How BactaServe FOG SR Bar Transformed Hotel Wastewater Treatment Efficiency?

Every time a kitchen drain clears out used oil, butter, or cooking grease, it directs non-visible trouble down the drain. Fats, oils, and grease (FOG) in wastewater seem to be a minor issue, but they are indeed the most obstinate and hazardous pollutants for hotel wastewater systems to deal with.

To understand the impact, we must begin with basics:

• What are fats and oils? / fats and oils definition Fats are triglyceride compounds typically solid at ambient temperature (e.g. butter, lard), while oils are similar triglycerides that remain liquid (e.g. vegetable oil, sunflower oil).

• Difference between fats and oils The primary difference lies in their saturation and physical state: saturated fats tend to be solid, unsaturated fats tend to be liquid. But in wastewater, both act similarly as long-chain hydrocarbons.

• Examples of fats and oils Butter, ghee, animal fats, coconut oil, sunflower oil, palm oil, and cooking oils are all common.

  
  

When the above-mentioned substances are disposed of through the drainage systems, they are together called fat oil, grease, or FOG. The large-scale usage of oils, the frequent frying of food, and the poor separation of fats and oils in hotel kitchens not only result in huge amounts of FOG but also lead to its direct entry into the drainage and wastewater treatment system.

FOG is quite annoyingly tricky: it emulsifies, solidifies, rises, chokes pipes, hampers pumps, and makes the efficiency of microbial treatments lower. Moreover, up to 40% of the sewer blockages in some cities are caused by the accumulation of FOG.

For a hotel, untreated FOG means:

• Recurring blockage of grease traps

• Building of scum layer in primary clarifiers

• Odour, unclean surfaces, and chemical attack

• Increased expenditure on maintenance and operation

• Possibility of violating discharge standards

  
  

BactaServe FOG SR Bar case study comes into play here. However, first, let's check out the wider picture regarding hotel wastewater and FOG removal.

Why FOG is a Critical Challenge for Hotels?

1. Elevated FOG loads in kitchen wastewater

A full-service hotel, as per the usual case, will have its kitchen, banquet halls, and laundry producing a large amount of wastewater that contains fats and oils. Some research has indicated that the level of FOG in the wastewater streams can be as high as 2000 mg/L, which is about 30% of the total organic load in the water. 

Many STPs (sewage treatment plants) which mainly handle BOD, COD, and suspended solids, are unable to manage sudden FOG influxes without being stressed. This could result in:

• Scum layers forming on the surface that impede air–liquid contact

• Microbial biomass being trapped

• The rate of degradation being slowed down

• Desludging being done frequently

  
  

2. Traditional controls are insufficient

In most cases, hotel systems will have grease traps or grease interceptors installed at the kitchen drains to capture the FOG before it flows into the main wastewater stream. The lighter FOG is separated from the water by gravity in these interceptors.

However, these methods also have drawbacks:

• They depend a lot on cleaning done once a week to once a month.

• Emulsified or very small droplets get through.

• When the system is overloaded, grease gets “pushing” and comes to the next unit.

• Manual cleaning requires a lot of labor and is unhygienic.

  
  

At the treatment plant, flotation, skimming, dissolved air flotation (DAF), and coalescers are frequently employed to remove any remaining FOG. But for a lot of mid-size hotel STPs, such units might really be unaffordable or hard to fit in physically.

3. Financial and regulatory risks

Uncontrolled FOG leads to:

• Frequent blockages in pump stations

• Equipment wear, corrosion, and repair costs

• Emergency interventions and downtime

• Fines for non-compliance with effluent FOG limits

  
  

The NEWEA FOG white paper warns:

“Allowing FOG to enter sanitary wastewater systems can lead to accelerated corrosion, premature equipment failure, and costs many times higher under emergency conditions.”

Given this backdrop, hotel operators need solutions that go beyond mechanical separation - solutions that biologically degrade FOG in situ, continuously and reliably. That is where BactaServe FOG SR Bar enters the picture.

Let’s go through one case study for more clarity.

Case Study: Hotel’s Struggle with FOG Overload

Amalgam Engineering has presented a case study where a hotel confronted the following issues repeatedly:

• Continuous presence of oil and grease in the wastewater 

• Scum buildup in the primary clarifier 

• Complaints about odors 

• Decrease in the capacity of the STP (in the biological section) 

• Desludging and cleaning by manual intervention 

The customer had a regular STP designed with old-fashioned pre-treatment (screening, grit extraction) and a grease trap, but the FOG load was more than these measures could handle. Consequently, the treatment of wastewater to remove oil and grease was ineffective and the biological performance of the plant was affected negatively.

When the hotel's effluent was tested pre-intervention:

• BOD: ~ 250 mg/L

• COD: ~ 800 mg/L

• Oil & Grease (O&G): ~ 243 mg/L

  
  

These numbers risk noncompliance in many jurisdictions. The STP was stressed, operating costs were high, and maintenance demands were rising.

This was the stage at which BactaServe FOG SR Bar was introduced to the system.

The Solution: BactaServe FOG SR Bar 

Classification of fats and oils in context

In wastewater parlance, FOG includes:

• Free FOG (coalesced droplets)

• Emulsified FOG (stuck in colloidal form)

• Associated FOG (adsorbed on solids)

  
  

To comprehensively remove them, a solution must break emulsions, degrade fatty acids, and convert grease into biodegradable intermediates.

How does the FOG SR Bar work?

• Slow-release solid bar containing specialized lipase-producing microbes

• As the bar dissolves gradually, it releases a controlled dose of enzymes and bacteria into the grease trap, pump sump, or holding tank

• These microbes target triglycerides (fats/oils), splitting them into glycerol and fatty acids, which are further mineralized

• Continuous dosing ensures no “dead zone” or FOG accumulation

  
  

In short: it’s like handing your wastewater a grease-digesting medicine over weeks—all without daily dosing.

Advantages over chemical or one-shot enzyme solutions

Feature	BactaServe FOG SR Bar	Chemical / Enzyme Injection
Long-duration dosing	Yes (bar dissolves slowly)	Requires frequent dosing
Safety	Non-toxic, biodegradable	May require pH control or residual chemicals
Maintenance	Low — drop-and-forget	High — frequent monitoring/dosing
Avoid downstream saponification	Better control over kinetics	Risk of soap or scum formation
Compatibility	Works in grease traps, drain lines, sump tanks	Usually just limited to tanks/doses

This combination of sustained release + biological activity is what made the solution viable for a hotel STP with variable flows and heavy FOG loads.

Results: Before & After 

After deploying the FOG SR Bar system (in conjunction with standard STP operations), the hotel saw dramatic improvements:

• BOD dropped from ~ 250 mg/L to ~ 30 mg/L

• COD dropped from ~ 800 mg/L to ~ 150 mg/L

• Oil & Grease dropped from ~ 243 mg/L to < 21 mg/L

  
  

These are not just numbers — they reflect over 90% reduction in O&G load, and major relief for the biological system. The scum layer in the clarifier vanished, odours subsided, and the STP handled peak loads without stress.

Such performance is consistent with modern FOG removal theory: properly engineered systems can remove > 98 % of FOG when combining separation + biological breakdown.

Why It Worked: Key Drivers of Success

1. Continuous dosing

Due to the slow dissolution of the bar, there is an uninterrupted FOG-degrading activity even at off-peak times.

2. Balanced microbial community

The bar does not hinder the system by introducing a large number of foreign microbes, but rather it provides the support for the very gradual and stable growth of the grease-degrading strains.

3. Avoidance of scum rebound

The dosing is timed in such a way that it not only minimizes saponification (soap formation) but also prevents FOG from reprecipitating downstream.

4. Integration with existing infrastructure

The bar was placed in the grease trap, pumping sump, and selected drains, without requiring major modifications.

5. Low operational attention

The system essentially needed no supervision, thus allowing the engineering personnel to concentrate on the more pressing tasks.

Conclusion: From Hidden Nemesis to Managed Resource

In the opinion of hotel facility managers, FOG is frequently perceived as the “silent saboteur” of wastewater systems. Although it is not conspicuous, it slowly depletes the efficiency of the system, increases costs, and endangers compliance. Nonetheless, as illustrated by this case study, the implementation of a microbial solution such as BactaServe FOG SR Bar not only prevents but also turns the problem into a manageable process.

The hotel was able to enjoy a huge reduction in O&G, BOD, and COD, thanks to the combined biological and physical separation approach in the bar-based dosing method, without the need for extensive infrastructure upgrades or heavy chemical usage. Consequently, a better-working STP, lower maintenance cost, odor control and great effluent quality.

Frequently Asked Questions

What are fats and oils in wastewater?

They are organic compounds (triglycerides, fatty acids) derived from cooking, food waste, and lipids. In wastewater, they cluster as free droplets or emulsions, collectively called FOG.

How does FOG affect hotel STPs?

FOG creates scum layers, inhibits oxygen transfer, clogs pumps, increases maintenance, and can lead to noncompliance or system failure.

What is a good grease remover for kitchen wastewater?

Options include enzyme-based cleaners, surfactant degreasers, or biological dosing (like FOG SR Bars). Biological options are safest and sustainable over time.

How is BactaServe FOG SR Bar different from chemical solutions?

It offers slow-release bioaugmentation, minimal chemical residue, low manual intervention, and consistency. Chemical solvers often require frequent dosing and carry risk of side reactions.

How often should FOG SR Bars be replaced?

It depends on your wastewater flow and grease loading—but typically every 3–8 weeks or as guided by the dosing vendor.

Can the bar handle emulsified grease and fine droplets?

Yes—because the microbes and enzymes released help break emulsions and hydrolyze fine FOG into biodegradable constituents.

Will this work in colder climates or winter?

Microbial activity slows at low temperature, but dosing plus occasional warm flush cycles usually maintain efficacy.