WHY DO WE NEED TO KNOW EQUATIONS FOR FERMENTATION?

To most of us we only see or appreciate the fermentation process qualitatively, just like admiring the beauty of fishes in the aquarium. Such observations don’t tell us more about the fermentation process. May be a whiff of the gas coming out of the fermentor tell us about the presence of alcohol or volatile organic products.

In the fermentation industries such qualitative data are almost of no use. The observation port is of limited use as the data are just visual.

The management of the fermentation industry wants to know much more in depth of the fermentation process. They want reliable numerical data that will allow them to operate the fermentation process in the most efficient and economic way possible.

They need to know the fermentation process in numbers, data and graphs, so that they understand what is going on in the fermentation vat. The data will provide them to make decisions in improving, optimizing or even in trouble shooting the fermentation process. They need to make the decision in comparing and choosing between one substrate and the other for the fermentation process in terms of the yield and productivity,

It is for these reasons that mathematical equations and mathematical models of the process are of utmost importance. It is the tool for decision making and optimized fermentation

It is sad that most people detest the use of equations in fermentation or technology OR that they are unable to exploit fully the data obtained from the equations. Equations in fermentation technology has been most times regarded as an unnecessary evil for you to take if you want to take fermentation technology

For most times the hatred or poor understanding towards the needs of the mathematical equations arises more due to the inability of the teacher to demonstrate is importance and application in fermentation technology. Equations are just regarded more as just a boring mathematical exercise

In any attempt to describe the fermentation technological process will usually involve the understanding of the various data generated by the process

In order to show the relationship between the change in one parameter will only be possible by making sense of the data produced and then to execute the necessary changes

In order to find the optimum conditions for a particular fermentation process we will have to analyze data obtained through various studies and experiments

Only mathematical data will allow us the ability to compare and decide to change the set parameters or not

The trouble is most teachers do not try to stress the importance and application of such equation… maybe because they are just pure mathematicians and do not see the applied implications of the equation

The most important thing, fermentation process is a very complex system which involves the idiosyncrasies of the fermentation microorganisms. It is not that straight forward and direct.

Now let us try to look at the significance of the Monod equation in fermentation technology. Monod equation is in fact one of the most important equation in biology especially in fermentation technology.


THE FAMOUS MONOD EQUATION

We use the Monod equation in calculating the growth of cells or microbes. This equation is then related to the substrate consumption rate equation for the purposes of the fermentation reactor design or analysis The Monod equation is empirical having been developed to describe experimental data; nonetheless, it works fairly well.
The Monod equation is represented as the following:

dX/dt = KmXS/(Ke + S)

where r (or dX/dt) is the rate of microbe growth,
X is the quantity of the microbes,
S is the concentration of the substrates, and
Km and Ke are constants.

What the equation is trying to sum up in the simplest terms is that the number of microorganisms is directly affected by the concentration of substrate over time. And that irrespective there are two constants that occur in the equation. Once we know the value of these constants we can extrapolate a lot of things if we adjust the other values such as time, substrate
We can try to relate the equation to the characteristics of fermentation reaction. The reaction has been determined to require additional supplement for cellular growth in order for the fermentation to proceed significantly. These substances probably vary for fermentation by different microbes.
However we should not see the fermentation process as simple as the Monod equation. There are cautions to be taken in applying it. The Monod equation is not as simple as the various complex parameters and diversity of microbial reactions could affect it.


A more expansive discussion of this material could be found at the GB-Analysts Reports site. www.gbanalysts.com





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CONSIDERATIONS IN THE DESIGN OF SIMPLE OVERFLOW DEVICE

The overflow device is an important component in any bioreactor design to ensure that the desired volume of the broth or medium in the working volume remain constant. This is especially required in continuous culture or chemostat and even in activated sludge system. Overflow devices too are required in fed batch culture systems.

Although the primary aim of the overflow device is to maintain the constant volume of the reaction tank, considerations must be taken that the composition of the reaction tank and the wastewater overflow remains homogenous or with the same composition of the media in the reaction tank. In many over flow devices this aspect is not often considered as a very simple attitude is taken just to retain the constant volume in the reaction tank.

In most wastewater bioreactor such as activated sludge and sedimentation tank or even clarifier the over flow device are often too simple in design and function and are located at the interphase of the surface of the water and the air. This would inevitabily resulted in drastic changes in the composition of the wastewater overflows and errors in the sampling procedures.

Having such simple over flow devices in fact help in the enrichment of solids and large particles being retained in the tank.

This characteristic is very crucial if involved in continuous cell cultures as we really need the over flow spent liquour to be truly representative of what really occur in the chemostat.

The overflow device must be located in the truly homogenous zone of the fermentor and where it is continuosly mixed. The design of the overflow device must not in any way changes the physical, chemical and microbiological composition of the sample as it pass through the overflow device

Samplings taken through the overflow device must ensure that dead space samples existing in the overflow device must be completely removed before the real sample taken

The overflow device must be specially designed to ensure aseptic procedures


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THE POOR MAN’S CHIVAS REGAL (a.k.a TODDY)

Malaysia is a nice country to live in. It doesn’t cost a lot to get drunk. Nether do you have to patronize pubs to enjoy the expensive alcoholic drinks. (Mind you the tax levied on alcohol is high!).

The simple and alternative way to get drunk is to enjoy the poor man’s Chivaz Regal or Toddy. Its cheap and its powerful! Making Toddy is easy. The problem is getting the sap high up on the palm tree!

Toddy is an alcoholic drink made by fermentation of the coconut or palm sap. The fermentation of the palm sap is carried out by yeasts which occur naturally.

Historically it is generally believed that the knowledge of making Toddy was brought by the South Indian workers. And Toddy is also consumed mainly by Indians in the estate plantations.

Toddy drinking has been blamed for a lot of social problems especially among the poor. It was not uncommon years ago to see drunken Toddy drinkers walking wobbly or sleeping on the road in drunken stupor. However at the same time there are those that will swear by it for its nutritional and health values.

Toddy are commonly sold in Toddy shacks. There are a few Toddy shacks in around Kuala Lumpur where you can get yourself a glass or two of Toddy. In fact just around Brickfields at Jalan Berhala is a licensed Toddy shack. Toddy is often sell by the litre for about RM2, whereas for the same amount beer costs RM12.

The only problem with Toddy drinking it seems it lacks class. It is the poor man’s drink. Public city also do not help with problems of the Toddy drinkers who often go over board. All the drunkards and brawls are too often associated with Toddy

I guess the drunkenness is not because of the significant higher concentration of alcohol as its alcohol content is equivalent to beer. Wine got a much higher alcohol content. It must be the volume of Toddy taken over the long time spent drinking Toddy. After all Toddy is cheap!

Have you tried Toddy with curry???. I heard it is a fantastic combination

TODDY FERMENTATION
Palm sap begins fermenting immediately after collection, due to natural yeasts in the air (often spurred by residual yeast left in the collecting container). Within two hours, fermentation yields an aromatic wine of up to 4% alcohol content, mildly intoxicating and sweet. The wine may be allowed to ferment longer, up to a day, to yield a stronger, more sour and acidic taste containing about 5% alcohol, which some people prefer.

As I see it Toddy will always remain a traditional fermentation which has great potential if the whole process of Toddy fermentation undergoes the modern fermentation technology process. Repackaging it and good marketing would put the modern brewers to shame! ( Eat your heart out Guinness and Carlsberg!)








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ALL IT TAKES IS A SIMPLE AIRLOCK!

In the business of fermentation, simple solutions are often the answers to some of the major fermentation problems. The answers do not lie in complicated apparatus or academic research papers in eminent journals. A good example is the use of air locks!

The success or failures of many fermentation processes depends often on:
1 Releasing the pressure of fermentation gases to prevent excessive in built pressure
2 The maintenance of anaerobic conditions or excessive exposure to oxygen.

But in most cases these factors are often over looked!

A good example of the airlock is found in the design of toilet bowl. The water seal is sort of airlock but more towards the prevention of odours and the crawlies from crawling up as you are doing your job.

The use of airlocks is only practicable for mixed culture fermentations such as those in food fermentations, wine fermentation


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THE GREAT OXYGEN DECEPTION

In aerobic biological wastewater treatment, the supply of oxygen is of great critical importance. It is one of the parameters that is mandatory and heavily relied upon to assess the efficiency of wastewater treatment. However it is one of the parameters that must be approached with the greatest caution as many wrong conclusions could be reached by wrong interpretation.

The importance of oxygen could not be denied as it is the indicator for the ability of the system to support life or whether the treatment system is properly functioning. The values of 2mg/litre have generally been accepted as the minimum concentration to support aerobic life. Below which the system is anaerobic.

I can always see how many engineers, chemists and even consultants are very excited prematurely to see if their WWTP registered a dissolved oxygen (DO) of about 4 mg/lit and declaring “MISSION ACCOMPLISHED!”

If only they stop the * Drum rolls!* *Applause!* Thunderous claps! * * Cheers!* and * Confettis!*

There is the possibility that something could be wrong if you register too high DO. You can only reach definite conclusions in conjunction with other observations or studies to support you

A high DO could be the result of various factors such as:
1 System too toxic to support life
2 The absence of microorganisms
3 Low number of microorganisms
And a few other causes

So before celebrating, and making hasty conclusions please analyse the other parameters or at least observe the situation over a few weeks analyses






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CSI- VALUABLE LESSONS IN FORENSICS IN WASTEWATER TREATMENT PLANT

It is very exciting when you are called to determine what causes a wastewater treatment plant to malfunction. Sometimes the reasons are too obvious, but sometimes the cause may be complex and require some sort of detective work such as in the popular television series “Criminal Scene Investigation” or CSI. There are evidences every where and it is up to us the wastewater forensic team to determine the cause and put it right!

When a wastewater treatment plant fails it is providing us with various valuable clues to why the process fails. Analyses of the evidences from physical, chemical and microbiological observations will be able to inform us why the WWTP fails.

To repair the WWTP without doing proper clinical studies of the stuck WWTP is not scientific, time and money wasting and would not lead to the proper solution.( Unless chances in a million you are lucky enough!)

WWTP failures do not occur just like that. There must be a reason for the failures to occur. Usually failures take time to occur, and if the WWTP is monitored closely you will see signs of the impending failure. To this purpose records or data of the WWTP are very important.

Biological WWTP is a very complex system. Almost anything could go wrong, so proper approach in determining the cause of failure is important to treat the WWTP

The approach to determine the cause of malfunction must be approached with an open mind.

The first step in the investigation often involved digging into the background and history of the WWTP, discussions with the production and engineering staff.

Water audit and process flow in and out of the WWTP are essential

Site visits are very important to determine the real situation. Only a trained eye or experience will allow you to detect the anomalies that could have contributed to the failure.

Analyses of the past and present water treatment operation data are essential

Sometimes not only in situ or separate analyses are required, experiments or laboratory studies are needed to confirm the cause.



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COMMISSIONING BIOLOGICAL WASTEWATER TREATMENT PLANTS

At the end of the construction of the WWTP, and before officially handing over from the contractors to the company, the WWTP is usually subjected to the commissioning of the plant.

In most cases it involves the easier part of civil, electrical and mechanical engineering to see that the plant follows the specifications laid, and that the various equipments are functioning such as the pumps, blowers, motors.

This is usually the easiest part of commissioning and easy to see if there are any defects or replacements needed.

The most challenging part of the commissioning process is to see whether the built WWTP can function and treat the wastewaters to the standards of effluent required.

The period of commissioning can be short or even a few months to achieve depending on whether the process is complicated or the process of commissioning are properly carried out.

If the commissioning fails or take a long time to carry out then the handover will be delayed and so will be the stages of payment to the contractor. If it is carried out fast and successful the payment will be fast and a lot of money will be saved for labour and time. As for the owner it would mean that the WWTP could enter the service faster.

There are a few objectives in carrying out the commissioning procedure:

1 It will ensure the owner that the WWTP built is in compliance and can achieve the standards set
2 The process will allow detecting any possible errors
3To fine tune the process of the WWTP to be process efficient
4 To subject the WWTP to stress test to see its safety factor and range it can tolerate to treat wastes. This acts like guarantee!

Commissioning of biological WWTP is not as simple as just pushing the power supply button and let it the WWTP operates. It is a process where data needs to be monitored and collected for the duration of commissioning. These data will act as evidences that the commissioning of the WWTP is successful or not.

In most cases the WWTP designed might not function as expected from the blueprints. So experts are needed to commission the WWTP and suggest ways of overcoming the obstacles from which the engineers will take the necessary recuperative actions

Commissioning of WWTPs require long periods on site monitoring and adjustments. In most cases the failure to commission the WWTP is not so much due to the fault of the WWTP design but poor understanding of the process of commissioning and the process of wastewater treatment

Commissioning WWTP is a scientific operation which should be able to identify the steps of process failure taking steps to make it right. One of the most biggest and frequent blunder carried out by engineers or plant operators during commissioning is to pump the raw wastewaters as if the treatment plant is already 100% functional. No wonder most times it is not because the WWTP do not worked as designed but more due to failure of start up procedures and commissioning







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