Industrial Wastewater Treatment for Petroleum Refineries: High Sulfide Removal Using Biocultures
A reputed petroleum refinery approached us due to high concentration of sulfides in their effluents. They tried multiple solutions, including electroplating, RO, etc., but they were very cost-intensive. Also, they received multiple notices from the pollution control board and were paying heavy fines.
In such industries wastewater treatment methods like RO and chemical dosing prove unsustainable so we offered them biological wastewater treatment as an eco-friendly alternative.
To upgrade your facility’s efficiency with proven biological wastewater treatment methods, microbial solutions, and expert consultation, Contact Us.
ETP Details:
| Parameter | Value |
| Flow (current) | 450 KLD |
| Flow (design) | 450 KLD |
| Type of process | Facultative |
| Capacity of UASB | 1250 KL |
| Capacity of AT | 450 KL |
| Retention Time | 90.66 hours (combined) |
Challenges:
| Parameters (PPM) | Avg. Inlet | Avg. Outlet |
| COD | 5500–9010 | 2200–4600 |
| BOD | 2500–5800 | 1300–3000 |
| Sulfides | 2000 | 2000 |
| PAH | 1250 | 680 |
Operational Challenges:
- The primary treatment was working at 10% efficiency in terms of COD reduction
- The biological treatment worked at an average of 50% efficiency in terms of COD reduction
They were struggling to control the higher Sulfide levels, and it was inducing shock loads as explained earlier. In this case, the Inadequate aeration in water treatment, systems contributed to sulfide accumulation, highlighting the need for advanced ETP water treatment process design and management.
Tackling Sulfides in ETPs:
To tackle sulfides in ETP, the presence of SOBs or sulfide-oxidising bacteria is a must. The SOBs oxidize sulfides into sulfates. To prevent sulfate accumulation, SRBs or sulfur-reducing bacteria are required; however, SRBs are only effective in anaerobic systems.
Issues with Process:
The main issue with the process was that there was no provision of a separate aeration tank before UASB, where sulfides need to be oxidized into sulfates. This gap in the industrial wastewater treatment design reduced system effectiveness and highlighted the importance of using effective biocultures for wastewater treatment.
The Approach:
The industry partnered with us to commission their UASB and aeration tank with increased capacity and restart the plant at its full capacity in terms of hydraulic load.
We adopted a 3D approach:
- Research/Scrutiny:
- Our team visited their facility to go through the process of the new ETP and to scrutinize the value-addition factors.
- Analysis:
- We analyzed the 3-month cumulative data of their ETP to see trends in the inlet-outlet parameters’ variations and the permutation combinations related to it.
- Innovation:
- After the research and analysis, our team curated customized products and their dosing schedules with formulation keeping in mind the plan of action to get the desired results.
This process is called bioaugmentation.
Our tailor-made microbial blends reflect Team One Biotech’s leadership among top biotech companies in India, offering scalable solutions based on site-specific microbial demand.
Desired Outcomes:
- Reduction in Sulfide levels in the final outlet
- Development of strong biology to withstand shock loads and prevent upsets
- Making ETP more efficient regarding COD/BOD and PAH degradation
- Reduction in FOG
- Improved microbial culture for wastewater treatment effectiveness under both aerobic and anaerobic conditions
Execution:
Products Used:
- T1B Aerobio: Our aerobic bioculture for wastewater treatment consists of blends of several strains SOBs and facultative microorganisms, usually bacteria, along with key trace elements on a complex inert media.

- T1B Anaerobio: Our anaerobic bioculture blend consists of SRBs and other anaerobic microbes that effectively reduce sulfates into H2S and enhance COD/BOD control.

Plan of Action:
- A tank of 300 KL before UASB was converted into an aerobic tank, and T1B Aerobio with SOBs was dosed for sulfide oxidation.
- T1B Anaerobio was dosed in UASB for sulfate and COD reduction.
- The addition of T1B Aerobio was also done in the aeration tank after UASB every day.
This strategic integration of wastewater treatment methods significantly boosted operational stability and treatment consistency.
Results:
| Parameters (PPM) | Avg. Inlet | Avg. Outlet (Secondary Clarifier) |
| COD | 5500–9010 | 900–1300 |
| BOD | 2500–5800 | 350–750 |
| Sulfides | 2000 | 180 |
| PAH | 1250 | 220 |
Before & After Bioaugmentation:

Performance Highlights:
- The COD/BOD degrading efficiency increased from 50% to 83%
- Sulfide reduction was achieved up to 91%
- PAH was also getting degraded up to 82.4%
- MLSS: MLVSS ratio was optimized
- Biomass in the ASP system displayed great stability even during shock load situations
- Methane gas production increased by 12%
These results demonstrate the superior impact of our biological treatment approach when combined with engineered aeration in water treatment design.
To upgrade your facility’s efficiency with proven wastewater treatment methods, microbial solutions, and expert consultation, Contact Us.
Email: sales@teamonebiotech.com
Visit: www.teamonebiotech.com
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