Leefbaarheid grote steden

Sinds enkete jaren wonen er weretdwijd meer mensen in een stad dan op het ptattetand en dat percentage groeit nog steeds. Elke week komen er acht mitjoen stadsbewoners bij door geboorte en door migratie van pLatteLand naar stad. Naar verwachting zal in 2050 driekwart van de weretdbevotking (bijna 7 van de 9 mitjard mensen) in een stad wonen, een...

A GIS-based approach for the long-term prediction of human health risks at contaminated sites

A Health Index/Risk Evaluation Tool (HIRET) has been developed for the integration of risk assessment and spatial planning using GIS capabilities. The method is meant to assist decision makers and site owners in the evaluation of potential human health risk with respect to land use. Human health risk defined as the potential adverse effects on...

Intrinsic and stimulated in situ biodegradation applied in in-situ treatment zones at sites contaminated with hexachlorocyclohexane (HCH)

The pollution of soil and groundwater with hexachlorocyclohexane (HCH) has caused serious environmental problems. Mineralisation of some HCH isomers can be expected under aerobic conditions whereas all isomers are known to be bioconverted to intermediate products under anaerobic conditions. Hence, redox conditions can be expected to have strong...

Hydrogen as indicator for redox conditions and dechlorination

The use of intrinsic degradation processes (natural attenuation) is becoming the basis for the restoration of many contaminated sites. Within this context, measuring concentrations of hydrogen in groundwater is important in two ways. Firstly, the hydrogen concentration can be used to characterize redox conditions. Secondly, hydrogen may be an...

Innovative reactive barrier technologies for regional contaminated groundwater

At many industrial sites inadequate waste disposal, leakages and war damages have led to severe groundwater contamination on a regional scale. Standard hydraulic groundwater remediation methods, such as pump-and-treat, in most cases do not lead to satisfactory results, due to the persistence of organic contaminants and the resulting very long...

DLVO and steric contributions to bacterial deposition in media of different ionic strengths

Intrinsic and enhanced biodegradation of benzene in strongly reduced aquifers

Laboratory microcosm studies were performed to examine intrinsic and enhanced benzene bioremediation using five different sediment and groundwater samples from three deeply anaerobic aquifers sited in northern Netherlands. The influence of addition of nitrate, sulfate, limited amounts of oxygen, and combinations of these electron acceptors was...

Combined intrinsic and stimulated in situ biodegradation of hexachlorocyclohexane (HCH)

Intrinsic and enhanced bioremediation in aquifers contaminated with chlorinated and aromatic hydrocarbons in The Netherlands

The feasibility of intrinsic and enhanced bioremediation approaches for 16 contaminated sites in the Netherlands are discussed. At at least five out of 10 chlorinated solvent sites, natural attenuation can be used as one of the tools to prevent further dispersion of the plume. At two sites stimulation of the intrinsic dechlorination processes in...