AN ETP WALL OF FOAM

                                                               47. AN ETP WALL OF FOAM

There is a Country Music Hall of Fame in Nashville, Tennessee : this I can understand.  I find also a South Dakota Rock and Roll Hall of Fame in Sioux Falls, S.D. ; National midget car Hall of Fame in Wisconsin;  International Jewish sports Hall of Fame in Israel ; Baseball Hall of Fame, Basketball Hall of Fame, Oddball Hall of Fame etc.  And there are further extensions to this theme such as the Walk of Fame, Wall of Fame and so on.  The numbers and variety are truly mind boggling.

http://en.wikipedia.org/wiki/List_of_halls_and_walks_of_fame

It makes me wonder what kind of people are desperate enough to go visiting these places ? What is their mental acumen and maturity level ?  and what is their takeaway from such memorable outings ?    Be that as it may, this story is about the time I inadvertently walked into a Wall of Foam in an ETP      ( Effluent Treatment Plant).

I moved to Bangalore from Bombay in the year 1986, after quitting Voltas International in disgust ( see a Joint Venture Company in Yemen). I found temporary accommodation in Bangalore for the family and myself on Charles Campbell Road in Cox Town.  Quite by accident one day, I bumped into an old colleague of mine from Dorr-Oliver now settled in the very same neighbourhood.  B. Velan was a brilliant mechanical engineer, and headed the engineering and drawing operations of Dorr-Oliver in the Madras office.  After quitting Dorr-Oliver, he set up Scorpio Engineering in Bangalore, manufacturing bulk material handling systems and equipments. 

With active encouragement from Venkataraman ( RIP) another old colleague of mine from Voltas based in Madras,  Velan ventured into wastewater treatment, banking on his past experience in Dorr-Oliver and Venkat’s process and design expertise.  Little did he realise the pitfalls in the business. They had managed to bag an order for an ETP at Mysore Acetate and Chemicals ( MACC) a particularly complex wastewater, and had completed erection of the plant when I walked into their parlour and was roped in to startup, stabilize and commission the treatment plant.  This was possibly one of the first assignments for Ecotech in Bangalore in the year 1987, and to keep the home fires burning, I grabbed this opportunity.

The Mysore Acetate and Chemicals Ltd. is one of the oldest industrial undertakings of the Govt. of Karnataka, now defunct and boarded up, as ought to be the case with all ventures of the Govt., including that of governance.  MACC is located in a place very imaginatively named Acetate Town, on the outskirts of the equally drab and unimpressive town of Mandya in the South Eastern part of the State.  MACC produced Cellulose Triacetate and related products used for making tooth brush handles, TV cabinets, photo film and so forth from cellulosic materials such as cotton, wood chips and wood pulp.  In the main, two streams of process waste were generated from the operations, the one called black liquor and the other the high COD ( organic content)  stream.  The two streams were segregated at source and in the ETP, received separate and different treatment.

Velan the master had excelled himself In this project insofar as of some of the mechanical equipments he designed : Instead of Circular clarifiers, there were rectangular clarifiers ( highly space efficient) with the bridge moving up and down along rail tracks, fitted with limit and reversing switches at both extremities,  much like Overhead traveling cranes.  I was fairly comfortable with this design having previously commissioned such units at the Dudeshwar Water Treatment pant for the Ahmedabad Municipal Corporation about 5 years previously.

At the exit end of the treatment plant, in order to collect a composite sample of  treated water ( as opposed to a grab sample)  there was a Ferris wheel like contraption going round and round, picking up a smidgeon of a sample of the water at every rotation and depositing it in a compositing bottle placed alongside.  The speed of the Ferris wheel could be varied at will by the simple device of turning a screw.  The Aeration tanks in the Treatment plant were however outfitted with High Speed Floating Aerators, which were not entirely to my liking.

The fault lay however in the design of the Treatment plant.

The usually meticulous and diligent Venkataraman had slipped up in the design.  He did later confess to me that in their hurry to put in the tender, he had not made a detailed independent study of the effluent characteristics, nor validated the figures specified by MACC :  The High COD stream indeed lived up to its name.   But instead of the design value of 3000 mg/L of COD, in reality it turned out to be in the range of around 10,000 mg/L, when I was commissioning the treatment plant. This high COD stream was absolutely clear, colourlesss and odourless much like the bottled mineral water of today, and would deceive any person at first glance.   This always brings to my mind the haughty boast of an ex chairman of the Karnataka Pollution Control Board ( an Academic, mind you)  who claimed he could determine the COD of any wastewater by merely looking at it.  May be if we had more such super human specimens, we would not need scientific testing laboratories with associated paraphernalia of chemists, chemicals, glassware, instruments etc.

The very refractory black liquor stream also was very difficult to stabilize because of the high speed floating aerators which were simply shearing and pulverizing the bacterial flocs and not allowing them to settle in the clarifier. 

Although we could demonstrate good performance of the ETP in terms of pollutant removals in absolute terms ( Kg COD/ day), we could not achieve the low concentration levels ( mg/L ) on account of the wrong design figures supplied by MACC.  The clients too reconciled themselves to this fate, albeit with some reluctance.

I had posted a chemist full time at MACC to supervise the commissioning of the ETP, and I made fortnightly visits from Bangalore to monitor the progress and give necessary guiding instructions.

It was a cold, cold morning in December, when Nagaraj ( the MACC Chemical engineer in charge of the ETP) and I walked towards the ETP a little distance away from the main factory.  The ETP was now hidden from view by a 12 foot high wall, apparently a new construction, not there on my previous visit, neatly whitewashed and shining bright against the winter sun.  Lumbering towards the Wall and the ETP on that cold winter morning,  I expressed my surprise to Nagaraj that a Government owned unit could put up such a huge construction in such a short period of time.

And that was when I walked into a Wall of Foam. For a few moments I was absolutely stunned when I discovered the wall to be entirely made up of thick white foam, churned up by the high speed aerators, bobbing forlornly in the middle of the aeration tank, trapped within the four walls of foam.

Dr. Ananth S Kodavasal                                                                                December 03, 2011

P.S :  A combination of wrong design ( incorrect COD figure), wrong engineering ( High speed aerators shearing the bacterial flocs), and environmental factors ( Cold Night Temperatures) conspired overnight to build the huge wall of foam.

A WIN WIN PPP

54. A WIN - WIN PPP

This is a success story of a residential community in a smallish apartment complex consisting of 160 flats, off Hosur Road in Singasandra, Bangalore.  Singasandra ! – a lyrical name as a reporter of a local newspaper noted while describing this quaint little village it was about 20 years ago : farms and agriculture fields dotted the landscape and the only noteworthy landmark in the neighbourhood was the newly opened Manipal County Club, far from the madding crowd !  A swanky resort, ahead of its times, spread over several acres of lush greenery and lawns - a legacy of this laid back farming community, oblivious of the devastation that was to befall it a few years later from the fledgling IT industry in the neighbouring Doddatogur Village,  now only known and recognized as Electronics City.

This apartment complex had a Sewage Treatment Plant ( STP) based on the Sequencing Batch Reactor ( SBR) technology designed to handle 100 KLD, which was not performing satisfactorily for various reasons : also a good proportion of the incoming wastewater bypassed the STP totally.

Now, several architects, plumbing consultants ( my favourite villains), vendors of equipment and indeed even prospective clients and the Pollution Control Board officials are of the opinion that I promote only the tried, time tested and successful conventional extended aeration biological system for an STP of a residential complex.  They are right of course.  They also believe that I actively discourage other variants of the technology ( Electrocoagulation, SBR, MBBR, MBR etc.) for this application.  Right on the money again.  Let me explain the rationale for my preferences.

It is my firm belief borne out of close interactions for over 25 years with the worthies mentioned above that finer nuances of available treatment technologies and the specific engineering challenges unique to these technologies are totally beyond their comprehension.  It requires a keen chemical engineering brain coupled with sound knowledge of environmental engineering principles and a large dose of common sense ( all of which with due modesty, I claim to have in great abundance) to  assess and determine the Best Available Technology ( BAT) or Best Practicable Technology ( BPT) as the case may be for a particular situation. 

As a student of Chemical Engineering I am fully cognizant of advantages of a batch reactor where first order reaction kinetics prevail.  Also, Fluidised Bed reactors have been in use in chemical engineering practice for several decades now ( MBBR being the STP equivalent ) to not overly excite me like a new kid on the block.  What is new now is application of these age old technologies in biological wastewater treatment.  Similar is the case with Membrane Bio Reactor (MBR) technology, which has now been in use for decades for milder applications such as dialysis, osmosis etc., operating on simpler fluids ( blood, sea water ) vastly different from the harsh character of wastewater -  more so under Indian conditions.

I fully approve of these technologies, provided they are applied with appropriate engineering principles and precepts to deliver satisfactory treatment performance at optimal cost over the life of the STP : and when this is done, the conventional STP stands head and shoulders above all of these technologies as on date.  I speak with some authority, after having completed detailed studies on several STP’s  with these technology variants on a specific assignment given to us by the Karnataka State Pollution Control Board.  So what reason would I have to recommend second best or to offer an option to my client ?  I have been tasked to give him the best advice : not to sit on the fence.

Enough of digression and let me get back to Singasandra.

Due to acute constraints of space, we could not convert the SBR to the conventional mode of treatment.  Therefore, we did the next best thing available to us : to apply better engineering principles demanded by the SBR technology, and reengineer the plant. The total cost was around Rs. 4.5 lakhs to revive and resuscitate this dead STP.  Simple arithmetic showed that if 50 KLD of out of the 100 KLD of treated water could be reused for purposes such as toilet flushing, gardens and car wash, savings in fresh water purchase through tankers will pay back this amount within six months.  The rest of 50 KLD of treated water had to perforce be disposed off outside.

Enter Manipal County Club in the picture.  Suffering from huge shortage of water to tend to their greenery and lawns, this neighbour was looking for a perennial source of good quality water for their irrigation needs.  We drafted a model Sale – Purchase Agreement for this transaction between the two good neighbours whereby the excess 50 KLD could find productive use, for mutual benefit.

Surely a Win - Win situation for the parties where Private -Private Partnership can prove beneficial to both and also their immediate Environment.

Have excess treated water ? Talk to your neighbour.  The draft Agreement is ready.

Dr. Ananth S Kodavasal                                                                 September 24, 2012

DRAFT OF AGREEMENT

THIS AGREEMENT made at Bangalore on the _____ Day of ____________ BETWEEN

XXXXX  Apartment Owners’ Association,  a Housing Society registered under the Registrar of Societies, Bangalore, and having its office at ___________  Hereinafter referred to as PROVIDER on the ONE PART

And YYYYYY, carrying on business of a social club at ____________ hereinafter referred to as “RECIPIENT” on the SECOND PART  

NOW, it is hereby Agreed by and between the parties hereto as follows in respect of  Excess Treated water from the STP of the Provider to be supplied to the Recipient, and the Terms and Conditions governing same :

PREAMBLE

1.     The Provider is a residential Apt. complex with an STP of installed capacity of 100 KLD

2.     The STP is functioning satisfactorily after a recent exercise in upgradation of physical facilities in the STP and operational practices.

3.     The treated water meets quality specifications of the KSPCB as per their “Urban Reuse Standards”.

4.     The Provider is already utilizing treated water for their own reuse purposes such as gardening and toilets flush

5.     After exhausting all reuse options, there remains an excess of treated water ranging from 40 to 50 KLD from the STP at the disposal of the PROVIDER

6.     The Recipient is a commercial Social club in the neighbourhood of the Provider, and has sufficient garden and lawn space and is need of good quality water for irrigation and upkeep of the green areas.

7.     In order to conserve fresh water, and to be an environmentally friendly and responsible corporate citizen, the Recipient is desirous of  procuring excess treated STP water from the Provider for garden and irrigation use

TERMS AND CONDITIONS

8.     The Agreement shall be for a period of one calendar year from date of signing of this Agreement

9.     The Agreement may be renewed at the end of the year for such further period by mutual consent, incorporating any amendments, if necessary

10.  The Provider agrees to provide excess STP treated water to the extent of 40-50 KLD meeting KSPCB stds. for Urban Reuse, on a best effort basis which is far superior to the quality of water required for irrigation use as prescribed under the Environment Protection Act and Rules made thereunder

11.  No liability direct, indirect or vicarious or of any other description will attach to the Provider consequent to the  Recipient transporting and  using treated water on his premises for whatsoever purpose(s) he deems fit

12.  The Recipient agrees to lift the excess treated water even in the event of temporary failure to meet Urban Reuse quality, as  long the water meets quality requirements specified for irrigation use in Schedule VI,  Rule 3A of the Environment Protection Rules.(1986)

13.  The Recipient shall be solely responsible for loading, transportation and unloading of the excess treated water from the premises of the Provider to and on his own premises.

14.  For loading of the excess treated water into tankers provided by the Recipient, the Provider shall maintain a pump with necessary piping of upto 20 m in length

15.  The Recipient undertakes to lift all excess treated water upto 50 KLD on a daily basis, and the Provider undertakes to deliver the said quantity, without let and without exception throughout the period of the Agreement

16.  The 50 KLD shall be delivered by the Provider not as a single consignment, but spread over 16 hours in the day as determined and dictated by hourly generation of excess treated water

17.  This Agreement is subject to Force Majeure conditions such as scarcity of fresh water at the Provider’s premises,  Acts of God,  Civil strife, Accidents in the STP or unforeseen breakdown of equipment(s) in the STP.

18.   The Recipient agrees to pay the Provider as consideration for above supply of treated water, a sum of Rs. ZZ  per Kiloliter of excess treated water lifted from the STP of the provider, the measure used  being the volumetric capacity of the tanker used by the Recipient for transportation

19.  A log book/ manifest shall be maintained at the STP of the Provider for the purpose of  recording the quantity of excess treated water thus lifted by the Recipient, which shall be signed by authorized representatives of both parties to this Agreement as necessary and sufficient proof of delivery of the recorded quantity of excess treated water

20.  Payment for the treated water thus lifted by the Recipient shall be paid to the Provider at the end of every month based on records maintained as above.  An invoice shall be raised by the Provider at the end of every month in the name of the Recipient, and payment shall be made within 7 days of raising of invoice

21.  The rate as specified above shall be fixed and valid for the entire period of the Agreement, subject to revision by mutual consent at the time of each renewal of Agreement

IN WITENESS WHEREOF, the Parties have appended their signatures on the Day, Month and Year mentioned above as token of  having accepted above Terms and Conditions.

For XXX Apt. Owners’ Assoc.                                                                         For YYYY

Authorised Signatory                                                                                         Authorised Signatory

Witness 1 :                                                                                                            Witness 1 :

Witness 2 :                                                                                                            Witness 2 :