1. April 2016 Leather International | www.leathermag.com 49
Insight CSR
T
he historic principles of tanning
hides are being challenged by a
revolutionary process that uses
wastewater. BIOSK Chemicals, located in
Shangqiu, a city in eastern Henan province,
central China, has developed technology
capable of constantly using all discharged
waters from the beamhouse through the
retanning processes. With an impressive
legacy and dynamic leadership, the
company is embarking on a global strategy
to assist tanners with a solution that is
not only timely but appropriate for today’s
industrial climate. Imagine being able to
reduce water usage by over 70%, minimise
effluent discharge by up to 70% and lower
chemical usage by 30%. This is now a
reality and no longer an aspiration.
Established 30 years ago, BIOSK
has grown into the largest company
specialising in the research and
development of tanning processes and
the supply of chemicals to the Chinese
tanning industry, as well as managing
many production and distribution centres
around China. Their core products
encompass soaking and liming agents,
degreasing chemicals, bactericide and
fungicides. This is in addition to its recent
breakthrough development of wastewater
recycling technology.
Eureka moment
The genesis of addressing the challenge to
recycle wastewater was based on BIOSK
chairman Zhuangdou Zhang’s experience
with pollution, together with the need to
change the public’s negative perception
of tanning. In 2005, with a defined goal,
he began his journey. He closed his
tannery, and established a research
and development test centre, and by
using the equipment together with new
investments in laboratory materials, he
began trials, and became obsessed with
developing a solution. To support his
efforts, he hired technicians, engineers
and scientists. He then expanded his
thought process to include medical
science, and after four years, in December
2009, after making some radical changes,
results improved. He repeated the tests
until a eureka moment.
The most interesting aspect of his
discovery was that his wastewater
recycling technology is a combination
of two things: chemistry and process.
It is not as simple as adding a secret
ingredient, but a change in the concept
of managing wastewater and therefore
providing tanners with the ability to
reuse the effluent stream to create good,
consistent leather.
New parts of the process
The traditional tanning process follows the
historic principle of using fresh, original
ingredients with each new batch of
hides processed. This formula requires
a continuous flow of clean water, fresh
chemicals and associated utilities.
Tanning is a batch process operation,
but creates a constant flow of effluent
and spent liquors all of which must
be managed through a complex water
treatment system prior to being released
to the local municipality. This becomes
a reactionary process and managing the
waste streams becomes challenging. There
are a multitude of initiatives around the
globe to address polluting industries and
the demands set upon businesses are
becoming increasingly strict each year.
A paradigm shift
With an advanced RD department developing technology that is being adopted by several
large Chinese tanners, Professor Dobre Jovanoski looks at the latest development from
BIOSK and how it has taken an innovative approach with its waste management methodology.
Looking at the concept of tanning
from a different perspective, BIOSK has
taken a proactive approach by applying a
waste management methodology to the
processing of hides. Instead of dealing
with the resulting problem of effluent, it
has addressed the symptoms causing the
discharge by approaching the issue of
reusing the constituents. Imagine only
having to charge the float once, and retain
the spent tanning liquors for reuse on
the subsequent batch. The concept of
recycling all tanning waters is a major
paradigm change and it appears that
BIOSK has developed the key to unlock
this untapped resource.
The BIOSK technology works by
adjusting and re-engineering the
process together with adding certain
pharmaceutical agents. This has the
effect of turning hindering materials into
beneficial agents, essentially turning the
multitude of compounds, micro-organisms
and enzymes into productive agents that
assist in reusing spent liquors. This new
technology is also able to enhance the
wet-blue product as finished leather
quality and yields all improve.
Today, this technology is being used
by several large-scale tanneries in China,
having been adopted successfully for over
three years. BIOSK’s technology has gained
several patents in China and it is in the
process of applying for patents in several
other countries, including the US. ■
■ Wet-blue yield increases by 3–10%
■ Shrinkage temperature increases by 3–10°C
■ Tear strength increase by 15%
■ Yield of split leather increase by 15–20%
■ Loose surface decreases by more than 20%
■ Chrome and other chemicals penetrate more evenly
■ Water use is reduced by more than 85%
■ Energy use is reduced by more than 25%
■ Solid waste (sludge for example) discharge is reduced by more than 70%
■ A reduction in the use of other resources such as land, equipment, chemicals
and labour by more than 80%
Key benefits of BIOSK’s new technology