TES

Test Your Knowledge

TES Quiz:

Instructions: Choose the best answer for each question.

1. What does TES stand for in the context of environmental and water treatment?

a) Total Effective Size b) Total Efficiency System c) Treatment Evaluation Standard d) Total Environmental Solution

2. How does a smaller TES value generally affect filtration efficiency?

a) It reduces filtration efficiency. b) It increases filtration efficiency. c) It has no significant impact on filtration efficiency. d) It depends on the type of filter media used.

3. What is the primary role of the anthracite coal layer in a dual media gravity filter?

a) To remove fine particles and contaminants. b) To provide structural support for the sand layer. c) To efficiently remove coarse particles. d) To regulate the flow rate of water through the filter.

4. Which of the following is NOT an advantage of USFilter/Davco's dual media gravity filters?

a) High filtration efficiency b) Long service life c) Low initial cost d) Cost-effectiveness

5. What is the primary factor that determines the frequency of backwashing a gravity filter?

a) The type of filter media used. b) The size of the filter vessel. c) The flow rate of water through the filter. d) The level of contamination in the water.

TES Exercise:

Scenario: You are designing a gravity filter for a municipal water treatment plant. The plant requires a filter that can handle a high flow rate while achieving a high level of filtration efficiency. You are considering two options:

• Option 1: A single media filter with a large TES value (coarse filter media).
• Option 2: A dual media filter with a top layer of coarse media (larger TES) and a bottom layer of fine media (smaller TES).

Task:

1. Analyze: Explain the advantages and disadvantages of each option based on the flow rate and filtration efficiency requirements.
2. Recommendation: Based on your analysis, recommend which option would be more suitable for the water treatment plant and justify your choice.

Techniques

Chapter 1: Techniques for Determining TES

This chapter delves into the practical methods employed to measure and determine the Total Effective Size (TES) of filter media.

1.1 Sieve Analysis:

• Description: A standard and widely used technique involving passing filter media through a series of sieves with progressively smaller openings.
• Procedure: A known weight of filter media is placed on the top sieve, and the sieves are stacked in descending order of mesh size. The assembly is then shaken to separate particles based on size.
• Results: The weight of media retained on each sieve is recorded, and the data is used to calculate the percentage of media in each size range. This information is then plotted on a cumulative distribution curve, allowing the determination of TES.
• Advantages: Simple, inexpensive, and provides a good overall picture of the size distribution.
• Limitations: May not be suitable for very fine media due to potential clogging of sieves.

1.2 Hydrometer Analysis:

• Description: This method utilizes the principle of buoyancy to determine the particle size distribution.
• Procedure: A known weight of filter media is dispersed in a liquid of known density. The hydrometer, a device that measures the density of the liquid, is used to determine the volume of particles suspended in the liquid at different times.
• Results: The readings are used to calculate the cumulative percentage of particles smaller than a specific size, generating a particle size distribution curve.
• Advantages: Suitable for analyzing fine media, and can be used for both granular and powdered samples.
• Limitations: Requires a well-dispersed sample and a stable liquid environment.

1.3 Laser Diffraction:

• Description: A sophisticated and precise method based on the principle of light scattering.
• Procedure: A beam of laser light is passed through a sample of filter media, and the scattered light is detected and analyzed by sensors.
• Results: The scattering pattern is analyzed to determine the size distribution of particles.
• Advantages: High accuracy, rapid analysis, and can measure a wide range of particle sizes.
• Limitations: More expensive than other methods and requires specialized equipment.

1.4 Other Techniques:

• Image Analysis: Using digital image processing to analyze microscopic images of filter media.
• Dynamic Light Scattering: Measures the Brownian motion of particles to determine their size.
• Atomic Force Microscopy (AFM): Provides a detailed surface profile of individual particles.

1.5 Conclusion:

Choosing the appropriate technique for determining TES depends on the specific application, the properties of the filter media, and the level of accuracy required. Sieve analysis is often a good starting point, while more advanced techniques like laser diffraction are used when high precision is needed.