Reducing nitrogen loading of inland and marine waters--evaluation of Danish policy measures to reduce nitrogen loss from farmland

An evaluation in December 2003 of the Danish National Action Plan for the Aquatic Environment II showed that nitrogen leaching from farmland had declined to almost half the amount of that in 1989. This can be ascribed to successful implementation of several measures, the most efficient of which were related to the use of fertilizers: lowered nitrogen standards for crops, increased nitrogen utilization in manure and catch crops. Although the objectives of the plan were almost met and measurements have shown a similar, but not percentually as high a decrease in nitrogen concentrations in both inland and coastal waters, the ecological impact in estuaries and coastal areas is not yet satisfactorily significant. As a consequence, a new National Action Plan for the Aquatic Environment III, including both nitrogen and phosphorus reduction from farming, was agreed to in April 2004. To ensure that good ecological status can be achieved in water bodies according to the requirements of the European Union Water Framework Directive, the national measures will be combined with additional measures for individual river basins.     

Treatability of water-based paint wastewater with Fenton process in different reactor types

Water-based paint wastewater which is formed during the coating step of metal surfaces performed with various spray processes include binders, pigments and additives. Binders and other additives may also affect the toxicity of the paint depending on the specific characteristics of the paint. This study deals with Water-based paint wastewater, which is hard to treat. Fenton oxidation process was principally used to treat the wastewater. Treatability runs were carried out by using rust (oxidized iron) particles obtained as a waste of the metal rolling process, as the Fenton's catalyst. In order to change the variables such as dimensions of the column, packing material size, reactive dosage, pH value and reaction time, the experiments on the basis of packed columns and mixed reactors were carried out to increase the COD removal. COD eliminations with pH adjustment were about 20%. With the contribution of Fenton process in both column and mixed-reactor studies, the COD removal was improved by about 80%.     

Uncertainty assessment of contaminant plume length estimates in heterogeneous aquifers

The Virtual Aquifer approach is used in this study to assess the uncertainty involved in the estimation of contaminant plume lengths in heterogeneous aquifers. Contaminant plumes in heterogeneous two-dimensional conductivity fields and subject to first order and Michaelis-Menten (MM) degradation kinetics are investigated by the center line method. First order degradation rates and plume lengths are estimated from point information obtained along the plume center line. Results from a Monte-Carlo investigation show that the estimated rate constant is highly uncertain and biased towards overly high values. Uncertainty and bias amplify with increasing heterogeneity up to maximum values of one order of magnitude. Calculated plume lengths reflect this uncertainty and bias. On average, plume lengths are estimated to about 50% of the true plume length. When plumes subject to MM degradation kinetics are investigated by using a first order rate law, an additional error is introduced and uncertainty as well as bias increase, causing plume length estimates to be less than 40% of the true length. For plumes with MM degradation kinetics, therefore, a regression approach is used which allows the determination of the MM parameters from center line data. Rate parameters are overestimated by a factor of two on average, while plume length estimates are about 80% of the true length. Plume lengths calculated using the MM parameters are thus closer to the correct length, as compared to the first order approximation. This approach is therefore recommended if field data collected along the center line of a plume give evidence of MM kinetics.     

Capital markets and the costs of climate policies

Environmental Economics and Policy Studies - Globalization is accompanied by increasing current account imbalances. They can undermine the positive impacts of increasing international cooperation...