Removal of emerging pollutants from water using enzyme-immobilized activated carbon from coconut shell

This work reports the removal of diclofenac, amoxicillin, carbamazepine, and ciprofloxacin by utilizing three commercially available granular activated carbons (GACs) (Activated carbon, Silcarbon, and Donau) loaded with laccase. Adsorption was used to successfully immobilize laccase on the GACs, as revealed by scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX) and Fourier transform infrared spectroscopy (FTIR). In the three types of GACs tested, pH 5, 30 °C, and 2 mg mL−1 laccase content were found to be the optimum immobilization parameters. Laccase immobilization yields of 65.2%, 63.1%, and 62.9% were achieved with activated carbon, Silcarbon, and Donau respectively. The adsorption behaviors of the pharmaceuticals onto the tested activated carbons are best described as a spontaneous endothermic process that follows Langmuir isotherm and first-order kinetics. The reusability of the immobilized enzyme was evaluated using 2, 2′-azino-bis 3-ethylbenzothiazole-6-sulphonic acid (ABTS) as a substrate within six cycles for all adsorbents. In 120 mins, nearly a complete removal of the pharmaceutical compounds (50 mg L−1) was obtained in the case of activated carbon type and more than 90% for other adsorbent types when synergistic adsorption and enzymatic degradation were applied. With adsorption alone, 74% removal was obtained with activated carbon and < 56% for other adsorbents. The finding of this study suggests that biochar produced from coconut shell (same as the one used in this study) can effectively be used as a substrate and adsorbent for pharmaceutical removal. This enzymatic physical removal system has the potential to be applied on a large-scale

Ecological and human health risk assessment of polycyclic aromatic hydrocarbons (PAH) in Tigris river near the oil refineries in Iraq

Recent Iraqi battles against ISIS in 2014 and 2015 resulted in the destruction or severe damage to several refineries' infrastructure. This, along with other factors, has led to the release and accumulation of a wide range of hazardous chemicals into the environment, for instance, polycyclic aromatic hydrocarbons (PAH). Thus, for the first time, a comprehensive 16 PAHs measurements campaign over the course of six months near the oil refineries along the Tigris River and its estuaries was investigated. The 16 PAHs concentrations in surface water and the sediments for the following oil refineries: Baiji, Kirkuk, Al-Siniyah, Qayyarah, Al-Kasak, Daura, South Refineries Company, and Maysan were examined. The overall findings indicated that the 16 PAHs concentrations ranged from 567.8 to 3750.7 ng/L for water and 5619.2–12795.0 ng/g for sediment. Water samples in South Refineries Company recorded the highest PAH concentrations while Baiji oil refinery registered the highest PAH concentrations in the sediment samples. The percentages of high molecular weight PAH (5–6 rings) in water and sediment samples were the highest, ranging from 49.41% to 81.67% and from 39.06% to 89.39% of total PAH for water and sediment, respectively. The majority of 16 PAHs measured in water and sediment samples of the Tigris River were derived from pyrogenic sources. Based on sediment quality guidelines (SQGs), most sites showed a possible effect range with occasional biological effects of most of the PAH concentrations in all sediments’ samples. The calculated incremental lifetime cancer risk (ILCR) value was high risk with adverse health effects, including cancer

Temporal and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in the Danube River in Hungary

The Danube is a significant transboundary river on a global scale, with several tributaries. The effluents from industrial operations and wastewater treatment plants have an impact on the river's aquatic ecosystem. These discharges provide a significant threat to aquatic life by deteriorating the quality of water and sediment. Hence, a total of 16 Polycyclic Aromatic Hydrocarbons (PAHs) compounds were analyzed at six locations along the river, covering a period of 12 months. The objective was to explore the temporal and spatial fluctuations of these chemicals in both water and sediment. The study revealed a significant fluctuation in the concentration of PAHs in water throughout the year, with levels ranging from 224.8 ng/L during the summer to 365.8 ng/L during the winter. Similarly, the concentration of PAHs in sediment samples varied from 316.7 ng/g in dry weight during the summer to 422.9 ng/g in dry weight during the winter. According to the Europe Drinking Water Directive, the levels of PAHs exceeded the permitted limit of 100 ng/L, resulting in a 124.8% rise in summer and a 265.8% increase in winter. The results suggest that the potential human-caused sources of PAHs were mostly derived from pyrolytic and pyrogenic processes, with pyrogenic sources being more dominant. Assessment of sediment quality standards (SQGs) showed that the levels of PAHs in sediments were below the Effect Range Low (ERL), except for acenaphthylene (Acy) and fluorene (Fl) concentrations. This suggests that there could be occasional biological consequences. The cumulative Individual Lifetime Cancer Risk (ILCR) exceeds 1/104 for both adults and children in all sites

A sustainable nano-hybrid system of laccase@M-MWCNTs for multifunctional PAHs and PhACs removal from water, wastewater, and lake water

This study examined the use of modified multiwall carbon nanotubes (M-MWCNTs) with immobilized laccase (L@M-MWCNTs) for removing ciprofloxacin (Cip), carbamazepine (Cbz), diclofenac (Dcf), benzo[a]pyrene (Bap), and anthracene (Ant) from different water samples. The synthesized materials were characterized using an array of advanced analytical techniques. The physical immobilization of laccase onto M-MWCNTs was confirmed through Scanning electron microscope (SEM)-dispersive X-ray spectroscopy (EDS) analysis and Brunner-Emmet-Teller (BET) surface area measurements. The specific surface area of M-MWCNTs decreased by 65% upon laccase immobilization. There was also an increase in nitrogen content seen by EDS analysis asserting successful immobilization. The results of Boehm titration and Fourier transform infrared (FTIR) exhibited an increase in acidic functional groups after laccase immobilization. L@M-MWCNTs storage for two months maintained 77.8%, 61.6%, and 57.6% of its initial activity for 4 °C, 25 °C, and 35 °C, respectively. In contrast, the free laccase exhibited 55.3%, 37.5%, and 23.5% of its initial activity at 4 °C, 25 °C, and 35 °C, respectively. MWCNTs improved storability and widened the working temperature range of laccase. The optimum removal conditions of studied pollutants were pH 5, 25 °C, and 1.6 g/L of M-MWCNTs. These parameters led to >90% removal of the targeted pollutants for four treatment cycles of both synthetic water and spiked lake water. L@M-MWCNTs demonstrated consistent removal of >90% for up to five cycles even with spiked wastewater. The adsorption was endothermic and followed Langmuir isotherm. Oxidation, dehydrogenation, hydroxylation, and ring cleavage seem to be the dominant degradation mechanisms

Removal of Pharmaceuticals from Water Using Laccase Immobilized on Orange Peels Waste-Derived Activated Carbon

The ongoing discharge of containments into the environment has raised concerns about the potential harm they pose to various organisms. In the framework of eliminating pharmaceutical chemicals from aqueous solutions, enzymatic degradation by laccase is an environmentally friendly option. In this investigation, laccase immobilized on biochar derived from agricultural waste (orange peels, OPs) was used for the first time to remove carbamazepine and diclofenac from aqueous media. Different characterizations, such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), X-Ray diffraction (XRD), specific surface area (SBET), Boehm titration, proximate and ultimate analysis, as well as the point of zero-charge (pHPZC) analysis, were used in this study. The immobilization of laccase results in enhanced stability with respect to storage, temperature, and pH compared to laccase in its free form. The findings showed that the ideal conditions for immobilization were a pH of 4, a temperature of 30 °C, and a laccase concentration of 4.5 mg/mL. These parameters led to an immobilization yield of 63.40%. The stability of laccase immobilized on biochar derived from orange peels (LMOPs) was assessed over a period of 60 days, during which they preserved 60.2% and 47.3% of their initial activities when stored at temperatures of 25 °C and 4 °C, respectively. In contrast, free laccase exhibited lower stability, with only 33.6% and 15.4% of their initial activities maintained under the same storage conditions. Finally, the use of immobilized laccase proved to be effective in eliminating these pollutants in up to five cycles. Upon comparing the two systems, namely LMOPs and modified orange peels (MOPs), it becomes apparent that LMOPs exhibit an estimated 20% improvement in removal efficiency. These results affirmed the viability of activated carbon derived from OPs as a cost-effective option for immobilizing laccase. This approach could potentially be further scaled up to effectively eliminate organic pollutants from water sources

Ketoprofen and aspirin removal by laccase immobilized on date stones

In recent years, enzymatic remediation/biocatalysis has gained prominence for the bioremediation of recalcitrant chemicals. Laccase is one of the commonly investigated enzymes for bioremediation applications. There is a growing interest in immobilizing this enzyme onto adsorbents for achieving high pollutant removal through simultaneous adsorption and biodegradation. Due to the influence of the biomolecule-support interface on laccase activity and stability, it is crucial to functionalize the solid carrier prior to immobilization. Date stones (PDS),as an eco-friendly, low-cost, and effective natural adsorbent, was utilized as a carrier for laccase (fungus Trametes Versicolor). After activating PDS through chemical treatments, the surface area increased by thirty-six-fold, and carbonyl groups became more prominent. Batch experiments were carried out for ketoprofen and aspirin biodegradation in aqueous solutions. After six cycles, the laccase maintained 54% of its original activity confirmed by oxidation tests of 2,2′-azino-bis (3 ethylbenzothiazoline-6-sulphonic acid) (ABTS). In addition, the storage, pH, and thermal stability of immobilized laccase on functionalized date stone (LFPDS) were found to be superior to that of free laccase, demonstrating its potential for ongoing applications. In the aqueous batch mode, this immobilized laccase system was used to degrade 25 mg L-1 of ketoprofen and aspirin, resulting in almost complete removal within 4 h of treatment. This study reveals that agricultural wastes such as date stone can successfully be valorized through simple activation techniques, and the final product can be used as an adsorbent and substrate for immobilization enzyme. The high efficiency of the LFPDS in removing ketoprofen and aspirin highlights the potential of this technology for removing pharmaceuticals and merits its continued development

Ketoprofen and aspirin removal by laccase immobilized on date stones

Funding Information: First and foremost, we are grateful to the anonymous reviewers for improving the paper's quality. The authors acknowledge the support in the form of various facilities provided by Aalto University, Finland and Liverpool John Moores University, UK. We also appreciate the facilities provided by the Environmental Research and Studies Center (ERSC), University of Babylon, Iraq. This article represents the views or opinions of its authors. Funding Information: The ÚNKP-22-3-I-PE-12 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund supported this research. The study was partially supported by the Stipendium Hungaricum, and the Environmental Research and Studies Center, University of Babylon. Publisher Copyright: © 2022 The AuthorsIn recent years, enzymatic remediation/biocatalysis has gained prominence for the bioremediation of recalcitrant chemicals. Laccase is one of the commonly investigated enzymes for bioremediation applications. There is a growing interest in immobilizing this enzyme onto adsorbents for achieving high pollutant removal through simultaneous adsorption and biodegradation. Due to the influence of the biomolecule-support interface on laccase activity and stability, it is crucial to functionalize the solid carrier prior to immobilization. Date stone (PDS), as an eco-friendly, low-cost, and effective natural adsorbent, was utilized as a carrier for laccase (fungus Trametes versicolor). After activating PDS through chemical treatments, the surface area increased by thirty-six-fold, and carbonyl groups became more prominent. Batch experiments were carried out for ketoprofen and aspirin biodegradation in aqueous solutions. After six cycles, the laccase maintained 54% of its original activity confirmed by oxidation tests of 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). In addition, the storage, pH, and thermal stability of immobilized laccase on functionalized date stone (LFPDS) were found to be superior to that of free laccase, demonstrating its potential for ongoing applications. In the aqueous batch mode, this immobilized laccase system was used to degrade 25 mg L−1 of ketoprofen and aspirin, resulting in almost complete removal within 4 h of treatment. This study reveals that agricultural wastes such as date stone can successfully be valorized through simple activation techniques, and the final product can be used as an adsorbent and substrate for immobilization enzyme. The high efficiency of the LFPDS in removing ketoprofen and aspirin highlights the potential of this technology for removing pharmaceuticals and merits its continued development.Peer reviewe

Polycyclic aromatic hydrocarbons in the surface water and sediment along Euphrates River system: Occurrence, sources, ecological and health risk assessment

This study presented for the first time a comprehensive measurement campaign of 16 PAHs along the Euphrates River for five months, in both water and sediment samples. Our study revealed that the PAHs contamination increased along the flow direction due to the increasing non-point pollution and the return flows of agriculture. The 5–6 rings PAHs were dominant in water and sediment samples with an average of 42 % and 50 %, respectively. The diagnostic ratios of PAHs suggest that the pollution of these compounds originated mainly from petroleum product combustions. The carcinogenic PAHs formed 46 % and 55 % of the total measured compounds in water and sediment samples, respectively, which highlights potential ecological and human health risks. Based on sediment quality guidelines (SQGs), most sites exhibit an effect range between low and medium. The calculated incremental lifetime cancer risk (ILCR) for adult and children were in the 10−2–10−3 range, which is 3–6-fold higher than what was reported in the literature. These observations call for urgent attention from environmental authorities of countries sharing this key water source in Western Asia

Removal of Pharmaceuticals from Water Using Laccase Immobilized on Orange Peels Waste-Derived Activated Carbon

The ongoing discharge of containments into the environment has raised concerns about the potential harm they pose to various organisms. In the framework of eliminating pharmaceutical chemicals from aqueous solutions, enzymatic degradation by laccase is an environmentally friendly option. In this investigation, laccase immobilized on biochar derived from agricultural waste (orange peels, OPs) was used for the first time to remove carbamazepine and diclofenac from aqueous media. Different characterizations, such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), X-Ray diffraction (XRD), specific surface area (SBET), Boehm titration, proximate and ultimate analysis, as well as the point of zero-charge (pHPZC) analysis, were used in this study. The immobilization of laccase results in enhanced stability with respect to storage, temperature, and pH compared to laccase in its free form. The findings showed that the ideal conditions for immobilization were a pH of 4, a temperature of 30 °C, and a laccase concentration of 4.5 mg/mL. These parameters led to an immobilization yield of 63.40%. The stability of laccase immobilized on biochar derived from orange peels (LMOPs) was assessed over a period of 60 days, during which they preserved 60.2% and 47.3% of their initial activities when stored at temperatures of 25 °C and 4 °C, respectively. In contrast, free laccase exhibited lower stability, with only 33.6% and 15.4% of their initial activities maintained under the same storage conditions. Finally, the use of immobilized laccase proved to be effective in eliminating these pollutants in up to five cycles. Upon comparing the two systems, namely LMOPs and modified orange peels (MOPs), it becomes apparent that LMOPs exhibit an estimated 20% improvement in removal efficiency. These results affirmed the viability of activated carbon derived from OPs as a cost-effective option for immobilizing laccase. This approach could potentially be further scaled up to effectively eliminate organic pollutants from water sources