Steps to Grow MLSS in Biological Aeration System

 What is MLSS?

MLSS stands for Mixed Liquor Suspended Solids. It is a measurement parameter used in wastewater treatment processes to quantify the concentration of suspended solids in the mixed liquor. Mixed liquor refers to the mixture of wastewater and microorganisms (activated sludge) present in the aeration tank of a biological treatment system.

MLSS represents the total mass of solids (organic and inorganic) that are suspended in the wastewater and carried along with the mixed liquor. These suspended solids include microorganisms, organic matter, inert particles, and other particulate substances.

MLSS is an important parameter in wastewater treatment as it provides information about the biomass concentration in the system. It is used to assess the efficiency of the treatment process, monitor the biological activity, and make operational adjustments. Maintaining an appropriate MLSS concentration is crucial for effective pollutant removal and stable treatment performance.

MLSS is typically measured by collecting a representative sample of the mixed liquor, filtering out the solids, drying and weighing them, and then expressing the result as milligrams per liter (mg/L) or grams per liter (g/L) of wastewater. The measurement can be done using laboratory techniques or online monitoring devices installed in the treatment plant.



What are the steps to grow MLSS in Aeration Plant:-


To grow Mixed Liquor Suspended Solids (MLSS) in an aeration plant, follow these general steps:

  1. Set up the aeration tank: Ensure that the aeration tank is clean and ready for operation. Check the equipment, such as diffusers or mechanical aerators, and ensure they are functioning properly. There should must not be any air short circuiting while hydro testing.

  2. Prepare the seeding material: MLSS is typically seeded with a small amount of activated sludge from a healthy and well-established wastewater treatment plant. Obtain a suitable amount of activated sludge for seeding. It should contain a diverse microbial community capable of degrading organic matter. Other way is to use Ready Made BioCulture.

  3. Introduce the seeding material: Add the activated sludge to the aeration tank. The amount of seeding material depends on the desired MLSS concentration and the tank's volume. Generally, a seeding rate of 1-2% of the tank volume is a good starting point. As starting 25% of tank volume to be filled with sewage water to start culture growth.

  4. Provide aeration: Start the aeration system to ensure sufficient oxygen supply for the microorganisms. The microorganisms in the activated sludge will utilize the oxygen and begin growing. Use Oxygen meter to monitor the oxygen level generally 2-3ppm Oxygen must be available for good growth.

  5. Monitor and adjust operating conditions: Regularly monitor the MLSS concentration, dissolved oxygen levels, pH, and other relevant parameters. Adjust the operating conditions as needed to optimize microbial growth. Maintain a dissolved oxygen concentration of around 2-3 mg/L to support aerobic microbial activity. Daily one or two samples to be observed for growth observations.

  6. Control the food-to-microorganism (F/M) ratio: The F/M ratio is the ratio of the organic load (food) to the microorganism population. Adjust the F/M ratio by controlling the influent flow rate and the amount of organic matter (BOD/COD) entering the system. A higher F/M ratio promotes biomass growth. If influent is lean add some additional food like jaggery , urea , molasses, DAP, bread etc.

  7. Provide sufficient retention time: Ensure that the wastewater remains in the aeration tank for an adequate duration to allow the microorganisms to degrade the organic matter and grow. The retention time depends on the specific requirements of the treatment plant and the MLSS concentration desired.

  8. Monitor and manage the sludge age: Sludge age refers to the average time that microorganisms spend in the system. It is typically measured in days. Adjust the sludge age by controlling the biomass wasting rate (the rate at which excess biomass is removed) to maintain an appropriate MLSS concentration and microbial activity.

  9. Avoid toxic substances: Regularly monitor and avoid the introduction of toxic substances into the system, as they can inhibit microbial growth and lead to poor MLSS development. Floor wash, kitchen waste, automobile lubricants etc to be pretreated before adding in Biological Aeration Tank.

  10. Perform regular process optimization: Continuously evaluate the performance of the aeration plant and make adjustments as needed. This may include fine-tuning operating conditions, optimizing nutrient addition (if required), and ensuring proper maintenance of equipment.

Remember that the specific steps may vary depending on the design and requirements of the aeration plant and the treatment process being employed. It's essential to consult with experts or process engineers familiar with the specific plant for detailed guidance.

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