L-23

Sugar IndustrySugar Industry

Industrial Waste Treatment

Introduction

• Sugar can be manufactured from

- Sugarcane in countries like Cuba, Jamaica and IndiaJamaica and India

- Beetroots

• In India sugar factories operate for about 4 to 8 months after the harvesting of sugar cane.

• Sugar Industry in India is the second largest agro-based industry in the country next to cotton textiles.

• The Indian Sugar Industry is playing a pivotal role in rural development, supporting over about 50 million sugarcane farmers.

Manufacturing flow-sheet

Manufacturing Process

General Characteristics of Combined waste

Characteristics Mill house waste

Filter cloth washing

Condenser water

Boiler house and floor washings

Combined waste

Rate of flow (Lit/tonne of sugarcrushed)

730 360 1640 230 ---

crushed)

pH 6.7 9.5 --- 7.2 4.6-7.1

COD --- --- --- --- 600-4380

BOD --- --- --- --- 300-2000

TS mg/lit 1760 6970 --- 5130 870-3500

TVS mg/lit --- --- --- --- 400-2200

TSS 910 4000 --- 120 220-800

Total nitrogen

--- --- --- --- 10-40nitrogen

COD/BOD ratio

--- --- --- --- 1.3-2.0

Treatment alternatives

• Volume of waste can be reduced by adopting in house measures (good house keeping)house keeping)

• Floors can be dry washed instead of wet washing.

• Organic load can be reduced by proper control of operations

• The reasonable COD/BOD ratio indicate the waste is amenable to biological treatment

• TF and ASP are not much efficient for • TF and ASP are not much efficient for sugar industry molasses. (efficiency of 51% is reported with TF and ASP together).

• Anaerobic treatment using lagoons and digesters is more effective and economical.

Treatment alternative

Solid wastes

• Bagasse :- can be used in boilers

• Press mud: - can be used for composting with bagasse and composting with bagasse and Spent wash (liquid waste from distillery)

Objective Questions

1. Press mud is generated during ________ process.

2. pH of sugar mill waste is ___ to ____.

3. BOD of molasses is in the range of ____ to _____.

4. Total nitrogen for sugar mill waste is in the range of __________.

5. Sugar industry is ______ largest sector in India.

Theory Questions

Q1. Draw a neat flow sheet of sugar industry. Discuss processes in brief and clearly mention types and sources of wastes generated.wastes generated.

Q2. Give general characteristics of molasses.

Q3. Discuss treatment alternatives for sugar mill waste.