Article about MBR, MBBR, SBR & SBBR

MBR, MBBR, SBR & SBBR

Activated Sludge Process:

The most common suspended growth process used for waste water treatment is the activated sludge process as shown in figure:

Activated sludge plant involves: Aeration tanking presence of microbes Solid-liquid separation followed by Aeration Discharge of clarified effluent Wasting of excess biomass, and Return of remaining biomass to the aeration tank. In activated sludge process waste water containing organic matter is aerated in an Aeration tank which micro-organisms degrade the soluble organic matter. Part of organic matter is synthesized into new cells and part is oxidized to CO2 and water to derive energy. In activated sludge systems the new cells formed in the reaction are removed from the liquid stream in the form of a flocculent sludge in settling tanks. A part of this settled biomass, described as activated sludge is returned to the aeration tank and the remaining forms waste or excess sludge sent to Sludge Drying beds.

 Conventional Activated Sludge Process Limitations:

•         MLSS values – 3500 ppm

•         Sludge carry over  in the treated water

•         Media filter efficiency max 100 Microns

•         Colloidal Particles – Poor SDI

•         Difficult to maintain consistent treated water quality

•         Odor  in the Treated effluent

•         Upset in system due to inlet variations

•         Large area and huge civil works required

•         Maximum 70 – 80 % of Bio degradation of BOD/COD.

To overcome the above limitations the following new technologies was innovated for better performance in waste water treatment. They are

Sequencing Batch Reactor (SBR)

Definition:

An SBR operates in a batch mode with aeration and sludge settlement both occurring in the same tank.

 All the process like Equalization, Aeration and Sedimentation will take place in a single tank. Sequencing batch reactors operate by a cycle of periods consisting of fill, react, settle, decant, and idle. The In-fluent will enter the tank through bottom distribution will contact with Microorganisms and Air was supplied for Micro organisms through  Aerator and the Process of Aeration will take place until complete bio degradation of BOD and the Air blower will stop automatically depend upon the BOD load of the Influent and the same tank will act as Settling tank. The clear liquid from the top of the tank will let out after completes settlement and the Extra Bio mass also was sent out through bottom line. During this clarifying period no liquids should enter or leave the tank to avoid turbulence in the supernatant.

The wasted sludge is pumped to an anaerobic digester or sludge drying bed  to reduce the volume of the sludge to be discarded. The frequency of sludge wasting ranges between once each cycle to once every two to three months depending upon system design.

The major differences between SBR and conventional continuous-flow, activated sludge system is that the SBR tank carries out the functions of equalization aeration and sedimentation in a time sequence rather than in the conventional space sequence of continuous-flow systems.

Advantages:

1.       SBR system can be designed with the ability to treat a wide range of influent volumes whereas the continuous system is based upon a fixed influent flow rate. Thus, there is a degree of flexibility associated with working in a time rather than in a space sequence.

2.      SBRs produce sludges with good settling properties providing the influent wastewater is admitted into the aeration in a controlled manner.

3.      Controls range from a simplified float and timer based system with a PLC to a PC based SCADA system with color graphics using either flow proportional aeration or dissolved oxygen controlled aeration to reduce aeration to reduce energy consumption and enhance the selective pressures for BOD, nutrient removal, and control of filaments

4.      . Working with automated control reduces the number of operator skill and attention requirement.

5.      Lesser Foot prints.

6.      . The duration, oxygen concentration, and mixing in these periods could be altered according to the needs of the particular treatment plant.

 Disadvantages:

1.      Appropriate aeration and decanting is essential for the correct operations of these plants.

2.      The aerator should make the oxygen readily available to the microorganisms.

3.      The decanter should avoid the intake of floating matter from the tank.

 Sequencing Batch Biofilm Reactors (SBBR)

To optimize the operation of traditional SBR’sand reduce the aeration phase with less HRT, a new technology has been developedwhich  is called as Sequencing Batch Biofilm Reactor (SBBR), a newly developed System in which intelligent controlling system (ICS) has been  adopted to control the SBBR. Stable performance was achieved in the SBBR at a hydraulic retention time (HRT) of 7 h, at which point the removal efficiencies ofNH3-N, TP and COD reached 99%, 100% and 96%, respectively. When compared with conventional SBR, theSBBR controlled by the ICS reduced the HRT and total aeration time by 56% and 50%, respectively, and achieved better performance in removing the COD. In addition, the optimal carbon nitrogen (COD/N) ratio for theSimultaneous removal of nitrogen and COD in the SBBR was found to be 12.5, and no accumulation of NO3—Nor NO2−-N was detected at this ratio, indicating that efficient simultaneous nitrification and denitrification. (SND) was occurring in the reactor. The SND efficiency reached 98%.

Recently, the sequencing batch biofilm reactor (SBBR) system has

attracted a great deal of attention due to its ability to take advantages of

both a biofilm reactor and a SBR.

Advantages:

1. SBBR systems show improved biomass concentration in reactors with corresponding higher

specific removal efficiencies, greater volumetric loads, increased process stability toward shock loadings and are capable of covering small areas.

2. SBBR systems canremove nitrogen and phosphorus simultaneously.

3.      Presence of an anoxic microzone in the biofilm could result in Simultaneous nitrification and denitrification in the SBBR during the aeration phase.

 4.       In such cases, nitrification occurs on the surface of the biofilm, whereas denitrification occurs in the inner layers due to a dissolved oxygen (DO) gradient within the biofilm.

 Disadvantages:

1.      Even though we will get good bio degradation of BOD, we will get some Suspended Solids which cannot able to remove by SBBR.

2.      Capital cost is high.

 MOVING BED BIO REACTOR (MBBR)

In the MBBR biofilm technology the biofilm grows protected within engineered plastic carriers, which are carefully designed with high internal surface area.   The bio reaction is carried out in controlled environment in this process. The MBBR biofilm technology is based on specially designed plastic biofilm carriers or biocarriers that are suspended and in continuous movement within a tank or reactor of specified volume.  The Bio reactors comprises of a tank, fitted with aeration grid. The bacterial activity needs dissolved oxygen, to synthesize the organic matter. This is supplied by passing air in the form of small bubbles. The air is passed at the bottom of tank, so that complete volume of tank is utilized. Oxygen dissolved in liquid which can now be used by the bacteria. The bacterial population is present on the media, which forms an integral part of the reactor system. The media is made of small plastic elements. Millions of such pieces are kept in the MBBR. The bacteria grow on the plastic media, by using the organic content in the raw sewage and the dissolved oxygen available. Due to constant aeration the media is set in whirling motion, so that continuous mixing takes place. The bacterial layer growth on the media surface increases to a certain extent, and then gets sloughed off after a specific period. This phenomenon is called sloughing. This creates new surface for further bacterial growth. Sloughing takes place only after complete growth and subsequent dyeing – off the bacterial layer.

Diffused aeration involves the introduction of Atmospheric air into the sewage through the submerged diffusers. Part of organic matter is synthesized into new cells and part is oxidized to carbon dioxide and water. The sloughed bio mass must be removed before the treated effluent is taken for downstream treatment. The Sloughed bio mass is drained to sludge drying beds.

 Advantages:

  

         1. It is efficient, compact and easy to operate.

         2. It can be an excellent solution, since it is a standalone process.

Disadvantages:

1.      Continuous monitoring is required.

2.      We may get some dead mass in clear supernatant which increase the filter load.

MEMBRANE BIO REACTOR (MBR)

Definition:

Activated Sludge Process (ASP), an Old technique in waste water treatment is combined with highly efficient membrane filtration to start a sophisticated technique called Membrane Bio Reactor (MBR). Membrane bioreactors (MBRs) combine the use of biological processes and membrane technology to treat wastewater.Within one process unit, a high standard of treatment is achieved, replacing the conventional arrangement of  settling tank and filtration that generally produces what is termed as a tertiary standard effluent. The advent of membranes makes the wastewater treatment easier nowadays. It is an efficient process for maintaining a long solids retention time (SRT) at a relatively short hydraulic retention time (HRT), which is needed for the treatment of waste water.The dependence on disinfection is also reduced, since the membranes with pore openings, generally in the 0.1-0.5µm, range trap a significant proportion of pathogenic organisms. The more common MBR configuration is to have the membrane immersed in the wastewater, although a side stream configuration is also possible, with the wastewater pumped through the membrane module and then returned to the bioreactor. Operating at Mixed liquor suspended solids (MLSS) concentration of up to 12,000 mg/L and a sludge age of 30-60 days

 MBR is favored to all other conventional techniques because the treated water is free from suspended solids and microorganisms, thus making it suitable for reuse. This unique application gives high degradation rates, extremely low sludge production and very compact design.

MBR

Advantages:                                                                                       

•          SUPERIOR TREATED WATER QUALITY

•          Safe rejection of Bio Mass

•          Enhanced Standard of Hygiene through barrier filtration

•          Consistent BOD levels of 3-7 ppm

•          Ultra filtered water free of pathogens.

•          SDI < 3 achieved consistently

•          PROCESS SUPERIORITY

•          Can  tolerate larger input variations

•          Aeration tank MLSS levels

•          8000 - 12000 ppm

•          Reduction in aeration tank size

•          Aeration  system can handle higher loads

•          Sludge can be wasted directly to sludge handling equipments.

•          Low SDI in treated water

•          Removes difficult pre treatment for downstream Recycle systems

•          Modular units facilitate easy plant expansion

•          Eliminates filters – No Back wash waste.

•          Disinfection only based on specific requirement

•          Smaller footprint.

Comparison between SBR, SBBR& MBBR and MBR

Parameters	SBR/SBBR/MBBR	MBR
BOD	30 ppm	3 - 7 ppm
TSS	< 25 ppm	< 1 ppm
SDI	> 6	< 3
Pathogens & Bacteria	Depends on Disinfection	Complete removal

	* Source of information is based on personal finding & Technical handbooks, no Propriety claim would be entertained.

No" is the New "Yes": Four Practices to Reprioritize Your Life

I was sitting with the CEO and senior team of a well-respected organization. One at a time, they told me they spend their long days either in back-to-back meetings, responding to email, or putting out fires. They also readily acknowledged this way of working wasn’t serving them well — personally or professionally.

It’s a conundrum they couldn’t seem to solve. It’s also a theme on which I hear variations every day. Think of it as a madness loop — a vicious cycle. We react to what’s in front of us, whether it truly matters or not. More than ever, we’re prisoners of the urgent.

Prioritizing requires reflection, reflection takes time, and many of the executives I meet are so busy racing just to keep up they don’t believe they have time to stop and think about much of anything.

Too often — and masochistically — they default to “yes.” Saying yes to requests feels safer, avoids conflict and takes less time than pausing to decide whether or not the request is truly important.

Truth be told, there’s also an adrenaline rush in saying yes. Many of us have become addicted, unwittingly, to the speed of our lives — the adrenalin high of constant busyness. We mistake activity for productivity, more for better, and we ask ourselves “What’s next?” far more often than we do “Why this?” But as Gandhi put it, “A ‘no’ uttered from the deepest conviction is better than a ‘yes’ merely uttered to please, or worse, to avoid trouble.”

Saying no, thoughtfully, may be the most undervalued capacity of our times. In a world of relentless demands and infinite options, it behooves us to prioritize the tasks that add the most value. That also means deciding what to do less of, or to stop doing altogether.

Making these choices requires that we regularly step back from the madding crowd. It’s only when we pause — when we say no to the next urgent demand or seductive source of instant gratification — that we give ourselves the space to reflect on, metabolize, assess, and make sense of what we’ve just experienced.

Taking time also allows us to collect ourselves, refuel and renew, and make conscious course corrections that ultimately save us time when we plunge back into the fray.

What follows are four simple practices that serve a better prioritized and more intentional life:

1. Schedule in your calendar anything that feels important but not urgent — to borrow Steven Covey’s phrase. If it feels urgent, you’re likely going to get it done. If it’s something you can put off, you likely will — especially if it’s challenging.

The key to success is building rituals — highly specific practices that you commit to doing at precise times, so that over time they become automatic, and no longer require much conscious intention or energy. One example is scheduling regular time in your calendar for brainstorming, or for more strategic and longer term thinking.

The most recent ritual I added to my life is getting entirely offline after dinner each evening, and on the weekends. I’m only two weeks into the practice, but I know it’s already created space in my mind to think and imagine.

2. As your final activity before leaving work in the evening, set aside sufficient time — at least 15 to 20 minutes — to take stock of what’s happened that day. and to decide the most important tasks you want to accomplish the next day.

Clarifying and defining your priorities — what the researcher Peter Gollwitzer calls “implementation intentions” — will help you to stay focused on your priorities in the face of all the distractions you’ll inevitably face the following day.

3. Do the most important thing on your list first when you get to work in the morning, for up to 90 minutes. If possible, keep your door closed, your email turned off and your phone on silent. The more singularly absorbed your focus, the more you’ll get accomplished, and the higher the quality of the work is likely to be. When you finish, take a break to renew and refuel.

Most of us have the highest level of energy and the fewest distractions in the morning. If you can’t begin the day that way, schedule the most important activity as early as possible. If you’re one of the rare people who feels more energy later in the day, designate that time instead to do your most important activity.

4. Take at least one scheduled break in the morning, one in the afternoon, and leave your desk for lunch. These are each important opportunities to renew yourself so that your energy doesn’t run down as the day wears on. They’re also opportunities to briefly take stock.

Here are two questions you may want to ask yourself during these breaks:

1. Did I get done what I intended to get done since my last break and if not, why not?

2. What do I want to accomplish between now and my next break, and what do I have to say “no” to, in order to make that possible?

By Tony Schwartz          

How to Accomplish More by Doing Less - Marketing Tacks

Two people of equal skill work in the same office. For the sake of comparison, let’s say both arrive at work at 9 am each day, and leave at 7 pm.

Bill works essentially without stopping, juggling tasks at his desk and running between meetings all day long. He even eats lunch at his desk. Sound familiar?

Nick, by contrast, works intensely for approximately 90 minutes at a stretch, and then takes a 15 minute break before resuming work. At 12:15, he goes out for lunch for 45 minutes, or works out in a nearby gym. At 3 pm, he closes his eyes at his desk and takes a rest. Sometimes it turns into a 15 or 20 minute nap. Finally, between 4:30 and 5, Nick takes a 15 minute walk outside.

Bill spends 10 hours on the job. He begins work at about 80 percent of his capacity, instinctively pacing himself rather than pushing all out, because he knows he’s got a long day ahead.

By 1 pm, Bill is feeling some fatigue. He’s dropped to 60 percent of his capacity and he’s inexorably losing steam. Between 4 and 7 pm, he’s averaging about 40 percent of his capacity.

It’s called the law of diminishing returns. Bill’s average over 10 hours is 60 percent of his capacity, which means he effectively delivers 6 hours of work.

Nick puts in the same 10 hours. He feels comfortable working at 90 percent of his capacity, because he knows he’s going to have a break before too long. He slows a little as the day wears on, but after a midday lunch or workout, and a midafternoon rest, he’s still at 70 percent during the last three hours of the day.

Nick takes off a total of two hours during his 10 at work, so he only puts in 8 hours. During that time, he’s working at an average of 80 percent of his capacity, so he’s delivering just under 6 ½ hours of work — a half hour more than Bill.

Because Nick is more focused and alert than Bill, he also makes fewer mistakes, and when he returns home at night, he has more energy left for his family.

It’s not just the number of hours we sit at a desk in that determines the value we generate. It’s the energy we bring to the hours we work. Human beings are designed to pulse rhythmically between spending and renewing energy. That’s how we operate at our best. Maintaining a steady reservoir of energy — physically, mentally, emotionally and even spiritually — requires refueling it intermittently.

Work the way Nick does, and you’ll get more done, in less time, at a higher level of quality, more sustainably.

Create a workplace that truly values a balanced relationship between intense work and real renewal, and you’ll not only get greater productivity from employees, but also higher engagement and job satisfaction.

There’s plenty of evidence that increased rest and renewal serve performance.

Consider a study conducted by NASA, in collaboration with the Federal Aviation Administration, of pilots on long haul flights. One group of pilots was given an opportunity to take 40 minute naps mid-flight, and ended up getting an average of 26 minutes of actual sleep. Their median reaction time improved by 16 percent following their naps.

Non-napping pilots, tested at a similar halfway point in the flight, experienced a 34 percent deterioration in reaction time. They also experienced 22 micro sleeps of 2-10 seconds during the last 30 minutes of the flight. The pilots who took naps experienced none.

Or consider the study that performance expert Anders Ericcson did of violinists at the Berlin Academy of Music. The best of the violinists practiced in sessions no longer than 90 minutes, and took a break in between each one. They almost never practiced more than 4 ½ hours over a day. What they instinctively understood was the law of diminishing returns.

The top violinists also got an average of more than 8 hours of sleep a night, and took a 20-30 minute nap every afternoon. Over a week, they slept 16 hours more than the average American does.

During my 30s and 40s, I wrote three books. I sat at my desk each day from 7 am to 7 pm, struggling to stay focused. Each book took me at least a year to write. For my most recent books, I wrote in a schedule that matched the great violinists — three 90 minute sessions with a renewal break in between each one.

I wrote both those books in six months — investing less than half the number of hours I had for each of my first three books. When I was working, I was truly working. When I was recharging — whether by getting something to eat, or meditating, or taking a run — I was truly refueling.

Stress isn’t the enemy in the workplace. Indeed, stress is the only means by which we can expand capacity. Just think about weightlifting. By stressing your muscles, and then recovering, you gradually build strength. Our real enemy is the absence of intermittent renewal.

by Tony Schwartz

The Magic of Doing One Thing at a Time

Why is it that between 25% and 50% of people report feeling overwhelmed or burned out at work?

It’s not just the number of hours we’re working, but also the fact that we spend too many continuous hours juggling too many things at the same time.

What we’ve lost, above all, are stopping points, finish lines and boundaries. Technology has blurred them beyond recognition. Wherever we go, our work follows us, on our digital devices, ever insistent and intrusive. It’s like an itch we can’t resist scratching, even though scratching invariably makes it worse.

Tell the truth: Do you answer email during conference calls (and sometimes even during calls with one other person)? Do you bring your laptop to meetings and then pretend you’re taking notes while you surf the net? Do you eat lunch at your desk? Do you make calls while you’re driving, and even send the occasional text, even though you know you shouldn’t?

The biggest cost — assuming you don’t crash — is to your productivity. In part, that’s a simple consequence of splitting your attention, so that you’re partially engaged in multiple activities but rarely fully engaged in any one. In part, it’s because when you switch away from a primary task to do something else, you’re increasing the time it takes to finish that task by an average of 25 per cent.

But most insidiously, it’s because if you’re always doing something, you’re relentlessly burning down your available reservoir of energy over the course of every day, so you have less available with every passing hour.

I know this from my own experience. I get two to three times as much writing accomplished when I focus without interruption for a designated period of time and then take a real break, away from my desk. The best way for an organization to fuel higher productivity and more innovative thinking is to strongly encourage finite periods of absorbed focus, as well as shorter periods of real renewal.

If you’re a manager, here are three policies worth promoting:

1. Maintain meeting discipline. Schedule meetings for 45 minutes, rather than an hour or longer, so participants can stay focused, take time afterward to reflect on what’s been discussed, and recover before the next obligation. Start all meetings at a precise time, end at a precise time, and insist that all digital devices be turned off throughout the meeting.

2. Stop demanding or expecting instant responsiveness at every moment of the day. It forces your people into reactive mode, fractures their attention, and makes it difficult for them to sustain attention on their priorities. Let them turn off their email at certain times. If it’s urgent, you can call them — but that won’t happen very often.

3. Encourage renewal. Create at least one time during the day when you encourage your people to stop working and take a break. Offer a midafternoon class in yoga, or meditation, organize a group walk or workout, or consider creating a renewal room where people can relax, or take a nap.

It’s also up to individuals to set their own boundaries. Consider these three behaviors for yourself:

1. Do the most important thing first in the morning, preferably without interruption, for 60 to 90 minutes, with a clear start and stop time. If possible, work in a private space during this period, or with sound-reducing earphones. Finally, resist every impulse to distraction, knowing that you have a designated stopping point. The more absorbed you can get, the more productive you’ll be. When you’re done, take at least a few minutes to renew.

2. Establish regular, scheduled times to think more long term, creatively, or strategically. If you don’t, you’ll constantly succumb to the tyranny of the urgent. Also, find a different environment in which to do this activity — preferably one that’s relaxed and conducive to open-ended thinking.

3. Take real and regular vacations. Real means that when you’re off, you’re truly disconnecting from work. Regular means several times a year if possible, even if some are only two or three days added to a weekend. The research strongly suggests that you’ll be far healthier if you take all of your vacation time, and more productive overall.

A single principle lies at the heart of all these suggestions. When you’re engaged at work, fully engage, for defined periods of time. When you’re renewing, truly renew. Make waves. Stop living your life in the gray zone.

by Tony Schwartz