industrial holidays Anaerobic Wastewater Treatment in Industries
The effect of industrial holidays on ETP health

The ecosystem of industries is complex as well as consistent. However, shutdowns due to festivals, season, operational failure, or force give a halt to the whole system. Although mostly planned, these industrial holidays are intended to give relief, but deep down in the concrete basins of effluent treatment plants brews a storm of crisis, whether it may be in the primary, secondary, or tertiary systems.

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And if we focus on the secondary system, the microbial population gets the worst hit. This blog focuses on what happens inside the secondary system during an industrial holidays, its effects, precautions, and prevention.

The living Microbial world of ETP:

The secondary system is like a society where microbial populations i.e, bacteria, fungi, yeast, metazoans etc. thrive on:

Food: Readily biodegradable organic matter.

Shelter: Biofilms, flocs, or suspended habitats.

Environmental Comfort: pH, temperature, DO, and nutrients in a narrow optimal range.

Maintaining microbial diversity and stability is crucial for consistent ETP performance.

Microbial Starvation- A Hidden Shutdown Crisis

A 10-15 day shutdown without influent feed creates what we call a starvation phase in the bioreactor. The period can trigger several microbial stress responses:

Autolysis Begins:
  • Without food, heterotrophic bacteria begin digesting their own cellular reserves.
  • When reserves run out, cell walls rupture, releasing intracellular enzymes and ammonia into the mixed liquor.
Shift in Community Structure:
  • Fast-growing, high-COD degraders die off first.
  • Resilient microbes like filamentous bacteria and nitrifiers may survive longer, but their metabolic activity drops drastically.
Dissolved Oxygen (DO) Becomes Redundant:


  • With no substrate to oxidize, aeration continues but becomes wasteful.
  • High DO levels can paradoxically stress certain facultative anaerobes used to fluctuating oxygen levels.


MLSS/MLVSS Decline:
  • The Mixed Liquor Volatile Suspended Solids (MLVSS)- the biologically active portion of MLSS drops due to decay.
  • Settling characteristics deteriorate, and the SVI (Sludge Volume Index) can spike due to deflocculation.
Recovery is Not Instant – The Myth of “Rest and Run”

When production resumes, many assume the ETP will bounce back like a machine switched on. But biological wastewater treatment systems have no reset button.

Lag Phase in COD Reduction
  • Microbial populations take time to rebuild numbers and enzyme systems.
  • Expect 2-5 days of poor performance and higher COD/BOD in the outlet, especially in systems with no pre-seeding plan.
Sludge Age Misbalance
  • Sludge that has aged during the shutdown may have lost its settling efficiency.
  • Decayed sludge may also release toxins and nutrients, creating internal loading.
Shock Loads on Restart
  • Sudden reintroduction of full-strength effluent can lead to shock loading.
  • This exacerbates foaming, odor, and even system upset.
Preventive Measures

ETP health during shutdowns doesn’t have to be a gamble. Here are proven strategies, drawn from both research and field practices.

1.Feed Synthetic System:
  • Use glucose, molasses, milk whey, or diluted Urea/COD substitutes to mimic organic load at low levels (10-20% of actual COD).
  • Feed once or twice daily to maintain microbial respiration and floc integrity.\
2.Aerate intermittently:
  • Continuous aeration is wasteful. Instead, apply 4-6 hours/day intermittent aeration to maintain DO and prevent anoxic.
3.Monitor pH and ORP
  • During starvation, microbial metabolism can skew pH or ORP. Keep these in range to avoid unfavorable drift.
4.Bioaugmentation on Restart
  • Introduce high-count commercial biocultures tailored to your effluent type. This accelerates recovery.
  • Use starter cultures or preserved sludge from pre-holiday if available.
5.Sludge Management 
  • Remove aged or decaying sludge before shutdown. 
  • During long holidays, periodic recirculation or RAS/WAS adjustments prevent septic conditions.
Conclusion:

Industrial holidays are an unavoidable part of operations across industries such as textiles, pharmaceuticals, and chemicals and can’t be avoided but the problems related to it in an ETP can surely be avoided by taking the right steps, proper planning, and taking proactive measures.Investing in bioaugmentation, sludge handling, and strategic aeration ensures microbial resilience during shutdowns.

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📩 Reach out now to enhance your wastewater treatment efficiency.

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Phosphate removal in a chemical manufacturing plant in Madhya Pradesh
Background

A prominent chemical manufacturing unit situated in MP near Ratlam is our existing client to whom we provided technology to treat high COD and TDS effluent. They again approached us due to their experience working with us. They wanted to treat an effluent stream with high phosphate content upto 1500-2000 ppm. They asked us to use their old ETP, revive it , commission and make it efficient for phosphate treatment.

👉 Looking to optimize your ETP for phosphate treatment, COD, or BOD removal? Contact us to explore the right biological phosphorus and removal technologies for your industry!

1st Phase: Scrutiny

Our team of experts visited the factory to introspect and identify scope of improvements.

OLD ETP details:

The ETP had primary treatment, biological treatment (Anaerobic), and then a tertiary treatment.

Flow (current)350 KLD
Type of processUASB
No. of UASBR1
Capacity of biological tank950 KL
Parameters of the stream with Phosphate:

Parameters Avg. Inlet parameters(PPM)
COD4300
Phosphate Content1500-1800
TDS3000
2nd Phase : The Blueprint

After scrutiny and brainstorming with our R&D, we concluded to transform the old ETP apparatus into an EBPR unit, i.e., Enhanced Biological Phosphorus removal unit, which involves the introduction of PAOs (polyphosphate-accumulating bacteria) into the biological system along with physico-chemical treatment in primary and tertiary systems, respectively, of the old ETP.

ETP process optimization:

An efficient EBPR unit requires anaerobic as well as aerobic system, as in anaerobic the RbCODs get transferred into VFAs, which are then absorbed by PAOs for efficient phosphate uptake, which is dispersed during the anaerobic process. The PAOs then absorb the phosphate rapidly in the aerobic system. Hence, biomass with phosphate-absorbed PAOs is allowed to settle in the clarifier, and then WAS is removed.

In this scenario, the ETP had a UASB system, but no Aeration system, hence:

  1. We utilized a spare tank of capacity 300 KL located next to USABR, and transformed it into an aeration tank by installing diffusers.
  2. After our recommendation, the industry installed a 50 KL FRP clarifier after the sedimentation system.

Thus, we converted the old ETP into a facultative EBPR unit with integrated biological phosphorus removal capability.

3rd Phase : Technology and Execution

1. Selecting biocultures:

For UASB:

T1B Anaerobio: 

T1B Anaerobio bioculture solutions for phosphate treatment

The perfect solution for an Anaerobic system consists of robust bacteria that can efficiently work in anaerobic conditions, leveraging efficiency in terms of:

  • COD reduction
  • Biomass Generation
  • Methane Generation
  • F/M ratio optimization

Here, since our goal was phosphate treatment and reduction, we amalgamated PAOs as well, which made the product extremely effective to be used in the developed EBPR system.

For Aerobic Tank:

T1B Aerobio:

T1B aerobio bioculture solutions for phosphate treatment

Equipped with highly robust and selective strains of bacteria which when combined with PAOs, made T1B Aerobio the best-suited weapons to remove phosphate levels, thereby increasing the efficiency of the EBPR unit.

2.Dosing:

Initially, we provided a dosing schedule for 60 days, in which 1st 30 days was loading dose, with a higher product quantity, and the second  30 days dose was maintenance dose, which was 1/4th of the loading dose.

ProductT1B AnaerobioT1B Aerobio
Loading Dose100 kgs60 kgs
Maintenance dose40 kgs20 kgs
Point of additionUASBAerobic Tank
3.Process optimization:

Our target was to achieve MLSS of 3500-4000 in the first 15 days. After that, the WAS was wasted at 15 KLD, and RAS was recirculated at 5 KLD.

Results:

After 60 days of implementation:

Parameters Primary OutletUASB OutletClarifier Outlet
COD39001900800
Phosphate1300-1500850-900180
COD Reduction10 %~ 55 %82 %
Phosphate reduction %8-10%~ 65 %~85-90%
Conclusion

With the combined effect of T1B Anaerobio and T1B Aerobio bioculture and process optimization, the client achieved an 85-90 % reduction through the biological system, which further increased after tertiary system. This translated into:

  • Improved microbial activity and settleability.
  • Stable effluent quality, meeting compliance standards.
  • Biocultures are effective in phosphate removal.

This case demonstrates how biology-driven solutions, coupled with system know-how, can deliver tangible performance and cost benefits in industrial wastewater treatment.

👉 Want similar results at your facility? Let’s talk! Contact us now to implement sustainable, biology-based solutions.

📧 Email: sales@teamonebiotech.com

🌐 Visit: www.teamonebiotech.com

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