Palm Oil Mill Effluent Treatment Research Articles

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.

Integrated bipolar electrocoagulation and PVC-based ultrafiltration membrane process for palm oil mill effluent (POME) treatment

In this study, the effectiveness of integrating electrocoagulation (EC) and ultrafiltration (UF) membranes for palm oil mill effluent (POME) wastewater treatment was investigated. The impact of various parameters on contaminant removal efficiency, including electrode configuration (monopolar and bipolar), number of anodes, agitation rate, and current density, was studied. The findings demonstrated that using bipolar (BP) electrodes in the EC reactor improved coagulation efficiency. However, an increase in agitation rate led to a decrease in removal efficiency. The electrode configuration of 2A-2C–2B achieved high contaminant removal with a lower electrode consumption compared to the 4A-2C and 4A-2C–2B configurations. The removal efficiencies for total dissolved solids (TDS), total suspended solids (TSS), chemical oxygen demand (COD), and biological oxygen demand (BOD) were 59.1%, 99.9%, 96.8%, and 96%, respectively. The operating cost for the electrode configuration of 2A-2C–2B was estimated to be 2.71 US$ m−3 at an effluent capacity of 50 m3 d−1 and 20 h d−1 of operating time, while the energy requirement was 6.20 kWh m−3. An increase in operating time from 5 to 24 h d−1 raised the specific operating cost from 2.17 to 2.85 US$ m−3. This study provides valuable insights into optimizing EC and UF processes for POME wastewater treatment, which could have significant implications for sustainable industrial practices.

The effect of hydraulic retention time on stabilisation unit in anaerobic – contact stabilisation (A-CST) for treating palm oil mill effluent

The increased use of palm oil in Indonesia has triggered an increase in the quantity of Palm Oil Mill Effluent (POME). The contents of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), as well as oils and grease in palm oil mill effluent, need to be reprocessed, in accordance with the provisions of the Ministry of Environment Regulation No. 5 of 2014, concerning Wastewater Quality Standards, before being discharged into water bodies. In this study, a modification of the treatment unit involving the integration of suspended growth and attached growth in anaerobic and aerobic processes, known as Anaerobic – Contact Stabilisation (A-CST) unit, was conducted to reduce the high concentration of organic matter in POME. This modification can shorten the detention time and reduce the land usage for treatment. The objective of this research was to analyse the performance of the modified A-CST system, based on variations in the detention time and modelling the estimation of biokinetics under unsteady-state conditions, through numerical analysis, statistical tests, and model validation. The research focused on the stabilisation unit, with variations in Hydraulic Retention Time (HRT) of 6 hours, 5 hours, and 4 hours. The results of this study revealed that, the highest percentage of removal was obtained at an HRT variation of 6 hours, with a COD 88%.

Review of techniques for biohydrogen production from palm oil mill effluent

Due to rapid growth in population and societal development, the demand for energy is on the increase. The production of palm oil as one of the major edible oils consumed in the world has increased tremendously. Palm oil mill effluent (POME), a wastewater from the most significant agricultural industry is produced in tremendous amounts that requires proper management to mitigate its negative environmental effects. Studies have shown that Palm oil mill effluent (POME) possesses the properties of a good carbon feedstock for hydrogen generation in fermentation processes. In this study, several methods for biohydrogen production from Palm oil mill effluent (POME) were discussed. An apprehension into the different pre-treatment methods on POME including physicochemical, chemical and biological and their effects on the characteristics of POME including pH, temperature, sugar content, solid content, viscosity, nutrients and by-product toxicity on the biohydrogen production and effluent quality were reviewed. Various bioreactor designs were used for biohydrogen from POME, the modifications applied on the system design to increase the stability and productivity of POME treatment have been examined. The individual and interactive effects of pH, different temperatures of heat treatment, different inoculum sizes and substrate concentrations on biohydrogen production were discussed. Moreover, higher biohydrogen productivity could be obtained with the addition of nanoparticle nutrients and introducing genetically modified H2-producing bacteria. Finally, further investigation in the future shall focus on the development of a more inclusive and efficient POME treatment via DF process that favours biohydrogen production, environmental benign and economically viable.

Enhancing palm oil mill effluent treatment through initial granulation of fruit and vegetable eco-enzymes

Enhancing palm oil mill effluent treatment through initial granulation of fruit and vegetable eco-enzymes

A Hybrid Ultrasonic Membrane Anaerobic System (UMAS) Development for Palm Oil Mill Effluent (POME) Treatment

The high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels in palm oil mill effluent (POME) wastewater make it an environmental contaminant. Moreover, conventional POME wastewater treatment approaches pose economic and environmental risks. The present study employed an ultrasonic membrane anaerobic system (UMAS) to treat POME. Resultantly, six steady states were procured when a kinetic assessment involving 11,800–21,700 mg·L−1 of mixed liquor suspended solids (MLSS) and 9800–16,800 mg·L−1 of mixed liquor volatile suspended solids (MLVSS) was conducted. The POME treatment kinetics were explained with kinetic equations derived by Monod, Contois and Chen and Hashimoto for organic at loading rates within the 1–11 kg·COD·m−3·d−1 range. The UMAS proposed successfully removed 96.6–98.4% COD with a 7.5 day hydraulic retention time. The Y value was 0.67 g·VSS/g·COD, while the specific micro-organism decay rate, b was 0.24 day−1. Methane (CH4) gas production ranged from 0.24 to 0.59 litres per gram of COD daily. Once the initial steady state was achieved, the incoming COD concentrations increased to 88,100 mg·L−1. The three kinetic models recorded a minimum calculated solids retention time of 12.1 days with maximum substrate utilization rate, K values ranging from 0.340 to 0.527 COD·g−1·VSS·d−1 and maximum specific growth rate, µmax from 0.248 to 0.474 d−1. Furthermore, the solids retention time (SRT) was reduced from 500 to 12.1 days, resulting in a 98.4% COD level reduction to 1400 mg·L−1.

Treatment of diluted palm oil mill effluent (POME) synchronous with electricity production in a persulfate oxidant-promoted photocatalytic fuel cell.

Attributable to the prosperous production growth of palm oil in Malaysia, the generated palm oil mill effluent (POME) poses a high threat owing to its highly polluted characteristic. Urged by the escalating concern of environmental conservation, POME pollution abatement and potential energy recovery from the effluent are flagged up as a research topic of interest. In this study, a cutting-edge photocatalytic fuel cell (PFC) system with employment of ZnO/Zn nanorod array (NRA) photoanode, CuO/Cu cathode, and persulfate (PS) oxidant was successfully designed to improve the treatment of POME and simultaneous energy production. The photoelectrodes were fabricated and characterized by field emission scanning electron microscopy with energy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Brunauer, Emmett, and Teller analysis (BET). Owing to the properties of strong oxidant of PS, the proposed PFC/PS system has exhibited exceptional performance, attaining chemical oxygen demand (COD) removal efficiency of 96.2%, open circuit voltage (Voc) of 740.0mV, short circuit current density (Jsc) of 146.7 μA cm-2, and power density (Pmax) of 35.6μWcm-2. The pre-eminent PFC/PS system performance was yielded under optimal conditions of 2.5mM of persulfate oxidant, POME dilution factor of 1:20, and natural solution pH of 8.51. Subsequently, the postulated photoelectrocatalytic POME treatment mechanism was elucidated by the radical scavenging study and Mott-Schottky (M-S) analysis. The following recycling test affirmed the stability and durability of the photoanode after four continuous repetition usages while the assessed electrical energy efficiency revealed the economic viability of PFC system serving as a post-treatment for abatement of POME. These findings contributed toward enhancing the sustainability criteria and economic viability of palm oil by adopting sustainable and efficient POME post-treatment technology.

Comparative analysis in the performances of four in‐ground lagoon anaerobic digesters treating palm oil mill effluent (POME)

AbstractWhile palm oil mill effluent (POME) from different sources will have varying characteristics due to the different process flows in mills, efficient monitoring and performance evaluation of anaerobic digesters in POME treatment are crucial to ensure stable biogas production with minimal operational problems. Therefore, this study aims to evaluate and compare the performances of in‐ground lagoon anaerobic digesters under mesophilic conditions in four different biogas plants (BGPs A, B, C and D) located in Malaysia with respect to total chemical oxygen demand (COD) removal and total biogas produced. Results show that all BGPs are still functioning well with satisfactory methane yields (.135–.364 Nm3 CH4/kgCOD removed) and COD removal efficiencies (67%–85%). ANOVA analysis shows that organic loading rate (OLR), temperature (T) and recirculation ratio (RR) have significant effects on the COD removal and biogas production of all four plants. BGP B has the highest amount of biogas produced (4.12 × 105 Nm3/month) and COD removal rate amongst other BGPs due to its most stable and lowest T (<40°C), high RR, and consistent and high COD load. Conversely, BGP D has the lowest COD removal and biogas production, which are mainly contributed by a high COD inlet (92 000 mg/L) and a high T in the anaerobic digester (48.7°C). Despite having a similar design of an anaerobic digester, this comparative study reveals that different BGPs will have different optimum operating conditions and limitations, depending not only on the operating conditions of the BGP (OLR, T and RR) but also on the raw POME quality stemming from the palm oil milling process. A future study would be focused on the optimisation of four BGPs for maximum biogas removal.

Fabrication of novel Z-scheme BaFe2O4/BiOCl nanocomposite with promoted visible light photocatalytic palm oil mill effluent treatment and pathogens destruction

Fabrication of novel Z-scheme BaFe2O4/BiOCl nanocomposite with promoted visible light photocatalytic palm oil mill effluent treatment and pathogens destruction