**2. Characteristics of dairy wastewater**

Dairy wastewater comprises of compound organic substances like carbohydrates, amino acids, and lipids which get converted into sugars, acids, and fatty acids upon hydrolysis [9]. Milk is a natural supplement for humans and animals. This consists of various nutrients including protein, vitamin, carbohydrate, and fat [10]. Milk is one of the most valuable items that join commerce, and it is vital as an object of food in daily life. Dairy wastewater contains large amounts of milk components like casein, lactose, fat, inorganic salts excluding detergents and sanitizers that accord greatly towards high BOD and COD [11]. In order to increase milk volumes and improve meat quality antibiotics and antimicrobials have been used in dairy animals at the sub-therapeutic level. This does not only harm the animal's health and well-being, but also significantly affects the health and well-being of humans through the intake of animal products like milk and meat, thereby affecting


#### **Table 1.**

*Standard norms of Central Pollution Control Board of India for dairy effluents (Environment (Protection) Rules, 1986).*

**101**

per m3

*Treatment of Dairy Wastewaters: Evaluating Microbial Fuel Cell Tools and Mechanism*

public health [12]. According to the Environment (Protection) Rules, 1986 of India, the standard norms and limiting characteristics of dairy effluents as mandated by the Central Pollution Control Board (CPCB) of India are mentioned in **Table 1**. Effluents from milk production have increased temperatures and varying pH, TSS, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen, total phosphorus and fat, oil and grease [3, 5, 13–16]. Generally, dairy wastewater has a white color with an undesirable odor and turbidity [4, 17, 18]. With 16–25°C annual temperatures, dairy effluent waste flows are hotter than urban wastewater (10–20°C), leading to accelerated biological deterioration correlated to other sewage treatment plants. Industrial dairy effluent average temperatures range

Water has an important role in milk processing. It involves cleaning, washing, disinfection, heating, and cooling in every step of the technologies used. There is a massive requirement for water [19]. A large amount of wastewater is generated through manufacturing processes [20]. Contaminated water from sanitary practices amounts to 50–80% of the actual water utilized in the dairy industry, while the rest of the 20–50% is clean water [20, 21]. It has been measured in volume units stating the quantity of wastewater is around 2.6 times more of the processed milk. The characteristics and the amount of the wastewater generated rely mainly on the size of the factory, technology used, efficacy and convolution of clean-in-place methodologies, good manufacturing practices, and so on [2, 5]. However, the world's mean

of milk processed with the introduction of GMP [5, 22]. Nowadays, the

Cooling the milk in separate coolers along with condensation from the evaporation of whey and milk leads to the production of water for fermentation. Vapors are extracted from the milk and whey drying process that after condensation produces the cleanest effluent, but they can also consist of volatile compounds, whey, and milk droplets. Processing waters eliminate toxins, and after minimal pretreatment may be stored or released with stormwater [3]. Water can be reused for systems where the derivative materials are not in close contact. Typical applications involve

discharges installed in the washing of tank on transport trucks, mediator pipelines, or machinery after every cycle are a significant aspect of the volume-based loading of wastewater treatment plants designed for dairies. In these cases, the effluent volumes are greater than those of the milk produced [23]. On average, the amount of wastewater discharged is 70% of freshwater being used at the plant [20]. Effluents from dairy products primarily include milk and its products misplaced in the processing cycles (milk spills, skimmed milk, spoiled milk, and curd remnants), inoculums used in processing, byproducts generated by manufacturing techniques (whey, milk and there permeates), and several additives used in manufacturing [16, 21, 24, 25]. Milk lost in wastewater treatment is about 0.49–2.5% of milk

to 0.5–2.0 m3

of effluent per ton of milk produced. The instant

of effluent

*DOI: http://dx.doi.org/10.5772/intechopen.93911*

from 17 to 18°C in winter, and from 22 to 25°C in summer.

**3. Factors affecting characteristics of wastewater**

wastewater volume can be decreased from 0.49–36.0 m3

**3.1 Volume of wastewater**

volumetric charge designed is 1 m3

processed, which may rise up to 4% [26].

**3.2 Categories of wastewater**

*3.2.1 Processing water*

#### *Treatment of Dairy Wastewaters: Evaluating Microbial Fuel Cell Tools and Mechanism DOI: http://dx.doi.org/10.5772/intechopen.93911*

public health [12]. According to the Environment (Protection) Rules, 1986 of India, the standard norms and limiting characteristics of dairy effluents as mandated by the Central Pollution Control Board (CPCB) of India are mentioned in **Table 1**.

Effluents from milk production have increased temperatures and varying pH, TSS, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen, total phosphorus and fat, oil and grease [3, 5, 13–16]. Generally, dairy wastewater has a white color with an undesirable odor and turbidity [4, 17, 18]. With 16–25°C annual temperatures, dairy effluent waste flows are hotter than urban wastewater (10–20°C), leading to accelerated biological deterioration correlated to other sewage treatment plants. Industrial dairy effluent average temperatures range from 17 to 18°C in winter, and from 22 to 25°C in summer.
