REMOVAL OF ORGANIC LOAD ANDGENERATION … OF ORGANIC LOAD ANDGENERATION OF BIOGAS FROM DAIRY ... It is used to manufacture the dairy products like milk, ... Daily samples from Aavin

REMOVAL OF ORGANIC LOAD

ANDGENERATION OF BIOGAS FROM

DAIRY WASTE WATER JANANI.R1, JAYAKEERTHANA.E2, GNANAPRAGASAM.G.G3

1,2UG STUDENTS, 3SENIOR ASSISTANT PROFESSOR

DEPARTMENT OF CIVIL ENGINEERING

IFET COLLEGE OF ENGINEERING, VILLUPURAM.

ABSTRACT The dairy industry plays a vital role among all food industries. It is used to manufacture the dairy products like milk,

cheese, butter, ghee etc., so, it produces more amount of wastewater which contains large organic load. 2.5-3.0 liters of

wastewater is produced per liter of milk processed in the dairy industry. An experimental investigation was carried out to

remove the organic load and generate biogas (methane) by anaerobic treatment (mixer reactor) with varying percentage of 10%,

25%, 50%, 75% and 100%. From that 75% of wastewater treated with anaerobic bacteria, results maximum reduction of COD

and biogas generated with an average of 0.35m3/day.

Keyword: organic load, anaerobic treatment, COD, biogas

1. INTRODUCTION

In India, farmers directly distributed the

milk to the consumers whereas the remaining part of

the milk processed in dairy industries to manufacture

various types of milk products. In dairy industry, the

process of starting, equilibrating, stopping and

rinsing of the production units produces some

amounts of wastewater. More amount of wastewater

is produced from the cleaning operations, while the

milk converted into different types of dairyproducts

by specific production process and cleaning

operations. In an intermittent way, dairy processing

effluents are generated and the effluents flow rates

will change significantly. The quantity of the product

content in the dairy industry wastewater at a given

time changes with the application of another

technology cycle in the processing line. Average of

2.5-3.0 liters of wastewater produced from the dairy

industry for per liter of the milk processed. Generally

dairy waste water sludge contains large quantities of

fat, inorganic salts, casein, and lactosebesides

detergents, sanitizers etc., used for washing. The

valuable nitrogen and phosphate present in the dairy

sludge when compare with conventional mineral

fertilizers nutrient content of potassium is low.

Compared to municipal sludge, dairy sludge has

considerably more fertilizers value.The process

involves in the dairy products produces wastewater,

the composition of this wastewater is mostly suitable

for the biological wastewater treatment. Aerobic

process consumes more volume of electricity for the

treatment of dairy wastewater. To overcome the more

energy consumption and to remove more amount of

organic load anaerobic technology is recommended

for the dairy wastewater treatment. Anaerobic

technology used for the treatment of dairy wastewater

to remove the organic load by converting COD into

bio-gas. Biogas is used for the production of

electrical and thermal energy.

2. SOURCE OF WASTEWATER

Following are the sources of wastewater

from dairy industry:

2.1 Milk receiving

Milk is received by tank and truck. After the

usage of milk, washing can be done. Hence, the

wastewater produced by washing of storage tank,

washing of pipe line and sanitizing. Wastewater

consists of milk wastes, milk solids, detergents and

sanitizers.

2.2 Whole milk products

More amount of wastewater is produced

from the cleaning operations, while the milk is

converted into different types of dairy products by

specific production process and cleaning operations.

Wastewater contains organic loads and inorganic

loads due to the process of washing and milk

processing units. In developing countries, the main

problem of pollution can be caused by spoilage of

milk.

2.3 Cheese/whey/curd

Wastewater is mainly produced from the production

of whey (liquid by-products from cheese),wash

water, curd particles etc., the whey and wash water

from cottage cheese results more fine curd particle

compared to other chesses. If mechanical washing

process is used, the amount of fine particle in the

wash water will increaseautomatically. Because

manual washing process did not result much fine

particles in the wash water.

2.4 Butter/Ghee

Wash water from butter processing unit

containing buttermilk. Skim milk powder can be

produced by skim milk and buttermilk in the factory

itself. The skim milk powder may be shipped to

another dairy food plant tank truck. The potential

waste load can be reduced by the continuous butter

production process material. By eliminating the

buttermilk production and the washing steps.

2.5 Milk powder

By cleaning and emission of CO2 and CO

during the drying process consumes high energy. It

caused severe environmental problems.

2.6 Condensed milk/cream/khoa

The production of condensed milk, cream

and khoa consumes more energy during the

evaporation process. It also results environmental

problems. The coagulated milk and fine particle of

cheese curd are the main suspended solids which are

produced by milk processing units.

Table 1 Waste production data

Reference 1 2

Avg Range Avg Range

Wastewater

Production

2300 120-

12000

2300 100-

7000

BOD 7 0.2-

70.2

5.6 0.2-7.2

SS 2.1 0.07-

10.6

Nitrogen 0.16 0.002-

0.42

Phosphorus 0.011 0.007-

0.14

Table 2 Volume of wastewater and BOD

production from the different types of dairy

product

Type of

product

Wastewater

volume

BOD

Avg Range Avg Range

Milk 3150 100-

5000

4.1 0.20-

7.6

Condensed

milk

2110 1000-

2700

7.5 0.22-

13.5

Butter 810 0.84

Milk

powder

3600

1400-

5900

2.1

0.02-

4.6

Cottage

cheese

6000 800-

12400

34.0 1.30-

71.2

3. CHARACTERISTICS OF WASTEWATER

Dairy wastewater contains detergents, milk

wastes, milk solids and cleaning water. The

characteristics of wastewater consist of high

concentrations of organic, inorganic and nutrient

contents. High salinity levels in wastewater due to

salting activities of the cheese production. Acids,

alkali with a number of active ingredients, and

disinfectants, as well as a significant microbiological

load, pathogenic viruses and bacteria are present in

the wastewater.

Parameters Units Guideline value

pH - 4-12

SS mg/l 24-5700

BOD mg/l 450-4790

COD mg/l 80-95000

Nitrogen mg/l 15-180

Phosphorus mg/l 11-160

Oil and grease mg/l 10

Coliform

bacteria

MPN/100ml 400

Magnesium mg/l 25-49

Potassium mg/l 11-160

Chloride mg/l 48-469

Calcium mg/l 57-112

4. ANAEROBIC TECHNOLOGY

Anaerobic technology is a biological method

of treatment of wastewater. It involves in the process

of methane production (CH4). The micro-organisms

involves in this process is called anaerobic bacteria,

because these bacteria does not requires oxygen to

survive. The anaerobic process involves four process.

They are as follows:

Hydrolysis

Acidification

Acetogenesis

Metanogeneza

The anaerobic process removes the bulk of

COD from the wastewater by converting it into

biogas (= methane + carbon dioxide) at low costs.

4.1 Benefits of anaerobic technology

It can be used to reduce the

uncontrolled emissions of methane

(CH4) as the waste breaks down.

It is used to produce the renewable

energy which displaces fossil fuel

energy.

It recovers the energy from organic

waste and produces a material which is

suitable for land spreading.

4.2 Combining aerobic and anaerobic biological

cleaning of wastewater

Figure 1: combination of aerobic and anaerobic

process

Anaerobic process of waste water cleaning results

Sludge production is nearly 70% less

After floatation 80% COD still in the

wastewater, which is converted into methane

and it is used as energy.

Energy consumption for the process of

anaerobic is less when compared to aerobic

process.

4.3 Energy efficiency

Dairy wastewater cleaning by anaerobic

technology generates on an average of 2m3 of biogas

per m3, which replaces about 1.2 liters of fuel oil.

80% of excess sludge volumes are reduced by

reduces their disposal costs. The excess sludge

contains high concentration of calcium and

phosphates which is created in the anaerobic plant.

High phosphate content in the sludge is used as

fertilizer.

Whey is the by-product of cheese, which

produced 40m3 of biogas by anaerobic process (40m3

of biogas is converted into 6.5 KWh/Nm3 biogas by

thermal value of biogas). Hence, per tonne of whey

produces 260KWh of thermal energy.

5. EXPERIMENT

5.1 Study site

Present study was carried out at Aavin Co-

op Milk Producers’ Federation Ltd., Villupuram,

India. To release the treated effluent a seasonal drain

was located near the complex.

5.2 Volume of the effluent

In dairy industry, the milk processes is

nearby about 4500-5000liters/day. Volume of

effluent discharged from dairy products

manufacturing is about 20,000liters/day.

5.3 Analysis of dairy effluent

a. pH

b. COD (chemical oxygen demand)

c. Bio-gas

The effluents from dairy were analyzed with respect

of the given parameters.

5.4 Methods of sampling

Daily samples from Aavin industry were

collected in plastic bottles. Samples are first rinsed

with distilled water in the laboratory and then rinsed

with effluent at the sampling site. From the plant,

samples of inlet were collected and an outlet sample

was collected from the mixer reactor.

5.5 Module making of mixer reactor

Treatment of wastewater done by anaerobic

process (mixer reactor). Module making of mixer

reactor can be done by using water bottles 20 liters,

pipe, ¾ PVC pipe, volve, t-valve, funnel and tyre

tube, PVC pipe cap.

Figure 2: Module of a reactor

5.6 Analysis of samples

Sample of inlet and outlet can be analyzed

after the treatment process.

5.6.1 Analysis of samples by varying the

percentage

Table 3 shows results of COD for various

percentage of wastewater treatment

Percentage of

wastewater

treated (%)

COD (mg/l) Biogas

generatio

ns

(m3)

Inlet Outlet

10 504.2 201.7 0.25

25 463.8 208.7 0.23

50 728.7 327.9 0.36

75 894.5 358.9 0.45

100 710 390.5 0.36

5.6.2 Analysis of samples by increasing its pH

From table 3, taking the percentage of

wastewater which produces more biogas. Increase its

pH for 3 times and determine its COD after the

treatment process.

75%

of

waste

water

pH COD (mg/l) Biogas

generations(m3) Inlet Outlet

6.8 894.5 358.9 0.45

6.9 894.5 305.7 0.451

7.0 894.5 208.2 0.453

5.6.3 Analysis of samples by treating it for 2days

75% of waste water can be treated in the

mixer reactor for 2days. Biogas and COD

determination can be carried for 24, 36 and 48 hours

intervals.

75%

of

waste

water

Time

interval

(hours)

COD (mg/l) Biogas

generation

(m3)

Inlet Outlet

24 894.5 358.9 0.45

36 894.5 278.4 0.452

48 894.5 201.3 0.453

5.7 Results

Present study showed that at inlet effluent

analysis COD value ranged from 400mg/liter to

900mg/liter and average value has 650mg/liter. The

analysis of COD at outlet sample showed variation

from 200mg/liter to 400mg/liter. The study showed a

total reduction of COD of 78 percent. The

fluctuations in percentage COD reduction between

inlet and outlet samples are graphically depicted in

below figure 3, figure 4 and figure 5.The gas

generation fluctuated between 0.23m3/day to

0.46m3/day with an average of 0.35m3/day. The

fluctuations in gas generation are graphically shown

in figure 6.

Figure 3: percentage of COD reduction for

various percentage of waste water

40

45

50

55

60

65

70

0 50 100 150

% o

f C

OD

red

uct

ion

% of waste water treated

Figure 4: percentage of COD reduction at time

intervals

Figure 5: percentage of COD reduction at

different pH values

Figure 6: Biogas generation

6. Conclusion:

Effluent from the dairy can be treated by

anaerobic technology which is cost effective. It also

produces biogas. Biogas is considered as renewable

natural gas. Biogas can provide number of social and

environmental benefits and it is an cost effective

substitute for fuel wood. Anaerobic technology is

secured process for generating biogas.

7. References:

1. Amanpreet kaur, Sonia chaman (2014).

Bioaugmentation for Dairy Wastewater,

International Journal of Science and

Research , ISSN:2319-7064.

2. Baisali Sarkar, Vijay Kale, Pradosh

Chakrabarti (2006). Wastewater treatment in

dairy industries-possibility of reuse.

3. Bharati S. Shete, N.P.Shinkar (2013). Dairy

Industry Wastewater Sources,

Characteristics & Effects on Environment,

International Journal of Current Engineering

and Technology, ISSN: 2277-4106.

4. Central Pollution Control Board (1997).

National inventory of large and medium

industry and status of effluent treatment and

emission control system, New Delhi CPCB,

pp 411 (Programme objective series

PROBES/68/1997-98)

5. Dairy Wastewater Generation and

Characteristics, Waialee Livestock Farm

Polluted Runoff Control.

6. Debowski.M, Krzemieniewski.M,

Janczukowicz.W, Pesta.J (2004). Effect of

the Constant Magnetic Field on the

Composition of Dairy Wastewater and

Domestic Sewage, Polish Journal of

Environmental studies Vol.13, No.1, 45-53.

7. Feroz.S, Nageswara Rao.L, Thuraiya Mahir

Al Khusaibi, Joefel Jessica Dumaran, and

Geetha Devi.M (2015).Treatment of Dairy

Wastewater using Orange and Banana Peels,

Journal of Chemical and Pharmaceutical

Research, 7(4):1385-1391.

8. Ilona Sarvari Horvath, Meisam Tabatabaei,

Keikhosro Karimi, Rajeev Kumar (2016).

Recent updates on biogas production – a

review, Biofuel Research Journal 10, 394-

402.

9. Jadhav.M.V, Kankal.S.B, Pachpute.A.A

(2014). Use of Artificial Wetland for

Treatment of Dairy Industry Wastewater for

Analysis of BOD and COD, International

Journal of Scientific Engineering and

Research, ISSN:2347-3878.

50

60

70

80

0 20 40 60

% o

f C

OD

red

uct

ion

Time (hr)

50

55

60

65

70

75

80

6.7 6.8 6.9 7 7.1

% o

f C

OD

red

uct

ion

pH value

50

55

60

65

70

75

80

0.448 0.45 0.452 0.454

% o

f C

OD

red

uct

ion

Biogas (m3)

10. Lawson P.S. (1992). Municipal solid waste

conversion to energy, Biomass and

Bioenergy. 2 (1-6), pp 319-330.

11. Mahendra.B.G, Shridhar Mahavarkar

(2013). Treatment of Wastewater and

Electricity Generation using Microbial Fuel

Cell Technology, International Journal of

Research in Engineering and Technology,

eISSN: 2319-1163.

12. Mohammed Manzer Imam, Prof. N.B.Singh,

Ruchi Singh (2014). Wastewater

Management in Dairy Industry: Pollution

Abatement and Preventive Attitudes,

International Journal of Science,

Environment and Technology, Vol.3, No 2,

672-683.

13. Murthy N.R.K and Kulshrestha.S.P (1985).

Effect of pH and temperature on biogas

production, Proceedings Silver jubilee

convention, Indian Society of Agriculture

Engineers 4, 13-19.

14. Orhon.D, Gorgum.E, Germirli.F, and

Artan.N (1993). Biological treatability of

dairy wastewaters, Water Research, 27, (4),

pp 635-663.

15. Onet Cristian (2010). Characteristics of the

untreated wastewater produced by food

industry.

16. Quasim.S.R, Warren.K, (1984). Methane

Gas Production from Anaerobic Digestion

of Cattle Manure, Energy Sources, 7(4), pp

319-341.