Title: Remediation technologies for the removal of arsenic
from water and wastewater
Chairman: Hemda Garelick
Khoda Bux, Deoraj
(Harry) Caussy, Agnieszka
Dybowska, Bryan Ellis,
Huw Jones, Nick
Priest, Yehuda Shevah,
Ross Sneddon, Eva
Valsami Jones, and Pornsawan
Completion Date: 2008 - project completed
Produce a review of critically evaluated methods used for the removal
of arsenic from water and wastewater.
Arsenic currently threatens millions of people in West Bengal,
Bangladesh and Thailand, as a result of their exposure to contaminated
groundwater (where concentrations may reach 0.06 mg/L to 1.86 mg/L,
a value far in excess of the WHO Maximum Permissible Levels). Major
problems have also been identified in some areas in the USA and China
and south America (1,2 ).
The WHO and USEPA recommended limit for arsenic in drinking water is
currently 10 μg/L (3). It is not so much the difficulty of removing
arsenic from water, as the extremely low levels to which it must be
reduced to ensure safety, that presents the challenge to water treatment
initiatives, especially in developing countries where the issues of
cost and expertise often make 'high-tech' solutions impractical.
Arsenic may be released into natural waters from a variety of hosts,
most commonly either iron oxides, organic matter or sulphides. Elevated
concentrations of dissolved arsenic may be expected under conditions
where these phases are unstable, or where arsenic is weekly bound (i.e.
adsorbed) to the host phase. Arsenic speciation in waters is complex
(4); fundamentally, it is a function of both pH, and Eh, as arsenic
occurs naturally in two common oxidation states (III and V).
In considering arsenic removal from water, the principal processes
of interest are those involving adsorption to particle surfaces, those
defined as precipitation reactions and those involving filtration process
(e.g. reverse osmosis or electrodialysis) (5).
We propose that a critical review of these processes and technologies
will be carried out and will include an evaluation of their appropriateness
to different situations.Each process would be reviewed on a case-by-case
basis with a literature review, compendium of the data available and
critical analysis. Draft publication will be provided on the web and
final publication as an IUPAC volume.
(2) Caussy D.H 2003 The arsenic catastrophe in India and Bangladesh-
can it be solved? Special seminar report. LSHTM August 2003.
(3) Smedley,P.L Kinniburgh DG. 2002. A review of the source, behaviour
and distribution of arsenic in natural waters. Appl. Geochem.
(4) Feguson, J.F.; Gavis, J. Water Res. 1972, 6, 1259.
(5) USEPA. 2000. Technologies and costs for removal of arsenic from
drinking water. EPA 815-R-00-028.
The task group met in Bath, UK, on 5 Jan 2005. At the meeting the group
specifically identified the need for a simplified and practical guide
which condenses the available literature in a form that will allow informed
decisions to be taken. We aim to produce a scientifically sound report
that will at the same time inform and advise non-specialists on key
aspects of arsenic remediation technologies. The report should ideally
help people in arsenic affected areas by providing a practical and easy
to follow guide similar to the WHO guide for infectious agents in water.
The project will consider outcomes of remediation technologies in the
wider context of overall water quality (e.g. microbiological contamination)
rather than just arsenic contamination.
The following contributions and tasks have been agreed, and tentatively,
a first draft should be available by April 2005, and the final document
by September 2005.
Lead: Nick Priest in
consultation with Harry Caussy
To provide a brief historic overview and comment on the nature/form
of arsenic and its changing economic significance to society.
2. Arsenic pollution sources
Lead: Hemda Garelick
and Huw Jones
Arsenic pollution sources divided into point sources (industrial, mining)
and diffuse sources (geochemical, water supply) categories: a) natural
water (wells, hot springs), b) industrial (end of pipe), and c) mining/industrial
(diffuse - either from past or current mining activities)
3. Chemical behaviour
Lead: Eva Valsami
Processes of transformation of arsenic in the environment and their
effect on arsenic toxicity (speciation).
Factors affecting natural immobilisation
(e.g. iron, other metals, pH, organic matter, hardness chemical biological,
climatic, geographical, jungle, river, lake, volcanic)
4. Testing for As on site
Lead: Jörg Feldmann
Field test kits evaluation in terms of sensitivity, reliability, applicability
5. Remediation technologies and disposal of residues
Lead: Jean-Claude Bollinger
and Pornsawan Visoottiviseth.
These will be divided according to type of water treated - potable water,
irrigation water, environmental water, and wastewater,
6. Case studies
Lead: Hemda Garelick
and Agnieszka Dybowska
will be collecting them from each group member. A decision will have
to be made whether these should be included in the various chapters
or should form a separate chapter.
7. Summary recommendations
A decision making system will be provided, supported by information
flow from the above aspects.
project completed - a conference report has been published in Chem. Int. July 2008, p. 7-12.
another IUPAC project, complementary to this one, is coordinated within
CHEMRAWN > see project 2003-050-1-021
Last Update: 12 September 2008
<project announcement published in