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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]

To replace the obsolete ponding system, palm oil mill effluent (POME) steam reforming (SR) over net-acidic LaNiO 3 and net-basic LaCoO 3 were proposed as the POME primary treatments, with promising H 2 -rich syngas production. Herein, the long-term evaluation of POME SR was scrutinized with both catalysts under the optimal conditions (600 °C, 0.09 mL POME/min, 0.3 g catalyst, & 74–105 μm catalyst particle size) to examine the catalyst microstructure changes, transient process stability, and final effluent evaluation. Extensive characterization proved the (i) adsorption of POME vapour on catalysts before SR, (ii) deposition of carbon and minerals on spent SR catalysts, and (iii) dominance of coking deactivation over sintering deactivation at 600 °C. Despite its longer run, spent LaCoO 3 (50.54 wt%) had similar carbon deposition with spent LaNiO 3 (50.44 wt%), concurring with its excellent coke resistance. Spent LaCoO 3 (6.12 wt%; large protruding crystals) suffered a harsher mineral deposition than spent LaNiO 3 (3.71 wt%; thin film coating), confirming that lower reactivity increased residence time of reactants. Transient syngas evolution of both SR catalysts was relatively steady up to 4 h but perturbed by coking deactivation thereafter. La 2 O 2 CO 3 acted as an intermediate species that hastened the coke removal via reverse Boudouard reaction upon its decarbonation. La 2 O 2 CO 3 decarbonation occurred continuously in LaCoO 3 system but intermittently in LaNiO 3 system. LaNiO 3 system only lasted for 13 h as its compact ash blocked the gas flow. LaCoO 3 system lasted longer (17 h) with its porous ash, but it eventually failed because KCl crystallites blocked its active sites. Relatively, LaCoO 3 system offered greater net H 2 production (72.78%) and POME treatment volume (30.77%) than LaNiO 3 system. SR could attain appreciable POME degradation (>97% COD, BOD 5 , TSS, & colour intensity). Withal, SR-treated POME should be polished to further reduce its incompliant COD and BOD 5. [Display omitted] • Prolonged catalytic POME steam reforming over LaNiO 3 (13 h) and LaCoO 3 (17 h). • Similar carbon deposition of spent LaCoO 3 (50.54 wt%) and spent LaNiO 3 (50.44 wt%). • Harsher mineral deposition in spent LaCoO 3 (6.12 wt%) than spent LaNiO 3 (3.71 wt%). • Overall net H 2 production of LaCoO 3 system was 72.78% larger than LaNiO 3 system. • Total POME treatment volume of LaCoO 3 system was 30.77% higher than LaNiO 3 system. [ABSTRACT FROM AUTHOR]

Abstract In this work, the influence of pyrolysis temperature on the physicochemical properties of palm oil mill sludge biochar (POSB) and its adsorption properties towards cadmium (Cd) and copper (Cu) was investigated. Characterization experiments suggested that POSBs' surface functional groups play the major role in the adsorption process. POSB pyrolyzed at 400 °C showed the best characteristics for Cu and Cd removal. Adsorption study indicated that contact time and shaking speed enhances the adsorption capacity of POSB. It was affirmed that pH adjustment is not necessary for POSB to adsorb Cu and Cd. Mechanism studies fitted well with Langmuir and Pseudo-Second Order model. Thermodynamic parameters indicated that the adsorption was spontaneous, endothermic and correspond to chemical adsorption. The highest uptakes of Cu and Cd were recorded at 48.8 mg/g and 46.2 mg/g respectively. This work verifies that the temperature used for palm oil mill sludge (POS) pyrolysis and adsorption condition played the most prominent role in Cu and Cd removal from aqueous solutions. Highlights • Optimized palm oil mill sludge biochar for copper and cadmium removal. • Unique character at pyrolysis temperature of 400 °C. • High adsorption removal capacity compared to other similar work. • Removal of heavy metal by palm oil sludge biochar was dominated by chemical adsorption at monolayer. [ABSTRACT FROM AUTHOR]

Abstract Palm oil mill effluent (POME) is a serious and expensive environmental problem in Malaysia. In this paper, CaFe 2 O 4 is introduced as a novel photocatalyst for the degradation of POME under visible light irradiation. Two synthesis routes, auto-combustion and co-precipitation, and two calcination temperatures 550 °C and 700 °C were used to produce four CaFe 2 O 4 catalysts AC550, AC700, CP550 and CP700. CP550 exhibited the greatest photocatalytic degradation at 56% chemical-oxygen-demand (COD) removal after 8 h of irradiation which dropped to 49% after three consecutive cycles indicating reasonable conversion and high recyclability. BET analysis indicated CP550 had the highest S BET (27.28 m2/g) and pore volume (0.077 cm3/g) which dropped precipitously for CP700 upon increasing the calcination temperature to an S BET of 9.73 m2/g and pore volume of 0.025 cm3/g due to annealing which created a smoother surface area as evidenced by the SEM images. UV–Vis DRS indicated CP550 had the highest band-gap (1.52 eV) which is likely due to the presence of a highly crystalline pure CaFe 2 O 4 phase compared to the other products which existed as a mixture of Fe oxidation states evidenced by the XRD data. The PL spectra for all catalysts indicated significantly lower recombination rate for both CP550 and CP700. Introduction of IPA into the reaction mixture to eliminate hydroxyl radicals resulted in a diminishing of COD removal from 56% to 7% proving hydroxyl radicals to be the primary reactive species responsible for photodegradation of POME. Highlights • Visible light-active CaFe 2 O 4 was synthesized to treat POME. • Auto-combustion and co-precipitation were employed to produce CaFe 2 O 4. • Scavenging studies showed OH. as a responsible radical to degrade POME. • Recyclability studies showed a mere 7% reduction in POME degradation. [ABSTRACT FROM AUTHOR]

Abstract Palm kernel shells (PKS), empty fruit bunches (EFB), and trunks are by-products of the palm oil industry and form approximately 50 wt % of fresh fruit bunch (FFB). In particular, EFB accounts for approximately 20 wt % of FFB. Although large amounts of EFB are generated from palm oil mills every year in Indonesia and Malaysia, EFB is treated as waste because commercial technologies for thermo-chemical conversion of EFB into renewable energy are still under development. A robust conversion method can transform EFB into an appealing renewable energy source. In order to secure this renewable energy source, Korea can import EFB as biomass. This paper investigates literature on the status of utilization of EFB, by-products from palm oil mills in order to identify the best available technological process to use EFB as bio-solid refuse fuels (SRF). Meanwhile, physico-chemical analyses (proximate, elemental, and calorific value analyses), biomass and heavy metal content were measured in order to assess whether EFB would be suitable for use as a bio-SRF, in accordance with the Korean quality standard for SRF. According to the analysis results, EFB showed applicability to use as bio-SRF; main analysis results - moisture (9.63 wt %), ash (5.94 wt %), biomass content (97.82 wt %) and calorific value (3668 kcal kg). Graphical abstract Image 10060 Highlights • Many information on EFB such as utilization status of imported biomass, policy and laws in Korea were summarized.. • Physico-chemical analysis was also carried out to assess whether EFB would be suitable for use as a bio-SRF. • The effect of combustion on heavy metal concentrations (Hg, Cd, Pb, As, Cr, Cu) was also assessed. • All analysis results were found out to be in line with those outlined in the quality standard. [ABSTRACT FROM AUTHOR]

This study aimed at investigating the biohydrogen and biomethane potential of co-digestion from palm oil mill effluent (POME) and concentrated latex wastewater (CLW) in a two-stage anaerobic digestion (AD) process under thermophilic (55 ± 3 °C) and at an ambient temperature (30 ± 3 °C) conditions, respectively. The batch experiments of POME:CLW mixing ratios of 100:0, 70:30, 50:50, 30:70, and 0:100 was investigated with the initial loadings at 10 g-VS/L. The highest hydrogen yield of 115.57 mLH 2 /g-VS was obtained from the POME: CLW mixing ratio of 100:0 with 29.0 of C/N ratio. While, the highest subsequent methane production yield of 558.01 mLCH 4 /g-VS was achieved from hydrogen effluent from POME:CLW mixing ratio of 70:30 0 with 21.8 of C/N ratio. This mixing ratio revealed the highest synergisms of about 9.21% and received maximum total energy of 19.70 kJ/g-VS. Additionally, continuous hydrogen and methane production were subsequently performed in a series of continuous stirred tank reactor (CSTR) and up-flow anaerobic sludge blanket reactor (UASB) to treat the co-substate. The results indicated that the highest hydrogen yield of POME:CLW mixing ratio at 70:30 of 95.45 mL-H 2 /g-VS was generated at 7-day HRT, while methane production was obtained from HRT 15 days with a yield of 204.52 mL-CH 4 /g-VS. Thus, the study indicated that biogas production yield of CLW could be enhanced by co-digesting with POME. In addition, the two-stage AD model under anaerobic digestion model no. 1 (ADM-1) framework was established, 9.10% and 2.43% of error fitting of hydrogen and methane gas between model simulation data and experimental data were found. Hence, this research work presents a novel approach for optimization and feasibility for co-digestion of POME with CLW to generate mixed gaseous biofuel potentially. • Bio-hythane production yield of CLW could enhance by co-digesting with POME. • The POME:CLW mixing ratio at 70:30 revealed the highest synergisms of about 9.21%. • The co-digestion gave 28.76% higher energy production yield than mono-CLW digestion. • The hydrogen yield of 95.45 mLH 2 /g-VS was achieved at HRT 7 days of co-digestion. • The methane yield of 204.52 mLCH 4 /g-VS was obtained at HRT 15 days of co-digestion. [ABSTRACT FROM AUTHOR]

Abstract In oil milling, in order to obtain high-quality oils without reducing the industrial yield, to the use of coadjuvants with a physical action and adequate operating conditions is necessary. The aim of this study was to evaluate the influence of talc addition during the malaxation stage in an oil mill on the resulting oil. Moreover, the oil obtained by talc treatment can be classified as extra virgin olive oil as this coadjuvant has a physical action. Talc increases the extraction efficacy by up to 2.35%, but retains 26.2% of its weight in oil; therefore, it is disadvantageous to use a dose higher than 0.75%. The volatile compound contents were increased in trials using lower doses of talc. In contrast, the quantity of the phenolic compounds was increased in trials using higher talc doses. In low doses, talc does not influence the content of antioxidants and volatile compounds. Highlights • Talc increases extraction efficacy by a maximum of 2.35%. • Talc retains 26.2% of its weight in oil. • The content of volatile compounds is not altered by the talc addition. • Small doses of talc reduce the ethanol content of olive oils. • The antioxidant potential of olive oils is slightly decreased by talc addition. [ABSTRACT FROM AUTHOR]

In this study, we have employed a photocatalytic method to restore the liquid effluent from a palm oil mill in Malaysia. Specifically, the performance of both TiO 2 and ZnO was compared for the photocatalytic polishing of palm oil mill effluent (POME). The ZnO photocatalyst has irregular shape, bigger in particle size but smaller BET specific surface area (9.71 m 2 /g) compared to the spherical TiO 2 photocatalysts (11.34 m 2 /g). Both scavenging study and post-reaction FTIR analysis suggest that the degradation of organic pollutant in the TiO 2 system has occurred in the bulk solution. In contrast, it is necessary for organic pollutant to adsorb onto the surface of ZnO photocatalyst, before the degradation took place. In addition, the reactivity of both photocatalysts differed in terms of mechanisms, photocatalyst loading and also the density of photocatalysts. From the stability test, TiO 2 was found to offer higher stability, as no significant deterioration in activity was observed after three consecutive cycles. On the other hand, ZnO lost around 30% of its activity after the 1st-cycle of photoreaction. The pH studies showed that acidic environment did not improve the photocatalytic degradation of the POME, whilst in the basic environment, the reaction media became cloudy. In addition, longevity study also showed that the TiO 2 was a better photocatalyst compared to the ZnO (74.12%), with more than 80.0% organic removal after 22 h of UV irradiation. [ABSTRACT FROM AUTHOR]

This paper reports on the optimization of palm oil mill effluent (POME) degradation in a UV-activated-ZnO system based on central composite design (CCD) in response surface methodology (RSM). Three potential factors, viz. O 2 flowrate ( A ), ZnO loading ( B ) and initial concentration of POME ( C ) were evaluated for the significance analysis using a 2 3 full factorial design before the optimization process. It is found that all the three main factors were significant, with contributions of 58.27% ( A ), 15.96% ( B ) and 13.85% ( C ), respectively, to the POME degradation. In addition, the interactions between the factors AB , AC and BC also have contributed 4.02%, 3.12% and 1.01% to the POME degradation. Subsequently, all the three factors were subjected to statistical central composite design (CCD) analysis. Quadratic models were developed and rigorously checked. A 3D-response surface was subsequently generated. Two successive validation experiments were carried out and the degradation achieved were 55.25 and 55.33%, contrasted with 52.45% for predicted degradation value. [ABSTRACT FROM AUTHOR]

This work investigates the electrochemical oxidation of palm oil mill effluent (POME) treatment using platinum (Pt) as anode and graphite as a cathode. The response surface methodology was used to investigate the relationships between different factors conditions (voltage, electrolysis time and chemical support) and responses of the treatment (chemical oxygen demand reduction, colour removal, and total oil removal). A quadratic mathematical model was chosen for all responses using Box-Behnken Design (BBD) with R2 0.9853 for COD reduction, R2 0.9478 for colour removal and R2 0.9185 for total oil removal. According to Derringer's function desirability, under the optimum condition (Voltage 15, electrolysis time 2 h, and 19.95 mg/L NaCl) of POME treatment, 84% of COD reduction, 98% of colour removal and 99% total oil of removal could be achieved. These results indicate that platinum as an anode material is effective for the electrochemical oxidation treatment of POME. [ABSTRACT FROM AUTHOR]

Biological hydrogen production using palm oil mill effluent (POME) as a carbon source through dark fermentation process has been suggested to be a promising bioenergy potential and enacts as alternative renewable energy source. Results have indicated that among various 1.5% (w/v) chemical pre-treatments (sodium hydroxide, NaOH; hydrochloric acid, HCl; sulphuric acid, H 2 SO 4 ; phosphoric acid, H 3 PO 4 and nitric acid, HNO 3) on POME, using H 3 PO 4 would generate maximum biohydrogen production of 0.193 mmol/L/h, which corresponded to a yield of 1.51 mol H 2 /mol TC consumed with an initial total soluble carbohydrate concentration of 23.52 g/L. Among H 3 PO 4 concentrations (1%–10%), the soluble carbohydrate content and the biohydrogen produced was highest and increased by 1.70-fold and 2.35-fold respectively at 2.5% (w/v), as compared to untreated POME. The batch fermentation maximum hydrogen production rate and yield of 0.208 mmol/L/h and 1.69 mol H 2 /mol TC consumed were achieved at optimum pre-treatment conditions of pH 5.5 and thermophilic temperature (60 °C). This study suggests that chemical pre-treatment approaches manage to produce and improve the carbohydrate utilisation process further. Continuous fermentation in CSTR at the optimum conditions produce heightened 1.5-fold biohydrogen yield for 2.5% H 3 PO 4 at 6 h HRT as compared to batch scale. Bacterial community via next-generation sequencing analysis at optimum HRT (6 h) revealed that Thermoanaerobacterium thermosaccharolyticum registered the highest relative frequency of 20.24%. At the class level, Clostridia , Bacilli , Bacteroidia , Thermoanaerobacteria, and Gammaproteobacteria were identified as the biohydrogen-producing bacteria in the continuous system. Insightful findings from this study suggest the substantial practical utility of dilute chemical pre-treatment in improving biohydrogen production. [Display omitted] • Acid pre-treatment of POME enhanced biohydrogen production than alkaline treatment. • 2.5% (w/v) H 3 PO 4 pre-treatment at 20 min increased total sugar content by 2-fold. • pH 5.5 and temperature of 60 °C represented optimum pre-treatment conditions. • CSTR at 6-h HRT produced HY of 2.25 mol H₂ /mol TC from pre-treated POME. • Biohydrogen attributed to genera Thermoanaerobacterium , Clostridium and Bacillus. [ABSTRACT FROM AUTHOR]

Palm oil mill waste has a complex cellulosic structure, is rich in nutrients, and provides a habitat for diverse microbial communities. Current research focuses on how the microbiota and organic components interact during the degradation of this type of waste. Some recent studies have described the microbial communities present in different biodegradation processes of palm oil mill waste, identifying the dominant bacteria/fungi responsible for breaking down the cellulosic components. However, understanding the degradation process's mechanisms is vital to eliminating the need for further pretreatment of lignocellulosic compounds in the waste mixture and facilitating the commercialization of palm oil mill waste treatment technology. Thus, the present work aims to review microbial community dynamics via three biological treatment systems comprehensively: composting, vermicomposting, and dark fermentation, to understand how inspiration from nature can further enhance existing degradation processes. The information presented could be used as an umbrella to current research on biological treatment processes and specific research on the bioaugmentation of indigenous microbial consortia isolated during the biological degradation of palm oil mill waste. [Display omitted] • Necessitate to foster biodegradation of various palm oil mill waste at the industrial level. • Monitoring the interaction between microbiota and organic components is the key factor. • The microbial community shifts during different stages of aerobic/anaerobic phases. • Bacteria secret specific enzymes associated with the degradation of different waste biomass. • Bioaugmentation of microbial consortium enhances the efficient production of biofuels. [ABSTRACT FROM AUTHOR]

Palm oil is the most utilized vegetable globally which is mostly produced in countries such as Malaysia, Indonesia and Thailand. The great amount of POME generation from palm oil mills is now a threat to the environment and require a suitable treatment of POME to reduce the organic strength in accordance with the standard discharge limit before releasing to the environment. Currently, the technology to combine the anaerobic process and biofilm system in bioreactors have produced a fresh idea in treatments of high strength wastewater like POME. Anaerobic biofilm reactor is a convincing method for POME treatment due to its significant advantages over the conventional biological treatments consisting of anaerobic, aerobic and facultative pond systems. Overall, integrated anaerobic-aerobic bioreactor (IAAB) can remove more than 99% of chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) with the combination of anaerobic and aerobic digestion for POME treatment. It has better performance as compared to up-flow anaerobic sludge blanket (UASB) and up-flow anaerobic filter (UAF) with 80% and 88–94% COD removal efficiency respectively. Anaerobic pond was found to perform well also by removing 97.8% of COD in POME but require long retention time and larger land. Hence, this study aims to provide intensive review of the performance of the anaerobic biofilm reactor in treating POME and the recent advancements in this technology. The limitations and future perspectives in utilization of anaerobic biofilm reactor during its operation in treating POME are discussed. [Display omitted] • Integrated anaerobic-aerobic bioreactor can remove 99% of chemical oxygen demand. • UASB generates highest amount of methane gas with 438 mL/gVS added. • Clogging issues remain the major problem in anaerobic biofilm system. • Anaerobic biofilm reactor as green technology is great source of renewable energy. [ABSTRACT FROM AUTHOR]

Abstract: The olive paste obtained after crushing was fast preheated under different time/temperature conditions and then malaxed in an industrial oil mill (600 kg Frantoio/Leccino olive blend). Legal parameters (peroxides, free acidity and sensory panel), oil yield, total phenolic content, oxidative stability and phenolic profile were monitored during 12 months of storage of the virgin olive oil (VOO) kept in closed bottles in the dark. A fast preheating not longer than 72 s at 38 °C without malaxation lead to an extra VOO with a shelf-life of at least 12-months, similarly to the traditional EVOO obtained with malaxation. A fast preheating not longer than 72 s at 38 °C followed by 10 min malaxation lead to an EVOO with a ‘mild’ sensory profile and a shelf life of at least 12-months. Thus, the use of a specific designed fast preheater instead or before (a shortened) malaxation allows to obtain an EVOO with a low bitter/pungent attribute from olives which are rich of (sometimes unpleasant) phenolic compounds with the aim to meet the preference of targeted groups of consumers. Time and temperature of fast preheating are the critical parameters of the process. [Copyright &y& Elsevier]

Palm Oil Mill Effluent (POME) treatment has always been a topic of research in Malaysia. This effluent that is extremely rich in organic content needs to be properly treated to minimize environmental hazards before it is released into watercourses. The main aim of this work is to evaluate the potential of applying natural, chemically and thermally modified banana peel as sorbent for the treatment of biologically treated POME. Characteristics of these sorbents were analyzed with BET surface area and SEM. Batch adsorption studies were carried out to remove color, total suspended solids (TSS), chemical oxygen demand (COD), tannin and lignin, and biological oxygen demand (BOD) onto natural banana peel (NBP), methylated banana peel (MBP), and banana peel activated carbon (BPAC) respectively. The variables of pH, adsorbent dosage, and contact time were investigated in this study. Maximum percentage removal of color, TSS, COD, BOD, and tannin and lignin (95.96%, 100%, 100%, 97.41%, and 76.74% respectively) on BPAC were obtained at optimized pH of 2, contact time of 30 h and adsorbent dosage of 30 g/100 ml. The isotherm data were well described by the Redlich–Peterson isotherm model with correlation coefficient of more than 0.99. Kinetic of adsorption was examined by Langergren pseudo first order, pseudo second order, and second order. The pseudo second order was identified to be the governing mechanism with high correlation coefficient of more than 0.99. [Copyright &y& Elsevier]

The potential of oil palm ash (OPA) to enhance H 2 S and CO 2 removal from biogas by scrubbing with maturation pond effluent (MPE), and further the treatment of biogas scrubber effluent (BSE) by Ceratophyllum demersum L. (hornwort) cultivation were investigated in this study. The results show that OPA + MPE solution with pH 9.3 and alkalinity 7525 mg CaCO 3 /L was obtained with 0.7 kg/L OPA loading. A pilot scale scrubber was used to study the effects of absorbent flow rates of 60–210 L/h on upgrading to 300 L/h field biogas stream. At 210 L/h, the CO 2 removal efficiencies were 33% and 53% for MPE and OPA + MPE, respectively. To approach 100% H 2 S removal efficiency, the minimum flow rates were 120 L/h for MPE and 90 L/h for OPA + MPE. 50–150 g wet weight of hornwort in 30 L diluted POME were loaded to investigate appropriate initial hornwort loading level for hornwort cultivation. The highest specific growth rate of 0.045 day−1 with biomass production of 3.8 g/day were obtained with a 50 g initial loading. Among the wastewaters (MPE, OPA + MPE, and BSE) treatment using hornwort cultivation, the highest 0.035 day−1 specific growth rate and 2.6 g/day biomass production of hornwort were obtained in diluted BSE cultivation, and in 3 weeks of cultivation. COD, nitrate, phosphate, and alkalinity decreased by 76%, 76%, 55%, and 5%, respectively. The Eco-Efficiency concept for palm oil mill waste utilization proposed in this study has a high potential for enhanced biogas upgrading by using OPA + MPE, and hornwort is a good candidate for BSE post-treatment integrated with biomass production. [Display omitted] • The Eco-Efficiency concept for palm oil mill waste utilization is proposed. • Biogas scrubbing with maturation pond effluent is improved by OPA. • 99.9% H 2 S and 53% CO 2 removal obtained with 0.7 kg/L OPA loading. • Biogas upgrading effluent was treated by hornwort cultivation. • Hornwort biomass was produced at 0.035 day−1 specific growth rate. [ABSTRACT FROM AUTHOR]

Abstract: Oil production is an important aspect of ancient Mediterranean economy; therefore, archaeological studies on oil-producing installations using archaeometry and in particular the chemical analysis of absorbed residues is valuable in identifying the substances actually produced and to understand the spatial distribution of the activities carried out at oil mills. Modern contexts may provide a good reference for interpreting the archaeological chemical traces. This study examines the chemical traces in three abandoned oil mills in the Mediterranean: Polveraia (Tuscany, Italy), Martina Franca (Puglia, Italy) and Binibassi (Mallorca, Balearic Islands). To identify the residues released by the production of oil and absorbed by the floors, samples were taken from the floors of these installations and analysed using spot tests aimed at identifying the presence of fatty acids and phosphates. Some of the samples were analysed also with gas chromatography–mass spectrometry. The results of the analyses were plotted in the Geographic Information System (GIS) platform and interpolated with Inverse Distance Weighting (IDW) to determine the spatial distribution of the residues. Overall, the results show a large presence of fats in the analysed floors in all of the installations. [Copyright &y& Elsevier]

Malaysia is one of the countries that is well known for its palm oil based products and exports all over the world. Over the years, palm oil mill has been rising at alarming rate in Malaysia, causing palm oil-based wastes to increase especially palm oil mill effluent (POME). POME in Malaysia are channelled into water bodies such as rivers after treated mostly with conventional biological method. However, with current technologies and knowledge, conventional POME treatments are seen to be outdated and require major improvements as greenhouse gaseous are emitted to the environment as well as being less cost effective. Integrated systems that combine two or more conventional methods are introduced and reviewed to provide insights on the advantages and disadvantages of the system if it is to be implemented in real life plant. Integrated systems that focus on combining conventional methods are compiled and reviewed specifically for POME treatment. Among the integrated methods that are reviewed includes biological with membrane, adsorption with magnetic field exposure, adsorption with membrane and electrocoagulation with membrane. The systems are seen to give excellent color, chemical oxygen demand (COD) and total suspended solids (TSS) removal with average of higher than 90%. Reduction in space utilization, improved treatment time as well as simplified operating system were reported when integrated systems are applied as compared to conventional treatment of POME. • Palm oil mill effluent emission poses environmental problems as 90% of fruit are discarded as wastes. • Conventional treatments limitations include long treatment time, costly and huge space consumption. • Integrated systems combine conventional methods to incur more than 90% color, organic content and suspended solids removal. • Reduction in space and cost consumption as compared to conventional methods. [ABSTRACT FROM AUTHOR]

This study assessed the environmental impacts of the formulation of graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) conductive membranes and of the process operating parameters of electrically-enhanced palm oil mill effluent (POME) filtration. Two different analyses approaches were employed, cradle-to-gate approach for conductive membrane production and gate-to-gate approach for the POME filtration process. The parameters in conductive-membrane formulation (e.g. the weight ratio of carbon nanomaterials, and concentration of GO/MWCNT nanohybrids) and process operating parameters (e.g. electric field strength and electricity operating mode) were investigated. The findings herein are twofold. Firstly, for the fabrication of GO/MWCNT conductive membranes, the best weight ratio of GO:MWCNTs was found to be 1:9, given its superior membrane electrical conductivity with lower environmental impacts by 8.51% compared to pristine MWCNTs. The most suitable concentration of carbon nanomaterials was found to be 5 wt%, given its lowest impacts on resource depletion, human health, and ecosystems. Secondly, for the electrically-enhanced POME filtration, the optimum process operating parameters were found to be the application of an electric field of 300 V/cm in the continuous mode, given its lower environmental impacts (22.99%–89.30%) secondary to its requirement of the least electricity to produce permeate. The present study has established not only the optimized conditions in membrane formulation but also the operating parameters of electrically-enhanced filtration; such findings enable the use of cleaner production and sustainable approach to minimize fouling for industrial applications, whilst maintaining excellent efficiency. • Assessed environmental impacts of the GO/MWCNTs conductive membranes treating POME. • Assessed impacts of electric field strength and operating mode of electrically-enhanced filtration. • Best weight ratio of GO:MWCNTs was 1:9, with lower total endpoint impacts by 8.51%. • Best concentration of nanomaterials was 5 wt%, given its lowest total endpoint impacts (67.55 mPt). • Continuous electric field (300 V/cm) gave lower endpoint impacts (22.99%–89.30%). [ABSTRACT FROM AUTHOR]

The stimulant and toxicity effects of reported organic (acetic acid, propionic acid, butyric acid, formic acid, oil & grease) and inorganic (copper) by-products presented in palm oil mill effluent on anaerobic bacterial population were examined in this paper. The toxicity test had shown that acetic, propionic and butyric acids tend to stimulate the bacterial density level (survival rate more than 50%), while formic acid, copper, oil and grease were shown to have suppressed the density level (survival rate less than 50%). The highest biomass recorded was 1.66 mg/L for the concentration of acetic acid at 216 mg/L and lowest biomass concentration, 0.90 mg/L for copper at 1.40 mg/L. Biohydrogen-producing bacteria have a favourable growth rate around pH 5.5. The comparison of half maximal effective concentration (EC 50) values between two test duration on the effects of organic and inorganic by-products postulate that bacteria had a higher tolerance towards volatile fatty acids. While acetic, butyric and propionic acids had exhibited higher tolerance EC 50 values for bacteria, but the opposite trend was observed for formic acid, copper and oil & grease. Image 1 • Acetic, butyric and propionic acid were proven to elevate bacterial biomass concentration. • Formic acid, copper, oil and grease have the ability to arrest bacterial growth. • Optimum pH for mixed culture anaerobic bacteria growth was mildly acidic. [ABSTRACT FROM AUTHOR]

This study was conducted to examine the production of bioflocculants using agricultural wastewater as a fermentation feedstock under different temperatures and incubation times. The mechanism of flocculation was studied to gain a detailed understanding of the flocculation activity. The highest bioflocculant yield (2.03 g/L) at a temperature of 40 °C was produced in a palm oil mill effluent medium (BioF-POME). Bioflocculant produced from a fermented SME medium (BioF-SME) showed the highest activity. The flocculation tests for colour and turbidity removal from lake water indicated that BioF-SME and BioF-POME performed comparably to commercial alum. Analyses of the bioflocculants using liquid chromatography-mass spectrometry (LC-MS) found that the bioflocculants contained xylose and glucose. The mechanism study showed that flocculation occurred through charge neutralization and interparticle bridging between the bioflocculant polymer and the particles in the lake water. Thus, agricultural wastewater can be used as a fermentation feedstock for high-quality bioflocculants. Image 10995 • Agriculture wastewater as a bioflocculant fermentation media. • Fermentation was investigated under different temperatures and incubation times. • Performances of extracted bioflocculants were comparable to alum. • Extracted bioflocculants contain xylose and glucose. • Flocculation mechanism was through charge neutralization and interparticle bridging. [ABSTRACT FROM AUTHOR]

Environmental monitoring is important to determine the extent of eco-system pollution and degradation so that effective remedial strategies can be formulated. In this study, an environmentally friendly and cost-effective sensor made up of novel carbon electrode modified with cellulose and hydroxyapatite was developed for the detection of trace lead ions in aqueous system and palm oil mill effluent. Zinc, cadmium, and copper with lead were simultaneously detected using this method. The electrode exhibited high tolerance towards twelve common metal ions and three model surface active substances - sodium dodecyl sulfate, Triton X-100, and cetyltrimethylammonium bromide. Under optimum conditions, the sensor detected lead ions in palm oil mill effluent in the concentration range of 10–50 μg/L with 0.11 ± 0.37 μg/L limit of detection and 0.37 ± 0.37 μg/L limit of quantification. The validation using tap water, blood serum and palm oil mill effluent samples and compared with Atomic Absorption Spectroscopy, suggested excellent sensitivity of the sensor to detect lead ions in simple and complex matrices. The cellulose produced based on "green" techniques from agro-lignocellulosic wastes, in combination with hydroxyapatite, were proven effective as components in the carbon electrode composite. It has great potential in both clinical and environmental use. Image 1 • Cellulose-hydroxyapatite carbon electrode composite for trace lead ions detection. • High and reproducible current response of lead ions. • Multi-metal ion detection with no disturbances from interfering ions or surfactants. • Detection limit of 0.11 ± 0.37 μg/L for lead in Palm Oil Mill Effluent. • Validation was successful in aqueous, blood serum and Palm Oil Mill Effluent. [ABSTRACT FROM AUTHOR]