Many treatment systems simply remove an undesirable process waste or by-product from one media and capture it in another. For e.g. scrubbers on smokestacks remove undesirable combustion product by dissolving them in water. Another example is the biodegradation of chemical waste in textile waste water, which produces waste sludge (a solid waste). These solids have to be disposed and traditional land filling of sludge has an associated problem of contamination of ground water. Thus, treatment strategies tend to create a chain of waste production which leads to expenses and liability of various type.
An important alternate is source reduction. This concept helps to determine changes which can be made to reduce waste at the source.
Different technics of source reductions often used are :
- Raw material control
- Conservation/optimization of chemicals
- Chemical substitution
- Process modification
- Equipment modification
- Maintenance Procedures
- Housekeeping
- Waste recovery (for reuse/recycle)
-
Segregation
Combinations of these technics may be used to achieve substantial savings. Such
savings keep on increasing with the ever rising coat of inputs. On the other hand,
losses and costs of waste treatment will produce an ever increasing economic disadvantage
to processors.
Raw material control, optimization of chemicals and chemical substitution are important technics of source reduction. Theses also forms integral part of chemical management. In totality, they aims towards cleaner production by helping to meet requirement of eco labeling and discharge standards along with meeting regulations such as REACH for SVHC (Substances of Very High Concern), GOTS (Global Organic Textile Standard) and ZDHC (Zero Discharge of Hazardous Chemicals).
Increasingly large number of chemicals have now been categorized as toxic, carcinogenic allergenic or hazardeous, Use of such chemicals is undesirable and thus loosing favour.
Raw material control includes identification of the harmful chemicals and their probable source in fibres in sizing ingredients, certain dyes, preparation chemicals and finishing chemicals etc. Safety data sheet of each input to be referred for LC 50 or IC 50 values and the biodegradability of the product in addition to safe handling procedures or should be confirmed by testing prior to use.
Avoid use of toxic, carcinogenic and allergenic banned dyes, chlorine based bleaching agents and chlorinated solvents (which give rise to the problem of AOX) and other toxic pesticides & chemicals which persists biodegradation and thus are bio-accumulative.
It also include minimizing the quantities of restricted chemicals like formaldehyde, sulphides and heavy metal salts etc.
Chemical substitution for harmful chemicals is an important task. The environment forces are driving chemical manufactures to provide new, friendly and “green” preparations and finishing chemicals are being developed and these are surely going to sweep away the traditional agents.
Good housekeeping does not necessarily means sweeping or cleaning of the chemicals and water which spills over or falls on the floor, but avoiding their spillage by proper handling. Sweeping or cleaning transfers the chemicals in to the effluent thus increasing the load on effluent treatment.
Other elements of source reduction contributes towards conservation of natural resources – Energy and Water, which are becoming costly and scare day by day.
BENEFITS OF SOURCE REDUCTION :
- Decreased waste liability (waste collection, handling and treatment costs)
- Decreased loss of material & energy, i.e. more profits
- Possibility of recycling to have recovery value of waste
- Meeting requirement of eco labels & discharge standards.
- Compatible with philosophy of regulations like REACH, GOTS and ZDHC.
