Search Results (44)

Palm oil mill effluent (POME), a byproduct of palm oil processing, has substantial resource recovery potential. Its rich biodegradable content supports methane (CH₄) production via anaerobic digestion, enabling renewable energy generation. Additionally, the significant water content of POME can be reclaimed for use in boiler feed, irrigation, and drinking water. However, selecting appropriate technologies to recover valuable resources from POME is challenging, particularly for the purification and upgrading of biogas. Membrane technologies offer an effective approach for transforming POME treatment from an energy-intensive process into a resource recovery system, supporting the decarbonization of palm oil production and advancing global sustainability objectives. This technique is cost-effective and ecofriendly for biogas purification and water reclamation. For biogas purification and upgrading, membrane systems offer the lowest capital and operational costs at 5.654 USD/m³, compared to other technologies, such as 6.249 USD/m³ for water scrubbers and 6.999 USD/m³ for chemical absorbers. This review primarily explores the potential of membranes for gas purification from POME and examines their integration with other processes to develop advanced systems, such as ultrasonicated membrane anaerobic systems and membrane anaerobic systems, to enhance biogas production. In addition, water reclamation from POME is discussed, with ultrafiltration membranes emerging as the most promising candidates. Proton exchange membranes, such as Nafion, are used extensively in microbial fuel cells to improve electricity generation, and this is also summarized. Finally, challenges and future perspectives are highlighted, emphasizing the broader potential of membrane technology in POME wastewater resource recovery. Full article

This paper presents a strategic planning model aimed at optimizing the economic and environmental impacts of palm oil mill effluent (POME) treatment systems. The model determines the optimal selection of POME treatment systems to minimize the environmental impact, specifically focusing on three systems: an anaerobic digester tank system (ADT), a covered lagoon system (CL) with biogas capture, and an open pond system (OP). The model incorporates constraints related to fresh fruit bunch (FFB) production, POME generation, the biological oxygen demand (BOD), the chemical oxygen demand (COD), and carbon dioxide (CO₂) emissions. The optimization framework, formulated as a mixed-integer linear programming (MILP) model, is solved using the GAMS 40.1.0 software. Integer decision variables are used to represent the choice of POME treatment system that minimizes the environmental impact. The study specifically considers the ADT, CL, and OP systems, with the results indicating that the ADT system is the most effective in reducing the BOD, COD, and CO₂-equivalent emissions, thereby highlighting its environmental benefits. The model selects the ADT treatment system, which exhibits the lowest COD, BOD, and CO₂e emissions. Specifically, the COD registered an 85% reduction, from 84,830 mg/L to 12,725 mg/L. The BOD level was reduced by 88%, resulting in a BOD level of 41,208 mg/L to 4945 mg/L. The minimum CO₂e emissions that could be achieved was about 3173 t CO₂e per annum. This model provides a valuable tool for governmental agencies and policymakers to guide the private sector in developing environmentally sustainable POME treatment strategies. Full article

Palm oil mill effluent (POME) is a major contributor to industrial oily wastewater in Malaysia, demanding effective treatment solutions. This study explores the potential of esterified kenaf core (EKC) fiber as an oil adsorbent for oil removal from POME, optimized using a full central composite design (CCD) within the response surface methodology (RSM) framework. The optimum conditions achieved 76% oil removal efficiency, with a 1:0.5 ratio of mercerized kenaf core to stearic acid (MKC:SA), 15 wt% of catalyst, and 1 h reflux time during the esterification process. The regression model exhibited strong predictive capability, with a significant quadratic correlation and an R² value of 0.94. The Fourier transform infrared (FTIR) spectroscopy revealed the existence of ester functional groups characterized by significant hydrophobicity and a decrease in hydroxyl groups, indicating the chemical changes of EKC. Moreover, the scanning electron microscopy (SEM) research demonstrated structural alterations in EKC, including heightened surface roughness, fibrillation, and pore development, which improved oil adhesion relative to raw kenaf core (RKC). These findings indicate that EKC provides an effective, environmentally sustainable solution for managing oil wastewater issues in the palm oil sector, facilitating enhanced ecological sustainability and resource management. Full article

The treatment of palm oil mill effluent (POME) poses a significant challenge for Malaysia’s palm oil industry, necessitating compliance with the Department of Environment (DOE) regulations prior to discharge. This study introduces an eco-friendly synthesis method utilizing mangosteen (Garcinia mangostana L.)-leaf aqueous extract to fabricate copper oxide (CuO), zinc oxide (ZnO) nanoparticles (NPs), and their nanocomposite (CuO-ZnO NCs). The physicochemical properties of these nanomaterials were characterized using various analytical tools and their effectiveness in reducing the chemical oxygen demand (COD) of palm oil mill effluent (POME) was assessed under the illumination of two types of light sources: monochromatic blue- and polychromatic white-light emitting diodes (LEDs). CuO-ZnO NCs demonstrated superior performance, with the lowest energy bandgap (1.61 eV), and achieved a COD removal efficiency of 63.27% ± 0.010 under blue LED illumination, surpassing the DOE’s discharge limit of 100 mg/L. This study offers a cost-effective and environmentally friendly method for synthesizing heterojunction materials, which show great potential as photocatalysts in reducing POME COD to permissible levels for discharge. Full article

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. Full article

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. Full article

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, µ_max 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. Full article

The rapid increase in demand for renewable energy has led to a need for more efficient and effective ways to produce biogas from palm oil mill effluent (POME), which is rich in biological and chemical oxygen demand (BOD and COD). Despite its potential as a source of biogas, POME is not always effectively utilized in biogas production due to a lack of optimization of the treatment process. This study aims to address this issue by identifying the critical parameters affecting biogas production from POME and optimizing the process for maximum biogas yield and COD removal. This study employed comparative analysis and response surface methodology to optimize the performance of palm oil mill effluent (POME)-based biogas plants in Malaysia. Historical data from three commercial POME-based biogas plants in Malaysia were analyzed to identify the most critical parameters for biogas yield and COD removal. Response surface methodology, using Box–Behnken design and Design-Expert software, was then used to optimize these parameters. Sensitivity analysis was performed to interpret the impact of parameters on biogas production, with Organic Loading Rate (OLR) found to be the most critical factor for methane yield. The results showed that the optimum conditions for maximum methane production were OLR of 1.23 kg/m³·day, inlet Total Solids (TS) of 46,370 mg/L, pH of 4.5, and temperature of 45.4 °C, resulting in a 39.6% increase in methane yield (0.335 m³ CH₄/kgCOD_removed) and a 1.1% increase in COD removal (93.4%). Full article

Diabetic retinopathy (DR) primarily progresses into retinal degeneration caused by microvascular dysfunction. The pathophysiology of DR progression is still uncertain. This study investigates the function of beta-carotene (PBC) originating from palm oil mill effluent in the treatment of diabetes in mice. An intraperitoneal injection of streptozotocin (35 mg/kg) was used to induce diabetes, which was then accelerated by an intravitreal (i.vit.) injection of STZ (20 µL on day 7). PBC (50 and 100 mg/kg) and dexamethasone (DEX: 10 mg/kg) were also administered orally (p.o.) for 21 days. At various time intervals, the optomotor response (OMR) and visual-cue function test (VCFT) responses were evaluated. Biomarkers, such as reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARSs), and catalase activity were determined in retinal tissue samples. DR significantly lowers the spatial frequency threshold (SFT) and time spent in the target quadrant (TSTQ), increases the reaching time in the visual-cue platform (RVCP), lowers retinal GSH and catalase activity levels, and elevates TBARS levels. The treatments of PBC and DEX also ameliorate STZ-induced DR alterations. The potential ameliorative activity of PBC in DR is attributed to its anti-diabetic, anti-oxidative, and control of blood–retinal barrier layer properties. Full article

The commercial thin-film composite (TFC) nanofiltration (NF) membrane is unsuitable for engineered osmosis processes because of its thick non-woven fabric and semi-hydrophilic substrate that could lead to severe internal concentration polarization (ICP). Hence, we fabricated a new type of NF-like TFC membrane using a hydrophilic coated polyacrylonitrile/polyphenylsulfone (PAN/PPSU) substrate in the absence of non-woven fabric, aiming to improve membrane performance for water and wastewater treatment via the engineered osmosis process. Our results showed that the substrate made of a PAN/PPSU weight ratio of 1:5 could produce the TFC membrane with the highest water flux and divalent salt rejection compared to the membranes made of different PAN/PPSU substrates owing to the relatively good compatibility between PAN and PPSU at this ratio. The water flux of the TFC membrane was further improved without compromising salt rejection upon the introduction of a hydrophilic polydopamine (PDA) coating layer containing 0.5 g/L of graphene oxide (PDA/GO0.5) onto the bottom surface of the substrate. When tested using aerobically treated palm oil mill effluent (AT-POME) as a feed solution and 4 M MgCl₂ as a draw solution, the best performing TFC membrane with the hydrophilic coating layer achieved a 67% and 41% higher forward osmosis (FO) and pressure retarded osmosis (PRO) water flux, respectively, compared to the TFC membrane without the coating layer. More importantly, the coated TFC membrane attained a very high color rejection (>97%) during AT-POME treatment, while its water flux and reverse solute flux were even better compared to the commercial NF90 and NF270 membranes. The promising outcomes were attributed to the excellent properties of the PAN/PPSU substrate that was coated with a hydrophilic PDA/GO coating and the elimination of the thick non-woven fabric during TFC membrane fabrication. Full article

Palm oil mill effluent (POME) is considered the most environmentally harmful when discharged without proper treatment. In addition to conventional biological treatment methods, physicochemical treatment techniques are considered alternative methods to treat POME as polishing or post-treatment techniques to meet the discharge water quality standards set by authorities. Recently, electroflotation (EF) has gained popularity in wastewater treatment owing to its high efficiency, no harmful by-products, and ease of operation. However, EF has limitations on energy consumption because high current density and long electrolysis time are often used to increase the density of gas bubbles and metallic ions produced in the EF system used in pollutant removal. Polyaluminum chloride (PAC) and cationic polyacrylamide (CPAM) are used as alternative options for the production of coagulants instead of using a sacrificial anode in EF. In this study, we hypothesized that PAC and CPAM could enhance the efficiency and reduce the specific energy consumption of EF by minimizing the electrolysis time used in POME treatment. The effects of electrolysis time, current density, and coagulant dosage on POME treatment were investigated. EF treatment at a current density of 2.5 mA/cm² has achieved 82% of turbidity and 47% of chemical oxygen demand (COD) removal after 45 min electrolysis time, consuming 0.014 kWh of specific energy for the treatment of one gram of COD. There was no improvement in terms of turbidity removal when the current density was increased from 2.5 to 5 mA/cm²; however, the COD removal efficiency was increased up to 52% at 5 mA/cm². When EF was performed at 1 A combined with PAC at a dosage of 40 mg/L and CPAM at a dosage of 20 mg/L, it was noticed that turbidity and COD removal increased up to 96% and 54%, respectively, within 15 min electrolysis. Subsequently, the specific energy consumption was reduced to 0.004 kWh (by 71%) per one gram of COD treatment. Results confirmed that the chemical coagulants could increase the POME treatment efficiency and reduce the specific energy consumption of EF. However, this method can be improved aiming at further reduction of COD by mineralizing the dissolved organic compounds to fulfill the POME discharge quality standards. Full article

High organic materials in palm oil mill effluent (POME) can result in serious water pollution. To date, biological treatment has been used to reduce the environmental risks of these effluents prior of their discharge into water streams. However, the effluents’ dark brownish colour remains as a significant issue that must be addressed, as it affects the overall quality of water. Although membrane technology has been frequently used to address these difficulties, membrane fouling has become a serious limitation in POME treatment. On the other hand, zwitterions with balanced charge groups have received growing interest in the fabrication of antifouling membranes due to their hydrated nature. The development of a simple and efficient covalent bonding technique to improve the stability of zwitterions on membrane surfaces remains a challenge. By grafting and co-depositing polyethylenimine (PEI)-based zwitterion (Z-PEI) with super hydrophilic polydopamine (PDA) on the surface of a commercial polysulfone (PSf) ultrafiltration membrane at ambient temperature, a new zwitterionic surface with a neutral surface charge was created (PDA/Z-PEI). This study aims to investigate the effect of different loading ratios of PDA/Z-PEI (1:1, 1:2, and 1:3) and evaluate their performance on treating brownish coloured anaerobically treated POME (AT-POME). SEM and FTIR analysis showed the successful incorporation of the PDA/Z-PEI membrane while the zwitterionic feature is indicated by zeta potential analysis. Water flux analysis demonstrated that a lower water flux was achieved for M-ZPEI membranes as compared to the PSf and PSf-MDPA membranes, attributed by the tight skin layer of PDA-ZPEI. In the development of a tight hydration layer on the membrane surface by zwitterions, zwitterionic membranes demonstrated excellent antifouling capabilities, particularly PDA/Z-PEI with a loading ratio of (1:2) with a flux recovery ratio of around 84% and colour rejection of 81.75%. Overall, this research contributes to the development of a unique coating with improved stability and antifouling properties by altering the membrane surface in a simple and reliable manner. Full article

Palm oil mill effluent (POME) is a potential alternative sources of biomass fuel upon phycoremediation treatment using microorganisms. In this study, Coccomyxa dispar and Scenedesmus parvus, as acidophilic microalgae, were used to investigate growth and the production of biomass fuel from the cultivation of POME, as well the effectiveness of removing contaminants from POME. Individual cultivation was conducted at 26 ± 3 °C for 14 days under three growth modes (mixotrophic, heterotrophic, and autotrophic). To elucidate the potential phycoremediation properties, the characteristics of treated POME were compared, such as optical density (OD), cell dry weight (CDW), calorific energy values (CEV), chemical oxygen demand (COD), biochemical oxygen demand (BOD), carbon, hydrogen, and nitrogen (CHN) elemental analysis, including oil and grease content. S. parvus exhibits an outstanding growth profile for all growth modes compared to C. dispar, with measurements of 228.8, 37.08, and 118.2 mg/L observed at day 14 of cultivation. The highest CEV is 32.30 MJ/kg, which was obtained from S. parvus in the mixotrophic mode. Maximum removal efficiency for COD and BOD was 81% and 19% in the mixotrophic growth mode with S. parvus. These results pinpoint that S. parvus has the potential to be utilized for biomass fuel production with high CEV and effective POME phycoremediation. Full article

A pre-culture stage is required to obtain robustly-dividing cells with high hydrogen (H₂) production capabilities. However, a step-by-step process for biohydrogen production is scarcely reported, mainly from palm oil wastewater. Therefore, this study developed a guideline to find the best inoculum heat treatment conditions and implement the selected conditions for biohydrogen production using palm oil wastewater. This study used raw palm oil mill effluent (POME) and POME sludge as substrate and inoculum, respectively. Our findings reveal that 80 °C and 30 min were the best conditions for inoculum heat treatment. When testing the conditions on POME sludge and inoculating with raw POME (28 g COD/L) at 37 °C (reaction temperature), 24 h (reaction time), and pH 5.5, 34 mL H₂/d was recorded. A slight increase (1.1-fold) was observed compared to 5 g COD/L POME co-digested with 5 g/L glucose (31 mL H₂/d). This discovery indicates that raw POME is a potential source for biohydrogen production under anaerobic fermentation and can be directly used as substrate up to 30 g COD/L. The proposed guideline could also be implemented for different organic wastes for biohydrogen production study. Full article

Beta carotene is a natural anti-oxidant agent, and it inhibits the matrix metalloprotease (MMP) activity. Diabetic neuropathic pain (DNP) is produced by cellular oxidative stress. The role of the beta carotene effect in diabetic neuropathic pain is not explored yet. The present study is designed for the evaluation of the palm oil mill effluent-derived beta carotene (PBC) effect in DNP in zebrafish. The DNP was induced by the intraperitoneal administration of streptozotocin (STZ). Blood glucose levels of above 15 mM were considered to be diabetic conditions. The zebrafish were exposed to test compound PBC (25, 50, and 100 µM), pregabalin (PG: 10 μM), and an MMP-13 inhibitor (CL-82198; 10 μM) for 10 consecutive days from day 11. The neuralgic behavioral parameters, i.e., temperature test, acetic acid test, and fin clip test were assessed on day 0 and the 7th, 14th, and 21st days. On the 22nd day, the blood glucose and MMP-13 levels and brain thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), and MMP-13 activity levels were estimated. The treatment of PBC ameliorated the DNP-associated behavioral and biochemical changes. The results are similar to those of PG and CL-82198 treatments. Hence, the PBC possesses a potentially ameliorative effect against DNP due to its potential anti-oxidant, anti-lipid peroxidation, and MMP-13 inhibitory actions. Full article