Coffee processing produces two main types of wastewater pollution streams: effluents from pulpers which contain quickly fermenting sugars and effluents from fermentation tanks containing hydrolyzed sugars and pectins. This wastewater has a high biochemical oxygen demand that can deplete the oxygen in waterways. Coffee wastewater also releases methane during evaporation, contributing to climate change. Various waste management strategies are employed like using coffee pulp as organic manure or compost, anaerobic digestion of wastes, and equipment upgrades to reduce water usage. Coffee roasting also produces air pollutants like particulate matter and volatile organic compounds that require emissions control technology.

1. Coffee processing industries waste
and its effect on water and air
quality

2. COFFEE
• Coffee is a major plantation crop grown worldwide and is
one of the most popular beverages consumed throughout
the world.
Three common species of coffee: robusta, arabica and
liberica.
• India is in sixth place in the world coffee production
• Coffee is processed either by wet or dry method.
Wet method -superior quality
Dry method-inferior quality

4. mucilage

5. Characteristics of wastewater
• Wet processing-uses a lot of water
• The resultant effluent is rich in total suspended and
dissolved solids which are biodegradable
• Two main pollution stream
Effluents from pulpers
Effluents from fermentation tanks
EFFLUENTS FROM PULP :
it is highly loaded with quickly fermenting
sugars from breaking down pulp and parts of the
mucilage

6. EFFLUENTS FROM FERMENTATION
TANK:
• hydrolysed sugars from fermentation and/or thick pectin
loaded effluent from mechanical mucilage removers
• The sugars and pectins in the water are fermenting into
acetic acid ,when they are released into local water ways.
• Where they can only be broken down by oxygen in water.
• the amount of oxygen needed to break down pollutants in
the wastewater – referred to as biological oxygen demand,
or BOD
• So the rivers and streams has natural ability to purify the
coffee wastewater effluents

7. • Coffee wastewater also releases methane into the
atmosphere
• as it evaporates, contributing to climate change.
• coffee waste water should follow preliminary
treatment due to the presence of tannins,
polyphenolics and caffeine
• Wastewater quantities: between 1 and 20 cubic
metre/tonne fresh cherry
• The waste water generally has a pH of 4.0 to 4.5.

8. Waste management
• The coffee pulp can be used as organic manure to
the coffee farms. They can also be used as planting
soil for mushrooms.
• Anaerobic digestion has been applied to treat
liquid and solid wastes from the coffee processing
units.
• Employment of new machineries that use low
water for washing
• Coffee pulp solid waste is being converted into
compost, which was used by the suppliers in
fertilizing their coffee farms
• Pulp water for few cycle prior to discharge

9. Effects in air
• Usually the air get affected during roasting
• The air pollutant emissions resulting from coffee
roasting operations include particulate matter
(PM), volatile organic compounds (VOCs),
organic acids, and natural gas combustion
byproducts such as CO, and CO2 .
• The odorous and visible emissions (smoke)
resulting from the roasting process have the
most obvious and direct impact on public

10. Air management
• Each roaster must be equipped with a cyclone
capable of reducing uncontrolled emissions of
particulate matter by at least 70%
• Each roaster must be equipped with an
afterburner capable of reducing uncontrolled
emissions of volatile organic compounds by
atleast 95%