All About Screening of Water : Types, Purpose of Screening

All About Screening of Water : Types, Purpose of Screening

Water screening is a crucial process in the treatment and distribution of clean water for human consumption. It involves the physical removal of large particles and debris from water, ensuring its safety and quality. With the increasing demand for clean water, it has become necessary to implement efficient screening methods in water treatment facilities. In this article, we will explore the various types of water screening, their purposes, and the importance of this process in ensuring the provision of safe drinking water to communities.

What is Screening of Water?

What is Screening of Water?

Screening of water refers to the process of removing large objects, debris and solids from raw water before it enters a water treatment plant or distribution system. This is an important step in the treatment process which ensures the quality and safety of drinking water.

There are different types of screening methods that are used depending on the source and quality of the water. In general, screening can be divided into three categories: coarse screening, medium screening, and fine screening.

Coarse screening is the first step in the screening process, where large objects and debris such as branches, rocks, and trash are removed. This is usually done by using a bar screen or a coarse rotary screen. The water passes through the screen while the debris is collected and removed manually or with the help of mechanical equipment.

Medium screening involves the removal of smaller particles such as sand and gravel. This is achieved by using a medium screen with openings ranging from 6-20 mm. The water is forced through the screen while the particles are trapped and removed from the system.

Fine screening is the final step in the screening process. This is done to remove the smallest particles and suspended solids from the water. Fine screens have openings as small as 0.2 mm and are used to remove insects, algae, and other organic matter. The screen is usually cleaned by a mechanical rake or brush and the collected material is removed and disposed of.

The screening process has several benefits. It not only protects the treatment equipment from clogging and damage but also reduces the workload of the treatment plant. By removing large and small particles, the efficiency of the treatment process is improved, resulting in better quality water.

Screening also plays a crucial role in protecting the environment. By removing debris and pollutants from raw water, it prevents them from entering water bodies such as rivers and lakes, which can harm aquatic life and ecosystems.

In addition, screening can also help to reduce the need for chemical treatment as it removes some of the contaminants before they enter the treatment process. This leads to cost savings and a more sustainable water treatment process.

In conclusion, screening of water is an essential step in providing clean and safe drinking water. It not only protects the treatment equipment and improves the efficiency of the treatment process, but also helps to preserve the environment. With the increasing need for clean water, proper screening methods are crucial in ensuring the quality and safety of our water supply.

Types, Purpose of Screening

Types, Purpose of Screening

Screening is a process that is commonly used in civil engineering to separate or classify different materials based on their size, shape, and composition. It plays a vital role in various construction and engineering projects, such as road construction, building foundations, and water treatment facilities. Screening is used to remove unwanted materials and segregate the desirable ones for further processing, thus ensuring the quality and efficiency of the final product.

Types of Screening:

1. Static Screens: Static screens are stationary equipment with a surface covered with holes or slots of varying sizes. The material is fed onto the screen, and the larger particles are retained on top while the smaller ones fall through the holes or slots below. Static screens are commonly used in water treatment facilities and mining operations.

2. Grizzly Screens: Grizzly screens are heavy-duty, high-capacity screens that use bars or rails to remove oversized materials. These screens are commonly used in the extraction of minerals and in the primary crushing stage of rock and ore processing.

3. Vibrating Screens: Vibrating screens use one or more vibrating motors to provide a constant vibration, causing the material to move across the screen. This helps to separate the materials based on size, shape, and weight, making it useful for a wide variety of applications such as scalping, sizing, and dewatering.

4. Trommel Screens: Trommel screens consist of a rotating cylindrical screen with holes of various sizes along its length. The material is fed into one end of the screen, and as it rotates, the smaller particles pass through, and the larger ones are retained. These screens are commonly used in screening soil, sand, and gravel.

Purpose of Screening:

1. Separation of Materials: The main purpose of screening is to separate materials according to their size, shape, and composition. This helps to segregate the desirable materials from the undesirable ones, ensuring the quality and efficiency of the end product.

2. Scalping and Sizing: In the construction industry, it is vital to have a consistent size of materials for various applications. Screening helps to remove oversized and undersized particles, ensuring that the materials are of the desired size.

3. Dewatering: In many civil engineering projects, it is necessary to remove excess moisture from the materials. Screening can help to achieve this by separating the dry materials from the wet ones, thus reducing the need for further processing.

4. Safety and Efficiency: Screening also plays a critical role in ensuring the safety and efficiency of construction and engineering projects. By removing unwanted materials, it reduces the risk of hazardous incidents and equipment damage, resulting in a smoother and more productive operation.

In conclusion, screening is an essential process in civil engineering, with various types available to serve different purposes. It helps to achieve high-quality materials, energy efficiency, and cost-effectiveness in a wide range of applications. As technology advances, the screening process continues to evolve, making it an integral part of many construction and engineering projects.


In conclusion, screening of water is an essential process in ensuring the safety and cleanliness of our water supply. There are various types of screening methods, such as mechanical, manual, and biological, each with its own advantages and purposes. The primary goal of screening water is to remove any unwanted debris, particles, and pollutants before it can be consumed or used for various purposes. With proper screening, we can prevent potential health hazards and protect our environment. It is crucial to understand the importance of water screening and to employ appropriate methods to ensure the quality and safety of our water. By doing so, we can contribute to a healthier and sustainable future for all.


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