Promoting Resource Efficiency in Small & Medium size ... - UNEP

What Type of Waste Does
Your Business Produce?
Scrap Metal/Plastic/
Some Paper
Evaluate Waste
Leaving Your Business
General Trash
Industrial Waste
Sewer Waste
e. Assembling input and output information for unit
operations
The total of what goes into a process must equal the total of what
comes out. Preparing a material balance is designed to gain a better
understanding of the inputs and outputs, especially waste, of a unit
operation so that areas where information is inaccurate or lacking
can be identified.
Recycle
Requires County License
Reduced Regulatory Requirements
Non-Hazardous
Characteristic
Wastes
Ignitable
Corrosive
Reactive
Toxic
Oxidiser
Hazardous
Figure 39: Example of a waste flowchart 63
May Require Futher
Evaluation to Determine
if Hazardous
Specifically Listed
Wastes From:
Solvents
Electroplating
Manufacture Process
PCB’s
Acute Hazardous
Toxic Discard
Special Wastes
Fluorescent Tubes
Batteries
Computers
Electronics
Silver Wastes
Oil
Antifreeze
materials and their use, and wastewater treatment and disposal.
Discuss the sequence of activities with the relevant people in your
company and confirm that this is correct.
Review the flowchart with your workers and your business partners:
- Workers and supervisors
- Suppliers
- Transporters
- Customers
- Other relevant stakeholders
Check if they agree that the process is drawn accurately.
Step 2: Create a Material Balance
A material balance may be defined as a precise account of the inputs and
outputs of an operation. The general form quoted for a mass balance is
that the mass that enters a system must, by conservation of mass, either
leave the system or accumulate within the system.
Steps:
a. Determine inputs
Quantify inputs such as raw materials, chemicals, water, air and
power
b. Measure current levels of waste reuse/recycling
Take notice of the number of bins or containers that are removed.
You might want to weigh them (or some of them and extrapolate).
Some waste can be directly reused and may be transferred from one
unit to another; others require some modification before they are
suitable for reuse in a process. Quantify reuse waste streams.
c. Quantify process outputs
Outputs include primary product, by-products, wastewater, gaseous
wastes, liquid and solid wastes that need to be stored or sent off-site
for disposal and reusable or recyclable wastes.
d. Accounting for off-site waste
The process may produce waste that cannot be treated on-site.
These need to be transported off-site for treatment and disposal.
Waste of this type is usually non-aqueous liquids, sludge or solids.
Minimisation of these wastes yields a direct cost benefit.
f. Deriving a preliminary material balance for unit
operations
Make use of the conservation law: what goes in must come out. This
must work out for the plant as a whole, as well as for each of the
individual units and activities.
g Evaluating the material balance
The individual and sum totals making up the material balance
should be reviewed to determine information gaps and inaccuracies.
If outputs are less than inputs look for potential losses or waste
discharges. Outputs may appear to be greater than inputs if large
measurement or estimating errors are made or some inputs have
been overlooked.
h. Refining the material balance
Do the material balance in iterations: do not struggle for 100%
accuracy of data from the very beginning. Make the process a
learning process, in which you and your team gradually build a
better understanding of material flows, waste generation and waste
sources.
Step 3: Locate Sources of Waste
Waste generation might be related to impurities in the raw materials,
the production process itself (a chemical reaction might generate a
certain quantity of byproducts; lubrication oils accumulate dirt over
time and need to be replaced), the organisation of the process (startup
waste, shut down waste, expired chemicals), cleaning (cast-off
materials cleaned out of machinery in between batches of different
products), to quality control (off-spec products).
Taking a bird’s-eye-view of the production process will help identify
various sources of waste and take measures to prevent it. Waste
reduction at the source is the first priority. What cannot be avoided
should be reused (for example waste textiles as cleaning rags, waste
sheet metal for setting up machines) and what cannot be reused
should be recycled (for example metals, but also solvents, fibres).
The following are some examples for waste minimisation:
Resource optimisation: Optimised use of raw materials can mean
optimising the pattern in which the parts in stamping are laid out on
the sheet metal to minimise the area used.
Reuse of scrap: Scraps can be taken back into the process; paper
mills return damaged paper from breakage into the pulper to recover
the fibres.
Improved quality control and process monitoring: Inspection and
even better automated continuous monitoring equipment can help to
minimise lost batches, because it helps to identify process problems
early.
Waste exchanges: Waste from one process can become raw material
for another: spent catalysts of a chemical company can become raw
material in the production of catalysts, collected motor oil can be
used as fuel in a boiler.
63) Washington County, Does your business generate hazardous waste? 2008.
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