Reason behind foaming in Biological Aeration Tank

Reason behind foaming in Biological Aeration Tank -

Foaming in an aeration tank refers to the formation of excessive foam on the surface of the wastewater during the treatment process. It is a common operational issue encountered in wastewater treatment plants.

Foaming can occur due to several factors, including:

  1. High organic loading: When the concentration of organic matter in the wastewater is high, it can lead to increased foam production. This is because organic compounds can act as surfactants, reducing the surface tension of the water and promoting foam formation.

  2. Presence of surfactants: Surfactants are substances that lower the surface tension of liquids, making them more prone to foam formation. Surfactants can enter the wastewater stream from various sources, such as industrial processes or household products, and contribute to foaming.

  3. Filamentous bacteria: Certain types of filamentous bacteria, such as those belonging to the genera Microthrix and Nocardia, can proliferate in the aeration tank and create foam. These bacteria produce extracellular polymeric substances (EPS) that stabilize the foam structure.

  4. Insufficient dissolved oxygen: Inadequate oxygen supply to the aeration tank can lead to incomplete degradation of organic matter. This can result in the accumulation of volatile fatty acids and other compounds that promote foam formation.

  5. Hydraulic and operational conditions: Improper hydraulic conditions, such as excessive turbulence or short-circuiting within the tank, can contribute to foam generation. Similarly, factors like temperature, pH, and nutrient imbalances can affect microbial activity and foam formation.

Foaming can have several negative impacts on the wastewater treatment process. It can reduce the effective volume of the tank, hinder the settling of suspended solids, decrease oxygen transfer efficiency, and lead to operational problems such as overflow or carryover of solids to downstream processes.



To mitigate foaming, wastewater treatment plants employ various strategies, including:

  1. Controlling organic loading: Optimizing the influent wastewater characteristics and reducing the organic loading can help minimize foam generation.

  2. Adjusting dissolved oxygen levels: Ensuring adequate dissolved oxygen levels in the aeration tank promotes the growth of non-foaming microorganisms and inhibits the growth of filamentous bacteria.

  3. Chemical additives: Addition of antifoaming agents or foam control chemicals can help reduce foam formation and improve foam collapse.

  4. Filamentous bacteria control: Implementing measures to control filamentous bacteria, such as improving solids retention time, optimizing nutrient dosing, or using biological control methods, can help reduce foaming caused by these organisms.

  5. Process optimization: Ensuring proper tank design, hydraulic conditions, and operational parameters can minimize the likelihood of foam formation.

It's important for wastewater treatment plants to monitor and address foaming issues promptly to maintain efficient operation and compliance with discharge regulations.

Comments

Post a Comment

Popular posts from this blog

Reasons why sludge is not settling properly in a clarifier!

Image
 Why sludge not settling in clarifier? There could be several reasons why sludge is not settling properly in a clarifier. Here are some possible explanations: High hydraulic or organic loading: If the clarifier is receiving a high volume of wastewater or if the wastewater has a high concentration of organic matter, it can overwhelm the settling capacity of the clarifier. The excessive flow or high organic load can disrupt the settling process and prevent the sludge from settling effectively. Hydraulic or design issues: Improper hydraulic design or inadequate equipment sizing can lead to short-circuiting or dead zones within the clarifier. Short-circuiting occurs when the flow patterns allow particles to bypass the settling zone, while dead zones are areas where there is minimal or no flow. Both conditions can hinder the settling of sludge. High influent solids concentration: If the influent wastewater has a high concentration of suspended solids, it can result in a dense sludge blanket
Read more

Drinking Water Parameters in India !

Image
  As per the Indian Standard for Drinking Water (IS 10500:2012), the following are the recommended parameters for safe and healthy drinking water in India: Microbial Parameters: Total coliform bacteria: No detectable coliforms per 100 mL Escherichia coli (E. coli): No detectable E. coli per 100 mL Faecal Streptococci: No detectable faecal streptococci per 100 mL Chemical Parameters: pH: 6.5 to 8.5 Total Dissolved Solids (TDS): Less than 500 milligrams per liter (mg/L Chloride: Less than 250 mg/L Nitrate: Less than 45 mg/L Fluoride: 0.6 to 1.5 mg/L Arsenic: Less than 0.01 mg/L Lead: Less than 0.01 mg/L 3.Physical Parameters: Turbidity: Less than 5 Nephelometric Turbidity Units (NTU) Color: No standard limit, but colorless or slightly colored water is preferable Odor: No standard limit, but no objectionable odor is preferable. It's worth noting that these parameters may vary depending on local or regional regulations and guidelines, and that water treatment facilities may have additi
Read more

Difference between MBR and SBR

Image
Difference between MBR and SBR   MBR (Membrane Bioreactor) and SBR (Sequencing Batch Reactor) are two different wastewater treatment technologies that are commonly used for treating and purifying wastewater. While both technologies employ biological processes for treatment, there are some key differences between MBR and SBR: Configuration: MBR: In an MBR system, the biological treatment and membrane filtration occur simultaneously. The membranes act as a physical barrier to separate the treated water from the biomass and solids. SBR: In an SBR system, the biological treatment occurs in a batch mode, meaning the treatment process occurs in a series of sequential steps. Each step includes a fill phase, react phase, settle phase, and decant phase. Filtration Method: MBR: MBRs utilize membrane filtration as the primary method for solid-liquid separation. The membrane modules contain fine pores that allow treated water to pass through while retaining suspended solids, bacteria, and other co
Read more