Treatment of wastewater from a carbon monoxide
production unit aimed at water reuse
R. B. Almada, G. A. T. Fontoura, D. M. Bila, G. L. Sant’Anna Jr and
M. Dezotti
ABSTRACT
The industrial wastewater from a carbon monoxide production unit was treated by physico-chemical
processes in order to achieve a quality level appropriate for reuse. In preliminary tests, coagulation/
flocculation (CF), sand filtration and activated carbon adsorption were investigated in order to select
the materials and the process conditions. Based on the results a combined treatment was proposed:
CF followed by down-flow filtration in a combined medium (sand and granular activated carbon). The
results obtained in a bench-scale treatment unit showed that the combined treatment removed
wastewater turbidity (95%), total suspended solids (97%), volatile suspended solids (81%), chemical
oxygen demand (74%) and dissolved organic carbon (65%). Polycyclic aromatic hydrocarbons (PAHs)
were removed to non-detectable levels. The residual conductivity of the treated wastewater is a
matter of concern, and considering the water characteristics of this industrial process, a reuse
scheme was proposed based on on-line monitoring and control of conductivity and partial reuse of
the treated wastewater.
R. B. Almada
G. L. Sant’Anna Jr
M. Dezotti (corresponding author)
Federal University of Rio de Janeiro,
COPPE, Chemical Engineering Program,
P. O. Box 68502, Rio de Janeiro, RJ,
21941-972,
Brazil
E-mail: mdezotti@peq.coppe.ufrj.br
G. A. T. Fontoura
Department of Analytical Chemistry,
Institute of Chemistry,
Federal Fluminense University,
Niteroi, RJ,
24020-150,
Brazil
D. M. Bila
Department of Environmental and Sanitary
Engineering,
State University of Rio de Janeiro,
Rio de Janeiro, RJ,
20550-013,
Brazil
Key words | carbon monoxide production, PAH, tannin coagulants, wastewater treatment,
water reuse
INTRODUCTION
Water utilization is a very important matter for discussion in
international environmental forums. Water stress is an
important issue for many European countries (Bixio et al.
). Water demand is growing, particularly in developing
countries, for agricultural, domestic and industrial uses
(Andrade et al. ; Dias et al. ). A recent report indi-
cated that China, India, Brazil and South Africa will
account for 42% of the worldwide water demand projected
for 2030 (McKinsey & Company ). Although industrial
demand is relatively moderate compared to those of other
economic sectors, as shown in Table 1 for a specific country
(Brazil), the industrial commitment to associated environ-
mental issues and sustainability is increasing. Water
economy and water reuse are subjects already on the
agenda of many industries.
Water scarcity is observed not only in dry regions but also
in cities, where water supply systems are overloaded and
water utilization by industries is restricted. However, due to
the diversity of water sources used in industry, it is possible
to select process streams that can be treated and reach a qual-
ity level that allows water reuse. The combination of water
demand management and cleaner production can lead to sig-
nificant reductions in water demand, as verified by Gumbo
et al. () for different industries. Particularly in large
chemical industries, many opportunities for reuse can be
found due to the degree of integration among production
units in terms of raw materials, products and utilities.
To implement a water reuse project at a particular indus-
trial plant, good knowledge of the industrial process, stream
characteristics, water demand, water costs and other rel-
evant factors is a fundamental requirement. In addition,
after the selection of a candidate stream, it is necessary to
find a feasible treatment technology that allows the pro-
duction of water with the required quality standards.
111 © IWA Publishing 2013 Journal of Water Reuse and Desalination | 03.2 | 2013
doi: 10.2166/wrd.2013.081
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