Palm Oil Mill Effluent Treatment Research Articles

Thermophilic Digestion of Palm Oil Mill Effluent: Enhancing Biogas Production and Mitigating Greenhouse Gas Emissions

This study investigates the impact of thermophilic anaerobic digestion on biogas production and methane emission reduction from Palm Oil Mill Effluent (POME). Conducted under controlled conditions at 55°C and 65°C, the research aims to optimize biogas yield and reduce Chemical Oxygen Demand (COD) levels. The findings indicate that thermophilic digestion at 65°C significantly enhances biogas production, yielding 1.81 L Biogas per liter of POME over an 8-day period, compared to mesophilic conditions. Furthermore, the study demonstrates substantial COD reduction, supporting a more efficient and environmentally friendly process. By capturing methane emissions and converting them into a renewable energy source, this method aligns with global climate policies and greenhouse gas reduction targets. The integration of thermophilic anaerobic digestion into POME treatment presents a viable solution for the palm oil industry to improve waste management practices and contribute to sustainable development goals. Future research should explore large-scale implementations to maximize the environmental and economic benefits of this technology.

Dual function of sea grapes (Caulerpa racemosa) as phytoremediator for palm oil mill effluent and as ornamental fish feed formulation

Phytoremediation is a promising technology for treating Palm Oil Mill Effluent (POME). Moreover, phytoremediators have the potential for various aplication, including as feedstock. Hence, this study aims to elucidate the ability of sea grapes (Caulerpa racemosa) in remediating POME and evaluate their suitability as ornamental fish feed. Results showed that application of sea grapes effectively decreased the COD, TSS, phosphate (PO43−), and nitrate (NO3−) levels in POME. Sea grapes maintained in POME with a concentration of 12.5% had the highest reduction rate and growth performance. Moreover, sea grapes biomass from the remediation process can be utilized as feed material for ornamental fish, as indicated by increasing skin coloration of fish. For the first time, this study provides sustainable options for managing POME using sea grapes and suggests sea grapes as a potential fish feed formulation for ornamental fish.

Biokinetic modeling approach to investigate the impact of rotational speed variations in modified rotating biological contactors for palm oil mill effluent treatment

Palm oil mill effluent (POME) contains high organic content, posing significant environmental challenges that demand effective treatment solutions. Conventional rotating biological contactor (RBC) used for POME treatment are limited by insufficient surface area for microbial growth and inefficient oxygen transfer, limiting their effectiveness. This study enhances RBC systems by incorporating bioballs to increase microbial attachment surfaces and improve treatment performance. Experiments were conducted at various rotational speeds, and biokinetic modeling was applied under unsteady-state conditions. The results showed that the RBC operated at 3 rpm achieved the highest removal efficiencies, with 67.4 % for SCOD, 92.4 % for TSS, and 73 % for NH3. The biokinetic model revealed that rotational speed did not significantly impact oxygen transfer, mainly during the aeration phase. Lower speeds optimized substrate degradation and microbial growth, while higher speeds caused biofilm detachment. The innovative use of bioballs improves POME treatment efficiency at lower speeds, offering a cost-effective solution.

Microalgae-fungal pellets as novel dual-bioadsorbents for dye and their practical applications in bioremediation of palm oil mill effluent

Microalgae-fungal pellets were applied as novel dual-biosorbents for dye removal compared to fungal pellets. Both pellet types effectively removed anionic dyes better than cationic dyes, with the maximum adsorbing efficiency being nearly 100 % at a wide pH range of 3–8. The adsorption isotherms of anionic Congo Red dye and Coomassie brilliant blue R-250 dye using both pellet types and their biosorption kinetics were intensively studied. Noteworthy, the maximum adsorption capacity and affinity of microalgae-fungal pellets were much higher than those of fungal pellets. Both fungal pellets were also applied in the bioremediation of palm oil mill effluent (POME). The repeated treatment of POME by replacing pellets every 12 h enhanced the percent removal of color, phenolic compounds, and COD up to 90.97 ± 0.36 %, 70.71 ± 0.90 % and 56.55 ± 1.98 %, respectively. This study has demonstrated the promising potential for addressing dye removal and bioremediation of colored-industrial effluent in a sustainable and economically viable manner.

Performance of combined organic precipitation, electrocoagulation, and electrooxidation in treating anaerobically treated palm oil mill effluents

Palm oil mill effluent (POME), wastewater generated from palm oil production, is known for its extremely high chemical oxygen demand and brownish color. Anaerobic digestion is the primary treatment method for POME in the palm oil industry; however, anaerobically treated POME has high concentrations of residual contaminants and color intensity. This study proposes an approach to treat anaerobically-treated POME in recycled water for industrial applications by integrating preliminary organic precipitation, electrocoagulation, and electrooxidation (EO). The EO process was optimized in terms of the current density, electrolysis time, electrode arrangement, and feed flow rate. At a current density of 60 mA/cm2 and an electrolysis time of 9 min, the EO process with a graphite anode and stainless-steel cathode in the monopolar electrode configuration reduced the phenolic concentration and color in the preliminary-treated POME from 8.95 mg/L and 317.19 ADMI to 0.25 mg/L and 26.10 ADMI, respectively. Additionally, the EO process exhibited a 92.26% efficiency in lowering the ammonium-nitrogen content.

Improving the pH of Palm Oil Mill Effluent (POME) with Aerator Treatment and Water Dilution

Palm Oil Mill Effluent/POME is a by-product produced from the processing of fresh fruit bunches/FFB into crude palm oil/CPO. Aeration of POME is one of the processing methods that aims to reduce the levels of organic matter and pollutants. This study aims to determine the dynamics of POME pH with aeration treatment and dilution variations in order to speed up the waste treatment time.The method used in this research is to make the treatment of pure POME, POME & water in a ratio of 1:1 & 1:2. The process carried out in the study was to place the solution into a 1 liter bottle and given an air flow using an aerator with a discharge of 0.66 l/min. POME samples were taken every 24 hours for a span of 7 days. The pH was measured using the electrometric method. On day 2, it was found that the pH of the 1:1 treatment POME had reached pH 6, while the 1:2 treatment on day 3 and the pure POME only reached pH 6 on day 5. Aeration is an effective method to neutralize the acidity of POME. The increase in POME pH was fastest in the 1:2, 1:1 and finally pure POME dilutions. All treatments met the pH quality standard on day 5. Aeration can help improve the quality of POME so that it is more environmentally friendly.

Treatment of wastewater from oil palm industry in Malaysia using polyvinylidene fluoride-bentonite hollow fiber membranes via membrane distillation system

Membrane distillation (MD) is gaining increasing recognition within membrane-based processes for palm oil mill effluent (POME) treatment. This study aims to alter the physicochemical characteristics of polyvinylidene fluoride (PVDF) membranes through the incorporation of bentonite (B) at varying weight concentrations (ranging from 0.25 wt% to 1.0 wt%). Characterization was conducted to evaluate changes in morphology, thermal stability, surface characteristics and wetting properties of the resulting membranes. The resulting membranes were also tested using direct contact membrane distillation (DCMD) with POME as the feed solution, aiming to generate high-purity water. Results indicated that the PVDF-0.3B and PVDF-0.5B membranes achieved the highest water vapor flux. The finger-like structure and macrovoids present in these membranes aid in minimizing mass resistance during vapor transport and enhancing permeate flux. All membranes demonstrated exceptional performance in removing contaminants, eliminating total dissolved solids (TDS) and achieving over 99% rejection of chemical oxygen demand (COD), nitrate nitrogen (NN), color, and turbidity from the feed solution. The permeate water analysis showed that the PVDF-0.3B membrane had superior removal efficiency and met the standards set by the local Department of Environment (DOE). The PVDF-0.3B membrane was chosen as the preferred option because of its consistent flux and high removal efficiency. This study demonstrated that incorporating bentonite into PVDF membranes significantly enhanced their properties and performance for POME treatment.

Integrated Struvite Precipitation and Fenton Oxidation for Nutrient Recovery and Refractory Organic Removal in Palm Oil Mill Effluent

Anaerobically treated palm oil mill effluent (AnT-POME), containing a high concentration of ammoniacal-nitrogen (NH4+-N) and soluble chemical oxygen demand (sCOD) was subjected to sequential processes of struvite precipitation to recover NH4+-N and Fenton oxidation for sCOD removal. The optimization of treatment was conducted through response surface methodology (RSM). Under optimized struvite precipitation conditions (Mg2+/NH4+, PO43−/NH4+ molar ratios: 1; pH 8.2 ± 0.1), NH4+-N concentration decreased to 41 ± 7.1 mg L−1 from an initial 298 ± 41 mg L−1 (78.8 ± 1.6 % removal). Field emission scanning electron microscopy (FESEM) coupled with energy-dispersive X-ray spectroscopy (EDX) confirmed NH4+-N was recovered as struvite. Subsequent Fenton oxidation under the optimized conditions (H2O2 dosage: 2680 mg L−1; molar ratio of Fe2+/H2O2: 0.8; reaction time: 56 min) reduced sCOD concentration to 308 ± 46 mg L−1 from an initial 1350 ± 336 mg L−1 (76.0 ± 1.0 % removal). The transparent appearance of treated AnT-POME validated the removal of sCOD responsible for the initial brownish appearance. Models derived from RSM demonstrated significance, with high coefficients of determination (R2 = 0.99). Overall, integrated struvite precipitation and Fenton oxidation effectively removed NH4+-N and sCOD from AnT-POME, contributing to nutrient recovery and environmental sustainability.

Emerging trends in POME treatment and applications: chemical and biotechnological aspects

Globally, environmental challenges are growing more and more significant. Changes in soil have been caused by the years-long discharge and careless disposal of palm oil mill effluent (POME). A systematic review explored emerging trends in POME treatment and applications, with a focus on recent, innovative methods for POME treatment with biological and chemical treatment technologies, chemical and biotechnological approaches. The review highlighted several key findings, including the efficiency and cost-effectiveness of these approaches, their ability to reduce environmental impacts, and their potential to recover resources such as energy and nutrients. Quantitative information on the efficacy of these approaches was also provided. Based on these findings, the review concludes that the aforementioned approaches can significantly improve POME treatment and offer a promising way to reduce environmental impacts and recover resources. However, further research is needed to optimize and scale up these approaches, as well as to assess their long-term sustainability. In addition, it is important to consider the social, economic, and environmental factors that may affect the successful implementation of these approaches.

Palm Oil Mill Effluent Treatment Technology using Sequencing Batch Reactor (SBR) with Oxidation Reduction Potential (ORP) Monitoring

Palm oil industries have products like Crude Palm Oil (CPO), and 70% of others contain waste. One of the wastes is the liquid waste known as Palm Oil Mill Effluent (POME). The potential of POME to be reprocessed into clean water will be profitable. One of POME's reprocessing methods is the Sequencing Batch Reactor with Aerobic Granulated Sludge (SBR-AGS), which has five main phases: filling, idling, aeration, settling, and discharge, with a cycle time of 360 minutes. The first step in using this reactor is the start-up process, a granule-forming process from some sludge that has already acclimatized. In one complete cycle, the Oxidation-Reduction Potential (ORP) parameter is used to observe the electron transfer process that shows the oxygen supply into the reactor, which enables the condition of each phase in the process to be analyzed. The trend of ORP value is constantly changing in every phase. For the idling phase, the ORP tends to decrease in a value of (-300)-(-400) mV, and for the aeration phase, it will increase in a value of (-100)-100 mV.

Utilization of Biomethane to Support Energy Security in Indonesia, Riau Province: A Case Study

As the largest global palm oil producer, Indonesia contributes 59% to the world’s palm oil supply, producing 46.9 million tons of Crude Palm Oil (CPO) in 2021. However, this extensive production poses an environmental challenge through Palm Oil Mill Effluent (POME), estimated at 156 million m3 annually. POME treatment facilities release Biogas, predominantly Methane (CH4) at 50%–75%, a potent Greenhouse Gas (GHG) with 21 times the global warming potential of CO2. Conversely, Methane is a key component of widely used Natural Gas. Properly treated, POME-derived biogas can be upgraded to Biomethane, a clean and carbon-negative alternative for the Natural Gas Grid or fossil fuel substitution, estimated at 1,280 MWe, equivalent to 288 MMSCFD CH4. Despite Biomethane’s potential, its utilization remains limited to self-use in Palm Oil Mills or power plants, even in Riau Province, home to Indonesia’s largest oil palm plantation. PT Perusahaan Gas Negara Tbk survey identified potential customers in Riau willing to adopt natural gas, hindered by infrastructure and economic scale challenges. This research analyzes obstacles to biomethane business development in Indonesia, focusing on Riau Province, aiming to formulate an optimal distribution scheme and sustainable strategies. Methodologically, a mix of quantitative and qualitative data collection techniques, including literature studies, interviews, and questionnaires, informed a comprehensive analysis employing geographical, transportation cost, financial modeling, SWOT, and risk analyses. Findings suggest trucking as the optimal distribution mode for biomethane to scattered customers. Economic viability hinges on biomethane volume, necessitating stability and increased sales volume strategies. For Riau, four potential customers with a total daily demand of 11,248.93 m3 can be served affordably by selecting palm oil mills within a 76 km radius. Price and security supply considerations are crucial. This research provides insights into overcoming challenges and optimizing the biomethane business in Riau, offering a sustainable model for broader adoption in Indonesia.

A Short Review: Photocatalysis As An Alternative Method for POME Treatment

The liquid waste produced due to palm oil processing is called palm oil mill effluent (POME). It is challenging to manage because of its high production and inadequate treatment. The discharge of raw POME into the environment will result in multiple detrimental effects and environmental pollution. This short review compares the conventional treatment methods in Malaysia, which are the ponding system for the treatment of POME and the open or closed digesting tank. These systems are unable to achieve the standards set by the Department of Environment (DOE) of Malaysia. Photocatalysts, which are well-known as catalysts in the decomposition of organic contaminants, are suggested as an alternative method for POME treatment. The viability of using photocatalytic technology to remediate POME waste is discussed in this short review. The advancement and improvement of the nanoparticle system for POME treatment are identified based on past studies. It is aimed at providing readers with a clear comparison of conventional POME treatment methods and information on photocatalysis as an alternative POME treatment method.

Advances and Perspectives in Biohydrogen Production from Palm Oil Mill Effluent

Palm oil, the main vegetable oil produced globally, serves diverse purposes, ranging from cooking to the production of processed foods, cosmetics, and biodiesel. Despite contributing significantly to the economies of major producing nations, the escalating production of palm oil raises serious environmental concerns, including deforestation, biodiversity loss, and various forms of pollution. Palm oil mill effluent (POME), a byproduct of palm oil extraction, poses a severe environmental threat when left untreated. As an eco-friendly alternative, anaerobic digestion in controlled bioreactors has emerged, offering simultaneous POME treatment and biofuel generation, particularly hydrogen, with high energy efficiency. This review explores the challenges and opportunities associated with biohydrogen production from POME. Key considerations involve optimizing parameters through pretreatments, nanoparticle incorporation, defining optimal bioreactor conditions, determining hydraulic retention times, and integrating multi-stage processes like dark fermentation followed by photofermentation. This review also emphasizes the significance of sustainable practices and economic analyses in shaping the future of hydrogen production from POME, positioning it as a pivotal player in the palm oil industry’s circular economy and the global energy transition.

Influence of pH on the anaerobic fluidised bed reactor performance for palm oil mill effluent treatment

The effect of pH on the performance of a pilot-scale anaerobic fluidised bed reactor (AnFBR) was studied using palm oil mill effluent (POME) as the substrate. The performance of the 2000-litre reactor at different operating conditions, such as organic loading rates and retention times was studied. This acidic agro-industrial wastewater (pH 4.0–5.0) was neutralised by adding slacked lime. It was observed that, within 12 hr of hydraulic retention time (HRT), the AnFBR removes as high as 85% of the substrate chemical oxygen demand (COD) at a loading rate of 4 kg/m3 day. High pre-treatment cost is needed to neutralise the bulk volume of wastewater that was generated from the palm oil industries. Thus, an attempt was made to study the performance of the AnFBR under pH shock load. The influent pH was increased to 9.2 and then dropped around 5.0 to intensify the effect of the pH shock load. At shock load, the reactor performance for COD removal dropped by about 25% lower than the optimum condition. The maximum and minimum COD removal rates during the short period of continuous shock load were 60% and 56.5%, respectively. The average effluent pH remained steady at around 6.1. From the analysis, it was revealed that the anaerobic fluidised bed had the buffering ability and was capable of treating POME with moderate removal efficiency at an influent pH of 5.0.

FERRIHYDRITE-CHITOSAN NANOCOMPOSITE AS A RECYCLABLE FLOCCULANT FOR PALM OIL MILL EFFLUENT

In the present study, ferrihydrite-chitosan nanocomposite (FCN) was successfully produced by co-precipitation method and used for the first time as a recyclable flocculant for pre-treatment of palm oil mill effluent (POME). The physicochemical properties of FCN were studied using Raman spectrometer, Scanning Electron Microscope (SEM) and Thermogravimetric Analyser (TGA). The feasibility of FCN to remove total suspended solids (TSS), turbidity, chemical oxygen demand (COD), and, oil and grease (O&G) from POME was investigated using a jar test method. The optimum conditions for contaminant removal from POME were determined by varying the experimental parameters such as flocculant dosage, solution pH and settling time. The results obtained showed that FCN, at a dosage of 1.5 g/L, a contact time of 60 min and pH of 5.0 gave a highest reduction of turbidity, TSS, COD and O&G levels by 72.38%, 77.32%, 71.60% and 53.40%, respectively. Besides that, FCN exhibited a better flocculation performance as compared to alum and chitosan. After three cycles of flocculation/deflocculation process, FCN retained satisfying flocculation efficiency and flocculants recovery in the range of 80-83% and 43.2-78.6%, respectively. Combination of charge neutralisation and polymer bridging was the main key mechanism of interaction between FCN and POME contaminants. The synergy effect between iron oxide/oxyhydroxide nanoparticle and chitosan has increased the physicochemical properties and flocculation performance of the FCN nanocomposite. Overall, FCN nanocomposite can be used an alternative flocculant for POME treatment.

Exploring Bio Augmentation as a Sustainable Approach for COD Reduction in Palm Oil Refinery

Purpose: This study aimed to investigate the effectiveness of Bioaugmentation Technology in addressing elevated levels of Chemical Oxygen Demand (COD) and reducing sludge volume in the aeration tank of a Palm Oil Refinery located in Kalimantan Island, Indonesia. In addressing these concerns, the study employed Bioaugmentation Technology, specifically tailored for the treatment of palm oil mill effluent in both aerobic and anaerobic ponds, with the aim of expediting the breakdown of organic compounds.
 Methodology: The research focused on evaluating the impact of this technology on organic degradation and sludge reduction in comparison to conventional treatment methods. Conventional Palm Oil Mill Effluent (POME) treatment systems typically utilize large-volume sequential pond arrangements with extended hydraulic retention times (>90 days), resulting in inefficient organic degradation. Conversely, the Bioaugmentation Technology utilized in this study emerged as a natural, non-toxic, and easily implementable solution to operational challenges faced by these systems.
 Findings: The technology facilitated the rapid breakdown of organic compounds, leading to a reduction in COD and subsequently, a decrease in sludge volume. Based on the observed positive outcomes, it is recommended to consider Bioaugmentation Technology as a viable and efficient solution for POME wastewater treatment in palm oil refineries.
 Unique contributor to theory, policy and practice: Its capacity to enhance organic degradation, reduce sludge volume, and improve overall treatment plant efficiency suggests its potential as a valuable complementary technology to existing treatment methods in similar operational conditions.

Long-term evaluation of palm oil mill effluent (POME) steam reforming over lanthanum-based perovskite oxides

To replace the obsolete ponding system, palm oil mill effluent (POME) steam reforming (SR) over net-acidic LaNiO3 and net-basic LaCoO3 were proposed as the POME primary treatments, with promising H2-rich syngas production. Herein, the long-term evaluation of POME SR was scrutinized with both catalysts under the optimal conditions (600 °C, 0.09 mL POME/min, 0.3 g catalyst, & 74–105 μm catalyst particle size) to examine the catalyst microstructure changes, transient process stability, and final effluent evaluation. Extensive characterization proved the (i) adsorption of POME vapour on catalysts before SR, (ii) deposition of carbon and minerals on spent SR catalysts, and (iii) dominance of coking deactivation over sintering deactivation at 600 °C. Despite its longer run, spent LaCoO3 (50.54 wt%) had similar carbon deposition with spent LaNiO3 (50.44 wt%), concurring with its excellent coke resistance. Spent LaCoO3 (6.12 wt%; large protruding crystals) suffered a harsher mineral deposition than spent LaNiO3 (3.71 wt%; thin film coating), confirming that lower reactivity increased residence time of reactants. Transient syngas evolution of both SR catalysts was relatively steady up to 4 h but perturbed by coking deactivation thereafter. La2O2CO3 acted as an intermediate species that hastened the coke removal via reverse Boudouard reaction upon its decarbonation. La2O2CO3 decarbonation occurred continuously in LaCoO3 system but intermittently in LaNiO3 system. LaNiO3 system only lasted for 13 h as its compact ash blocked the gas flow. LaCoO3 system lasted longer (17 h) with its porous ash, but it eventually failed because KCl crystallites blocked its active sites. Relatively, LaCoO3 system offered greater net H2 production (72.78%) and POME treatment volume (30.77%) than LaNiO3 system. SR could attain appreciable POME degradation (>97% COD, BOD5, TSS, & colour intensity). Withal, SR-treated POME should be polished to further reduce its incompliant COD and BOD5.

Utilization of Angsana Leaves (Pterocarpus indicus Willd) as a Natural Coagulant for Palm Oil Mill Effluent (POME) Treatment

This research aims to prepare natural coagulants from Angsana leaves (Pterocarpus indicus willd) for Palm Oil Mill Effluent (POME) treatment, especially reducing main variables such as TSS, COD, and pH. The amounts of 100 mesh Angsana powder (5, 10, 15, and 20 grams) were extracted using NaCl solvent with concentrations of 0.25 M and 0.5 M, respectively. The extract (200 mL) were added to 500 mL of POME and stirred (180 rpm) for 30 minutes. The concentrations of TSS, COD, and pH in POME were analyzed. Results showed that the coagulation-flocculation process using Angsana leaves powder was able to reduce COD by 55.79% at a coagulant dose of 5 g/L with 0.25 M NaCl solvent and TSS by 99.75% at a dose of 20 g/L with 0.25 M NaCl solvent. However, treatment using Angsana leaves extract was not able to reduce COD to the predetermined quality standard limits while the TSS value met the quality standard. Therefore, POME treatment still requires further processing.

Maximizing biogas yield from palm oil mill effluent (POME) through advanced simulation and optimisation techniques on an industrial scale

The palm oil industry generates a considerable amount of waste, known as palm oil mill effluent (POME), which is characterized by high levels of chemical and biological oxygen demand (COD and BOD). The anaerobic digestion of POME is a potential solution for generating biogas, a renewable energy source that can be used for power generation. However, optimizing biogas production from POME is a challenging task, particularly at the industry scale due to the complex nature of the waste stream. This study aimed to improve the performance of an existing POME-based biogas plant through simulation and optimization. The POME treatment process was simulated using SuperPro Designer software. The simulated results were validated against data obtained from the existing plant, including the environmental properties of COD, BOD, total suspended solids (TSS), and total solids (TS), as well as the composition of the biogas produced. The simulation results showed good agreement with the existing plant data, although some parameters had a high relative difference due to assumptions made during the simulation. The process parameters, including the recirculation ratio and hydraulic retention time, were optimized using Design Expert software. The optimized parameters obtained were a recirculation ratio of 148 % and an HRT of 22 days, resulting in a maximum biogas flow of 859 m3/h, corresponding to a methane yield of 0.259 m3 CH4/kgCOD removed. Confirmatory experiments were conducted over a period of 3 months using the optimized variables in the biogas plant. The results showed a high level of consistency between the predicted and experimental values with a percentage error difference ranging from 0.03 % to 2.3 %. This study's novelty lies in the integration of simulation and optimization tools to improve the performance of POME-based biogas plant. The findings of this study have significant implications for sustainable development in the palm oil industry, providing an efficient and cost-effective approach for treating POME and producing renewable energy.

Biogas Production from Palm Oil Mill Effluent at Low pH

The palm oil industry in Malaysia has aided our economy, but with any thriving industry comes the baggage of industrial waste. This paper focuses on palm oil mill effluent (POME), a waste product formed by palm oil milling operations. The objective of this paper is to evaluate the ability of POME to generate biogas through acid and heat pre-treatment methods. The feasibility of producing biogas at pH levels lower than 5 was investigated. The inoculum is effective microbe 1 (EM1), and the substrate is a liquid POME. Hydrochloric and phosphoric acid were used in this study, and the effect of low initial pH on biogas generation was investigated. The results show that POME alone produced the highest biogas volume (20.1 Nml). However, POME incubated with activated EM1 inoculant at low pH (3.74) generated consistent biogas during 57.75 hours of digestion. In conclusion, the EM1 is a good source of inoculum for POME treatment at low pH, with no pre-treatment required. The pre-treatment methods proposed in this study could have opened new doors for bio-renewable energy research, particularly in agricultural biomass, since substrate pre-treatment can enhance biogas production.