Glossary of Technical Terms Used in Wastewater Treatment: Block & Hong process

Block & Hong process

The Block & Hong Process: A Key Player in Biological Phosphorus Removal

The Block & Hong process is a well-established method for biological phosphorus removal (BPR) in wastewater treatment. Developed in the 1970s by researchers Dr. Block and Dr. Hong, it leverages the unique metabolic capabilities of certain bacteria to effectively remove phosphorus from wastewater.

The Core Principles:

The Block & Hong process relies on the interplay between two distinct bacterial groups:

  • Anaerobic Phosphorus Accumulating Organisms (PAOs): These bacteria utilize polyphosphate as an energy source during anaerobic conditions (absence of oxygen). They absorb phosphorus from the wastewater and store it within their cells as polyphosphate.
  • Aerobic Heterotrophic Bacteria: These bacteria consume organic matter in the presence of oxygen.

The Process in Action:

The Block & Hong process typically operates in a multi-stage system, employing a combination of anaerobic and aerobic conditions:

  1. Anaerobic Zone: Wastewater is first introduced to an anaerobic reactor. Here, PAOs thrive, consuming organic matter and absorbing phosphorus from the wastewater.
  2. Aerobic Zone: The wastewater then enters an aerobic reactor. Here, aerobic bacteria consume the remaining organic matter. The PAOs release their stored phosphorus as orthophosphate, which is subsequently removed through chemical precipitation.

Benefits of the Block & Hong Process:

  • High Phosphorus Removal Efficiency: The process can achieve significant phosphorus removal rates, often reaching over 90%.
  • Cost-Effective: Compared to chemical phosphorus removal methods, the Block & Hong process offers a more sustainable and cost-effective solution.
  • Reduced Sludge Production: As phosphorus is removed biologically, it minimizes the amount of sludge produced, simplifying sludge management.

USFilter/Krüger's Contribution:

USFilter, later acquired by Krüger, has played a significant role in developing and refining the Block & Hong process. They have introduced innovative technologies and designs, such as:

  • Krüger BioPACT: This patented process combines advanced biological phosphorus removal with a compact reactor design, optimizing space utilization and operational efficiency.
  • Integrated Solutions: USFilter/Krüger offers integrated solutions, incorporating the Block & Hong process within comprehensive wastewater treatment systems, tailored to specific needs.

Looking Forward:

The Block & Hong process continues to be a cornerstone of biological phosphorus removal. Ongoing research focuses on optimizing process parameters, further improving efficiency, and expanding its applicability to diverse wastewater streams.

Conclusion:

The Block & Hong process stands as a testament to the power of biological wastewater treatment. Its ability to effectively remove phosphorus, coupled with its cost-effectiveness and environmental benefits, makes it a crucial component in achieving sustainable wastewater management. USFilter/Krüger's contributions have further enhanced its practicality, making it a reliable and valuable tool for wastewater treatment facilities worldwide.


Test Your Knowledge

Quiz: The Block & Hong Process

Instructions: Choose the best answer for each question.

1. What is the primary mechanism for phosphorus removal in the Block & Hong process? a) Chemical precipitation b) Biological uptake by bacteria c) Filtration through membranes d) Adsorption onto activated carbon

Answer

b) Biological uptake by bacteria

2. Which type of bacteria is responsible for storing phosphorus during anaerobic conditions? a) Aerobic heterotrophic bacteria b) Anaerobic phosphorus accumulating organisms (PAOs) c) Nitrifying bacteria d) Denitrifying bacteria

Answer

b) Anaerobic phosphorus accumulating organisms (PAOs)

3. What is the main benefit of using the Block & Hong process over traditional chemical phosphorus removal methods? a) Higher removal efficiency b) Lower operating costs c) Reduced sludge production d) All of the above

Answer

d) All of the above

4. Which company has played a significant role in developing and refining the Block & Hong process? a) Siemens b) Veolia c) USFilter/Krüger d) GE Water

Answer

c) USFilter/Krüger

5. What is a key innovation introduced by USFilter/Krüger for the Block & Hong process? a) Development of the first anaerobic reactor b) Patented Krüger BioPACT process c) Use of activated carbon for phosphorus removal d) Introduction of membrane filtration technology

Answer

b) Patented Krüger BioPACT process

Exercise:

Scenario: A wastewater treatment plant is considering implementing the Block & Hong process for phosphorus removal. They have a daily influent flow of 10,000 m3 with a phosphorus concentration of 5 mg/L. They want to achieve a phosphorus effluent concentration of 1 mg/L.

Task:
1. Calculate the daily phosphorus load entering the plant (in kg). 2. Calculate the amount of phosphorus removed daily (in kg). 3. What is the overall phosphorus removal efficiency (%) for this scenario?

Exercice Correction

1. Daily Phosphorus Load: * Convert flow to liters: 10,000 m3 * 1,000 L/m3 = 10,000,000 L * Daily phosphorus load: 10,000,000 L * 5 mg/L = 50,000,000 mg = 50 kg

**2.  Amount of Phosphorus Removed Daily:**
    * Phosphorus removed: 50 kg - (10,000,000 L * 1 mg/L = 10 kg) = 40 kg

**3.  Overall Phosphorus Removal Efficiency:**
    * Efficiency: (40 kg / 50 kg) * 100% = 80%

</p>


Books

  • Wastewater Engineering: Treatment, Disposal, and Reuse by Metcalf & Eddy (This comprehensive textbook covers the Block & Hong process within its discussions on biological phosphorus removal.)
  • Biological Wastewater Treatment: Principles, Modeling and Design by Henze et al. (This book offers a detailed explanation of the process, including its mechanisms and optimization.)

Articles

  • "Enhanced Biological Phosphorus Removal: Principles and Processes" by Grady et al. (Water Science and Technology, 2003) - Discusses the principles and practical applications of the Block & Hong process.
  • "The Role of Polyphosphate Accumulating Organisms (PAOs) in Enhanced Biological Phosphorus Removal" by M.C.M. van Loosdrecht et al. (Water Research, 1997) - Focuses on the key microbial actors involved in the process.
  • "The Block & Hong Process: A Review" by R. H. Metcalf (Journal of the Water Pollution Control Federation, 1982) - Provides an in-depth review of the process and its early development.

Online Resources

  • Krüger BioPACT website: This website offers information about Krüger's specific implementations of the Block & Hong process, including case studies and technical details.
  • WEF (Water Environment Federation) website: Search for "biological phosphorus removal" or "Block & Hong process" to find relevant publications, research reports, and educational materials.
  • EPA (Environmental Protection Agency) website: The EPA provides information on wastewater treatment technologies, including biological phosphorus removal.

Search Tips

  • "Block & Hong process" + "wastewater treatment": This will return results specifically related to the process in the context of wastewater treatment.
  • "Biological phosphorus removal" + "PAOs": This search will uncover resources focusing on the microbial aspects of the process.
  • "Krüger BioPACT" + "case studies": This will lead you to real-world examples of the technology's implementation.
Similar Terms
Wastewater Treatment
Environmental Health & Safety
Water Purification
Air Quality Management
Resource Management
Sustainable Water Management
Most Viewed

Comments


No Comments
POST COMMENT
captcha
Back