How to Evaluate Techniques of MLSS in Wastewater Treatment?

The standard approach for evaluating MLSS in wastewater treatment was developed in the late 1800s and is being used today.

a)      The first step is to acquire a grab sample of MLSS and run it through the filter.

b)      Second, the filter should be ignited in a muffle furnace (550 degrees) for approximately 15-20 minutes. It is done in order to dry the residue.

c)      Once the filter has been cooled, the residue should be transferred to a desiccator for chilling.

d)      Finally, weigh the residue that remains on the filter. The volatile solids in the sample may then be calculated using the following formula: 

VSS, mg/l=Weight of Material Lost by burning/ sample volume

With the advent of technology in the 1970s, online instrumentation was created to continuously monitor MLSS. It aids in the optimization of Return activated sludge (RAS) flow for constant load during influent flow and load changes. However, because online instrumentation is expensive and requires continual calibration, manual assessment using a sample is still regarded a preferable alternative.

Several approaches for analysing and assessing MLSS in wastewater treatment have been developed during the last several decades. It consists of manual collection and laboratory testing targeted at improving the effectiveness of biological wastewater treatment.

A: Rate of Oxygen Consumption

The oxygen uptake rateis the rate at which biomass consumes oxygen. It also aids in the measurement of microbial activity. When oxygen uptake rate is lower than usual, it implies that toxin is affecting MLSS. Organic overloads are seen at higher levels.

Another possibility is that high oxygen uptake returns to normal in a short period of time. It demonstrates that MLSS concentration is low due to a lack of an appropriate diet to microbe ratio.

There are three stages of the Oxygen Uptake Rate test:

1st Level

These are 15-minute tests designed to determine bacterial health as well as the organic load entering the biological system.

2nd level

This level entails many testing over several hours with an aerated MLSS sample. It is useful in determining if the biological system is appropriately sized to accommodate the incoming organic load. Extended testing aids in determining how long it will take to finish biological therapy based on MLSS bacteria endogenous respiration.

Endogenous respiration of bacteria occurs when these microorganisms begin to oxidize their own cellular mass rather than the organic materials in the effluent. As a result, therapy is deemed to be complete when the endogenous respiration of MLSS begins.

3rd level

It comprises a treatability study, which is used to assess whether an entering wastewater stream would be beneficial or severely harmful to the microorganisms inside a bioreactor. One of the key components is that MLSS bacteria achieve endogenous respiration.

B: Test for Settleability

The effectiveness of biomass is determined by its density and how it settles in a clarifier. As a result, a Settleometer is used to perform a Settleability test.

Recording the biomass's Settled Sludge Volume - SVV helps operators to determine the age of the sludge. Solids that settle quicker may suggest older sludge, whereas solids that settle too slowly may be flushed out during strong hydraulic loads.

C: ATP analysis and plate counts

Plate Counts assays are performed in labs to assess tiny amounts of MLSS using plate count medium. It aids in the identification of the microbial community in wastewater.

D: Flow Cytometry

The use of fluorescent dyes to assess the vitality of individual bacterial cells in an effluent sample is involved.

E: Molecular Analysis

It is capable of quantifying the DNA of MLSS bacteria as well as certain higher life forms of bacteria such as nitrifiers and nocardia. This type of testing has the benefit of being both accurate and quick.

Netsol Water can assist you in identifying the appropriate microbial population for your biological system by validating its compatibility and sustainability based on the kind of industrial wastewater treatment plant.

For further information or product purchase related questions, call on +91 9650608473 or email at enquiry@netsolwater.com.