Sunday, 4 November, 2018

75. MBBR: The Riddle, wrapped in a Mystery, inside an Enigma —Cracked

It has baffled me no end why even a half educated Environmental engineer would start promoting the MBBR (Moving Bed Biofilm Reactor) for mini and small STPs when it militates against every prescribed design criterion, every desirable engineering feature which needs to be followed if this technology is to be successful on such small scale. Maybe I am expecting too much from this half-baked engineer. After all it was originally promoted in India by an even less cerebrally endowed company, but with a brand name famous for its sales acumen and not so much for its technical skills in the area of Wastewater Treatment. Yes. I am referring to the same old Zermatt you may have read about in my blog of several years ago :

About 25 years ago I even had the misfortune to totally berate and reject outright a 300 KLD MBBR STP by this company for a software major in Electronics City, Bangalore. Despite adding one more MBBR tank, the STP had to be finally totally scrapped on account of inherent deficiencies. Scrap merchants in Electronic city were the only happy folks.

Now, as happens in any large company, there were many engineers who were only ephemeral transit passengers and who upon parting Company continued the legacy of bankruptcy in technical knowhow and skills. As a result, the City of Pune is full of MBBR STPs dotting the landscape each worse than the previous version due to diminishing knowhow and skills syndrome. A city plagued by MBBRitis.

Recently I cracked the riddle visiting a fairly large MBBR STP in Pune apparently built by one of the offshoots of the Company in question. While chatting with the Supervisor of the plant, I was given a tutorial on the advantages of the MBBR over the Extended Aeration Activated Sludge (EAAS) system. The designer most probably an Ex-Zermatt guy or a plumbing consultant had educated him on the benefits of the MBBR and superiority over EAAS thusly:

The large mass of plastic media floating around in the MBBR tank offers much higher surface area for microbes to grow than the four bare walls of the Aeration tank in an EAAS STP. More the area, better the performance. Elementary my dear Kodavasal.

Brilliant ! My God ! How could I not know this fundamental difference between MBBR and  EAAS? And me with all my Chemical Engg. background (IIT Madras no less), PhD in Advanced Wastewater treatment from Vanderbilt University (Nashville, USA) under the legendary Prof. Eckenfelder!! I should have died of shame on the spot that day. 

For those of you wondering what's wrong in the designer's reasoning (or lack thereof): MBBR is a reactor operating in the Attached Growth regime. Microbes attach themselves to the plastic media. EAAS, on the other hand, is a reactor operating in the Suspended Growth regime. Microbes are fully suspended in the aeration tank (not attached to the four "bare" walls as the designer thinks). A fundamentally completely different operating principle.

November 01 is celebrated in our State as Karnataka Rajyotsava Day. The day the State was born.
On that Happy note, I wish for a rebirth as a brilliant engineer who knows what is and what is not.

Dr. Ananth S Kodavasal                                                    November 04, 2018
Brilliant! My God! How could I not know this fundamental difference between MBBR and  EAAS? And me with all my Chemical Engg. background (IIT Madras no less), PhD in Advanced Wastewater treatment from Vanderbilt University (Nashville, USA) under the legendary Prof. Eckenfelder!! I should have died of shame on the spot that day. 

For those of you wondering what's wrong in the designer's reasoning (or lack thereof): MBBR is a reactor operating in the Attached Growth regime. Microbes attach themselves to the plastic media. EAAS, on the other hand, is a reactor operating in the Suspended Growth regime. Microbes are fully suspended in the aeration tank (not attached to the four "bare" walls as the designer thinks). A fundamentally completely different operating principle.

November 01 is celebrated in our State as Karnataka Rajyotsava Day. The day the State was born.
On that Happy note, I wish for a rebirth as a brilliant engineer who knows what is and what is not.

Tuesday, 30 October, 2018


The undivided state of Andhra Pradesh was a great big state in the Union of India with its capital at Hyderabad.  Now, after the division of this State, it shares its borders with the State of Telengana (the sister Sate) and Karnataka to the West, Tamilnadu to the South, Orissa to the North and the tempestuous Bay of Bengal to its West with a long coastline of nearly 1000 Km.  Towards the end of October 2018, I set out along with three of my companions to the middle coastal region comprising broadly the very fertile East and West Godavari delta regions to study on shore coastal aquaculture practices.  This to explore if instrumentation and associated communication and control technology could be applied to better monitor and control breeding operations, improve yields and for early detection and prevention of virus attacks.

PVT Naidu ( A human Dynamo), Seetharam ( An unconventional Engineer cum farmer) and my good old classmate from IIT Madras - Madireddy Nagaraj ( fondly known as “Kakes”, short for Karate Killer) all from Bangalore were my constant companions on these four days as we travelled from Vijayawada through Machilipatnam, Bheemavaram, Kakinada, Rajahmaundry and back to Vijayawwada in Ranga Rao Garu’s car who joined us in this expedition. Ranga Rao himself was a big and progressive prawn cultivator of the region based in Machilipatnam.  After visiting several prawn ponds ( Royyala Cheruvulu ) and discussions, we got some of the basic facts and information of the business.  More on this on another day and another blog.

Courtesy the first named PVT Naidu, this trip turned out to be a Sweet Tooth Tour of Coastal Andhra.  PVT traces his ancestry from Kakinada where his mother and his brother live and own large tracts of fertile farmlands, Kakinada where he went to school and to college and knows the region like the back of his hand. And at every stop on this trip his friends, his relatives, his school mates, his College mates dropped him to greet him.  Truly amazing.  Now for the Sweet Tooth Tour organised by PVT.

MALLAIAH SWEET SHOP   ( Bandar Laddu )

The first pit stop in the Sweet Tooth Tour ( STT)  took us to the legendary Mallaiah Sweet shop in Machilipatnam world famous for its “Bandar Laddu “  which enjoys the prestigious Geographical Indication tag ( Bandar = Port.  Machilipatnam was a major port for the British, Dutch and the French).  The sweet shop now operates from a modest little room in a bylane of the town.  The pushcart used by the original founder Mallaiah still adorns the front of this shop.

Next stop for us pilgrims was the Bhaktanjaneya Suruchi  Foods at Tapeswaram, inventors of the imaginatively named Tapeswaram Khaja.  Dripping in ghee and moist, an image so evocative and indicative of the pleasures concealed within, that will transport you to seventh heaven just looking at it. Imagine biting into it !

SRI ABHIRUCHI SWEETS KAKINADA     ( Pootharekulu Sweet )

Another stunning concoction from the Godavari delta region is the wafer thin parchment like sweet wrapped and wrapped and rolled around itself until it becomes a handy little flat cigar full of sugar, dry fruits and other titbits and brushed with generous helpings of ghee. Typically this sweet called Pootharekulu is served one at a time and thoughtfully with a few paper napkins as mandatory accessories. I have always known Andhra for its hot spices, chillies, eye and nose watering dishes.  The Sweet side of Andhra came as a total surprise and a revelation.

GANGARAJU DAIRY     ( Gangaraju Khova )

The last shrine to be visited on this STT was the Gangaraju Dairy Sweets shop, again operating out a little  hole in the wall nondescript shop in the residential quarters of Rajahmundry,  now pompously rechristened Rajahmahendravaram, no doubt at the behest of some overzealous politicians. “ One ticket please to Rajamahendravaram”.   I am sure old man Gangaraju Nimmalapudi would turn in his grave at this sacrilege.

VIJAYAWADA AIRPORT   ( Airport Security )

The final kick of this Sweet Tooth Tour of Coastal Andhra was to come at the Vijayawada Airport .

I placed all the loot from the STT  in a large plastic bag on the conveyor of Airport security in Vijayawada Airport.   The young CISF officer at the Xray monitor could not believe his eyes. He took aside the package, sniffed at it and asked me if I was carrying Bandar Halwa.  “Sir, Halwa with so much Ghee dripping is not allowed on the aircraft” he said.  With a forlorn look I was preparing to discard the halwa packet muttering to myself “ You are worse than my wife” when the young fellow came over, patted me on the back and with a wink and smile, waved me through. “Good luck with your wife Sir, take care .”  CISF folks have gone up several notches in my view now.


Dr. Ananth S Kodavasal                                                                  October 30, 2018

Monday, 8 October, 2018



Opposition parties in India and more especially the principal opposition party appear to have lost their sense of balance, equanimity and the basic ability to think and apply their minds.  May be they have lost it, not having any real leaders to speak of.

They see a conspiracy to help the BJP party by anybody and everybody.

- Vladimir Putin signs a defence deal with India to help the BJP score points
- President of France Emmanuel Macron says Rafael deal is fair to help the BJP
- The IMF lauds India for its economic reforms to help the BJP
- The Army carries out Surgical strikes in Pakistan to boost the BJP
- The Election commission announces state polls ahead of time to benefit BJP
- Ms. Mayawati ditches the Congress party in collusion with the BJP
- Mr. Akhilesh Yadav does likewise to kick the Congress party at the behest of the BJP
- Various enforcement agencies of the Govt. are targeting opposition functionaries to help the BJP
- The RBI monetary policy is designed to help BJP in the general elections
- The courts in India are delivering judgements favourable to the BJP        
- The common man lauds the Governments performance to show the BJP in good light

And so on and on and on

At this rate, I am beginning to think the Opposition parties will view Ecotech’s single minded and unwavering advocacy of the EAAS Technology as best suited and most appropriate for mini and small STPs as a conspiracy also designed to help the BJP.

Well, coming to think of it, they may be right.  All our STPs work, help conserve precious fresh water resources.  All our STP’s work, generating good clean water for Recycle and Reuse.  All our STPs work contributing to water security of the nation.  All our STPs work and help protect the Environment. 

YES.  Ecotech’s efforts contribute mightily to the Swachh Bharath Abhiyan of the BJP and the Government.  So help me GOD if I have sinned.

          Dr. Ananth S Kodavasal                 
          October 07, 2018

Thursday, 14 June, 2018



Ecotech, as you may all well know by now, has been a staunch and unwavering advocate of the Classic, time tested, proven Extended Aeration Activated Sludge ( EAAS ) Technology for Micro, Mini and small STPs in Residential and Commercial complexes.  SBR -           
( Sequencing Batch Reactor ) and MBBR ( Moving Bed Biofilm Reactor) are indeed very fine technologies appropriate only in large scale Municipal STPs of say 10 MLD and above, where sewage flow characteristics are more uniform and favourable, where requisite and mandatory design & engineering features may be gainfully applied as also specialised equipments and treatment stages may be deployed such as the Mechanical Decanter in an SBR or a Primary Sedimentation stage in an MBBR.

For long we have been hesitant and shying away from engaging with small communities for their STP requirements :  the EAAS system was not economically viable for say 150 flats or less with sewage flow of less than 100 KLD.  The cost of operation & maintenance of such small STPs would be a killer and make the STP dysfunctional and a messy cesspool, breeding ground for mosquitoes and other disease vectors in double quick time. We wanted no part of this to become a blot on our escutcheon

Recently however, the Govt. of Karnataka mandated that all apartments with 50 flats or more must perforce set up an STP.  And this got us to rethink our policy on such micro STPs. There are several sharks, charlatans. Voodoo practitioners, shamans and of course the usual suspects – ignorant plumbing consultants who will swoop down upon these innocent communities like vultures of prey and suck the lifeblood out of honest citizens.  

As qualified and trained Chemical + Environmental engineers of high technical and professional integrity and ethical business practices we took it upon ourselves to rise to the challenge to help this hapless lot. And thus was born the Anaerobic Baffled Reactor (ANBR) system of STP for small communities.  Not exactly an invention, but an improvement over and adaptation for an Indian metro city urban setting, of a seminal work in this direction by Herr Ludwig Sasse of Germany in the 1990’s. We had to bring to bear all our Chemical Engineering knowledge and practice in conjunction with our Environmental Engg.  qualifications to fine tune Design and Engineering of the ANBR system to make it practically operator free with bare minimum of equipments and maintenance. As an aside : Herr Sasse’s technical brilliance is matched by his outlandish, peculiar sense of Teutonic humour – more on this in the footnote.

We recently commissioned our first 60 KLD ANBR STP for a residential complex in Bangalore.   After initial hiccups, caused not by our design, but by improper implementation of our instructions, the STP has settled down well now and is yielding treated water of excellent quality, now recycled and reused for toilet flush.  Even the lingering suspicion that long periods of stagnation of anaerobically treated sewage may result in turbid, blackish and odorous product was proved to be ill founded. Treated water retained its initial character even after 21 hours of standing well into the next day.  See Images below :

From left to right :

After ANBR, before Sand filter          : After Carbon Filter              : After Chlorination

Crystal Clear, Colourless Odourless !!!  What more can one ask for ??

FOOTNOTE : Pearls of Wisdom from Herr Ludwig Sasse’s Handbook

“Wastewater engineers are probably the only ones who love handling wastewater”

“It is the duty of the technician to deliver an appropriate design which will be realised with an
appropriate technology”    - (This is exactly what I have been preaching all along )

“Low maintenance does not mean NO-maintenance”

A wastewater treatment plant is NOT just another pair of shoes” -  ( I am still trying to figure this out)

The first economic question is "Why", only the second question is "How much"  - ( Well Said ! )

Dr. Ananth S Kodavasal                                                                                   June 14, 2018

Friday, 18 May, 2018

68.  AN STP IN THE TOWN OF KUPPAM ( Pop. 21,963 Census 2011)

This little story again illustrates and highlights the fact that I have been repeating again and again and again : The classical Extended Aeration Activated Sludge ( EAAS) system is still the best STP Technology for Micro , Mini and small STP’s in Res. Apt. complexes, Commercial Office complexes, Hospitals and colleges etc.

The small little town of Kuppam  best categorized as a Tier 4/ Tier 5 town, lies in the neighbouring state of Andhra Pradesh, roughly 130 Km ESE of Bangalore.  It can be reached  in about three hours by car on fairly well tended roads.  I had occasion today to visit this little town on an invitation from the prestigious PES  group of Institutions which runs a Medical college and a Hospital attached to the college in Kuppam.

My brief was to inspect, study and solve the riddle of excessive loss of water in their Water Treatment Plant ( WTP) in excess of 30 % when nearly 600 KLD of water extracted from their borewells was treated through a Pressure Sand Filter and a water softener. Sitting in Bangalore, my first thought was that the Ion Exchange resin in the softener may have outlived its usefulness and therefore was calling for frequent regeneration with common salt, followed by rinse operations which might explain the losses.  However, as is my wont, I reserved judgement until I did a Genba walk and an onsite physical inspection.

The puzzle was solved easily enough within minutes when the WTP operator at site confessed that he did a backwash of the sand filter once every three hours for 20 minutes on each occasion, which water was then wasted out on to the adjacent open Field. This practice was based on some Standard Operating Procedure ( SOP) possibly shared with him by the very same ignorant Plumbing Consultants whom I deride at the slightest chance that I get.. I showed the operator the quality and clarity of this “Backwash Waste”  and his folly in blindly following a fool’s advice  and gave him a fresh set of SOP based on scientific principles of pressure loss across the filter measured by two pressure gauges one fitted before and one after the filter.  The small town boy was beaming with pleasure, nodding his head at this simple, logical, common sense explanation when I left him to inspect the Sewage Treatment Plant on the other side of the campus.

Not one, but Two STP’s I was told were on campus, one rated at 200 KLD and the other at 400 KLD.  Having seen first hand sins of the past in the WTP, I trudged along towards the STP’s, expecting the worst.

LO and Behold ! Both STP’s were in perfect working condition, each receiving also the design quantity of wastewater and producing treated water of excellent quality like from any STP that we at Ecotech operate and maintain.  The secret of this Success was not far to seek.   Both STP’s were built on the Classical EAAS Technology, well designed and engineered. 

In a remote Small Little Town of Kuppam I saw a 100 % success rate of STPs. If only the self proclaimed  Hi tech City of Bangalore had this success rate, the lakes in Bangalore would not have to suffer.  For this to happen, one must cull out and permanently disable all commission seeking Plumbing consultants in Bangalore and the equally corrupt Architects who employ them

This story of Kuppam would be incomplete without a final piece of teaching and learning.

When I asked the Boy how many times he backwashed the Filter in the STP, he very respectfully replied that he did this procedure two times in a day.  Where was the need then to backwash the filter in a WTP every three hours I questioned him, when you are filtering clean water from a borewell and not STP water ? 

Good Environmental Engineering as I have often said is only 50 % knowledge, expertise and experience.  The other 50 % is the use of common sense to apply in practice what you have learnt.

Dr. Ananth S Kodavasal                                                                                    May 18, 2018

Saturday, 5 May, 2018


When I quit Voltas International Limited in utter disgust in the year 1986 ( see A JOINT VENTURE COMPANY IN YEMEN ), I did quite a bit of spade work before I took the next big plunge in my career : I scouted around for suitable business opportunities in Bangalore and Madras, before zeroing in on Bangalore as the city of choice to set up business.  Also, since I was not certain how long it would take me to find my feet in the consultancy business, and indeed find a sufficient number of clients to keep the Home fires burning bright, I had a fall back strategy. Before quitting Bombay, I called upon friends and associates manufacturing pumps, agitators, and other odds and ends which find extensive use in Water and Wastewater treatment plants, and convinced them to give me sole dealership for selling these items in the Southern states of India.  And since by temperament I am a poor salesman (short tempered and ill mannered when having to deal with lesser mortals), I took on board a Partner to look after the Sales end of the business.

The Environmental Consultancy Business would be handled by me under the name and style of Ecotech Engineering : The Sales activity would have a separate and distinct identity, under the name of Dixie Enterprises.  My other partner would be solely responsible for day to day running of this Company.  An equitable scheme of sharing of profits from the two companies was mutually agreed.  It was also expressly agreed that the highest level of professional ethics and integrity would be maintained, and Dixie was not to have any business dealings with Ecotech’s clients : this to avoid any potential conflict of interest.

Now, a brief description of this partner of mine is in order.  An old colleague of mine from my previous company, Dilip was an extremely outgoing and gregarious fellow : always smiling, playing pranks, playing the fool,  an eminently friendly and likeable character. His joie de vivre was infectious : A few minutes of Dilip’s company will lift your spirit, setting it free and flying high.

Nothing happened either in the Consultancy front, nor in the sales front in the first six months of startup.  I kept my cool, comforting myself that these things take time, patience and perseverance. 

A break came providentially, when an old colleague from Bombay asked me to take care of the supervision and guidance during execution of a Sewage Treatment Plant for the Indian Telephone Industries which he had bagged.  Another colleague from Madras entrusted the task of commissioning a particularly difficult industrial wastewater treatment plant for the Mysore Acetate and Chemicals in Mandya.  An old college mate of mine facilitated my getting a consultancy assignment for a Wastewater treatment plant for NP Chewing gums ( see Treatment Plant Design by Academics ).  Now the ball was set well and truly rolling in the consultancy business.

Dilip, meanwhile found it an uphill task to sell pumps, agitators etc., and develop his end of the business.  Towards the end of the first year much to my chagrin, I found him canvassing sales from my clients in the consultancy business.  By means of a quick surgery, I closed down Dixie Enterprises, terminated our partnership and concentrated on developing Ecotech.  I lost a business partner, but retained a friend : Dilip is still the same old prankster I knew about 30 years ago.

I seem not to have learnt my lesson from this unhappy episode.

I got myself into a loose association with another erstwhile colleague of mine.  Things were going well for quite a number of years, since he also had another partner as a mentor, a much older, wiser, seasoned professional, a hands on engineer, a genius and a gentleman. His was the voice of reason, the sane counsel that reined in the over the top and get rich quick schemes of his younger acolyte : I was the technology and process consultant to them with my chemical and environmental engineering background : many a difficult industrial wastewater treatment plants were successfully designed and executed by this arrangement.

All was smooth sailing until another junior partner was roped into their company : Coming from a totally vacuous background, with scant appreciation of business and professional conduct, this charlatan brought in new work ethic and standards which possibly were music to the ears of his over ambitious boss : indeed, I suspect that could be the very reason for inducting him into the company in the first place.

Soon came a day when the Senior partner possibly could not countenance the shady goings on in the business and quit to protect his fair name : shortly thereafter, I too opted out when it became clear to me that professionalism and business integrity and ethics was of no account in this association, and my fair name could be dragged through the mud and mire they were sinking into.

I neither regret this decision nor rejoice in having made it : only a deep sense of sadness and sorrow lingers in having lost a friend bowing to Mammon.


Dr. Ananth S Kodavasal                                                                                    December 05, 2011