Bio fouling and Endotoxins – ozone solutions

Blogging for ozone awareness

Endotoxins -They are known to be resistant to even high temperatures. They can survive 120° temperature for more than 1 hour. They are resistant to chlorine and UV. They can be filtered by UF but have known to pass through
them at times. They can also become sessile and lodge themselves to Bio fouling material which protects them from destruction.

Read on …….November_2018 endotoxin Ozone Column

Dreaded Pseudomonas – Ozone Solution

DREADED PSEUDOMONAS & OZONE    Download to read full article

Gram Negative Bacteria (Pseudomonas) are more susceptible to ozone

Pseudomonas is a gram Negative strain, dreaded by both Pharmaceutical companies as well as Hospitals. Gram-negative bacillus of late presents a  major clinical significance; Many instances of infections with these organisms have been noted regularly now . Infections include bacteraemia/septicaemia caused by contaminated solutions .Environmental studies have revealed that the organism can survive in chlorine-treated municipal water supplies, often colonizing sink basins and taps, intubation tubes, humidifiers, incubators for new-borns, ice chests and syringes, contaminated medical devices such as blood gas analysers, nebuliser equipment and has become a potential reservoir for infections in the hospital environment

Role of Bio films

The sources of water in most Pharmaceutical Industry /hospitals are from sources outside and unknown to them. Water supplies are under contract to these water suppliers. This  water is treated  and  used for all purposes including advanced treatment process for Pharmaceutical compounding, Water for Injections in Pharmaceutical companies and for all purposes in Hospitals.  Pseudomonas  can pass through even  advanced treatment process and emerge in the final product water. As these ordinary treatment processes continue, there is a formation of bio film in all the water pipes. Conventional Bio films removal process such as CIP with Hydrogen peroxide, per-acetic acid  or even steam have not found to be too effective against Bio film removal .These biofilms provide safe haven to most of these opportunistic bacteria and they proliferate when opportunity arises. The locations that has been identified are areas especially where there are increased storage facilities, and in areas where chlorine residuals are removed with SMBS .



Vent Ozone Distructors – A Must Safety Feature

Do you know that in most part of the world, installing a vent ozone distructor is a must and enforceable by law .  Most of ozone leakage in plant rooms and other large ozone systems come from contact tanks .

Vent ozone distructors must be properly designed as wrong designs could cause other danger situations such as implosion of tanks , due to wrong design, wrong choice of catalyst .

I have seen many ozone contact tanks in India operating without Vent ozone distructors either due to ignorance or to economize cost and those that have been installed have all been wrongly designed an the end user is completely unaware of the dangers he is being exposed .

Here are some tips to judge if the Vent ozone distructor is properly designed

SEPT_2018 vent ozone distructor

Creating Ozone Awareness – Things You Must Do First Before Buying Decision

Creating awareness .

More often you find clients who have purchased an ozone system from unprofessional manufacturers find that they have had a raw deal and have procured systems that do not perform, unreliable and contribute to failed process . awareness as to what one should do before a purchase decision will help the client a lot to avoid bad systems .

Ozone is a very good technology , and a savior to all environmental problems  and resolves most issues not solvable through the more classical system. Ozone technology does not come cheap and so getting value for the money is most important . You cannot change system designs later on , as this would be more cost than a new system itself . Once you purchase an ozone system you are wedded for life to the supplier  and even a divorce can not help the client . So better choose the right ozone partner for your process applications THINGS YOU MUST DO BEFORE YOU BUY O3G

Ozone And Hard Cod


Combination of bio filtration with ozone have been found to be very effective , especially for the removal of  organic content, natural Organic matters ,metals, and nutrients , such as  , ammonia and phosphates. Use of bio filtration in combination with ozone (also known as Biologically Active Filtration) has been a proven technology for reduction of hard COD. The ozonation is supposed to breakdown the hard COD to simpler readily bio degradable compounds

Biologically Active Filtration: These are filters that contain Bio media. Media can be simple PVC/PP balls , combination of sand and anthracite and/or carbon media . The choice of the bio media will depend on the surface area required for the process.  These are trickling filters  ( slow speed) Biological treatment has been used in Europe to filter surface water for drinking purposes since the early 1900s and is now receiving more interest in India .Biological water treatment involves the use of naturally occurring micro-organisms in the surface water to improve water quality. Under optimum conditions, the organisms break down material in the water and thus improve water quality.

Hard COD from Effluents;

The bio degradability of each substance is dependent on the BOD/COD ratio. The lower the ratio, the less bio degradable the substance is . They are known as Hard COD.   These Hard COD cannot be easily removed and requires combination of technologies for its removal.  The essence is ozone breaks the Carbon to carbon double bonds that are most non bio degradable . This makes the following bio filtration step to easily eliminate the hard COD

Single stage ozone – bio filtration system can reduce COD up to 60 % and incorporating a second stage can reduce COD up to 80% COD .

Hard COD are often found in effluents of the paper and pulp industry , pharmaceutical industry and petrochemical industry

When do you consider Ozone-Bio filtration technique? 

Using ozone for COD reduction is common. Ozone when used alone can be expected to reduce COD upto 30-35 % only . A combination of ozone with other technologies can improve this removal percentage as below

  1. Ozone alone – 30-35%
  2. Ozone and H2O2 – 60-70%
  3. Ozone and UV – 50-60%
  4. Ozone and single stage Bio filtration: – 60-65%
  5. Ozone with two stage Bio filtration: up to 85%

A good bio filtration system can also be designed to reduce BOD

So you can observe that you would chose the technology /combination depending on the extent to which you want the COD to be reduced . If your present system is efficiently removing COD then you can use ozone to polish and give you consistent results. If your present system is not capable of giving you the COD values you need, you need to consider combination technologies depending on the nature of the COD and the extent of COD reduction you need. Of course you need to work out the CAPEX and OPEX and see which is better for you.

It is also recommended that in all cases where the size of the project is large, it is always better to conduct laboratory trial first , then design a small pilot trial which would help you to  upscale the requirement . Not doing so, means , you lose an opportunity to save large amounts of capital costs which otherwise may not be needed  or you end up in process failures . There are no short cuts.

The use of ozone and BAF in drinking water treatment has various advantages and is used wherever water treatment authorities want to comply with the DBP rules

1) reduction in chlorine use and chlorine contact time – reduces operating costs

2) no formation of Hazardous by products

3) Increased TOC reduction ,

4) Process removes multiple contaminants together

5). With ozone media life is increased – hence operating costs reduced

6) disinfection by products  such as Halo acetic acid and THMs are reduced

Large storage tanks & contamination

Column OZONE – Apr 2011 tank cleaning

In industries requiring process water the water loops are usually very long with intermediate large storage tanks designed . Though many of them can still be avoided , these large tanks are normally proposed to ensure continuous supply of water , especially when the end user is not sure of his availability of raw water on a continuous basis . He needs to depend on outsourcing of his water requirement which is the origin of all contamination.  Now a days we are finding even bore well water contaminated with pathogens , including coliforms which means that even the borewell at such great depths is being contaminated by sewage . . .   Using ozone could help resolve these issues . Remember using ozone does not mean that you can totally forget tank cleaning procedures . A good and reliable tank cleaning process coupled with ozonation could help . Take care not to chlorinate too much before ozonation . presence of chlorine stripping compounds will hinder ozonation . Also depending totally on pre chlorination  has not found to be useful in many cases. A carefully designed ozone system can be used to totally eliminate prechlorination

Ozonating Cooling Water Has Potential Roi Of 2-3 Years

Managing a cooling water treatment is quite tricky. Most often schedules of  chemical addition are provided by the Chemical supplier and very often the CT owner is unaware of the chemical composition. Most often the CT maintenance team claim that there are no problems in their cooling tower. Yet there are numerous shut downs, bio fouling of condenser surfaces effecting heat transfer efficiency , frequent cleaning up of condensers , unmanageable high CFU counts , High COD of cooling tower water ( not often measured) , High AOX levels ( never measured) , unable to achieve the required Delta T –  Problems that are never accepted by the maintenance team . The blow down water which is a toxic mixture of chemicals is discharged either directly without treatment or into the STP/ETP water, further increasing the cost of STP/ETP treatment.  Apart from these issues scaling and corrosion are not within admissible limits

I have personally visited many cooling towers including large ones like power plants and have never seen a trouble free cooling tower. We do not expect cooling towers to be totally trouble free but there are definite ways of making the tower more efficient. “I have very good water and my tower is in excellent condition is a very common expression”  Yes the tower water looks clean  but on closer look lots can be done to make the tower water of better quality  and make the cooling tower  more efficient .

Any cooling water treatment regime strives to achieve the following

  • Lower CFU counts
  • Prevent bio fouling
  • Try reducing organic load
  • Reduce scaling & corrosion
  • Increase heat transfer efficiency
  • Try to reduce blow down by increasing cycles of concentration

Hidden performance parameters that are often not quantified: Other performance parameters that are mostly neglected (or taken for granted) are

  • Heat transfer efficiency ( potential for high savings)
  • Shut down costs of cooling tower
  • ETP treatment costs
  • Inventory of chemicals carrying costs
  • Labour


Large cooling towers such as power plants are water guzzlers. The operators use tonnes of toxic chemicals to keep the cooling water clean to protect the cooling towers. They discharge highly polluted blow down water that needs to be treated before discharge .There is tremendous pressure from environmentalists.

Users of Ozone Technology around the globe have always accepted the benefits of Ozonation; however the viability of using ozone in India has always been a question for lack of quantified studies and working references.

Power plants in India that have already resorted to ozonation have not found ozone very attractive. There are still frequent breakdowns, very high and monopolised maintenance costs and still addition of biocides although using ozone means Zero Biocides. Just go to the WEST and your find excellent use of ozone in Industrial cooling towers. The lack of trust in India on ozone use in cooling towers have come out of inefficient ozone systems, wrong designs, selfish motive to make one time money and run away . If ozone systems in cooling tower can work in the West, it should also work in India. Tower owner’s confidence in ozone must increase.  So going to the right Technology provider is very important. Ozone has a cost but the returns can be very fast if properly implemented

The use of ozone provides the following benefits in a nutshell:

  • Completely eliminates Biocides , making the discharge water cleaner
  • More than reduces 90% of Sulphuric acids and de-scalents
  • No hazardous chemical storage and Handling such as gas chlorine
  • Enables the CT to be operated at Higher COC , reduces controlled blow down frequency
  • Prevents scaling, corrosion and reduces algal growth
  • Saves energy in operation of the Cooling tower
  • Finally Saves water , Saves chemicals costs, allows the power plant comply with environmental needs and make them environmental friendly

In view of the restrictions for discharge of water with TDS greater than 2100, the decision to operate at a higher COC will be dependent on the quality of MUW .Using ozone; the same quality of MUW allows the cooling tower to more than double the COC of a chemically treated tower

Studies have revealed that a build-up of 0.1 inch (0.25 cm) of Calcium carbonate scale on heat exchanger surface will reduce the heat transfer by as much as 40 % .The energy savings accrue due to the fact that virtually limited scaling are noted with ozone treatment, and reduction in scale thickness improves the heat transfer efficiency of an Ozonated Cooling tower, thus saving power .Anticipated power savings can be upwards of 10 % .

Return of Investment.  All of us know that calculation of return of investment means the tower operator must be transparent with his chemical and other costs.  I have never come across any tower operator ( with whom I have had transactions) who can quantify entire costs (including hidden cost). Many tower operators refuse to reveal the actual chemical consumption. The Cooling tower maintenance of large industries are often out sourced and we do not get any Data here!!!  I have personally taken lots of pain in gathering all cost details in one power plant supported by a progressive Chief engineer and have worked out the ROI for incorporation of ozone . The result would be astonishing – an ROI between 2-3 years   .


Ozone Wonder

Ozone actions for micro pollutant removal, pesticides removal, TOC removal, endotoxin degradation , TOC reduction have all received international attention these days . Apart fro keep the water bacteria free , a stage has reached that water need to be free from the above too.  Ozone appears to be a very reliable solution   .  Contact OTSIL for reliable solutions 9840149184 , 9820278543




Thumb Rule Doses For Ozone Design

Blogging for ozone awareness

Prospective users of ozone may well keep themselves informed on the approximate ozone dose required for various applications . This will prevent acceptance of an design that provides for more ozone than required. ozone is expensive , ozone is also toxic , hence little knowledge could be of immense help . But take care . These are just  thumb rules and in many cases the ozone requirement can change depending on the quality of water .

Don’t get misled . It is better to say NO to ozone than use ozone where it wont work . Ozone does not perform magic . Ozone manufacturers are not magicians . Never overlook other technologies. They may be better than ozone .   Contact 9840149184  for YES or NO to ozone

Read on for more details  : Dec. 2013 OZONE DOSE