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Methods are investigated to prepare active hydrogen (H 2)-producing cultures originating from palm oil mill sludge using dark fermentation. The first successful method that produces potent H 2 -producing cultures and avoids growing H 2 -consuming methanogens involves heat pretreatment of the sludge at 100 °C for 2 h and then the sludge sample is shocked in an ice bath for 15 min. Subsequently, a glucose solution rich in nutrients (glucose-based substrate) of 14.80 g chemical oxygen demand (COD)/L is fed in to enrich the H 2 -producing cultures. The H 2 production reaches 78.63% on day 31. The second method involves acid pretreatment of sludge with 10 M hydrochloric acid at pH 3 for 48 h. Glucose-based substrate of 25.47 g COD/L is fed into the system. The H 2 production is 69.41% on day 27. For both methods, the H 2 production is stable after the H 2 content reached its maximum. The operation is performed semi-continuously using a hydraulic retention time of 1 day and at 30 °C. The optimum bacterial cells-to-COD level of substrate is approximately 0.60 in the start-up medium. The fermentation medium has an optimum initial pH of 5 and a final pH of 5.2–5.3. These two methods are recommended to produce active H 2 -producing cultures for plant start-up in bio-H 2 production. • Active H 2 -producing cultures are prepared for system start-up. • Pretreatment of palm oil mill sludges and preparation methods are proposed. • Glucose-based substrate is used in maximizing consistency for bacterial growth. • The fermentation medium has initial pH 5 and final pH 5.2–5.3. • The H 2 content reaches 78.63% on day 31 with production stable thereafter. [ABSTRACT FROM AUTHOR]

Alcaligenaceae and Chromatiaceae were previously reported as the specific pollution bioindicators in the receiving river water contaminated by palm oil mill effluent (POME) final discharge. Considering the inevitable sensitivity of bacteria under environmental stresses, it is crucial to assess the survivability of both bacteria in the fluctuated environmental factors, proving their credibility as POME pollution bioindicators in the environment. In this study, the survivability of Alcaligenaceae and Chromatiaceae from facultative pond, algae (aerobic) pond and final discharge were evaluated under varying sets of temperature (25–40°C), pH (pH 7–9) and low/high total suspended solid (TSS) contents of POME collected during low/high crop seasons of oil palm, respectively. Following treatment, the viability status and compositions of the bacterial community were assessed using flow cytometry-based assay and high-throughput Illumina MiSeq, respectively, in correlation with the changes of physicochemical properties. The changes in temperature, pH and TSS indeed changed the physicochemical properties of POME. The functionality of bacterial cells was also shifted where the viable cells and high nucleic acid contents reduced at elevated levels of temperature and pH but increased at high TSS content. Interestingly, the Alcaligenaceae and Chromatiaceae continuously detected in the samples which accounted for more than 0.5% of relative abundance, with a positive correlation with biological oxygen demand (BOD 5) concentration. Therefore, either Alcaligenaceae or Chromatiaceae or both could be regarded as the reliable and specific bacterial indicators to indicate the pollution in river water due to POME final discharge despite the fluctuations in temperature, pH and TSS. [Display omitted] • Changes in temperature, pH and TSS affected bacterial cells viability and HNA/LNA ratio in POME. • Bacterial composition in POME was shifted due to changes in temperature, pH and TSS. • Bacterial indicators were detected in POME despite the changes of temperature, pH and TSS. • The detection of Alcaligenaceae and Chromatiaceae in POME was positively correlated with BOD 5. • Alcaligenaceae and Chromatiaceae are reliable bioindicators to indicate POME pollution. [ABSTRACT FROM AUTHOR]

Some species of Basidiomycetes, specifically white rot groups, produce three ligninolytic enzymes, namely, Lignin Peroxidase (LiP), Manganese Peroxidase (MnP) and Laccase (Lac), which have low activity in degrading Palm Oil Mill Effluent (POME). The research objective was to obtain the data on the ability of the Coltricia cinnamomea to produce LiP, MnP, and Lac enzymes to degrade POME. This research also studied the effect of sucrose, alcohol, veratryl alcohol, CuSO4 and ZnSO4, as inducers. Isolates of Coltricia cinnamomea, which were stored in a PDA media at -20°C were obtained from the Microbiology section of the Research Center for Biology (LIPI). Furthermore, the growth media used were DM, Bean sprout Extract (TE) and PDB. The result indicated that PDB is the most suitable growth media for the production of ligninolytic enzymes, because in this medium these enzymes showed the highest activity. It was also observed that sucrose increased the laccase activity by 40.80%. Furthermore, Coltricia cinnamomea was able to reduce the concentration of Poly R-478 by 60.74%, after the addition of ZnSO4. In addition, it degraded and decreased the color and COD of POME, by 72.63% and 91.19% respectively, after the addition of veratryl alcohol, and incubation for 10 days. Therefore, this fungus can be used to degrade POME in order to prevent environmental pollution. Coltricia cinnamomea has not been used for POME degradation. By using Coltricia cinnamomea, we obtained new data regarding the activity of laccase and its ability to degrade POME. [ABSTRACT FROM AUTHOR]

The presence of free fatty acids (FFA) and chloride contents in crude palm oil is not desirable because they have an impact on oil quality and food safety. This work presents a method to reduce these compounds by washing the crude palm oil (CPO) with treated aerobic liquor (AL). The effects of process parameters on the reduction of FFA and chloride in CPO and the resultant 3‐monochloropropane‐1,2 diol ester (3‐MCPDE) formed after refining are investigated. The results show that the AL dosage, initial FFA content, mixing speed, and duration have significant influence on the reduction of FFA in the CPO. Meanwhile, the chloride content is reduced by approximately 50% regardless of the AL dosage used. Consequently, the 3‐MCPDE content in the oil after refining is up to 53% lower than that of the refined oil produced from the untreated CPO. Furthermore, an oil recovery above 97% can be achieved after the AL‐washing step. The implementation strategy of this method in the palm oil mills has also been proposed. In conclusion, an effective and sustainable method for in situ improvements of the quality and food safety of palm oil has been developed without the need for additional water or chemical. Practical Applications: Treated aerobic liquor can be used to wash the CPO in palm oil mill for in situ reductions of FFA and chloride contents in CPO to improve the oxidative stability of CPO. The lower content of chlorides in CPO could mitigate the formation of 3‐MCPDE during refining, thus improving the food safety of palm oil. This method can readily be implemented by the industry and it is sustainable because it does not require the use of additional process water or chemical. [ABSTRACT FROM AUTHOR]

The high phenolic content of Palm Oil Mill Effluent (POME) constitutes an environmental concern. In this study, laccase producing microorganisms were isolated from POME samples collected in Côte d'Ivoire for their possible use in POME treatment. Strain showing the highest laccase activity was identified by ITS1-5.8S-ITS2 region sequencing as Trametes polyzona. A maximum laccase production (156.3 U/mL) was obtained after 10 days of incubation under shaking condition, at 37 °C, pH 4, with starch (1%), tryptone (0.3%) and 10 mM of guaiacol. The partially purified laccase of 31 kDa exhibited maximum activity at 50 °C and pH 4.5 with a Km for guaiacol and Vmax of 0.7 mM and 0.04 mM/min, respectively. Metals, SDS and EDTA did not inhibit his activity. Used as biotreatment agent, T. polyzona MPS1-3 reduced COD, total suspended solids, total solids and total phenolics by 16.03%, 70.15%, 38.9%, 50.84%, respectively, for sterilized POME and by 13.09%, 58.07%, 36.53%, 42.05% for unsterilized POME. These results showed the promising application of T. polyzona for bioremediation of phenolics compounds in wastewater and it potentially useful in several other biotechnological applications. [ABSTRACT FROM AUTHOR]

This paper employs a partial equilibrium model to investigate the economic and environmental impact of commercial bioethanol production from biomass on the Malaysian agricultural markets. The results show that the palm oil mills can produce bioethanol commercially as the mills utilize the waste biomass created onsite and thus avoid the feedstock and hauling costs. Furthermore, by consuming biomass that recycles carbon dioxide from the atmosphere, a large bioethanol industry would help Malaysia reduce its GHG emissions and meet its GHG commitments in the Paris Agreement. With a potential to lead to greater forestation as landowners clear rainforests to enlarge oil palm plantations, such an industry could also be expected to expand the agricultural industry, reduce the agricultural prices, and raise agricultural employment. • Producing bioethanol from waste biomass is economically viable in Malaysia. • Gasoline-bioethanol blends can significantly reduce Malaysia's greenhouse gas emissions. • A commercial bioethanol industry would expand the agricultural sector and hasten deforestation. [ABSTRACT FROM AUTHOR]

BACKGROUND Olives are stored for a short time after harvesting pending processing in the oil mills. Furthermore, olives are often washed prior to fruit storage. In this work we study how washing and storage affect fruit ethanol content and the effect on virgin olive oil ethanol content and quality. RESULTS: Olive storage produced an increase in the fruit ethanol content, achieving values six times higher when storage was in silos. Washing the olives resulted in an increase in fruit ethanol content, although when washed olives were processed immediately no difference was found. The increase in fruit ethanol content during storage was reflected in higher oil ethanol concentration. Similarly, olive washing resulted in oils with higher ethanol concentration. Industrial conditions gave more important increases in oil ethanol content than that from olives processed by hand. For quality parameters all the olive oils were classified as 'extra virgin'. In general, oils showed a slight decrease in some sensory attributes. At industrial scale after 24 h storage oils were classified as 'virgin' because sensory defects were found. CONCLUSION: Olive storage should be avoided or reduced to less than 12 h; if possible, olives should not be washed before storage since this practice favors losses in sensory characteristics and the synthesis of ethanol, a precursor of ethyl esters. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Palm oil industries have become the main sector to boost the economic revenue in tropical countries, especially in South East Asia. In the recent years, the global production of palm oil reached 72 million metric tons in 2018, increasing from about 68 million metric tons in 2017. During that period, Malaysia is currently the second world producer of palm oil after neighbouring country Indonesia. Both countries are the leading exporters of palm oil with 84 % of worldwide production. A detailed analysis of the palm oil business in Malaysia, the environmental issues that have arisen, and the treatment technology used to effectively treat palm oil mill wastewater are reviewed to gain an understanding of environmental sustainability. In Malaysia, most of the oil palm plantations are owned by private conglomerates (61 %), followed by the independent smallholders (16 %), the Federal Land Development Authority (13 %), state agencies (6 %), the Federal Land Consolidation and Rehabilitation Authority (3 %), and Rubber Industry Smallholders Development Authority (1 %). However, the rate of deforestation has increased due to the expansion of oil palm plantations in Malaysia. Palm oil mill effluent is also considered as one of the major environmental issues since it reduces the water quality index. Some techniques are implemented to treat palm oil mill effluent, such as anaerobic ponding systems, integrated anaerobic-aerobic bioreactors, coagulation and flocculation, thermochemical treatment, vermicomposting, membrane filtration, photocatalysis, moving bed biofilm reactors, and zero liquid discharge. Zero liquid discharge method is considered an appropriate method since this method provides a better waste recovery. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the potential of boiler ash from palm oil mills to improve the quality of acid mine drainage (AMD). The experiment was conducted using boiler ash with five doses of 0, 3, 6, 9, 12, and 15 mg. Quicklime was used as a comparison material with doses of 0, 0.02, 0.03, 0.05, 0.1, and 0.3 mg. Boiler ash and quicklime were added to each 500 mL AMD. The parameters of the AMD quality measured were pH, dissolved iron (Fe) and manganese (Mn), and the precipitates of Fe and Mn. The results showed that the addition of boiler ash and quicklime into AMD increased the pH and decreased the concentration of dissolved Fe and Mn and increased the precipitate of Fe and Mn. The pH value of AMD increased with increasing doses of boiler ash and quicklime. An increase in the pH value was followed by a decrease in the dissolved Fe and Mn and anincrease in the Fe and Mn precipitate. The highest pH values, Fe and Mn precipitates, and the lowest dissolved Fe and Mn were obtained by the treatment of 15 mg/L boiler ash and 0.3 mg/L quicklime. The boiler ash showed promising potential as an alternative neutralizing reagent to improve AMD even though the amount of boiler ash needed to repair AMD was more than quicklime. [ABSTRACT FROM AUTHOR]

Carbon-encapsulated iron oxide nanoparticles (CE-nFe) have been obtained from an industrial waste (oil mill wastewater-OMW, as a carbonaceous source), and using iron sulfate as metallic precursor. In an initial step, the hydrochar obtained has been thermally activated under an inert atmosphere at three different temperatures (600 °C, 800 °C and 1000 °C). The thermal treatment promotes the development of core-shell nanoparticles, with an inner core of α-Fe/Fe 3 O 4 , surrounded by a well-defined graphite shell. Temperatures above 800 °C are needed to promote the graphitization of the carbonaceous species, a process promoted by iron nanoparticles through the dissolution, diffusion and growth of the carbon nanostructures on the outer shell. Breakthrough column tests show that CE-nFe exhibit an exceptional performance for H 2 S removal with a breakthrough capacity larger than 0.5–0.6 g H 2 S/g catalyst after 3 days experiment. Experimental results anticipate the crucial role of humidity and oxygen in the adsorption/catalytic performance. Compared to some commercial samples, these results constitute a three-fold increase in the catalytic performance under similar experimental conditions. [Display omitted] • Oil mill wastewater has been transformed into added value catalysts for H2S removal. • Well-designed Fe-based core-shell nanoparticles have been successfully prepared. • These composites exhibit an exceptional performance for H2S removal. [ABSTRACT FROM AUTHOR]

[Display omitted] Indonesia possesses the greatest potential in the world for bio-compressed natural gas (bio-CNG). This bio-CNG is purified from biogas that is generated from decomposing organic liquid waste at palm oil mills (POMs). Unfortunately, this great potential has not been utilized much due to several obstacles such as the remote location of POMs, transportation mode, and utilization purposes. These factors have a significant impact on the feasibility of bio-CNG selling prices. However, a case study conducted in the Riau province of Indonesia showed that by clustering POMs, selecting appropriate transportation modes, and generating additional income from carbon trading, the feasibility for bio-CNG selling price can be achieved. The study resulted in obtaining two clusters of seven POMs that were spread over a 30km radius from Pekanbaru City. Bio-CNG has a potential to substitute 97 % of gasoil for bus fuel, and trucking transportation was found to result in the lowest bio-CNG selling price, which was 10.7 USD/MMBTU. With additional income from carbon trading, the minimum price can reach 4.84 USD/MMBTU. The utilization of bio-CNG contributes to reducing greenhouse gas emissions, which, in turn, can increase the economic value of bio-CNG. The pattern of usage and the selection of the factors mentioned above should be considered when utilizing bio-CNG resulting from biogas-POME purification. It is still necessary to provide supportive policies from the government. [ABSTRACT FROM AUTHOR]

The escalating consumer demand for crabs results in a growing amount of waste, including shells, claws, and other non-edible parts. The resulting crab shell waste (CSW) is disposed of via incineration or landfills which causes environmental pollution. CSW represents a potential biological resource that can be transformed into valuable resources via pyrolysis technique. In this study, microwave pyrolysis of CSW using self-purging, vacuum, and steam activation techniques was examined to determine the biochar production yield and its performance in treating palm oil mill effluent (POME). The biochar produced through microwave pyrolysis exhibits yields ranging from 50 to 61 wt%, showing a hard texture, low volatile matter content (≤34.1 wt%), and high fixed carbon content (≥58.3 wt%). The KOH-activated biochar demonstrated a surface area of up to 177 m2/g that is predominantly composed of mesopores, providing a good amount of adsorption sites for use as adsorbent. The biochar activated with steam removed 8.3 mg/g of BOD and 42 mg/g of COD from POME. The results demonstrate that microwave pyrolysis of CSW is a promising technology to produce high-quality biochar as an adsorbent for POME treatment. [Display omitted] • Different microwave pyrolysis methods are examined for biochar production. • Biochar is further microwave-activated via steam and KOH. • High yield of biochar and activated biochar is obtained. • These biochar show desirable adsorption efficiency of COD and BOD. [ABSTRACT FROM AUTHOR]

Palm Oil Mill Effluents (POME) are complex fermentative substrates which habour diverse native microbial contaminants. However, knowledge on the microbiota community shift caused by the anthropogenic effects of POME in the environment is up to date still to be extensively documented. In this study, the bacterial and archaeal communities of POME from two palm oil processing systems (artisanal and industrial) were investigated by Illumina MiSeq Platform. Despite the common characteristics of these wastewaters, we found that their microbial communities were significantly different with regard to their diversity and relative abundance of their different Amplicon Sequence Variants (ASV). Indeed, POME from industrial plants harboured as dominant phyla Firmicutes (46.24%), Bacteroidetes (34.19%), Proteobacteria (15.11%), with the particular presence of Spirochaetes, verrucomicrobia and Synergistetes, while those from artisanal production were colonized by Firmicutes (92.06%), Proteobacteria (4.21%) and Actinobacteria (2.09%). Furthermore, 43 AVSs of archaea were detected only in POME from industrial plants and assigned to Crenarchaeota, Diapherotrites, Euryarchaeota and Nanoarchaeaeota phyla, populated mainly by many methane-forming archaea. Definitively, the microbial community composition of POME from both type of processing was markedly different, showing that the history of these ecosystems and various processing conditions have a great impact on each microbial community structure and diversity. By improving knowledge about this microbiome, the results also provide insight into the potential microbial contaminants of soils and rivers receiving these wastewaters. [ABSTRACT FROM AUTHOR]

In this study, physicochemical characteristics, phytochemical compositions, and antioxidant activities of Pinus halepensis Mill. seed oils (PHSO) from two geographical origins (Algeria and Turkey) and obtained through two different extraction processes (cold pressing and solvent extraction) were determined. PHSO were majorly consisted of linoleic and oleic acids. Cold pressing yielded oils with lower peroxide and totox values, higher tocopherols contents (309.42–318.04 mg/100 g), higher DPPH‐radical scavenging activities (25.33–26.94 mM TE/kg), and reducing capacity values (301.30–329.94 mg GAE/kg). The solvent‐extracted oils contained more phytosterols (5,683.25–5,964.20 mg/kg), particularly β‐sitosterol and campesterol. Phenolic compounds of PHSO were identified by HPLC‐DAD for the first time in this study. More phenolic compounds were detected in solvent‐extracted oils. Turkish PHSO were richer in individual phenolics (18,928.92 μg/100 g) than the Algerian variety (2,821.01 μg/100 g). Different extraction techniques and geographical origins led to differences in physicochemical and phytochemical attributes of PHSO. Novelty impact statement: This study revealed that extraction technique (cold‐pressing, solvent extraction) and geographical seed origin (Algeria, Turkey) influenced the Pinus halepensis Mill. seed oils (PHSO) composition. PHSO are rich in fatty acids, sterols, and tocopherols majorly linoleic acid, γ‐tocopherol, and β‐sitosterol which were detected for first time for the cold pressed oils. This is the first report on phenolics compounds of these oils, mainly luteolin. The high oxidative stability and good antioxidant activities of PHSO promote their exploitation in food, cosmetics, and pharmaceuticals uses. [ABSTRACT FROM AUTHOR]

Palm oil mill industry generates a large amount of POME (palm oil mill effluent) and EFB (empty fruit bunch) as a byproduct. Biogas production from anaerobic co-digestion of POME with EFB was investigated under mesophilic condition. High methane yield and high biodegradability were achieved as mixing POME with EFB material applied into an alkaline pretreatment method. The raw biogas from anaerobic co-digestion of POME and EFB contained 60% CH4, 34% CO2, and 200 ppm H2S and was available at 1.013 bar with a production rate of 48–65 m3/h. The biomethane has not utilized as a bio-CNG gas in Southeast Asian region yet. This paper aims to identify the potential of POME biogas into purified bio-CNG gas. The location, capacity and technology of biogas refinery plant were identified based on biogas production of Malaysian palm oil mill plant. The chelate-iron (EDTA-iron solution) process as a pre-treatment method of raw biogas is among the most promising techniques for the hydrogen sulfide (H2S) removal of 99%. The energy contents of biogas could be significantly enhanced by upgrading it to CNG fuel. A pilot-scale separation plant based on cellulosic spiral wound membrane for upgrading biogas to CNG fuel quality was constructed as having a capacity of 30 m3/h and operated at the biogas plant. The result shows that purifying yield contained 98% CH4, 2% CO2, 0.004% H2O, and 1 ppm H2S. [ABSTRACT FROM AUTHOR]

Palm oil mill effluent (POME) has high chemical oxygen demand (COD), thus requires effective treatments to environmentally benign levels before discharge. In this study, immobilized microalgae cells are used for removing pollutants in treated palm oil mill effluent (TPOME). Different ratios of microalgae beads to TPOME concentration were examined at 1:2.5, 1:5, and 1:10. The biomass concentration and COD removal were measured through a standard method. The color of the cultivated microalgae beads changed from light green to darker green after the POME treatment for 9 days, hence demonstrating that microalgae cells were successfully grown inside the beads with pH up to 9.84. The immobilized cells cultivated in the POME at 1:10 achieved a higher biomass concentration of 1.268 g/L and a COD removal percentage of 72% than other treatment ratios. The increment of the ratio of microalgae cells beads to POME concentration did not cause any improvement in COD removal efficiency. This was due to the inhibitory effect of self-shading resulting in the slow growth rate of microalgae cells which responsible for low COD removal. Therefore, this system could be a viable technology for simultaneous biomass production and POME treatment. This will contribute to research efforts toward the development of new and improved technologies in treating POME. [ABSTRACT FROM AUTHOR]

Because colony formation is essential to seek bacterial functions by the direct observation of phenotype, the diversification of colony formation for culturable bacteria is a big challenge in the research field of Environmental Biotechnology. In this study, the biodiversity of cultivable bacteria (colony or liquid culture) was compared by using Luria-Bertani (LB) medium and waste sewage sludge (WSS) under different dilutions and temperatures. When WSS was used as a bacterial source, whereas the highest number of colonies was found at the concentration of WSS (5%), a particular concentration of LB (10%) or WSS (1%) as a growth medium showed the best number of the operational taxonomic units (OTUs) of colonies. The results of bacterial community structure indicated that there are 1, 8, and 12 bacterial genera found uniquely in the agar plates of LB, 10% LB, and 5% WSS. By contrast, when palm oil mill effluent sludge was used as a bacterial source, the effect of dilution was different with WSS. When comparing the biodiversity between colonies and liquid culture, a high OTU value was observed in the colonies on the plate. In addition, 30°C showed the highest number of colonies in LB, 10% LB, and 5% WSS whereas the best OTUs were observed at 37°C for LB and 10% LB, and at 25°C for 5% WSS. This study demonstrates the diversification of cultivable bacteria through the number of OTUs in diluted LB medium and WSS, which is beneficial to isolate a unique bacterial strain. Key points • Impacts of diluted LB medium and WSS for colony formation were determined. • Difference of concentration of LB and WSS made different effects on colony formation. • Temperature change affected on diluted LB and WSS as media. [ABSTRACT FROM AUTHOR]

Palm oil mill effluent (POME) is a palm industrial waste by‐product that is readily available and possesses high quantities of the organic compounds that are necessary for microbial growth. This study investigated the potential of immobilized Aspergillus oryzae whole cells expressing Candida antartica lipase B (r‐CALB) when using a POME‐based medium as a low‐cost carbon source within biomass support particles. The dry cell weight, hydrolytic activity, and remaining protein were measured for a variety of POME (0–2% w/v) and carbon source concentrations (0–2% w/v) with an incubation time of 96 h. Using POME in the culture medium as a carbon source instead of glucose doubled the retention of cell weight from 1.16 ± 0.03 to 2.36 ± 0.02 g within the biomass support particles and improved the hydrolytic activity from 1.61 ± 0.02 to 2.23 ± 0.02 U mg−1 in whole‐cell lipase. This immobilized r‐CALB was used as a catalyst to esterify POME into biodiesel. This synthesis produced an ester content of 97.52 ± 0.21% w/w after 96 h. Immobilized r‐CALB was reusable for more than ten batches, and resulted in an ethyl ester content of more than 90% w/w even after 10 cycles. The present study demonstrated that POME could serve as a sustainable carbon source for industrial microbial culture with the additional incentive of being a treatment that is inexpensive and sustainable. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Treatment of palm oil mill effluent (POME) via fermentation under controlled conditions can produce a high‐value biohydrogen (H2) mixture containing carbon dioxide (CO2). This H2 can be enriched before it can be used for renewable energy, that is, in fuel cell. In this work, H2 was upgraded via two techniques, namely absorption column and membrane contactor system. Ammonium hydroxide (NH4OH), potassium hydroxide (KOH), and mixed solution of NH4OH and KOH were used as the chemical absorbents for both techniques. In the absorption column, it was found that the mixed solution provided the highest H2 purity (99%) at 1 M concentration with a gas flow rate of 0.2 L/min. Meanwhile, the mixed solution and KOH solution showed similar separation performance with H2 purity of up to 75% in the gas–liquid membrane contactor. On investigating the separation performance for each of the compared techniques, it was found that the absorption column has a superior ability to purify H2 than the membrane contactor system. However, the membrane contactor is more sustainable as it has the least drop in H2 purity at a longer separation time during the separation process. Both techniques have their own advantages in purifying H2, and thus they can be fairly considered for gas upgrading. [ABSTRACT FROM AUTHOR]

The increasing demand for water, food and energy poses challenges for the world´s sustainability. Tropical palm oil is currently the major source of vegetable oil worldwide with a production that exceeds 55 million tons per year, while generating over 200 million tons of palm oil mill effluent (POME). It could potentially be used as a substrate for production of microalgal biomass though. In this study, the microalgal strain Chlamydomonas biconvexa Embrapa|LBA40, originally isolated from a sugarcane vinasse stabilization pond, was selected among 17 strains tested for growth in POME retrieved from anaerobic ponds of a palm oil industrial plant located within the Amazon rainforest region. During cultivation in POME, C. biconvexa Embrapa|LBA40 biomass productivity reached 190.60 mgDW • L-1 • d-1 using 15L airlift flat plate photobioreactors. Carbohydrates comprised the major fraction of algal biomass (31.96%), while the lipidic fraction reached up to 11.3% of dry mass. Reductions of 99% in ammonium and nitrite, as well as 98% reduction in phosphate present in POME were detected after 5 days of algal cultivation. This suggests that the aerobic pond stage, usually used in palm oil industrial plants to reduce POME inorganic load, could be substituted by high rate photobioreactors, significantly reducing the time and area requirements for wastewater treatment. In addition, the complete mitochondrial genome of C. biconvexa Embrapa|LBA40 strain was sequenced, revealing a compact mitogenome, with 15.98 kb in size, a total of 14 genes, of which 9 are protein coding genes. Phylogenetic analysis confirmed the strain taxonomic status within the Chlamydomonas genus, opening up opportunities for future genetic modification and molecular breeding programs in these species. [ABSTRACT FROM AUTHOR]

The production of crude palm oil is a resource-intensive process because it requires a considerable amount of clean water during milling and generates a large amount of wastewater. The goal of this work was to improve the process sustainability by repurposing the treated wastewater (i.e. aerobic liquor, AL) for improving the quality of crude palm oil (CPO). The AL was first pre-treated by filtration and heating before it was used to wash the CPO under mixing. Critical quality parameters of CPO, i.e. free fatty acid, anisidine value and Deterioration of the Bleachability Index, showed improvement after washing with AL. The level of phytonutrient present in the CPO was not affected by washing. Furthermore, the amount of undesirable trace elements phosphorus, iron, copper and chlorine showed a significant reduction. By repurposing the AL to treat CPO, the quality of the CPO can be improved. This practical and sustainable treatment process can be performed in situ in a palm oil mill without the need for clean water and chemical. [ABSTRACT FROM AUTHOR]

BACKGROUND Oil mills could benefit by preparing their own aqueous extracts from olive leaves. Accordingly, the present study aimed to measure the bioactive compounds richness of such extracts, especially oleuropein. A water‐based microwave extraction procedure was developed and a selective and precise high‐performance liquid chromatography with diode array detection (HPLC‐DAD) method was validated for the determination of oleuropein and others bioactive compounds from olive leaves. RESULTS: The water solubility of oleuropein was determined to be 9.5 g L−1. The extraction procedure was optimized in terms of power, olive leaf weight/water volume ratio and time of extraction, and the results revealed that 2 mg mL−1 and a microwave irradiation at 800 W for 30 s resulted in the greatest efficiency. Oleuropein was determined by the new validation method, which showed good linearity (r2 = 0.996), precision (% relative standard deviation < 10%), recovery (118.6%), and limits of detection (17.48 mg L−1) and quantification (21.54 mg L−1). Good correlation (r2 = 0.979) was obtained between oleuropein of the olive leaf extracts determined by HPLC‐DAD and by UV‐visible spectrophotometry. CONCLUSION: A simple extraction method was developed and validated to obtain aqueous extract from olive leaves by microwave extraction, determining for the first time oleuropein water solubility. Validation of the method showed that oleuropein in olive leaves could be quantified when it is at least 1% of dry weight by means of HPLC‐DAD. UV‐visible spectrophotometry can be useful in oil mills because it enables the content of oleuropein and other bioactive compounds content to be determined in situ in such leaf aqueous extracts. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A start-up study of lab-scale up-flow anaerobic sludge blanket fixed-film reactor (UASFF) was conducted to produce biohydrogen from palm oil mill effluent (POME). The reactor was fed with POME at different hydraulic retention time (HRT) and organic loading rate (OLR) to obtain the optimum fermentation time for maximum hydrogen yield (HY). The results showed the HY, volumetric hydrogen production rate (VHPR), and COD removal of 0.5–1.1 L H 2 /g COD consumed , 1.98–4.1 L H 2 L−1 day−1, and 33.4–38.5%, respectively. The characteristic study on POME particles was analyzed by particle size distribution (PSD), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX). The microbial Shannon and Simpson diversity indices and Principal Component Analysis assessed the alpha and beta diversity, respectively. The results indicated the change of bacterial community diversity over the operation, in which Clostridium sensu stricto 1 and Lactobacillus species were contributed to hydrogen fermentation. • Fermentative hydrogen production from palm oil mill effluent. • Substrate particle size, surface morphology, elemental identification were studied. • Maximum H 2 production at HRT 8 h/OLR 45.4 g COD L−1 day−1. • Evolution in microbial community before and after dark fermentation. • Clostridium sensu stricto 1 mostly contributed to biohydrogen production. [ABSTRACT FROM AUTHOR]

• The 30 mg O 3 /L presented the greatest startup, performance, and solids degradation. • Ozonation could dissolve inorganics without reducing its concentration. • Long time ozonation resulted in extremely acidic and conductive effluents. • Pollutant accumulation occurred due to inadequate ozone concentration. • Foam can trap O 3 , house intense ozonation reactions, and destruct influent solids. Ozonation is recognized as an effective treatment to eliminate complex contaminants in wastewater. So far, past studies often applied ozonation for minutes or a few hours. These studies contradict each other in their findings about the ability of ozone to remove inorganics and organics. The present study, for the first time, applied ozone oxidation at doses of 15 and 30 mg/L for a long duration of 144 h to process high-strength wastewater, palm oil mill effluent. Both doses effectively dissolved non-biodegradable solids, ultimately enhancing toxicity removal. However, the 15 mg/L dose resulted in a slower start-up, instability in treatment, and lower solid degradation than the 30 mg/L dose because it was inadequate to abate influent pollutants. The undesirable results of the 15 mg/L dose demonstrated the need for a higher dosage of ozone to result in a higher rate of conversion of solids into biodegradable and dissolved solids over a shorter period of time. The high ozone dose (30 mg/L) demonstrated better startup, more stable performance, and higher final effluent quality than the low ozone dose (15 mg/L). The high ozone dose continued to deliver high-performance treatment over the duration of the study compared to the low ozone dose. During ozonation, particulate matter foams were detected on the surface due to aggregation of solids. [ABSTRACT FROM AUTHOR]

White-rot basidiomycetes are the only microorganisms with the ability to produce both hydrolytic (cellulases and hemicellulases) and oxidative (ligninolytic) enzymes for degrading cellulose/hemicellulose and lignin. In addition, they produce biologically active natural products with important application in cosmetic formulations, either as pure compounds or as standardized extracts. In the present work, three wild strains of Basidiomycetes fungi (Pleurotus citrinopileatus, Abortiporus biennis and Ganoderma resinaceum) from Greek habitats were grown in agro-industrial residues (oil mill wastewater, and corn cob) and evaluated for their anti-tyrosinase and antioxidant activity and for the production of biotechnologically relevant enzymes. P. citrinopileatus showed the most interesting tyrosinase inhibitory activity, while A. biennis showed the highest DPPH(2,2- diphenyl-1-picryl-hydrazyl) scavenging potential. Corn cobs were the most appropriate carbon source for maximizing the inhibitory effect of fungal biomasses on both activities, while the use of oil mill wastewater selectively increased the anti-tyrosinase potential of P. citrinopileatus culture filtrate. All strains were found to be preferential lignin degraders, similarly to most white-rot fungi. Bioinformatic analyses were performed on the proteome of the strains P. citrinopileatus and A. biennis, focusing on CAZymes with biotechnological relevance, and the results were compared with the enzyme activities of culture supernatants. Overall, all three strains showed strong production of oxidative enzymes for biomass conversion applications. [ABSTRACT FROM AUTHOR]

In Algeria, the olive oil extraction generates enormous quantities of olive-growing by-products: the olive residue and margines. So, the characterization and the valorization of these byproducts seem of great importance. The first shutter consists in characterizing the whole of fractions resulting from the centrifugation of the margines (liquid rejection) to knowing the liquid phase, the oily phase and the solid phase as well as the olive residue, with various physicochemical techniques of analysis available on the scale laboratory. The liquid fraction which was characterized shows a very strong organic and mineral matter concentration being able to be used in irrigation either directly, or diluted with water after having undergone physicochemical and biological treatments, enriching the composition and texture by the arable lands (fertilizing contribution). As for the oily fraction the results show a very good nutritional quality from the point of view analyzes physico chemical, dedicated to being used like salad oil or in our work, it was used for obtaining a dry soap. [ABSTRACT FROM AUTHOR]

Experimental study of the anaerobic digestion of palm oil mill effluent (POME) was carried out in an anaerobic upflow sludge blanket reactor (UASBR) with bauxite residue. The production rate of methane 114 L/gCOD/d and CH4 concentration was 205 L gCOD/d at 8.5 g/L of bauxite residue in UASBR. The results showed that the highest methane yield was 37.5 L gCODadded/h; CO2 reduction 1.5 L gCODadded and chemical oxygen demand (COD) removal reached 98.3% at 8.5 g/L of bauxite residue, respectively. The results the best by the modified kinetic model and Umax was 100 mg/L. The kinetic of methane production was also studied. The methane yield coefficient, YM, was 0.69 L CH4/gCODremoved. Anaerobic digestion of acetate was the dominant soluble metabolites in development and specific methanogenic activity results showed that high observed between stoichiometric and experimental higher methane production. [ABSTRACT FROM AUTHOR]

• First report of lipids production in the marine diatom Chaeotceros affinis. • Palm oil mill effluent (POME) was sole source of N, P and other trace elements. • POME growth media were compared with a standard control medium. • Biomass grown in a vitamins-free POME medium exceeded 48 % in lipids content. • Lipid productivity exceeded 16 mg L–1 d –1 in a 18-day batch culture. Biomass and lipid production by the marine diatom Chaetoceros affinis were characterized under continuous light with aeration. Media based on palm oil mill effluent (POME; 10, 20 and 30 % v/v in distilled water) were used together with a standard control medium. The maximum biomass concentration on day 12 of batch cultures in control medium was 821 ± 71 mg L–1. Under identical conditions, in the best POME medium (20 % POME v/v in distilled water with other inorganic components), the biomass concentration was reduced by ∼11 % to 734 ± 66 mg L–1. The lipid content of the biomass grown in the control medium was 50.8 ± 4.5 % by dry weight, but was a little lower (48.9 ± 4.1 % by dry wt) in the above specified best POME medium. In the best POME medium, oleic acid was the major fatty acid (72.3 ± 5.2 % by weight) in the total lipids extracted from the biomass and monounsaturated fatty acids were the main type of fatty acids (74.6 ± 5.2 %). POME levels of >20 % in the medium suppressed both biomass and lipid production relative to the medium with 20 % POME. [ABSTRACT FROM AUTHOR]

Rice husk ash (RHA), palm oil mill effluent (POME) sludge and decanter cake can be utilized together in compost production to minimize the environmental pollution. This study aims to evaluate the role of different composition of RHA in enhancing the physicochemical properties of palm oil-based compost. The composts were prepared by mixing different composition of RHA, in the range of 0% to 30%, with 1:1 (wt/wt) weight ratio of POME sludge and decanter cake. The moisture content, water holding capacity, pH, nitrogen (N), phosphorus (P), potassium (K), silica (Si) contents, and C:N ratio of raw materials were analyzed by using CHNS and WDXRF analyzers. The composting process was conducted in compost containers for 60 days, in which the temperature and pH of the composts were monitored daily. The finished composts were analyzed for physicochemical properties as same as raw materials. For physical properties of finished composts, RHA30 had the highest moisture content and water holding capacity which was 1.9 to 23.8% (wt/wt) and 4.2 to 26.8% higher compared to other finished composts, respectively. For chemical properties, the highest N and P contents were recorded by control compost. However, for K and Si content, the elements were found to be higher in RHA10 and RHA30, respectively, compared to other finished composts. Overall, RHA, POME sludge and decanter cake combination in compost production can create a well-balanced condition for the compost to perform effectively as an organic fertilizer. The addition of 5% to 10% RHA in compost formulation made from palm oil mill wastes is suggested to achieve the desirable condition. [ABSTRACT FROM AUTHOR]

Due to the alarming methane emission from anaerobic palm oil mill effluent (POME) treatment practices in palm oil mills, POME elimination strategy is considered as an alternative zero waste solution towards methane mitigation apart from biogas recovery. By dewatering the effluent, POME evaporation technology provides opportunities in water recycling, oil recovery, effluent elimination and process integration with downstream refinery. One of the challenges for implementing POME evaporation is the extensive thermal energy use, which threatens energy efficiency and carbon footprint of palm oil mill. Advanced technologies such as multieffect evaporation (MEE) and mechanical vapour recompression (MVR) can be considered to reduce steam demand for POME evaporation. Recently, electrical-driven MVR evaporator emerges as a popular solution for solution concentration and food powder production. In MVR systems, evaporated vapour is recompressed by power-consuming mechanical energy to enable steam reuse and reduction in fresh steam demand. In this paper, MEE and MVR evaporation systems are considered for POME dewatering in the integrated palm-oil based complex (POBC) optimisation. A fuzzy multi-objective optimisation model was developed to evaluate the trade-offs of economic benefits, energy consumption and environmental impacts between thermal and electrical driven evaporation techniques for sustainable POBC design. MEE was selected in the fuzzy optimal POBC with aggregate satisfaction of four objectives and improved the EP and GHG reduction of baseline study by 12 % and 61 %. Single-effect MVR POME evaporator contributed to 64 % thermal cost savings with overall 1.5 % reduction in POBC profitability. The optimal results and electricity-to-steam (ETS) price analysis have provided critical insights into the feasibility of MEE and MVR evaporation in POMs. Reducing electricity tariff to achieve ETS ratio below 1.27 could increase the economic favourability of MVR-implemented POBC. [ABSTRACT FROM AUTHOR]

Indonesia is currently the most significant crude palm oil (CPO) producer in the world. In the production of CPO, 0.7 m3 of Palm Oil Mill Effluent (POME) is emitted as the wastewater for every ton of fresh fruit bunches processed in the palm oil mill. With the increasing amount of CPO production, an effective POME treatment system is urgently required to prevent severe environmental damage. The high organic content in the POME is a potential substrate for bio-methane production. The biomethane production is carried out by two groups of microbes, i.e., acidogenic and methanogenic microbes. Each group of bacteria performs optimally at different optimum conditions. To optimize the biomethane production, POME was treated sequentially by separating the acidogenic and methanogenic microbes into two stages of anaerobic fluidized bed reactors (AFBR). The steps were optimized differently according to the favorable conditions of each group of bacteria. Although perfect separation cannot be achieved, this study showed that pH control could split the domination of the bacteria, i.e., the first stage (maintained at pH 4-5) was dominated by the acidogenic microbes and the second stage (kept neutral) was governed by methanogens. In addition to the pH control, natural zeolite was added as microbial immobilization media in the AFBR to improve the performance of the microorganisms, especially in preventing microbial wash out at short hydraulic retention time (HRT). This study was focused on the understanding of the effect of HRT on the performance of steady-state continuous AFBR. The first stage as the acidogenic reactor was run under acidic conditions (pH 4-5) at five different HRTs. In comparison, the second stage as the methanogenic reactor was run under the neutral condition at four different HRTs. In this work, short HRT (5 days) resulted in better performance in both acidogenic AFBR and methanogenic AFBR. The immobilization media was hence essential to reduce the risk of washout at such a short HRT. The two-stage system also resulted in quite a high percentage of soluble chemical oxygen demand (sCOD) removal, which was as much as 96.06% sCOD. [ABSTRACT FROM AUTHOR]

This study aims to evaluate how inoculum's origin affects the methane yield of palm oil mill effluent (POME) by measuring the specific methanogenic activities (SMA) and bio-methane potential (BMP) of POME at different dilutions (100, 80, 60, 40, and 20 % of initial POME) and by using active anaerobic sludge (as inocula) from 3 palm oil mills (S1, S2, S3). The anaerobic digesters were operated in batch mode at a temperature of 40 °C until methane generation ceased. The corresponding SMA were 0.0159, 0.0098 and 0.0333 gCOD/(gVSS d) for S1, S2 and S3, respectively. The results showed that POME without dilution gave the highest cumulative biogas, 4162, 2857 and 2678 mL for S2, S3 and S1, respectively. However, 20 % dilution from original POME gave the highest methane yield (as BMP) 126, 88 and 84 mL CH4/gCOD removed for S2, S3 and S1, respectively. In this study, 2 mathematical models were selected including the corrected Gompertz equation and Gompertz two substrate models. They were applied to characterize the kinetics of the anaerobic digestion processes and to compare the BMP data from the experiments. Both models could represent all BMP data satisfactory although only Gompertz 2 substrate model showed almost perfect fitting and could characterize the influence of slowly degradable portion of POME. Accordingly, the slowly degradable portion of POME was estimated to be 10 % of total COD. [ABSTRACT FROM AUTHOR]

The antifeedant activity of nanoemulsion formulation of arugula Eruca sativa Mill. oil was studied against elm leaf beetle Xanthogaleruca luteola (Müller)(Col.:Chrysomelidae) under laboratory conditions at 25±1ºC, 75±5% RH, and LD 16:8 hours. Ingestive LC50 values of the oil were studied in third instar larvae. Then, physiological parameters were evaluated following 24, 48, and 72 hours post feeding at LC50 level. LC50 values 24, 48 and 72 hours after application were 4.940, 3.791, and 2.938 mg mL-1, respectively. Arugula oil at LC50 level decreased the nutritional indices including efficiency of conversion of ingested food, relative growth rate, efficiency of conversion of digested food, and relative consumption rate, but increased feeding deterrence index significantly 72 hours post feeding. Nutritional reserves such as total carbohydrate, protein, and lipid contents and also digestive enzymes containing lipase, α-amylase, and protease activity were decreased showing post-ingestive toxicity. The activity of the detoxifying enzyme glutathione Stransferase was increased, indicating that this enzyme may be involved in detoxification of arugula oil, but general esterase did not change significantly. In general, it can be concluded that arugula oil possess antifeedant activity against X. luteola under laboratory condition. It seems that arugula oil has a great potential to be used as effective botanical pesticides. However, further studies such as greenhouse and field experiments are necessary before recommendation and commercialization process. [ABSTRACT FROM AUTHOR]

Montefrío is a paradigmatic case because, since the conquest of the Nasrid village by the Catholic Monarchs in 1486, it was named one of the seven towns that will supply cereal, mainly wheat to the capital Granada. From those times the cereal was extended by the ample municipal area of 254 km2, accompanied by the cattle ranch in the zones of dehesa of the municipality. It was in the 18th century that the first oil mills, documented in the Ensenada Cadastre, appeared. During the nineteenth century there was an increase in the extension of olive groves in Montefrío, as a result of the various agrarian reformations that took place at this time. This fact will provoke a greater number of peasants that will accede to the fields, and therefore, a greater extension of hectare analyse the evolution of the oil mills and their owners from the 18th cents dedicated to the culture of the olive tree, consequently, an increase of the number of oil mills and factories of oil by all the municipal term. Next, we analyse the evolution of the oil mills and their owners from the 18th century to the middle of the 20th century. For this we will use several sources of information: the Cadastre of Ensenada, Madoz, wealth and neighbourhood registers conserved in the Town Hall of Montefrío, the oral information and that of the property register. For it we join the information coming from the remains and conserved mills of this type of industry located in the municipe. [ABSTRACT FROM AUTHOR]

The palm oil extraction process generates large amounts of effluents with very high concentrations of pollutants, even though they are subjected to anaerobic pretreatment. Further treatment is needed in order to ensure that the effluent is safe for disposal or reuse. This work was conducted to evaluate the performance of an electrocoagulation process in removing pollutants from the anaerobically-pretreated palm oil mill effluent. A 1000 ml beaker glass equipped with a magnetic stirrer was used as an electrocoagulation reactor with four plates of aluminum electrode @ 12×2 cm and an effective area of 0.1 m² arranged in a bipolar configuration. The experiments run in a batch mode were carried out at various voltage levels and contact times, namely 10, 15, and 20 V for 15, 30, 45 and 60 min. The level of pollutant removal and electrical energy consumption were determined. The electrocoagulation process at 15 V for 30 min produced the highest level of pollutant removal for TSS, turbidity, color, COD, and BOD5, i.e. 90%, 86%, 93%, 87%, and 97%, respectively. The estimated operating costs for these process conditions are 1.48 USD/m³. A second order empirical model was developed to describe the TSS removal in the POME electrocoagulation process. The electrocoagulation with aluminum electrodes can significantly reduce various types of pollutants of anaerobically-pretreated POME, such as TSS, turbidity, color, COD, and BOD5. The estimated cost of EC operation is cheaper than the chemical coagulation process. [ABSTRACT FROM AUTHOR]

Purpose The upsurge of vegetable oil production in Nigeria and the equally increasing concern for the environment which arises due to indiscriminate disposal of phytotoxic vegetable oil mill effluent in a less regulated country like Nigeria makes the re-use of the effluent for fertigation a suitable strategy for its disposal if the appropriate treatment technique is adopted. Method A laboratory experiment was set up to study how the detoxification of soybean oil mill effluent (SOME) under different anaerobic digestion time (0, 20 and 40 days) and application rates (0, 50 and 100 m3/ha) will influence the suitability of the effluent for fertigation. Results SOME has a pH of 8.3, which decreased steadily to 7.4 as digestion time increased to 40 days. EC and potassium levels also decreased as digestion time increased, from 0.37 dS/m and 120.6 g/l to 0.28 dS/m and 70.1 g/l, respectively. However, levels of organic carbon, nitrogen and phosphorus did not change significantly. The effluent impacted negatively on germination after a one-time application, with the germination index going as low as 22% for untreated SOME and gradually increasing to 66% as digestion time increased. Continuous application of the untreated effluent also affected soil microbial activity negatively when compared to the treated effluent. Conclusion Anaerobic digestion detoxifies SOME and the efficiency of the treatment increased with increasing digestion time. The effluent also contains low to moderate amounts of NPK and therefore has a potential for fertigation. [ABSTRACT FROM AUTHOR]

Single anaerobic digestion of rubber latex effluent (LTE) is known to be difficult and low yield which produces biogas containing high sulfur dioxide and ammonia. This article investigates the potential of co-digestion of palm oil mill effluent (POME) and LTE both in terms of synergistic, inhibitory effects and process stability particularly in inferring what would happen in an industrial-scale biogas plant if this type of co-digestion is to be used. The article focuses on the biochemical methane potential (BMP) of POME-LTE at different mixing ratio within the temperature range of 30 - 45 °C, the range which is used in most commercial biogas power plants in Thailand. It was found that proper co-digestion between POME and LTE provided a good opportunity to optimize the bio-methane yield because of their synergistic effect. All mixing ratios provided stable biogas production up to at least 45 days. Co-digestion of POME and LTE had a synergistic effect that when mixing 80 - 90 % of POME with 10 - 20 % of LTE, it enhanced the BMP by 25 - 35 %. It is also recommended that, in mesophilic range, 45 °C would be the best for both methane yield and high methane content in the biogas. We also have illustrated that 2- substrate models (in this case the Gompertz 2 substrate (GTS) model) is very suitable for representing and describing co-digestion data because of their inherently multiple substrate tendency. In most cases, Gompertz-type equations for single substrate did not represent the accumulated biogas/methane data adequately. [ABSTRACT FROM AUTHOR]

• Raw Palm Oil Mill Effluent characterized; sample treated and 4000 mg/L Alum dose was obtained as the optimum. • 1000 mg/L of Ferric chloride significantly increased the removal efficiency in the experimental sample. • Chitosan as a biopolymer showed continuous removal efficiency until the optimum dose was reached at 400 mg/L. • Moringa Oleifera dose of 2000 mg/L as a natural coagulant was very efficient in heavy metals removal from the sample. • Zeolite dose of 1000 mg/L showed significant increase in removal efficiency as it provides the highest removal percentages for Cadmium, Zinc and Iron. This article aimed at determining the optimum coagulant dose for various coagulants. This is to ascertain coagulant with the potential for higher removal of contaminants. By fixing the initial pH, settling time, coagulant aid dose, rapid mixing speed & time, slow mixing speed & time as constant parameters, the study assessed the process efficiency in terms of percentage removals for TSS, oil & grease, COD, NH 3 -N, turbidity and colour. The results indicated that the optimum dosage for FeCl 3 , moringa oleifera , aluminum sulphate, chitosan and zeolite was found to be 1000, 2000, 4000, 400 and 1000 mg/L, respectively. Results were analysed using the one-way analysis of variance (One-Way ANOVA) of Statistical Package for Social Sciences (SPSS) Version 17 where P-values for all contaminants tested across various coagulants and their dosages found to be <0.05. Thus, the null hypothesis is discredited which indicate there is significant improvement in the removal efficiencies. [ABSTRACT FROM AUTHOR]

• Biohydrogen production with microbial consortia and a pure strain in POME medium. • Optimization of the biohydrogen production from POME. • Physicochemical characterization of POME. • Identification of microbial consortia genera. Palm oil mill effluent (POME) was tested as a substrate to produce hydrogen by dark fermentation. Two microbial consortia and a pure culture of Clostridium beijerinckii (ATCC 8260) were cultured anaerobically in raw, diluted and hydrolyzed POME to compare biohydrogen production yields in all three media. Experiments were done in 15 mL Hungate tubes containing 5 mL of medium and 1 mL of inoculum. When Clostridium beijerinckii was cultivated at 30 °C in the hydrolyzed POME (P003), containing 7.5 g/L of sucrose, during 8 days of fermentation and 20 % of the inoculum, the maximum biohydrogen production yield was 4.62 LH 2 /L med. Consortium C3 also showed the best production in hydrolyzed POME while consortium C6 achieved its maximum production in raw POME. This effluent is a potential substrate for biohydrogen production. [ABSTRACT FROM AUTHOR]

• Green synthesize of ZnO nanoparticle using different concentration of ZnO solution. • The ZnO-CC 3:1 indicated smaller size (6.6–42.9 nm) of nanoparticles. • Photocatalytic process with ZnO-CC resulting higher colour degradation of POMSE and minimize membrane fouling in membrane photocatalytic reactor (MPR). Green synthesis provides new avenues of nanoparticle synthesis using plants. In the present study, we attempted to synthesise ZnO nanoparticles via precipitation using different ratios of ZnO solution to leaf extract of Cymbopogon citratus (3:1, 5:1, and 9:1). The modified ZnO was characterised using Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray diffraction. The influences of the modified ZnO- C. citratus (ZnO-CC) nanoparticles on the removal of colour from and decline in the flux of palm oil mill secondary effluent (POMSE) in a membrane photocatalytic reactor (MPR) were studied. The performance of ZnO-CC 3:1 in terms of colour (99.84 %), COD (98.97 %), BOD (96.24 %) and turbidity removal (99.89 %) of the treated POMSE was significant. The improvement of the performance efficiency for POMSE treatment using MPR correlate with the reduction in the size of ZnO-CC 3:1 (6.6–42.9 nm) which promote higher degradation activity and minimize membrane flux decline during the process. Thus, it can be deduced that the coupled MPR system has significant potential for application in the palm oil mill effluent treatment industry as it mitigates membrane fouling and yields treated effluent of good quality. [ABSTRACT FROM AUTHOR]

Phytonutrients are plant‐derived bioactives which are widely utilized as colorants or supplements in food, cosmetic, and pharmaceutical products. To meet the global demand for phytonutrients, oil palm has emerged as a promising source of phytonutrients on account of its large‐scale plantation worldwide and high oil productivity. Phytonutrients including carotenoids, tocols, sterols, squalene, phospholipids, coenzyme Q10, and polyphenols can be found in crude palm oil as well as in the byproducts (e.g. palm oil mill effluent and palm‐pressed fiber oil) generated from the palm oil milling process. However, the high viscosity and semisolid properties of palm oil are problematic in phytonutrient extraction. Another major challenge is the retention of the sensitive phytonutrients during the extraction process. Over the years, the advances in the extraction methods have improved the extractability of phytonutrients. The emerging extraction methods can operate under mild conditions to mitigate the risk of phytonutrient degradation. This review outlines the types of phytonutrient in palm oil and their extraction strategies. The working principles and operating conditions of extraction methods are discussed along with their potential and limitations in terms of extraction efficiency and practicability. The methods for pretreatment of feedstocks for improving extraction efficiency are also highlighted. The challenges in the extraction of phytonutrient from palm oil feedstock are summarized. Lastly, we provide suggestions for overcoming the limitations and improving the performances of phytonutrient extraction. [ABSTRACT FROM AUTHOR]

Palm oil mill effluent (POME) contains a high concentration of organic matter that could be produced useful biogas. Ultrasonication is a promising alternative method of POME pre-treatment with the potential to enhance biogas production from wastewater treatment systems at palm oil mills. Ultrasonication with an input power of 0.27-0.44 W mL-1 for 90 min, in the batch experiment, increased oil separation efficiency by 29.0% compared with natural sedimentation. The soluble chemical oxygen demand/total chemical oxygen demand (SCOD/TCOD) ratio and reducing sugar concentration were increased under this optimal ultrasonication condition, indicating that the pre-treated POME was improved biodegradability. The pre-treated POME was fermented in a semi-continuous stirred treatment tank to determine biogas production efficiency. The ultrasonication pre-treated POME increased biogas production and also increased the proportion of methane from 40% to 63% and methane yield from 103.47 to 139.59 mL CH4 g-1 CODremoval compared to the control condition. The highest methane yield was obtained at a hydraulic retention time (HRT) of 16 d. However, longer HRT yielded slightly higher COD removal efficiencies. When the biogas produced is used for onsite electricity generation therefore, it is possible to diminish the electricity costs incurred to perform the ultrasonication setup and reduce greenhouse gases (GHGs) emissions to the environment. The overall GHGs emissions reduction from palm oil mill could reach up to 11% or 913.23 ton CO2eq y-1 when the optimal ultrasonication scenario from this study applied to wastewater treatment system. [ABSTRACT FROM AUTHOR]

Anaerobic membrane bioreactor (AnMBR) is an effective technology for the treatment of wastewater. However, the cost of membrane and membrane fouling has limited its application in wastewater treatment on a commercial scale. Therefore, in this study, different particle's sizes of powder activated carbon (PAC) were added into four identical AnMBRs to investigate their effects on chemical oxygen demand (COD) and natural organic matters (NOM) removals, mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) values, and membrane fouling control when treating of palm oil mill effluent. It was found AnMBRs with PAC performed better than the AnMBR without PAC. It was also found that the addition of a relatively smaller size of PAC (approximately 75 µm) enhanced the COD removal efficiency to 89.45 ± 2.48, while the concentration of MLSS and MLVSS were 21,420 and 16,452 mg/L, respectively, which was high enough to result in bigger floc size, lower NOM content and better membrane fouling control. Also, to investigate the performance of polyethersulfone membrane in fouling control, different concentrations of PAC had been incorporated into it. The results showed that integrated membrane with (5 wt.%) PAC was able to achieve up to 60% COD removal rate, compared to 38.6% without PAC. Besides, there was a trend where the membrane with a higher concentration of PAC integrated has a better performance in both membrane fouling control and pollutant removal ability. [ABSTRACT FROM AUTHOR]

Summary: By means of biorefinery, biogas production through anaerobic digestion is one of the most common treatments of wastewater in the palm oil industry. After biogas production, the treated palm oil mill effluent (POME) is generally discharged into the environment. However, certain level of hazardous compounds still exists in the treated wastewater, which can lead to the pollution of water bodies. In this study, we have investigated the dynamics of volatile organic acids dwelling in consecutive POME treatment lagoons as well as identified, and categorized, microbial species responsible for the treatment process. Bacteria and methanogens, both hydrogenotrophic and acetoclastic, related to methane production were identified using mcrA and 16S rRNA genes specific primers. Two hydrogenotrophic methanogens, Methanoculleus marisnigri and Methanoculleus chikugoensis, were found abundant in accordance with high formate concentration throughout the process of anaerobic digestion. This study has also isolated eight consortia of microbes that yielded different methane productions by utilizing formate as the substrate in the synthetic medium. The consortia of a group, containing M. marisnigri, M. chikugoensis, uncultured bacteria, Aminobacterium sp., and Ruminobacillus xylanolyticum, produced the highest methane yield of 259 mL/g COD after 25 days of incubation in the laboratory. The findings from this study are contributing to optimize and increase biogas production in POME, which will allow higher efficiency in palm oil mill wastewater treatment. [ABSTRACT FROM AUTHOR]

• POMSE treatment via MPR assisted biosynthesized ZnO-CC nanoparticles under various operational condition. • Response surface methodology (RSM) was used to analyze the effect of operating parameter in MPR. • The quality of treated POMSE are within the acceptable discharge limit of effluent. Membrane photocatalytic reactor (MPR) has become one of the promising methods for palm oil mill secondary effluent (POMSE) polishing process. However, the utilization of green synthesis zinc oxide- Cymbopogon citratus (ZnO-CC) nanoparticles to improve MPR performance for POMSE treatment has been rather limited to date. In this study, the effects of different operating conditions (pH, initial concentrations, and catalyst loadings) and membrane cleaning using distilled water for treating POMSE via MPR assisted ZnO-CC nanoparticles were elucidated. The behaviour of the membrane fouling was evaluated through normalized flux, colour rejection, water quality and membrane surface characteristics. The results revealed that colour rejection reached 99.9%, normalized flux up to 0.33 and the water quality parameters attained are within the acceptable discharge limit of wastewater, thus verifying the effectiveness of POMSE treatment via MPR assisted ZnO-CC nanoparticles. In addition, the best performance in terms of flux, colour, chemical oxygen demand (COD), and turbidity removal efficiency was achieved after six cycles of POMSE treatment via MPR. Hence, cleaning of the membrane was able to recover the quality of permeate to a certain extent and this results in reusability of the membrane, which can serve as an alternative to improving severe membrane fouling. [ABSTRACT FROM AUTHOR]

• An alternative palm oil mill effluent treatment was developed using a laboratory-scale MBBR. • Two types of supporting media in the MBBR system were compared. • Increasing the MFF and HRT improved the MBBR treatment of palm oil mill effluent. • More than 10 species of bacteria were found on the supporting media of the MBBR system. The treatment performance of palm oil mill effluent (POME) using a laboratory-scale moving bed biofilm reactor (MBBR) was investigated in this study. Two types of biofilm carriers were used to fill the MBBR: black plastic media (BPM) and Hexafilter (HEX). Three media filling fractions (MFFs: 25 %, 50 % and 70 %) and retention times (RTs: 24, 48 and 72 h) were investigated to achieve the best MBBR performance in terms of the removal of chemical oxygen demand (COD) and ammonia-nitrogen (NH 3 -N) from POME. Increasing the RT significantly improved the removal of COD and NH 3 -N, whereas increasing the MFF resulted in insignificant changes. Overall, HEX performed better than BPM at 50 % MFF (72 h RT). Metagenomics analysis identified approximately 13 phyla of bacteria on the HEX compared to the BPM with only 10 phyla. Based on these findings, the laboratory-scale MBBR deserved a vote as an alternative treatment for POME under appropriate RTs and MFFs and in the presence of a suitable microbial community. [ABSTRACT FROM AUTHOR]

Thermotolerant bacteria producing medium-chain-length polyhydroxyalkanoate (mcl-PHA) were isolated from various thermal sites, including palm oil mill effluent, textile wastewater, and hot spring water, in Thailand. Fifteen strains were isolated at 45 °C using nutrient-rich (NR) medium. However, only six isolates produced mcl-PHA at 0.41 ± 0.01 g/L to 0.80 ± 0.01 g/L, representing a mcl-PHA content of 29.44% to 50.77% of the dry cell weight (DCW). The six strains of bacterial isolates could utilise a variety of substrates; all were identified as Bacillus thermoamylovorans. The highest mcl-PHA content (50.77% of the DCW) was accumulated by the B. thermoamylovorans strain PHA005 isolated from palm oil mill effluent. The mcl-PHA from strain PHA005 was composed of five different monomers, 3-hydroxyoctanoate (3HO), 3-hydroxydecanoate (3HD), 3-hydroxytetradecanoate (3HTD), 3-hydroxyhexadecanoic acid (3HHD), and 3-hydroxyoctadecanoic (3HOD), with a monomer content of 24.12, 15.50, 13.00, 39.25, and 8.13 mol%, respectively. The optimum temperature for B. thermoamylovorans strain PHA005 growth is 45 °C, and it can survive at up to 60 °C. This is a first report of PHA synthesis by a thermotolerant B. thermoamylovorans. Moreover, the high content of 3HHD monomers (39.25 mol%) has never been reported in Bacillus. [ABSTRACT FROM AUTHOR]

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