Zero Liquid Discharge (ZLD): Can Bioremediation Make It Cost-Effective?

The global water crisis continues to intensify, driven by pollution and scarcity. This issue not only threatens current industries but also poses long-term environmental risks. To address these challenges, modern wastewater treatment innovations have introduced Zero Liquid Discharge (ZLD) — a comprehensive system that enables industries to recover, reuse, and recycle water with minimal environmental impact.Upgrade your wastewater management with Team One Biotech — delivering advanced biological treatment solutions that make sustainability and cost-efficiency work together contact us now.

What is Zero Liquid Discharge (ZLD)?

Zero Liquid Discharge is an effluent treatment process designed to ensure that no wastewater is released into the environment. It enables complete water recovery while isolating solid residues such as sludge and salts for disposal.

Industries such as textiles, power plants, chemicals, and pharmaceuticals frequently deal with high TDS, high COD and BOD, and ammonical nitrogen reduction challenges. In such cases, ZLD in wastewater treatment ensures efficient resource utilization while maintaining environmental compliance. The ultimate goal is zero discharge and maximum water reuse.Wastewater treatment is an essential step toward achieving Zero Liquid Discharge, ensuring that every drop of effluent is treated, recycled, and reused to minimize environmental impact.

Illustration of the process:

The Cost Factor in ZLD Implementation

While Zero Liquid Discharge systems are highly effective, they also involve significant CAPEX and OPEX. Implementation can increase wastewater treatment costs by up to 300% when dependent solely on physical and chemical processes. Incorporating biological or anaerobic treatment stages can substantially reduce these expenses and improve long-term sustainability.

How Does a ZLD System Work?

A standard ZLD process integrates physical, chemical, and biological stages to achieve complete recovery. The primary stages include:

1. Pre-Treatment

This step removes suspended solids, oils, and greases through chemical dosing, pH correction, and equalization. It ensures that the influent entering the next stages is stable and easier to process.

2. Biological Treatment

This involves microbial degradation of organic matter to lower COD and BOD levels. Commonly applied in textile, pharma, and tannery industries, it helps minimize scaling, fouling, and odour issues.

3. Reverse Osmosis (RO) / Membrane Bioreactor (MBR)

These systems separate clean water from dissolved salts and pollutants. The permeate is reused within the plant, while the reject moves to the evaporation stage for further concentration and recovery.

4. Evaporation (Multi-Effect Evaporator – MEE)

RO rejects are treated in Multi-Effect Evaporators (MEE) or Mechanical Vapour Recompression (MVR) units. These thermal processes recover clean water through vapor condensation while concentrating the remaining brine.

5. Crystallization

The final step converts concentrated brine into solid form for safe disposal or possible recovery, ensuring complete zero liquid discharge.

Challenges in Sustaining ZLD Operations

Despite its benefits, maintaining Zero Liquid Discharge operations is often difficult due to technical and operational constraints.

High Energy Consumption

Evaporators and crystallizers require large amounts of steam or electricity, accounting for 40–60% of total ZLD OPEX. High COD, TDS, and ammonical nitrogen loads further increase energy consumption.

Scaling and Fouling

Inadequate pre-treatment or high phenol content can lead to scaling and fouling in RO membranes. This reduces permeate recovery, increases cleaning frequency, and shortens membrane life.

Frequent Shutdowns

Industries handling variable effluents—such as textile, dye, and pharmaceutical units—face fluctuations in high COD and BOD loads. This can trigger growth of filamentous bacteria, excess sludge formation, and frequent system shutdowns, increasing operational costs.

Role of Bioremediation in Cost Reduction

Bioremediation offers a sustainable solution for optimizing effluent treatment in ZLD systems. By utilizing specialized microbial strains bioculture, it enhances organic degradation, minimizes sludge generation, and stabilizes biological processes.

Key benefits include:

1. COD and BOD Reduction

Microbes effectively degrade organic compounds, reducing COD/BOD by up to 90%. This lowers aeration energy and chemical usage, while preventing membrane fouling.

2. Sludge Reduction

Bioremediation converts organic waste into carbon dioxide and water, resulting in minimal sludge accumulation and preventing MEE tube blockage. This reduces power and maintenance requirements.

3. Reduced Evaporator Load

Improved settling and clear supernatant reduce the volume sent to evaporators, cutting down energy demand and improving overall ZLD efficiency.

4. Enhanced Operational Stability

By controlling filamentous bacteria and supporting anaerobic treatment, bioremediation strengthens system resilience, stabilizing operations during variable or shock loads.

Compliance and Environmental Benefits

Implementing bioremediation aligns with NGT, CPCB, and PCB guidelines for zero discharge systems. It ensures reduced reliance on chemicals, improved odour control, and better compliance with national environmental regulations. The approach contributes to sustainable development goals by promoting biological wastewater treatment over purely mechanical systems.

Conclusion: Achieving Cost-Effective Zero Liquid Discharge

Zero Liquid Discharge remains critical for sustainable industrial wastewater management, but its high operational costs require strategic optimization. Incorporating bioremediation enhances biological pre-treatment, reduces sludge generation, and improves overall efficiency, making ZLD more affordable and environmentally responsible.

When properly managed, pretreated effluent acts like a well-balanced system—easier to process, more energy-efficient, and more reliable. Integrating bioremediation ensures long-term operational stability and significant cost savings for industries implementing ZLD in wastewater treatment.Achieve compliance, efficiency, and sustainability in every drop. Get in touch with Team One Biotech for expert-driven ZLD solutions.

To achieve sustainable Zero Liquid Discharge with reduced operational costs, contact Team One Biotech for tailored biological solutions. 

As one of the leading biotech companies in India and trusted bioremediation companies in India, Team One Biotech continues to deliver solutions that redefine sustainability across wastewater treatment, agriculture, aquaculture, and hygiene management.

Email: sales@teamonebiotech.com

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Sulphide removal in refinery wastewater
Sulfide Removal in Petroleum Refinery Wastewater | Case Study

Introduction: 

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 petroleum refineries, Effluent Treatment Plants (ETPs) are critical for managing complex wastewater containing sulfides, phenols, and hydrocarbons. Our advanced bioculture-based solutions ensure consistent COD and BOD reduction, even under fluctuating hydraulic and organic loads. Reach out to us today to experience how our bioculture-driven solutions can turn wastewater challenges into success stories.

ETP details:

The industry had primary treatment, biological treatment, and then a tertiary treatment.

Previous Capacity

Flow (current) 4500 KLD
Flow (design) 4500 KLD
Type of process Facultative
Capacity of UASB 12500 KL
Capacity of AT 7500 KL
Retention Time 106.66 hours(combined)

Challenges: 

Parameters (PPM) Avg. Inlet parameters  Avg. Outlet parameters 
COD 5500-9010 2200-4600
BOD 2500-5800 1300-3000
Ammoniacal Nitrogen 200 120-150
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 AN levels, and it was inducing shock loads as explained earlier. 

Issues with Process:

The main issue with the process was that there was no significant reduction in AN at the outlet despite having a UASB and an Aeration tank

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 that included :

  • 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.

Desired Outcomes :

  1. Reduction in AN levels in the final outlet
  2. Development of strong biology to withstand shock loads and prevent upsets.
  3. Making ETP more efficient regarding COD/BOD  and PAH degradation.
  4. Reduction in FOG.

Execution:

Our team selected  the product :

For the Aeration Tank

  1. T1B Aerobio: Our aerobic Bioculture blend consists of blends of several strains of Nitrifying and Denitrifying bacteria and facultative microorganisms, usually bacteria, along with key trace elements on a complex inert media. t1b-aerobio

For the UASB tank

  • T1B Anaerobio:  Our Anaerobic Bioculture blend consists anaerobic microbes that will effectively reduce AN as well as enhance COD/BOD control. t1b-anaerobio

Our plan of action included:

  1. T1B Anaerobio was dosed in UASB for sulphate and COD reduction.
  2. The addition of T1B Aerobio was also done Aeration Tank after UASB every day 

Results:

Parameters

Parameters (PPM) Avg. Inlet parameters  Avg. Outlet parameters (secondary clarifier outlet)
COD 5500-9010 900-1300
BOD 2500-5800 350-750
AN 200 20-25 (After Aeration Tank)
PAH 1250 220

The implementation of the bioaugmentation program resulted in significant improvements in the performance of biological units in their WWTP:

  • The COD/BOD degrading efficiency increased from 50% to 83 % in the biological system.
  • AN reduction was achieved up to 90 %
  • 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%.

The application of Anaerobic Treatment through UASB reactors combined with Aeration tanks enabled effective Ammoniacal Nitrogen control and reduced PAH levels significantly. This approach minimized the risks of shock loads and enhanced the stability of biological systems.

With a focus on Industrial wastewater treatment, we targeted Sludge reduction and improved MLSS:MLVSS ratios to enhance operational efficiency. Our strategies also mitigated Odour issues and prevented the proliferation of filamentous bacteria, ensuring long-term system reliability.

By aligning with CPCB, PCB, and NGT compliance norms, the refinery avoided penalties while achieving sustainable wastewater management. The integration of bioaugmentation technology, nutrient balancing, and biogas recovery further optimized the performance of the effluent treatment process.

This case study demonstrates how refinery clients can achieve reliable wastewater treatment solutions while reducing OPEX, improving sulphide reduction, and ensuring a future-ready industrial effluent treatment system.

As one of the leading biotech companies in India, we provide a sustainable product range across multiple verticals, including probiotics for aquaculture, biofertilizers and plant growth promoters, eco-friendly cleaning solutions, animal probiotics, and on-site consultation for biocultures for ETP and STP.

Email:  sales@teamonebiotech.com

Visit: www.teamonebiotech.com

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