such environmental protection has become increasingly important as a mechanism for safeguarding the quality of air, water and land. This involves a range of activities from setting standards to monitoring and reporting on discharges and emissions, through to the enforcement of legislation. In theory, this is a simple challenge, in practice, it has proven to be an extremely complex equation that might only begin to be addressed through research. In this context it is strange, and alarming, to find that while it is an axiom of good practice that policy is informed by research there has been a dearth of investigation in this field. The purpose of this paper is, therefore, to consider the issue of pollution, how it impacts on the environment, what measures have been established in pursuit of reducing the number of incidences and, most significantly, which strategies might be employed to avoid or ameliorate detrimental impacts.

Applications of colloidal gas aphrons for pollution remediation

This work reviews the use of micron sized bubbles made from aqueous surfactant solution in environmental remediation. This is a novel technique and offers a low cost treatment option.

Increasing the accuracy of Nitrogen Dioxide (NO2) pollution mapping using geographically weighted regression (GWR) and geostatistics.

Nitrogen Dioxide (NO2) is known to act as an environmental trigger for many respiratory illnesses. As a pollutant it is difficult to map accurately, as concentrations can vary greatly over small distances. In this study three geostatistical techniques were compared, producing maps of NO2 concentrations in the United Kingdom (UK). The primary data source for each technique was NO2 point data, generated from background automatic monitoring and background diffusion tubes, which are analysed by different laboratories on behalf of local councils and authorities in the UK. The techniques used were simple kriging (SK), ordinary kriging (OK) and simple kriging with a locally varying mean (SKlm). SK and OK make use of the primary variable only. SKlm differs in that it utilises additional data to inform prediction, and hence potentially reduces uncertainty. The secondary data source was Oxides of Nitrogen (NOx) derived from dispersion modelling outputs, at 1km x 1km resolution for the UK. These data were used to define the locally varying mean in SKlm, using two regression approaches: (i) global regression (GR) and (ii) geographically weighted regression (GWR). Based upon summary statistics and cross-validation prediction errors, SKlm using GWR derived local means produced the most accurate predictions. Therefore, using GWR to inform SKlm was beneficial in this study.