1. A method of wastewater treatment containing mixed organic contaminants using acclimatized anaerobic microbial consortium, the method comprising of: (a) providing an anaerobic microbial consortium comprising combined phenol‑ and surfactant‑degrading microbial consortium; (b) contacting said anaerobic microbial consortium with wastewater containing phenolic compounds and surfactants in a reactor operated under predetermined operational conditions; (c) maintaining dissolved oxygen and pH of the mixture; and (d) allowing simultaneous degradation of the phenolic compounds and the surfactants in the wastewater.

2. The method as claimed in claim 1, wherein the providing the anaerobic microbial consortium combining acclimatized cultures of Phenol Eating Bacteria (PEB) and Surfactant Eating Bacteria (SEB) in a ratio of 1:1 (v/v) respectively, thereby forming the mixed consortium of Phenol-Surfactant-Eating Bacteria (PSEB) capable of simultaneous pollutant degradation.

3. The method as claimed in claim 2, wherein the PEB culture and SEB culture are acclimatized under anoxic conditions, selectively enriched and combined to form a unified consortium capable of degrading phenolic compounds and surfactants.

4. The method as claimed in claim 1, wherein the step of providing the anaerobic microbial consortium comprises: collecting mixed microbial sludge from a wastewater treatment system, supplementing the sludge with an auxiliary anaerobic microbial source, subjecting the mixture to factorial optimization under controlled anaerobic conditions, selectively acclimatizing PEB in a first reactor until a stable removal performance is achieved, and selectively acclimatizing SEB in a second reactor until a stable removal performance is achieved.

5. The method as claimed in claim 4, wherein the PEB culture is acclimatized in synthetic wastewater containing phenol at 25 - 50 mg/L, with an inoculum volume of 5–10 % (v/v), temperature range of 30 - 35°C, pH maintained at 6.8–7.2, COD:N:P ratio of about 100:5:1, and under continuous stirring for an acclimatization period of 10 days.

6. The method as claimed in claim 4, wherein the SEB culture is acclimatized in synthetic wastewater containing surfactant at 20 - 30 mg/L, with an inoculum volume of 5–10 % (v/v), temperature range of 30 - 35°C, pH maintained at 6.8–7.2, COD:N:P ratio of about 100:5:1, and under continuous stirring for an acclimatization period of 10 days.

7. The method as claimed in claim 1, wherein the step of providing the anaerobic microbial consortium or PSEB comprises a combination of microorganisms including Acinetobacter at about 18%, Clostridium sp. at about 6%, Exiguobacterium aestuarii at about 5–6%, UBA1062 (Desulfobacterota) at about 4–5%, Paraclostridium sordellii at about 3–4%, JAFNAG01 sp002007265 (Acidobacteriota) at about 3%, Anaerolineaceae at about 2–3%, Exiguobacterium at about 2–3%, Romboutsia A. weinsteinii at about 2–3%, Lentimicrobium at about 2–3%, Fen.1087.s (Syntrophales) at about 6–7%, and Methanothrix.sp002256595 at about 11%, Methanofollis ethanolicus at about 5%, Methanolinea A.sp002506105 at about 4-5%, Methanocorpusculum at about 2-3%, Methanosarcina at about 1-2% by relative abundance.

8. The method as claimed in claim 1, wherein the step of maintaining dissolved oxygen at ≤ 0.5 mg/L and pH within a range of 6.5–7.5.

9. The method as claimed in claim 1, wherein the phenolic compounds in the wastewater comprise at least one of phenol, substituted phenols, alkyl phenols, chlorophenols or phenolic derivatives originating from domestic or industrial sources, and wherein the surfactants comprise at least one of anionic surfactants, cationic surfactants, non-ionic surfactants, amphoteric surfactants or mixtures thereof, including surfactants originating from detergents, cleaning agents and personal care products.

10. The method as claimed in claim 1, wherein the method is capable of achieving phenol removal efficiency of ≤ 87.6% and surfactant removal efficiency of ≥ 90% under anoxic conditions.

Description:METHOD OF WASTEWATER TREATMENT CONTAINING MIXED ORGANIC CONTAMINANTS USING ACCLIMATIZED ANAEROBIC MICROBIAL SYSTEM

FIELD OF INVENTION
[0001] The present disclosure relates to development of a specialized anaerobic microbial consortium for the simultaneous degradation of phenolic compounds and surfactants in wastewater, and particularly relates to a method of wastewater treatment containing mixed organic contaminants using acclimatized anaerobic microbial system. The method includes isolating, enriching, acclimating, optimizing, and integrating Phenol-Eating Bacteria (PEB), Surfactant-Eating Bacteria (SEB), and their combined consortium (PSEB) for application in decentralized wastewater treatment systems.
BACKGROUND
[0002] Domestic and industrial wastewater streams frequently contain phenolic compounds and synthetic surfactants derived from detergents, personal care formulations, and industrial chemicals. Phenols are classified as priority pollutants due to their toxicity, persistence, and their inhibitory effects on biological treatment processes even at relatively low concentrations. Surfactants can alter membrane permeability and generate foaming or emulsification of organic matter, which interferes with separation processes and may inhibit microbial activity at elevated concentrations. Conventional centralized wastewater treatment systems are primarily designed to treat bulk organic loads (COD/BOD) and nutrients; however, their efficiency can decrease and become inconsistent when exposed to mixtures of phenols and surfactants, particularly during shock loading events or in decentralized treatment applications.
[0003] Most biological approaches for the removal of phenolic compounds have traditionally relied on aerobic treatment systems employing individual microbial strains or aerobic consortia. Such systems generally require substantial aeration, high energy input, and complex operational control, which can limit their applicability in decentralized or resource-constrained installations. Anaerobic treatment processes have increasingly gained attention due to their capability to operate at high organic loading rates, generate biogas as a value-added product, and produce comparatively lower amounts of sludge. However, elevated concentrations of phenolic compounds and synthetic surfactants may exert inhibitory or toxic effects on conventional anaerobic sludge, often resulting in reduced removal efficiencies and operational instability.
[0004] Anaerobic reactor configurations reported for the treatment of phenol-containing or phenol-surfactant wastewater, including anaerobic baffled reactors (ABR) and upflow anaerobic sludge blanket (UASB) systems, typically demonstrate only moderate phenol removal performance. These systems also tend to remain sensitive to fluctuations in influent composition because the resident microbial communities are generally not intentionally selected or acclimatized for the simultaneous degradation of both phenolic compounds and surfactants.
[0005] In addition, physicochemical treatment methods, such as adsorption using activated carbon or surfactant-modified sorbent materials, have been employed for the removal of phenols and surfactants. However, such approaches are associated with high media replacement costs, generation of secondary waste streams, and the absence of in-situ biodegradation mechanisms, thereby limiting their long-term sustainability and resilience under variable loading conditions.
[0006] High-rise buildings, residential complexes, institutional facilities, and semi-urban or rural communities are increasingly adopting decentralized wastewater treatment systems, wherein limitations related to available footprint, energy consumption, and operator expertise are common. In such installations, treatment technologies must demonstrate operational simplicity, resilience to variations in influent composition, and compatibility with low-energy anaerobic processes. However, many currently available biological treatment approaches are derived from systems originally designed for centralized treatment plants and are therefore not specifically optimized for wastewater streams containing combined phenolic and surfactant contaminants.
[0007] Conventional anaerobic reactors typically rely on naturally occurring sludge microbial communities without deliberate isolation, enrichment, or acclimatization of microorganisms capable of degrading phenolic compounds or surfactants. As a result, these systems often exhibit extended start-up periods, variable treatment performance, and increased susceptibility to process instability during shock loading conditions.
[0008] Various techniques and solutions have been developed for degradation of wastewater. For instance, Patent application JP2024101313A discloses a biological treatment method for nitrogen-containing organic wastewater. It provides a biological treatment method for nitrogen-containing organic wastewater capable of reducing an amount of chemicals used and an amount of sludge generated.
[0009] Patent application WO2014017642A1 discloses biological wastewater treatment device and biological wastewater treatment method. The invention provides a biological wastewater treatment device which is provided with a signal substance production unit which produces a signal substance by means of signal substance-producing bacteria, and a treatment unit which biologically treats wastewater by means of treatment bacteria, wherein the signal substance production unit has a supply means for supplying the signal substance to the treatment bacteria.
[0010] Accordingly, a technological gap exists for a defined and pre-acclimatized anaerobic microbial system that can be readily integrated into decentralized treatment reactors to facilitate reliable and simultaneous degradation of phenolic compounds and surfactants present in complex wastewater streams.
[0011] Therefore, there is a requirement for a systematic method that includes isolation, enrichment, acclimation, optimization, and integration of distinct functional groups of microorganisms for anaerobic treatment. Such a specialized anaerobic microbial consortium, when suitably acclimatized to mixed phenolic and surfactant loads, can improve degradation rates, reduce toxicity effects, stabilize reactor performance, and make low‑energy decentralized wastewater treatment systems technically and economically viable. The present disclosure addresses this unmet need by developing and deploying an anaerobic microbial system tailored for simultaneous degradation of phenolic compounds and surfactants in wastewater containing mixed organic contaminants, particularly suited for decentralized treatment installations.

OBJECTS OF THE INVENTION
[0012] It is an object of the present disclosure to provide a specialized anaerobic microbial consortium comprising Phenol‑Eating Bacteria, Surfactant‑Eating Bacteria and a combined consortium capable of simultaneous degradation of phenolic compounds and surfactants present in wastewater containing mixed organic contaminants.
[0013] It is an object of the present disclosure to provide a method of wastewater treatment using an acclimatized anaerobic microbial system, wherein the consortium is isolated, enriched, acclimated and applied in an anaerobic reactor to achieve enhanced and stable removal of phenolic compounds and surfactants under decentralized treatment conditions.
[0014] It is an object of the present disclosure to provide a low‑energy, low‑sludge‑generating and operationally simple treatment approach suitable for greywater and sewage in residential and institutional settings, thereby improving effluent quality with respect to phenolic compounds, surfactants and overall organic load.

SUMMARY
[0015] The present disclosure is directed towards a method of wastewater treatment containing mixed organic contaminants using acclimatized anaerobic microbial consortium, the method comprising of (a) providing an anaerobic microbial consortium comprising combined phenol‑ and surfactant‑degrading microbial consortium; (b) contacting said anaerobic microbial consortium with wastewater containing phenolic compounds and surfactants in a reactor operated under predetermined operational conditions; (c) maintaining dissolved oxygen and pH of the mixture; and (d) allowing simultaneous degradation of the phenolic compounds and the surfactants in the wastewater.
[0016] In an aspect of the present disclosure, the providing the anaerobic microbial consortium combining acclimatized cultures of Phenol Eating Bacteria (PEB) and Surfactant Eating Bacteria (SEB) in a ratio of 1:1 (v/v) respectively, thereby forming the mixed consortium of Phenol-Surfactant-Eating Bacteria (PSEB) capable of simultaneous pollutant degradation.
[0017] In an aspect of the present disclosure, the PEB culture and SEB culture are acclimatized under anoxic conditions, selectively enriched and combined to form a unified consortium capable of degrading phenolic compounds and surfactants.
[0018] In an aspect of the present disclosure, the step of providing the anaerobic microbial consortium comprises: collecting mixed microbial sludge from a wastewater treatment system, supplementing the sludge with an auxiliary anaerobic microbial source, subjecting the mixture to factorial optimization under controlled anaerobic conditions, selectively acclimatizing PEB in a first reactor until a stable removal performance is achieved, and selectively acclimatizing SEB in a second reactor until a stable removal performance is achieved.
[0019] In another aspect of the present disclosure, the PEB culture is acclimatized in synthetic wastewater containing phenol at 25 - 50 mg/L, with an inoculum volume of 5–10 % (v/v), temperature range of 30 - 35°C, pH maintained at 6.8–7.2, COD:N:P ratio of about 100:5:1, and under continuous stirring for an acclimatization period of 10 days.
[0020] In another aspect of the present disclosure, the SEB culture is acclimatized in synthetic wastewater containing surfactant at 20 - 30 mg/L, with an inoculum volume of 5–10 % (v/v), temperature range of 30 - 35°C, pH maintained at 6.8–7.2, COD:N:P ratio of about 100:5:1, and under continuous stirring for an acclimatization period of 10 days.
[0021] In another aspect of the present disclosure, the step of providing the anaerobic microbial consortium or PSEB comprises a combination of microorganisms including Acinetobacter at about 18%, Clostridium sp. at about 6%, Exiguobacterium aestuarii at about 5–6%, UBA1062 (Desulfobacterota) at about 4–5%, Paraclostridium sordellii at about 3–4%, JAFNAG01 sp002007265 (Acidobacteriota) at about 3%, Anaerolineaceae at about 2–3%, Exiguobacterium at about 2–3%, Romboutsia A. weinsteinii at about 2–3%, Lentimicrobium at about 2–3%, Fen.1087.s (Syntrophales) at about 6–7%, and Methanothrix.sp002256595 at about 11%, Methanofollis ethanolicus at about 5%, Methanolinea A.sp002506105 at about 4-5%, Methanocorpusculum at about 2-3%, Methanosarcina at about 1-2% by relative abundance.
[0022] In yet another aspect of the present disclosure, the step of maintaining dissolved oxygen at ≤ 0.5 mg/L and pH within a range of 6.5–7.5.
[0023] In another aspect of the present disclosure, the phenolic compounds in the wastewater comprise at least one of phenol, substituted phenols, alkyl phenols, chlorophenols or phenolic derivatives originating from domestic or industrial sources, and wherein the surfactants comprise at least one of anionic surfactants, cationic surfactants, non-ionic surfactants, amphoteric surfactants or mixtures thereof, including surfactants originating from detergents, cleaning agents and personal care products.
[0024] In another aspect of the present disclosure, the method is capable of achieving phenol removal efficiency of ≤ 87.6% and surfactant removal efficiency of ≥ 90% under anoxic conditions.

BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0026] FIG. 1 illustrates experimental workflow showing sample preparation, DOE setup, microbial consortia testing, and reactor-based evaluation for pollutant removal and biogas generation.
[0027] FIG. 2 illustrates schematic representation of the continuous-mode ABR–PBR system for wastewater treatment, showing flow direction, biogas collection, and principal components.
[0028] FIG. 3 illustrates phase-wise degradation trends of (a) phenol by Phenol-Eating Bacteria (PEB), (b) surfactant by Surfactant-Eating Bacteria (SEB), demonstrating the microbial adaptation and pollutant removal efficiency across four sequential operational phases.
[0029] FIG. 4 illustrates phase-wise degradation of phenol (panels A, A1, A2) and surfactant (panels B, B1, B2) under different hydraulic retention times (HRTs: 8 h, 24 h, 32 h).
[0030] FIG. 5 illustrates heatmap representation of phenol and surfactant concentration changes over 10 days under four experimental conditions (A -D), demonstrating the comparative performance of microbial degradation systems.
[0031] FIG. 6 illustrates temporal variation in phenol and surfactant concentrations over 45 days in a combined anoxic reactor inoculated with acclimatized PEB and SEB.
[0032] FIG. 7 (a, b, c) illustrates GC chromatogram showing peaks for methane, CO, and CO₂, with methane as the dominant component
[0033] FIG. 8 illustrates dominant microbial composition of combined consortium (PSEB).

DETAILED DESCRIPTION
[0034] Aspects of the present disclosure relate to a method of wastewater treatment containing mixed organic contaminants using acclimatized anaerobic microbial system.
[0035] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
1. MATERIALS AND METHODS
1.1. Origin and Source of Microorganisms
[0036] The wastewater samples were obtained from Mixed Liquor Suspended Solids (MLSS) collected from the inlet tank of a Moving Bed Biofilm Reactor (MBBR) unit at a wastewater treatment plant located at IIT Jammu, India (32.800148°N, 74.897907°E). The Mixed Liquor Suspended Solids (MLSS) obtained from this system served as the primary microbial inoculum. The collected sludge was selected for its diverse microbial population, capable of degrading organic contaminants under fluctuating environmental conditions. To enhance anaerobic activity and microbial diversity, cow dung (2–5%) was added as a secondary inoculum source. This combination provided a rich and resilient microbial population, including fermentative and methanogenic communities capable of degrading complex contaminants.
1.2. Optimization of Consortium Using Factorial Experimental Design
[0037] A four-variable factorial Design of Experiment (DOE) was conducted to determine the optimal combination for culture development.
Independent variables included:
• MLSS concentration: 2–5% (w/v)
• Cow dung concentration: 5–20% (w/v)
• Phenol concentration: 12–40 mg/L
• Surfactant concentration: 20–37 mg/L
• Initial COD: approximately 487 mg/L
[0038] Each experimental run was performed in sealed 300 mL anaerobic batch reactors with 200 mL working volume and 100 mL headspace at 35 ± 2°C for 18 days. Sampling was conducted on the 6th, 12th, and 18th days to monitor pollutant degradation and cumulative biogas production. Based on combined pollutant removal efficiency and biogas generation, run 16 was identified as the optimized consortium configuration for further enrichment and application.

1.3. Enrichment and Acclimatization Procedure
[0039] The optimized microbial mixture was subjected to staged enrichment under strict anoxic conditions.
Primary Enrichment
• Incubation period: 4–5 days
• Temperature: ambient laboratory conditions
• Carbon supplementation: glucose as a growth promoter
1.4. Development of Specialized Microbial Consortia
[0040] Two independent acclimatization reactors were developed to selectively enrich pollutant-specific degraders prior to consortium integration.

1.4.1. Development of Phenol-Eating Bacteria (PEB)
[0041] A borosilicate glass reactor with 2 L working volume was used.
Operational parameters:
• Type: Anaerobic batch reactor
• Synthetic wastewater containing phenol: 25 – 50 mg/L
• Inoculum volume: 5–10 %
• Temperature: 30 – 35°C
• Dissolved oxygen: ≤ 0.5 mg/L (anoxic)
• Mixing: 150 – 250 rpm (magnetic stirring)
• pH maintained at 6.8–7.2
• COD : N : P ≈ 100 : 5 : 1
• Operation time: 10-day acclimatization + total operation: 30 – 55 days
[0042] Phenol-Eating Bacteria (PEB)
Includes bacteria such as:
• Acinetobacter
• Exiguobacterium aestuarii
• Exiguobacterium
The acclimatized PEB consortium demonstrated phenol removal efficiency up to 87% under repeated substrate loading.
1.4.2. Development of Surfactant-Eating Bacteria (SEB)
[0043] An identical reactor configuration was employed with a modification of the substrate.
Operational parameters:
• Type: Anaerobic batch reactor
• Working volume: 2 L
• Synthetic wastewater containing anionic surfactant (SDBS): 20 – 30 mg/L
• Temperature: 30 – 35°C
• Dissolved oxygen: ≤ 0.5 mg/L
• Stirring speed: 150 – 250 rpm
• pH: 6.8–7.2
• Duration: 55 days
• Inoculum volume: 5–10 %
• COD : N : P ≈ 100 : 5 : 1
• Operation time: 10-day acclimatization + total operation: 30 – 55 days
[0044] Surfactant-Eating Bacteria (SEB)
Includes bacteria such as:
• Clostridium sp.
• Paraclostridium sordellii
• Lentimicrobium
• Romboutsia weinsteinii
• Anaerolineaceae
• UBA1062 (Desulfobacterota)
• JAFNAG01 sp002007265 (Acidobacteriota)
The SEB consortium achieved surfactant removal efficiency up to 91% and exhibited high resistance to shock loading.
1.4.3. Formation of Combined Consortium (PSEB)
[0045] After independent stabilization of PEB and SEB cultures, both were combined in a 1:1 (v/v) ratio to form a mixed consortium termed Phenol-Surfactant-Eating Bacteria (PSEB).
Combined reactor configuration
• Reactor volume: 2 L
• Inoculum: 1:1 ratio of PEB and SEB (500 mL mixed PEB and SEB)
• Synthetic wastewater containing both phenol and surfactant- Phenol: 20 – 35 mg/L, Surfactant: 20 – 25 mg/L
• COD : N : P ≈ 100 : 5 : 1
• Operation duration: 30 – 55 days
• Continuous monitoring of degradation kinetics
[0046] Combined Consortium (PSEB)-The PSEB consortium was developed by combining acclimatized PEB and SEB cultures in equal proportions. The dominant microbial composition includes:
Acinetobacter 18.48063
Clostridium_AM.sp025398335 6.137226
Exiguobacterium aestuarii 5.240777
UBA1062.sp029547185(Desulfobacterota) 4.309849
Paraclostridium sordellii 3.33295
JAFNAG01.sp020072565 (Acidobacteriota) 3.195035
Anaerolineaceae 2.884726
Exiguobacterium 2.850247
Romboutsia A.weinsteinii 2.792782
Lentimicrobium.sp023417935 2.528445
Fen.1087.s (Syntrophales) 6.872773
Methanothrix.sp002256595 11.34352
Methanofollis ethanolicus 5.183312
Methanolinea A.sp002506105 4.148948
Methanocorpusculum 2.149178
Methanosarcina 1.540053
Unclassifed 17.00034

The combined PSEB consortium integrates both metabolic pathways, enabling simultaneous degradation of phenol and surfactants through coordinated anaerobic and facultative mechanisms. The mixed consortium demonstrated cooperative metabolic interaction, enabling simultaneous degradation of phenol and surfactant under anaerobic conditions.

1.5. Soil-Based Validation for Decentralized Applications
[0047] To simulate field-scale decentralized treatment systems, sterilized soil-based reactors were developed.
Specifications:
• Compartment size: 10 cm × 10 cm × 10 cm
• Soil per compartment: 800 g
• Inoculum dosage: 10 mL acclimatized culture
• Initial pollutant concentrations: 6.25–25 mg/L
• Hydraulic Retention Time (HRT): 8, 24, and 32 hours
Maximum degradation performance and shock resilience were observed at 24–32-hour HRT.

2. RESULTS
[0048] The developed microbial consortia demonstrated high degradation efficiency, operational stability, and resilience under controlled laboratory conditions and simulated decentralized treatment environments.
2.1. Phenol Degradation Performance (PEB Consortium)
[0049] The acclimatized Phenol-Eating Bacteria (PEB) consortium achieved phenol removal efficiency of up to 87.6% under anoxic conditions. Stable degradation was observed across multiple operational phases, including repeated shock loading.
• Initial phenol concentration: approximately 50 mg/L
• Final concentration reduced to less than 6 mg/L under optimized conditions
• Demonstrated tolerance to high phenol concentrations up to 47 mg/L
• Maintained activity under repeated substrate re-dosing
The system showed sustained metabolic activity without collapse, confirming adaptation and inhibitory resistance under anaerobic conditions.
2.2. Surfactant Degradation Performance (SEB Consortium)
[0050] The Surfactant-Eating Bacteria (SEB) consortium demonstrated superior, consistent degradation efficiency.
• Initial surfactant concentration: 25–30 mg/L
• Removal efficiency: greater than 90%
• Final concentration reduced to less than 3 mg/L
• Complete removal achieved at lower concentrations (≤ 6.25 mg/L)
The consortium demonstrated high resilience under intermittent high-load shock dosing and maintained stable degradation kinetics throughout extended operation.
2.3. Simultaneous Degradation Performance (PSEB Consortium)
[0051] Upon combining PEB and SEB in a 1:1 (v/v) ratio to form the PSEB consortium, simultaneous degradation of phenol and surfactant was successfully achieved under anaerobic conditions.
• Rapid surfactant degradation within 3 days of dosing
• Gradual but sustained phenol degradation
• Combined pollutant concentrations were reduced to below 5 mg/L after acclimatization
• No observed metabolic inhibition during co-exposure
The mixed consortium exhibited cooperative metabolic interactions, enabling stable dual-contaminant removal without the need for additional chemical additives.
2.4. Soil-Based Reactor Performance
[0052] Under simulated soil-based decentralized treatment conditions:
• Optimal Hydraulic Retention Time (HRT): 24–32 hours
• Near-complete phenol removal at low and medium concentrations
• Greater than 90% surfactant removal.
2.5. Biogas Production and Process Stability
[0053] For biogas production and process stability:
• Progressive methane enrichment observed during operation
• Methane concentration increased from approximately 74% to greater than 99% under stabilized conditions
• Stable anaerobic digestion without acidification failure
3. UNIQUENESS OF THE INVENTION
[0054] The uniqueness of the invention lies in:
 Development of a Targeted Dual-Consortium System
The invention provides two independently acclimatized anaerobic microbial consortia, namely Phenol-Eating Bacteria (PEB) and Surfactant-Eating Bacteria (SEB), which are subsequently integrated in a defined ratio to form a unified Phenol-Surfactant-Eating Bacteria (PSEB) consortium. This staged enrichment approach ensures selective metabolic specialization prior to combined application, thereby enhancing the efficiency of dual-contaminant degradation.
 Selective Acclimatization Prior to Integration
Unlike conventional mixed-sludge systems, the present process isolates and acclimatizes pollutant-specific degraders separately before merging. This prevents competitive inhibition during early adaptation and promotes cooperative metabolic interaction in the final mixed consortium.
 Shock-Load Resilient Anaerobic Operation
The developed consortium demonstrates stable phenol and surfactant degradation performance under repeated shock loading. The system maintains high removal efficiency without process failure or biomass washout, making it particularly suitable for decentralized wastewater systems where influent characteristics fluctuate.
 Simultaneous Dual-Pollutant Removal Under Strict Anoxic Conditions
The invention enables effective degradation of phenol and surfactants under low dissolved oxygen (≤ 0.5 mg/L) conditions without the need for aeration, advanced oxidation, or chemical additives. This significantly reduces operational energy demand compared to aerobic treatment systems.
 Integration with Soil-Based and Hybrid Reactor Systems
The microbial consortium is compatible with soil-supported biofilm reactors and hybrid anaerobic baffled reactor–plant bioreactor (ABR–PBR) configurations. The soil matrix enhances microbial retention, biofilm stability, and pollutant mass transfer, improving overall degradation efficiency.
 Kinetically Validated and Statistically Robust Performance
The degradation process is supported by first-order kinetic modeling and validated using a Monte Carlo simulation with 10,000 iterations, confirming the predictability and reproducibility of the rate constants under variable operating conditions. This probabilistic validation strengthens scalability and engineering reliability.
 High Removal Efficiency with Energy Recovery Potential
The process achieves phenol removal up to approximately 87% and surfactant removal exceeding 90%, while simultaneously producing methane-rich biogas. This enables pollutant remediation and renewable energy generation within the same system.
 Low-Cost and Locally Adaptable Inoculum Development
The inoculum is derived from readily available wastewater sludge and cow dung, eliminating the need for genetically modified organisms, expensive commercial cultures, or synthetic microbial formulations.
 Applicability to Decentralized and Rural Wastewater Treatment
The invention is specifically designed for decentralized settings where centralized infrastructure is unavailable. The process tolerates variable pollutant concentrations and operates efficiently at moderate temperatures without complex control systems.
 Synergistic Biodegradation Mechanism
The consortium exhibits cooperative metabolic pathways in which surfactant-mediated solubilization enhances phenol bioavailability, thereby improving overall degradation performance.
4. INDUSTRIAL APPLICATION
[0055] The present invention is applicable in multiple industrial and environmental sectors where phenolic compounds, surfactants, and mixed organic contaminants are present in wastewater streams. The developed microbial consortium and associated treatment process are suitable for the following industrial applications:
 Petrochemical and Refinery Effluents
The invention can be employed for the treatment of wastewater generated from petroleum refining, resin manufacturing, plastic production, and chemical processing industries, where phenolic compounds are commonly present.
 Detergent and Surfactant Manufacturing Units
The process is applicable to the treatment of effluents containing anionic and nonionic surfactants, particularly linear alkylbenzene sulfonates (LAS) and similar compounds, discharged from detergent formulation facilities.
 Pharmaceutical and Chemical Industries
The microbial consortium can be integrated into the pre-treatment or polishing stages of the pharmaceutical and specialty chemical industries that produce phenol-based intermediates or surface-active compounds.
 Domestic and Institutional Wastewater Treatment Plants
The invention is particularly suitable for decentralized sewage treatment systems in residential complexes, campuses, hospitals, hotels, and peri-urban communities where surfactants and phenolic residues are intermittently discharged.
 Agro-Industrial and Food Processing Units
The process can be adapted for wastewater streams containing mixed organic loads with trace phenolic derivatives and cleaning-agent residues.
 Integration with Anaerobic Baffled Reactors and Constructed Wetlands
The developed consortium is compatible with anaerobic baffled reactors (ABRs), soil-based biofilters, plant-based bioreactors, and hybrid treatment configurations, enabling industrial scalability without major infrastructure modifications.
 Energy Recovery Systems
Since the process operates under anaerobic conditions and produces methane-rich biogas, it can be integrated with biogas collection systems to recover renewable energy, thereby reducing operational costs.
 Retrofit of Existing Treatment Facilities
The microbial culture can be introduced into existing anaerobic treatment units to enhance the efficiency of phenol and surfactant degradation without requiring additional aeration systems or advanced oxidation technologies.
 Low-Energy and Resource-Constrained Regions
Due to its low dissolved oxygen requirements, moderate operating temperature, and minimal chemical dependency, the invention is suitable for rural and developing regions with limited energy and operational resources.
, C , Claims:We Claim:
1. A method of wastewater treatment containing mixed organic contaminants using acclimatized anaerobic microbial consortium, the method comprising of:
(a) providing an anaerobic microbial consortium comprising combined phenol‑ and surfactant‑degrading microbial consortium;
(b) contacting said anaerobic microbial consortium with wastewater containing phenolic compounds and surfactants in a reactor operated under predetermined operational conditions;
(c) maintaining dissolved oxygen and pH of the mixture; and
(d) allowing simultaneous degradation of the phenolic compounds and the surfactants in the wastewater.
2. The method as claimed in claim 1, wherein the providing the anaerobic microbial consortium combining acclimatized cultures of Phenol Eating Bacteria (PEB) and Surfactant Eating Bacteria (SEB) in a ratio of 1:1 (v/v) respectively, thereby forming the mixed consortium of Phenol-Surfactant-Eating Bacteria (PSEB) capable of simultaneous pollutant degradation.
3. The method as claimed in claim 2, wherein the PEB culture and SEB culture are acclimatized under anoxic conditions, selectively enriched and combined to form a unified consortium capable of degrading phenolic compounds and surfactants.
4. The method as claimed in claim 1, wherein the step of providing the anaerobic microbial consortium comprises:
collecting mixed microbial sludge from a wastewater treatment system,
supplementing the sludge with an auxiliary anaerobic microbial source,
subjecting the mixture to factorial optimization under controlled anaerobic conditions,
selectively acclimatizing PEB in a first reactor until a stable removal performance is achieved, and
selectively acclimatizing SEB in a second reactor until a stable removal performance is achieved.
5. The method as claimed in claim 4, wherein the PEB culture is acclimatized in synthetic wastewater containing phenol at 25 - 50 mg/L, with an inoculum volume of 5–10 % (v/v), temperature range of 30 - 35°C, pH maintained at 6.8–7.2, COD:N:P ratio of about 100:5:1, and under continuous stirring for an acclimatization period of 10 days.
6. The method as claimed in claim 4, wherein the SEB culture is acclimatized in synthetic wastewater containing surfactant at 20 - 30 mg/L, with an inoculum volume of 5–10 % (v/v), temperature range of 30 - 35°C, pH maintained at 6.8–7.2, COD:N:P ratio of about 100:5:1, and under continuous stirring for an acclimatization period of 10 days.
7. The method as claimed in claim 1, wherein the step of providing the anaerobic microbial consortium or PSEB comprises a combination of microorganisms including Acinetobacter at about 18%, Clostridium sp. at about 6%, Exiguobacterium aestuarii at about 5–6%, UBA1062 (Desulfobacterota) at about 4–5%, Paraclostridium sordellii at about 3–4%, JAFNAG01 sp002007265 (Acidobacteriota) at about 3%, Anaerolineaceae at about 2–3%, Exiguobacterium at about 2–3%, Romboutsia A. weinsteinii at about 2–3%, Lentimicrobium at about 2–3%, Fen.1087.s (Syntrophales) at about 6–7%, and Methanothrix.sp002256595 at about 11%, Methanofollis ethanolicus at about 5%, Methanolinea A.sp002506105 at about 4-5%, Methanocorpusculum at about 2-3%, Methanosarcina at about 1-2% by relative abundance.
8. The method as claimed in claim 1, wherein the step of maintaining dissolved oxygen at ≤ 0.5 mg/L and pH within a range of 6.5–7.5.
9. The method as claimed in claim 1, wherein the phenolic compounds in the wastewater comprise at least one of phenol, substituted phenols, alkyl phenols, chlorophenols or phenolic derivatives originating from domestic or industrial sources, and wherein the surfactants comprise at least one of anionic surfactants, cationic surfactants, non-ionic surfactants, amphoteric surfactants or mixtures thereof, including surfactants originating from detergents, cleaning agents and personal care products.
10. The method as claimed in claim 1, wherein the method is capable of achieving phenol removal efficiency of ≤ 87.6% and surfactant removal efficiency of ≥ 90% under anoxic conditions.