Comparison of pollutant emission control strategies for cadmium and mercury in urban water systems using substance flow analysis

Abstract

The European Union (EU) Water Framework Directive (WFD) requires Member States to protect inland surface and groundwater bodies but does not directly stipulate how the associated environmental quality standards should be achieved. This paper develops and assesses the performance of a series of urban emission control strategies (ECS) with an emphasis on the scientific and technological benefits which can be achieved. Data from the literature, in combination with expert judgement, have been used to develop two different semi-hypothetical case cities (SHCC), which represent virtual platforms for the evaluation of ECS using substance flow analysis (SFA). The results indicate that the full implementation of existing EU legislation is capable of reducing the total emissions of cadmium (Cd) and mercury (Hg) by between 11% and 20%. The ability to apply voluntary reduction practices is shown to be particularly effective for Cd with the potential to further lower the overall emissions by between 16% and 27%. The most efficient protection of the receiving surface water environment is strongly influenced by the city characteristics with the introduction of stormwater treatment practices being particularly effective for one city (59% reduction of Hg; 39% reduction of Cd) and the other city being most influenced by the presence of efficient advanced wastewater treatment processes (63% reduction of Hg; 43% reduction of Cd). These reductions in receiving water loads are necessarily accompanied by either increases in stormwater sediment loadings (2.6 to 14.9 kg/year or 0.6 to 2.4 kg/year for Hg) or wastewater sludge loadings (45.8 to 57.2 kg/year or 42.0 to 57.4 kg/year for Cd).

Towards control strategies for microplastics in urban water

“…CSO stands for combined sewer overflow and WWTP for wastewater treatment plant. Developed from Revitt et al (2013) a local responsibility. Three levels were considered: EU, national and local (i.e.…”

“…Environmental pollution from a wide range of sources is concentrated in urban areas (Holten Lützhøft et al 2012 ), and urban waters, i.e. stormwater and wastewater, are important pathways (Revitt et al 2013 ). Microplastics (plastic particles < 5 mm) is a new type of pollution that has received increased attention in recent years.…”

Controlling environmental pollution in the urban water cycle

“…By considering the whole system, the most suitable places to intervene can increase the effectiveness of the measure. As many environmental toxins are of persistent character, some measures only move pollution from one medium to another [8]. A widened perspective reduces the risk of measures only moving pollution between the medium.…”

“…'Upstream work' as a concept and practice is widely known in the water and wastewater sector in Sweden, but outside the sector and in the international community it seems fairly unknown. Source control is the most similar concept, although it is wider and can include strategies for different types of water as well as air, soil and sediments [8].…”

Evaluation of stormwater micropollutant source control and end-of-pipe control strategies using an uncertainty-calibrated integrated dynamic simulation model

“…For each land usage it is possible to find MP release data in the existing literature, or using database systems supporting pollutant source mapping (e.g. Lützhøft et al, 2012;Revitt et al, 2013). Therefore integrated models which combine source characterization with measured data are essential tools to understand and analyze the behavior of complex stormwater systems and to evaluate different strategies to achieve desired water quality standards, as discussed for combined systems by Rauch et al (2005).…”