SimpleBox 4.0, A multimedia mass balance model for evaluating the fate of chemical substances

90 Pages·2015·1.15 MB·English

SimpleBox 4.0
A multimedia mass balance model for
evaluating the fate of chemical
substances
RIVM Report 2015-0161
Marian Schoorl | Anne Hollander |
Dik van de Meent

SimpleBox 4.0
A multimedia mass balance model for evaluating the
fate of chemical substances

RIVM Report 2015-0161
RIVM Report 2015-0161
Colofon

© RIVM 2014
Parts of this publication may be reproduced, provided acknowledgement
is given to: National Institute for Public Health and the Environment,
along with the title and year of publication.

Marian Schoorl, Universiteit van Amsterdam
Anne Hollander (author), RIVM
Dik van de Meent (author), RIVM

Contact:
Dik van de Meent
DMG
[email protected]

This investigation has been performed by order and for the account of
I&M, within the framework of project REACH

This is a publication of:
National Institute for Public Health
and the Environment
P.O. Box 1 | 3720 BA Bilthoven
The Netherlands
www.rivm.nl/en

Pagina 2 van 86
RIVM Report 2015-0161
Publiekssamenvatting
SimpleBox 4.0
SimpleBox is een van de rekenmodellen die het RIVM ontwikkelt voor
het milieubeleid. Met dit model kan worden geschat aan welke
concentraties chemische stoffen mens en milieu blootstaan. SimpleBox
wordt al twintig jaar gebruikt bij de ontwikkeling van Europese
regelgeving voor chemische stoffen (tegenwoordig: REACH-procedures)
om te berekenen welke concentraties als veilig mogen worden
beschouwd. Het model is in 2014 geüpdatet op basis van de nieuwste
wetenschappelijke inzichten en kan nu voor meer stoffen worden
ingezet. Dit rapport bevat de gedetailleerde beschrijving voor technisch-
wetenschappelijke onderzoekers en beleidsmakers.
Met SimpleBox kan de aanwezigheid van chemische stoffen in lucht,
water en de bodem worden weergegeven. Het beschrijft ook hoe snel en
in welke mate ze tussen deze compartimenten worden ‘uitgewisseld’.
Stoffen in de lucht kunnen bijvoorbeeld door regen in de bodem
terechtkomen.
De eerste versie van SimpleBox stamt uit 1986; de huidige versie 3.0,
die momenteel in REACH dienst doet, is uitgebracht in 2004. Het
vernieuwde model kan ook worden gebruikt voor stoffen die in het
milieu geheel of gedeeltelijk als elektrisch geladen deeltjes (ionen)
aanwezig zijn, zoals zware metalen en organische zuren en basen.
Toekomstige modelvernieuwingen van SimpleBox zullen bovendien
bruikbaar zijn voor nanomaterialen. Het RIVM ontwikkelt momenteel
zo'n SimpleBox4nano in samenwerking met de Radboud Universiteit
Nijmegen.
Het model wordt voor gebruik door onderzoekers en beleidsmakers
beschikbaar gesteld via de RIVM-website www.rivm.nl/SimpleBox.
Kernwoorden: milieumodellering, gifstoffen
Pagina 3 van 86
RIVM Report 2015-0161

Pagina 4 van 86
RIVM Report 2015-0161
Synopsis
SimpleBox 4.0
This document provides the technical description of the revised multi-
media fate model SimpleBox 4.01 (20150331).

SimpleBox is a nested multi-media environmental fate model of the so-
called Mackay level III/IV type. The environment is modelled as
consisting of well-mixed environmental compartments (air, water,
sediment, soil, etc.), at three spatial scales. Emissions to the
compartments, transfer and partitioning between the compartments,
and removal from the compartments are used to compute the steady-
state and quasi-dynamic masses of chemical substance in the
environment. The SimpleBox model simulates the environmental fates of
different substances in different landscape settings, of which the
characteristics are provided with the model database. In its default
settings, SimpleBox returns results for a typical chemical, given a typical
emission, to a typical environment.

SimpleBox vs. 4.01 (20150331) is an update of the SimpleBox vs 3.0
(20040614). Structural improvements made to the former version are
the removal of the local scale and the vegetation compartments, and the
addition of lake water and deep-sea water compartments. Further
improvements are a number of updates which implement new scientific
insights in transport and degradation processes. The model’s application
domain has been extended to cover a wider suite of chemical
substances, notably ionizing compounds such as metals, organic acids,
and bases.

This report has been written to provide technical documentation for the
new SimpleBox model.

Keywords: environmental fate modeling, toxic substances

Pagina 5 van 86
RIVM Report 2015-0161

Pagina 6 van 86
RIVM Report 2015-0161
Contents
Samenvatting — 9
1 Introduction — 11
1.1 Adjustments to the SimpleBox model — 11
1.2 Reader’s guide — 12
2 The SimpleBox model — 13
2.1 Model concept — 13
2.2 Scales and compartments — 13
2.3 Processes in SimpleBox — 13
3 Model calculations — 17
3.1 Model parameters — 17
3.2 Characteristics of the landscape — 22
3.3 Characteristics of the chemical — 23
3.3.1 Molecular weight — 23
3.3.2 Solid-water partitioning coefficient — 24
3.3.3 Gas-water partitioning coefficient — 25
3.3.4 Octanol-water partitioning coefficient — 26
3.3.5 pKa — 26
3.3.6 Fraction original species — 27
3.3.7 Vapour pressure — 27
3.3.8 Enthalpy of vaporization — 28
3.3.9 Solubility — 28
3.3.10 Enthalpy of dissolution — 28
3.3.11 Melting point — 28
3.3.12 Degradation rates — 28
3.4 Intermedia partitioning processes — 30
3.4.1 Air-water — 30
3.4.2 Aerosol solids-air — 31
3.4.3 Aerosol water-air — 32
3.4.4 Suspended solids-water — 32
3.4.5 Soil-water — 32
3.4.6 Sediment-water — 33
3.4.7 Colloidal organic matter-water — 34
3.5 Characteristics of the environment — 35
3.5.1 Air — 35
3.5.2 Water — 39
3.5.3 Sediment — 43
3.5.4 Soil — 44
3.6 Loss processes — 46
3.6.1 Degradation in air — 46
3.6.2 Degradation in water — 47
3.6.3 Degradation in sediment — 48
3.6.4 Degradation in soil — 49
3.7 Intermedia transfer processes — 50
3.7.1 Deposition — 50
3.7.2 Air to water and soil — 53
3.7.3 Water and soil to air — 56
3.7.4 Soil to water transfer — 58
3.7.5 Water and sediment exchange — 59
Pagina 7 van 86
RIVM Report 2015-0161
3.7.6 Ocean mixing — 61
3.8 Mass balance equations-62
3.8.1 Air compartment-62
3.8.2 Water compartment-62
3.8.3 Sediment compartment-66
3.8.4 Soil compartment — 66
4 Model output — 69
4.1 Steady-state computation — 69
4.2 Quasi-dynamic computation — 73
5 The SimpleBox model code — 75
5.1 SimpleBox sheets — 75
5.1.1 Input — 75
5.1.2 Output — 75
5.1.3 Quasi-dynamic computation (“dynamicR”) — 75
5.1.4 Database — 77
5.1.5 Definition (“regional”, “continental” and “global”) — 77
5.1.6 Steady-state computation (“engine”) — 78
5.1.7 Operation — 78
5.2 Running the model — 79
6 References — 81
Appendix – Landscape scenarios — 83

Pagina 8 van 86