Welcome to Visual MINTEQ

Visual MINTEQ is a freeware chemical equilibrium model for the calculation of metal speciation, solubility equilibria, sorption etc. for natural waters. It combines state-of-the-art descriptions of sorption and complexation reactions with easy-to-use menus and options for importing and exporting data to/from Excel. Chemical equilibrium modelling has never been easier!

The code, originally built on USEPA‚Äôs MINTEQA2 software, is maintained by Jon Petter Gustafsson at SLU, Sweden, since 2000.

Visual MINTEQ will run on most Windows platforms and relies on .NET Framework. For more details, see here. The current version is 3.1, but an upgrade is in progress, and version 4.0 will be available soon!

Is Visual MINTEQ what you are looking for?

Visual MINTEQ can simulate the chemical composition in solutions in contact with gases, solid compounds and particle surfaces. To determine whether it is relevant for you, check the following list of what Visual MINTEQ can and cannot do:

Examples of what you can do with Visual MINTEQ

– Calculate the speciation of inorganic ions and complexes in waters

– Evaluate the effect of dissolving or precipitating solid phases on water chemistry

– Investigate the equilibrium speciation of common redox couples

– Simulate the change in chemical composition of a water sample during a titration

– Estimate the binding of ions to (hydr)oxide surfaces and organic matter using state-of-the-art complexation models (SHM or NICA-Donnan for organic complexation, CD-MUSIC, TLM, CCM or DLM for surface complexation).

Examples of problems that are difficult or impossible to solve with Visual MINTEQ

– Problems that require transport calculations. Visual MINTEQ does not contain any transport model. If your aim is to estimate, e.g., the transport rate of heavy metals from a contaminant source to a water body, you will need to find another model. Visual MINTEQ only calculates the chemical composition in one single point.

– Partitioning of organic compounds. Although the partitioning of non-polar organic chemicals can be calculated (in principle) by Visual MINTEQ, there is no database for this type of calculations. Visual MINTEQ was developed mainly for the purpose of calculating equilibria for inorganic ions and trace metals in waters.

– Non-equilibrium processes such as weathering or biological degradation cannot be handled by Visual MINTEQ, since equilibrium is always assumed.

– Problems for environments having high pressure or temperature such as in deep geological formations. Visual MINTEQ has been optimized for use for waters in the temperature range 0-40 deg C and pressures near 1 atm. Again the calculation engine of Visual MINTEQ can, in principle, solve this kind of problems, but the necessary databases have not been assembled. You are therefore advised to use other software for high P-T problems.