Read the DyStar Sustainability Report 2011...

Wastewater
The issue of polluted wastewater in the textile industry has received
global attention in the past couple of years. Influential activist NGOs
such as Greenpeace®, have launched campaigns against the polluters
in China and elsewhere. Law enforcement to contain toxic discharge
from textile factories has intensified notably in China and India.
DyStar’s wastewater strategy places the company favorably in a toughening
regulatory regime and with increasing awareness of the issue due to
activists’ campaigns. While we manage our own wastewater responsibly,
we also continue to invest in developing products and processes that
reduce wastewater emissions in our customers’ operations.
Wastewater discharge from dyestuff production may contain significant
amounts of chemical compounds, intermediate products and in some
cases dyes, presenting an opportunity to recover these materials from
the wastewater for reuse and thereby reduce the pollutant load of the
final discharge.
We have a strict policy to comply with applicable national regulations
governing wastewater discharge. Whilst we do some pre-treatment of
wastewater at a number of our sites, most of our wastewater is channelled
into licensed third party wastewater treatment plants for further treatment.
The composition of wastewater from the production of dyes can vary
depending on the product mix. In other words, wastewater discharge
volume may differ from year to year if the proportion of products
changes.
Wastewater is generated during the production of dyes in our plants,
and as a result of washing of vessels and other equipment. In 2011,
production processes accounted for 20% of the overall water consumption.
A significant portion of our total water use is for cooling purpose
where water does not come into direct contact with chemicals and
hence does not get contaminated. In 2011, cooling systems accounted
46 2011 Sustainability Report - DyStar Group
for 73% of the total water use in DyStar.
In 2011, our plants discharged 1.79 million cubic meters of wastewater
compared with 1.75 million cubic meters in 2010. Discharge per tonne
of production was at 18.4 in 2011 against 18.05 in 2010.
In 2011, emissions of organic substances to water measured as the
chemical oxygen demand (COD) were 3,735 tonnes or 0.0363 tonnes
of COD per tonne of production, a minor increase over 2010.
The slight increase in wastewater and COD in 2011 is attributed to
higher production volume and a change in product-mix that included
higher proportion of synthesized intermediates and final product
stages. Another reason for increase is that DyStar plant in Leverkusen,
Germany operated for nine months in 2011 against six months in 2010.
DyStar Wastewater Initiatives
Our production plants continuously look for creative solutions to
reduce wastewater discharge or the toxicity levels. For example,
the DyStar plant in Apiuna, Brazil has been improving the process
for washing vessels and production area and has managed to
reduce wastewater from 255 litres per tonne of production in
2009 to 204 litres in 2010 and 133 litres in 2011.
The plant in Hangzhou, China recycles water from washing of
vessels to reduce wastewater. The plant in Nanjing recycles high
concentration mother liquor for the next batch of production.
At the plant in Wuxi, China, improvements made in the method
for cleaning filter bags, reuse of water from equipment washings,
and better production planning to reduce equipment cleaning
has resulted in huge reductions in wastewater. The plant managed
to reduce wastewater per tonne of production from 5.77 cubic
meters in 2008 to 3.57 cubic meters at the end of 2011.