Alum as a coagulant

ALUM AS COAGULANT

 

Alum, chemically known as aluminum sulfate [Al2(SO4)3], is a common coagulant used in water treatment processes to remove suspended particles, colloids, and impurities from raw water. When added to water, alum undergoes hydrolysis, forming aluminum hydroxide [Al(OH)3] and sulfate ions. The aluminum hydroxide particles act as flocculants, binding with suspended particles and colloids to form larger aggregates, which can be easily removed through sedimentation or filtration processes.

Applications:

1. Clarification of Raw Water: Alum is widely used in water treatment plants for the clarification and purification of raw water from surface water sources such as rivers, lakes, and reservoirs. It helps remove suspended solids, turbidity, and color-causing substances, resulting in clearer and aesthetically pleasing water.

2. Drinking Water Treatment: Alum is applied in the treatment of drinking water to meet regulatory standards and ensure the safety and quality of potable water supplies. By effectively removing contaminants and impurities, alum treatment helps protect public health and prevent waterborne diseases.

3. Industrial Water Treatment: Industries in Hyderabad, India, and elsewhere use alum as a coagulant in water treatment processes for various industrial applications. It is employed in sectors such as textiles, food and beverage, pharmaceuticals, and manufacturing to treat process water and wastewater streams.

4. Municipal Wastewater Treatment: Alum is utilized in municipal wastewater treatment plants to aid in the removal of suspended solids, organic matter, and nutrients from sewage and industrial effluents. It facilitates the formation of settleable floc, which can be separated from the treated water through sedimentation or filtration.

5. Swimming Pool Treatment: Alum is sometimes used in swimming pool treatment to clarify pool water and improve its appearance by removing suspended particles and colloids. It helps maintain water clarity and hygiene for swimmers and ensures compliance with health and safety regulations.

Occurrences and Examples in Hyderabad, India:

1. Hyderabad Metropolitan Water Supply and Sewerage Board (HMWSSB): The HMWSSB, responsible for water supply and sanitation services in Hyderabad, may use alum as a coagulant in its water treatment plants to treat raw water from the Krishna and Godavari rivers before distribution to consumers.

2. Industrial Applications: Industries located in Hyderabad, such as textile mills, food processing units, and pharmaceutical companies, may employ alum as a coagulant in their water treatment processes to treat industrial wastewater and comply with environmental regulations.

3. Community Water Treatment Facilities: Residential and commercial complexes in Hyderabad may have community water treatment facilities equipped with alum dosing systems to treat water from borewells or municipal supplies before consumption.

4. Recreational Facilities: Hotels, resorts, and recreational centers in Hyderabad with swimming pools may use alum as part of their water treatment regimen to maintain water clarity and quality for guests and patrons.

Alum is a versatile coagulant widely used in water supply engineering for the treatment of raw water, drinking water, industrial process water, wastewater, and swimming pool water. Its applications in Hyderabad, India, and other regions contribute to the provision of clean and safe water for various purposes, supporting public health, environmental sustainability, and economic development.