METALert – An Emergency Response System for Heavy Metals in the Environment

Ingeborg Joris(1), Piet Seuntjens(1,2,3), Jef Dams(1), Nele Desmet(1), Stijn Van Looy(1), Lieve Decorte(1), Wouter Lefebvre(1), Ingrid Raben(4), Chris Thijssen(4), Hongzhen Zhang(5), Jingqi Dong(5), Qianwen Zhang(5)

(1)VITO, Environmental Modelling Unit, Mol, Belgium; (2)Ghent University, Dept. Soil Management, Ghent, Belgium; (3)University of Antwerp, Dept. Bioscience Engineering, Antwerp, Belgium; (4)TNO, Urban Environment and Safety, Utrecht, The Netherlands; (5)CAEP, Chinese Academy of Environmental Planning, Beijing, China

1. Introduction

Accidental releases of heavy metals into the environment can have widespread and long-term impacts on environmental quality and on the health of humans and ecosystems. Therefore appropriate responses to emergency environmental incidents related to heavy metal pollution are necessary, and tools to forecast the impact of incidents are a prerequisite for this. METALert is a generic Emergency Response System (ERS) for accidental pollution incidents caused by key heavy metal related industries.

2. The METALert tool

The METALert tool is based on environmental models for forecasting, simulation and visualisation of dispersion of heavy metal pollution in water, air, and soil. The tool contains a generic database with typical emergencies in the key heavy metal related industries (at this moment this database is operational for China). Starting from an incident scenario, it can calculate the impact of an accident in water, air, and soil. It takes into account incident emissions as well as the effect of the legacy contamination present in a region. 

Figure 1: Scheme of the METALert system

The METALert tool for water calculates the discharge in the river with an adapted version of the LISFLOOD hydrological model and the propagation of the heavy metal plume in the river with the water quality model WASP. It takes into account the transport of the metal in surface water, sorption of the metals to sediment, and the resuspension and sedimentation of the river bed sediment.

3. Application in China

The tool has been applied in several regions in China, a country with a very important heavy metal mining and smelting industry and the world top producer for many heavy metals. One of the study sites is a catchment located in the Hunan province, one of the main heavy metal producing regions in China. In the region, mining activities have been going on for centuries, and there is an extensive legacy contamination present in the rivers, soils, and sediments of the study catchment.

Figure 2: Tailing pond at smelter site in Chenzhou and Wushui catchment in SE-China.

The tool has been set up for the Wushui catchment using a combination of world databases of land-use and topography and local data on meteo, river discharge, background concentrations of heavy metals in the region, and the location of historical mining sites. A simulation of an accident upstream in the catchment has been carried out, and the effect of an accidental discharge of Sb is evaluated at the location of the border between Hunan province and Guangdong province.

Figure 3: Location of accidental discharge, province border and catchment outlet and calculated concentration of Sb at the province border with accidental release (blue line) and without accidental release (yellow line).

Results show the effect of the accidental discharge on the concentrations in river water but also indicate the importance of the historical contamination in soils and sediments causing peaks of metal concentration after heavy rainfall from additional runoff to the river and the resuspension of river sediment into the water column.

4. Conclusions

The METALert tool can simulate the effect of an accidental release of heavy metals starting from accident scenarios and environmental data. METALert is flexible to be set-up for any mining area and can be used to prioritize actions in a region, guide monitoring strategies, and perform environmental impact assessments. 

 

Ingeborg Joris
ingeborg.joris@vito.be