Sources and Characteristics of liquid waste in dairy Industry

 Dairy Industries are one of the big industries across the world.

Sources and Characteristics of liquid waste in dairy Industry

The main Sources of liquid waste in dairy industry:

⇒ Receiving station

⇒ Bottling plant

⇒ Cheese plant

⇒ Butter plant

⇒ Casein plant

⇒ Condensed milk plant

⇒ Dried milk plant

⇒ Ice cream plant

⇒ Waste may also comes from water softening plant and from the bottle end and can also from washing plant.

⇒ At the receiving station the milk is received from the farms and the same is emptied into a large containers for transport to bottling or other processing plants.

⇒ The empty cans are rinsed, washed, stabilized and are returned to the farmers.

⇒ At the bottling plant the raw milk delivered by the receiving station is stored. This processing involves the cooling or refrigerate, clarification, filtration or purification, pasteurization or disinfect and then bottling.

⇒ The waste water from the cheese plant, which include mainly the discarded why and the wash water used for cleaning equipment's, floors etc.

⇒ The dry milky plant wastes consists of chiefly of the wash waters used to clean containers and equipment's.

⇒ The waste from the caseins plant includes whey washings and the chemicals used for precipitation.

Characteristics of Dairy Waste:

⇒ In Indian dairy, handling about 300000 to 400000 liters per day of milk will have the below characteristics.

PH - 7.2

Alkalinity - 600 mg/l

Total dissolved solids - 1060 mg/l

Suspended solids - 760 mg/l

BOD - 1240 mg/l

COD - 84 mg/l

Total nitrogen - 84 mg/l

Phosphorous - 11.7 mg/l

Oil and geese - 290 mg/l

Chloride - 105 mg/l

Treatment Process:

⇒ The dairy waste can be treated efficiently by the biological process due to the low COD or BOD ratio of the dairy waste.

⇒ These wastes contain sufficiently nutrients for the bacterial growth.

⇒ The volume and strength of the waste should be reduced for economical reasons, It may be accomplished by

• The prevention of spill, leakages and dropping of milks from cans.
• By reducing the amount of wash water
• By utilizing of the butter milk and whey from the production of the dairy by products.

⇒ Due to the intermittent nature of the waste discharge, it is desirable to provide equalization tank, with or without aeration before the biological treatment.

⇒ A provision of geese trap is also necessary as a pretreatment to remove fat and other greasy substances from the waste.

⇒ Both high rate trickling filters and activated sludge process can be employed very effectively for complete dairy waste treatment.

⇒ But these methods are involved much in maintenance, skilled personnel and specific type of equipment.

⇒ Low cost treatment methods like oxidation ditch, aerated lagoons, waste stabilization pond etc. can be employed with simple equipment and less maintenance.

⇒ Oxidation ditch with extended period of 1.5 days can be reduced BOD up to 95 to 98 percent.

⇒ In a waste stabilization pond a BOD reduction of 52 to 74 percent could be achieved after the completion of 12 days retention period.

⇒ The main use of the dairy waste for the disposal in irrigation after completion of the primary treatment in a aerated lagoon may also be a good solution for the disposal of the dairy liquid waste.

Conclusion:

⇒ These above are the Sources and Characteristics of liquid waste of dairy industry.