The production technology of dairy industry products, main sources of wastes and ways of its utilization. Description of milk processing. Waste generating processes. Handling of by-products and treatment of waste. Waste reduction. Economic considerations.
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NATIONAL AVIATION UNIVERSITY

Institute of Ecological Safety

Department of Biotechnology

TASK

on the execution of term paper

The theme of course work: Utilization of dairy industry wastes

student Anna Pokusaieva



Abstract

Explanatory notes to the term paper from discipline “Utilization and recuperation of biotechnological industries wastes”: 39 pages, 2 fig., 6 tables, 45 references.

Object of investigation - technology of wastes utilization on dairy industry plants.

Aim of work - to get acquainted with production technology of dairy industry products, main sources of wastes and ways of its utilization.

Method of investigation - analytic review of literature.

Key words: DAIRY INDASTRY, ORGANIC WASTES, WASTEWATERS, UTILIZATION.



Content

1. Dairy industry (farming)

1.1 Liquid milk products

1.2 Cheese/Whey/Curd

1.3 Butter/Ghee

1.4 Milk powder

1.5 Condensate/Cream/Khoa

2. Description of milk processing

3. Dairy industry products. Emissions

3.1 Solid waste

3.2 Wastewater. Whole milk products

3.3 Cheese/Whey/Curd

3.4 Butter/Ghee

3.5 Milk powder

3.6 Condensed milk/Cream/Khoa

4. Waste generating processes

5. Prevention of waste production

6. Handling of by-products and treatment of waste

6.1 Several ways may be followed to reduce the occurrence of waste.

6.2 Treatment of Dairy Waste Water

7. Main wastewater problems

7.1 Most treatment plants follow the following steps

8. Waste production and its consequences

8.1 Data availability and reliability

9. Waste reduction

10. Economic considerations

Conclusions

References



1. Dairy industry (farming)

Dairy farming is a class of agricultural, or an animal husbandry, enterprise, for long-term production of milk, usually from dairy cows but also from goats and sheep, which may be either processed on-site or transported to a dairy factory for processing and eventual retail sale.

Most dairy farms sell the male calves born by their cows, usually for veal production, or breeding depending on quality of the bull calf, rather than raising non-milk-producing stock. Many dairy farms also grow their own feed, typically including corn, and hay. This is fed directly to the cows, or is stored as silage for use during the winter season [3].

1.1 Liquid milk products

Dairy products are generally defined as food produced from the milk of mammals (the Food Standards Agency of the United Kingdom defines dairy as "foodstuffs made from mammalian milk"). They are usually high energy-yielding food products. A production plant for the processing of milk is called a dairy or a dairy factory. Apart from breastfed infants, the human consumption of dairy products is sourced primarily from the milk of cows, yet goats, sheep, yaks, camels, and other mammals are other sources of dairy products consumed by humans. Dairy products are commonly found in European, Middle Eastern and Indian cuisine, whereas they are almost unknown in East Asian cuisine [8].

1.2 Cheese/Whey/Curd

There are about 500 varieties of cheese produced throughout the world. These are classified in nine major cheese families. These varieties come about as a result of different types of production processes. The composition of the wastewater of each specific production process varies from variety to variety[32]. For the purpose of discussing the environmental impact, the production of cheese will be related to the production of whey. For hard cheeses (Cheddar cheese, Dutch cheese, etc.), the quantity of whey produced is high and equals more or less the amount of milk used. During the production of other types of cheeses, such as soft types, the whey production is much lower or there is no production of whey at all [11].

1.3 Butter/Ghee

In developed countries, butter is made from cream that has been churned (separation of sweet butter and sweet buttermilk). In developing regions the technology in use for the making of butter and ghee is closely related to the technology to make fermented milk. Traditional butter is made from fully soured whole milk that is churned.

1.4 Milk powder

Milk powder is made from raw milk, skim milk or sweet buttermilk. After pasteurization, decreaming etc. the water from the milk is removed through evaporation [28].

1.5 Condensate/Cream/Khoa

For condensed milk and cream, a portion of the water is removed by evaporation. Khoa is a product typically found in India and neighboring countries. It is produced by thermal evaporation of milk to 65-70% solid state and serves as base material for a variety of Indian sweets.



2. Description of milk processing

Dairy plants are found all over the world, but because their sizes and the types of manufactured products vary tremendously, it is hard to give general characteristics. The dairy industry can be divided into several production sectors. Each division produces wastewater of a characteristic composition, depending on the kind of product that is produced (milk, cheese, butter, milkpowder, condensate). Figure 1 presents a schematic flow sheet of the main dairy products[33].

Fig.1 A schematic flow sheet of the main dairy products



3. Dairy industry products. Emissions

3.1 Solid waste

Hardly any solid waste is produced by the dairy industry. The main solid waste produced by the dairy industry is the sludge resulting from wastewater purification. There are figures available about the amount of sludge production: in aerobic systems the sludge production is about 0.5 kg per kg of removed wastage and in anaerobic systems about 0.1 kg per kg of removed wastage [41].

3.2 Wastewater. Whole milk products

Wastewater from dairy industry may originate from the following sources:

Wastewater is mainly produced during cleaning operations. Especially when different types of product are produced in a specific production unit, clean-up operations between product changes are necessary. In developing countries, the main problem is pollution through spoilage of milk [1].

3.3 Cheese/Whey/Curd

Waste results mainly from the production of whey, wash water, curd particles etc. Cottage cheese curd for example is more fragile than rennet curd which is used for other types of cheese. Thus the whey and wash water from cottage cheese may contain appreciably more fine curd particles than that from other cheeses. The amount of fine particles in the wash water increases if mechanical washing processes are used [9].

3.4 Butter/Ghee

Butter washing steps produce wash water containing buttermilk.

Skim milk and buttermilk can be used to produce skim milk powder in the factory itself or these materials may be shipped to another dairy food plant by tank truck.

The continuous butter production process materially reduces the potential waste load by eliminating the buttermilk production and the washing steps[14].

3.5 Milk powder

Environmental problems are caused by high energy consumption (= emission of CO₂, CO etc.), by cleaning and by emission of fine dust during the drying process.

3.6 Condensed milk/Cream/Khoa

Environmental problems related to the production of condensate and khoa are mainly caused by the high energy consumption during the evaporation process.

The main suspended solids mentioned in the literature are coagulated milk and fine particles of cheese curd[15].

The effect of the type of product produced is illu...