Enhanced Removal Of Phenol Research Articles

Modeling the Kinetics, Equilibrium and Thermodynamics of Poly(acrylamide)/Sodium-Bentonite for Enhanced Phenol Removal from Aqueous Media

A composite based on polyacrylamide and Na-bentonite, designated as PAAm/Na-bentonite was prepared by in-situ radical polymerization using ammonium persulfate as an initiator and bis-acrylamide as a crosslinker. The structural and morphological features were examined by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunner − Emmet − Teller measurements. The results showed PAAm intercalation in the Na-bentonite layers. Equilibrium, thermodynamics, and kinetic studies were conducted by considering the effects of pH, initial phenol concentration, contact time and temperature. The zeta potential of the PAAm/Na-bentonite composite was calculated to understand the mechanism of phenol adsorption onto our product. The pollutant uptake behavior was determined by UV-Vis spectrophotometry. Adsorption results showed that PAAm/Na-bentonite composite showed a maximum adsorption of 160.3 mg.g−1 of 30 mg.L−1 phenol solution at pH 6 after 15 min of adsorption using 4 g.L−1 of the adsorbent. The presence of acrylamide modified the surface characteristics of the Na-bentonite and offered more adsorption sites as confirmed by XRD and SEM. Equilibrium modeling of the phenol removal process was carried out using Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) adsorption isotherms. The equilibrium adsorption data were well fitted with the Langmuir model. In addition, the kinetics of adsorption were best described by a pseudo-second-order expression rather than a first-order model. The interactions between phenol molecules and adsorbent were explained by electrostatic as well as hydrogen bonding interactions, as confirmed by the pseudo-second-order kinetic model. A model for the interactions between the composite and the phenol molecules is proposed. The negative values of Gibb’s free energy (ΔG°) confirmed that the process was spontaneous. The positive value of change in entropy (ΔS° = 0.922 JK−1mol−1) suggests that the randomness was increased at the solution/solid interface. We suggest, the results indicate that PAAm/Na-bentonite presents a significant potential as an adsorbent material for phenol removal from aqueous solutions.

Design and fabrication of magnetic cross-linked laccase aggregate using superparamagnetic metal-organic frameworks for phenol removal

Phenolic pollutants represent a significant environmental concern due to their widespread presence in industrial effluents, agricultural runoff, and urban waste streams. Enzymatic bioremediation emerges as a promising approach for the efficient removal of phenolic pollutants from contaminated environments. Laccases exhibit remarkable catalytic capabilities in degrading phenolic compounds into less harmful or even inert products. In this study, magnetic cross-linked laccase aggregate was prepared using superparamagnetic metal-organic frameworks and then was applied for phenol removal. The obtained results showed that the magnetic cross-linked laccase aggregate retains its activity across a broad pH range. Interestingly, (NH4)2SO4 exhibited a positive influence on enzyme activity, resulting in a relative activity of 137.7 %. The findings suggest that an optimal concentration range of 0.4–0.8 % can achieve maximum enzyme activity while avoiding potential negative impacts associated with excessive cross-linking. Optimal pH and temperature conditions were identified for enhanced phenol removal efficiency as pH 4.5 and 45℃, respectively. The investigation revealed the remarkable reusability of the cross-linked enzyme over multiple cycles. Harnessing the power of enzymes for phenolic pollutant remediation holds immense promise for mitigating environmental pollution and safeguarding public health.

Conductive adsorbents enhance phenol removal from wastewater by direct interspecies electron transfer "DIET"-based anaerobic biodegradation process

This study examined the hybrid adsorption and anaerobic biodegradation processes of phenol by using activated carbon cloth (CC) to stimulate direct interspecies electron transfer (DIET). Phenol biodegradation was tested over three sequential runs using 100 mL lab-scale bioreactors and compared with two different types of CC and granular activated carbons (GAC). The addition of the carbon adsorbents to the bioreactors significantly accelerated the methane production rate. This high rate of methane production was also accompanied by the complete removal of phenol, and a high COD(s) removal rate of about 95%, compared to 43.68% and 48.65% in the control sets in the first and second runs, respectively. The enhancement of the phenol biodegradation is attributed to the synergy of the adsorption and biodegradation processes. An initial adsorption stage has contributed to a significant and rapid reduction of phenol, leading to a lower inhibition effect of phenol, followed by anaerobic biodegradation of the adsorbed phenol stimulated by the DIET process. Specifically, the optimal concentration for Single Weave carbon cloth (CCSW) of 1.6 g L−1 promoted both the DIET and the adsorption processes. Microbial community composition analysis revealed that CCSW facilitated the growth of syntrophic bacterial groups (Rikenellae, Syntrophorhabdaceae, Gracilibacteraceae, and DTU014), and archaea (Methanosaetaceae and Methanoregulaceae), previously reported as key players in the DIET processes to promote phenol degradation. To the best of our knowledge, this is the first work that demonstrates the contribution of CC to stimulate DIET mechanism of anaerobic biodegradation synergistically combined with adsorption process for enhanced phenol removal.

Enhanced phenol removal from aqueous media by adsorption onto organo-modified bentonite

Enhanced phenol removal from aqueous media by adsorption onto organo-modified bentonite

Biochar enhances microbial degradation of phenol in water: Response surface optimization

The utilization of biochar-immobilized microorganisms is an effective method for eliminating phenol from water. However, the main challenge to the practical implementation of this method is the high susceptibility of bacteria to environmental factors. In this study, biochar was used to reduce microbial susceptibility to high concentrations of phenol. Demineralized biochar obtained at high temperatures (600/800/1000 °C) was used to immobilize phenol-degrading bacteria (PDB) and enhance phenol removal. Biodegradation was inhibited by high concentrations of phenol (>1300 mg/L). In contrast, when microorganisms were combined with biochar, up to 82.4% phenol removal occurred, surpassing the efficacy of phenol degradation by a single microorganism (42%). Characterization techniques such as SEM, XRD, and XPS were used to analyze the properties and immobilization effect of biochar. The addition of biochar altered the dominant species of PDB to include Serratia, Ralstonia and Enterobacter. Response surface analysis indicated that both biochar pyrolysis temperature and experimental temperature significantly influenced the phenol removal rate. Thus, this paper provides methodological guidance for the application of biochar-immobilized microorganisms for phenol wastewater treatment.

Enhanced phenol removal by permanganate with biogas residue biochar: catalytic role of in-situ formation of manganese dioxide and activation of biochar

Increased biogas residue related to the rapid development of anaerobic fermentation has become an urgent environmental problem. The pyrolysis of biogas residue into biochar is one of the most promising treatments. In this study, biochar derived from biogas residue was prepared, and the degradation efficiency of phenol by permanganate (KMnO4) increased from 25.3% to 73.4% in 60 min in the presence of biogas residue biochar (BRB). KMnO4 reacted with BRB to produce intermediate manganese dioxide (MnO2), while BRB was activated. The specific surface area increased by 132.25%, and the oxygen-containing functional groups C=O, C−O, and COOH increased after the reaction. The generated MnO2 complexed with BRB to form MnO2@BRB. The newly formed MnO2@BRB catalyzed KMnO4 to remove phenol, which explains the high removal efficiency of phenol. A significant removal rate was also observed for antibiotics and chlorophenols, which suggested that the KMnO4/BRB system has a relatively high ability to oxidize organic pollutants. In addition, the co-existing metal ions and the natural environment had little influence on the removal efficiency of the KMnO4/BRB system. This work provides a novel technology for the resource utilization of biogas residue and improved organic pollutant removal efficiency of KMnO4 in the presence of BRB.Graphical abstract

Preparation, Characterization, and Chemically Modified Date Palm Fiber Waste Biomass for Enhanced Phenol Removal from an Aqueous Environment.

The date palm tree is extensively cultivated in Middle Eastern countries such as Saudi Arabia, generating a large amount of waste in the form of leaves, seeds, and fibrous materials. This study examined the feasibility of using raw date palm fiber (RDPF) and NaOH chemically modified date palm fiber (NaOH-CMDPF) obtained from discarded agricultural waste for the removal of phenol in an aqueous environment. The adsorbent characterization was performed by using different techniques, i.e., particle size analysis; elemental analyzer (CHN); and BET, FTIR, and FESEM-EDX analysis. The FTIR analysis revealed the presence of various functional groups on the surface of the RDPF and NaOH-CMDPF. The results showed that chemical modification by NaOH increased the phenol adsorption capacity that was well-fitted by the Langmuir isotherm. Higher removal was obtained with NaOH-CMDPF (86%) than with the RDPF (81%). The RDPF and NaOH-CMDPF sorbents' maximum (Qm) adsorption capacities were more than 45.62 mg/g and 89.67 mg/g and were comparable to the sorption capacities of various other types of agricultural waste biomass reported in the literature. The kinetic studies confirmed that the adsorption of phenol followed the pseudo-second-order kinetic process. The present study concluded that the RDPF and NaOH-CMDPF were eco-friendly and cost-effective in promoting sustainable management and the reuse of the Kingdom's lignocellulosic fiber waste material.

Bamboo-derived nitrogen-doping magnetic porous hydrochar coactivated by K2FeO4 and CaCO3 for phenol removal: Governing factors and mechanisms

In this study, a novel nitrogen-doped magnetic Fe–Ca codoped biochar for phenol removal was successfully fabricated via a hydrothermal and coactivation pyrolysis method. A series of adsorption process parameters (K2FeO4 to CaCO3 ratio, initial phenol concentration, pH value, adsorption time, adsorbent dosage and ion strength) and adsorption models (kinetic models, isotherms and thermodynamic models) were determined using batch experiments and various analysis techniques (XRD, BET, SEM-EDX, Raman spectroscopy, VSM, FTIR and XPS) to investigate the adsorption mechanism and metal-nitrogen-carbon interaction. The biochar with a ratio of Biochar: K2FeO4: CaCO3 = 3:1:1 exhibited superior properties for adsorption of phenol and had a maximum adsorption capacity of 211.73 mg/g at 298 K, C0 = 200 mg/L, pH = 6.0 and t = 480 min. These excellent adsorption properties were due to superior physicomechanical properties (a large specific surface area (610.53 m2/g) and pore volume (0.3950 cm3/g), a well-developed pore structure (hierarchical), a high graphitization degree (ID/IG = 2.02), the presence of O/N-rich functional groups and Fe-Ox,Ca-Ox, N-doping, as well as synergistic activation by K2FeO4 and CaCO3). The Freundlich and pseudo-second-order models effectively fit the adsorption data, indicating multilayer physicochemical adsorption. Pore filling and π-π interactions were the predominant mechanisms for phenol removal, and H-bonding interactions, Lewis-acid-base interactions, and metal complexation played an important role in enhancing phenol removal. A simple, feasible approach with application potential to organic contaminant/pollutant removal was developed in this study.

Hybrid peroxi-coagulation/ozonation process for highly efficient removal of organic contaminants

Aromatic compounds such as phenols presented widely in coal chemical industry wastewater (CCW) render the treatment facing great challenge due to their biorefractory characteristics and potential risks to the environment and human health. Ozone-based advanced oxidation processes show promising for these pollutants removal, but the mineralization via ozonation alone is unsatisfactory and not cost-effective. Herein, a hybrid peroxi-coagulation/ozonation process (denoted as PCO) was developed using sacrificial iron plate as an anode and carbon black modified carbon felt as cathode in the presence of ozonation. An enhanced phenol removal of ∼100% within 20 min and phenol mineralization of ∼80% within 60 min were achieved with a low energy consumption of 0.35 kWh/g TOC. In this novel process, synergistic effect between ozonation and peroxi-coagulation was observed, and beside O3 direct oxidation, peroxone played a dominant role for phenol removal. In the PCO process, the hydrolyzed Fe species enhanced the generation of reactive oxygen species (ROS), while •OH was dominantly responsible for pollutant degradation. This process also illustrated high resistance to high ionic strength and better performance for TOC removal in real wastewater when compared with ozonation and peroxi-coagulation process. Therefore, this process is more cost-effective, being very promising for CCW treatment.

Establishment of low-carbon microbial network to enhance phenol removal in microbial electrochemical systems with whole process carbon source limitation

Microbial electrochemical system employs electroactive microorganisms as catalysts to generate energy and remove pollutants. The formation of electroactive biofilms (EABs) is essential to efficient pollutant removal as it provides the opportunity for microbial interspecies interaction. Bioavailable carbon source serves as the material basis for the energy supply, and its concentration plays a decisive role in EAB formation and pollutant removal. Unfortunately, the mechanisms of how bioavailable carbon source concentration affects microbial interspecies communication and metabolic activity during EAB formation and pollutant degradation have not been thoroughly investigated. Here, phenol was used as the pollutant to evaluate the performance of EABs formed at different acetate loadings (0.2, 0.5, and 1.0 g/L, marked as EAB-0.2 to 1.0). More phenol degrading microorganisms were enriched in EAB-0.2, achieving better phenol removal. Limited bioavailable carbon source forced microorganisms to adjust metabolites, thus facilitating the interspecies interaction. The close linkage between the up-regulated metabolic pathways facilitated the tricarboxylic acid cycle, leading to faster substrate metabolism. We demonstrated that EAB cultivated in a limited organic environment was more active in pollutant removal, which was essential to guide the application of MES in industrial wastewater treatment.

Bacillus thuringiensis A1 improve phenol tolerance and phytoextraction by Acorus calamus L

Phenol, as a very toxic pollutant, exists widely in rivers in China. To explore the effect of bacterial augmentation on phytoremediation of phenol by Acorus calamus L., some plant growth and physiological parameters and percent removal of phenol were determined in hydroponics containing phenol with addition of Bacillus thuringiensis A1. The A. calamus L. and B. thuringiensis A1 consortium increased the growth rate of plant height, chlorophyll content, the activity of superoxide dismutase (SOD) and peroxidase (POD) in A. calamus L. 10.00–36.54%, 0.62 − 22.15%, 3.94 − 11.25% and 1.37–10.50% respectively compared with single plant treatments at same phenol concentrations. However, the addition of B. thuringiensis A1 decreased the content of malondialdehyde (MDA) and relative electrical conductivity (REC) in A. calamus L. 12.99–23.66% and 8.38–29.98% respectively compared with single plant treatments. The removal efficiency of phenol (increased from 1.56% to 13.78%) by the A. calamus L. and B. thuringiensis A1 consortium was higher than the removal efficiency of phenol of the independent A. calamus L. system. In conclusion, the addition of B. thuringiensis A1 alleviated phenol stress to A. calamus L and enhanced phenol removal due to phenol removal by bacterial augmentation. Novelty statement The addition of B. thuringiensis A1 alleviated phenol stress to A. calamus L. and enhanced phenol removal due to phenol removal by bacterial augmentation.

Interface Derived Carrier Separation in G-C3n4/Moo3-X Heterostructures Towards Enhanced Phenol Removal

Interface Derived Carrier Separation in G-C3n4/Moo3-X Heterostructures Towards Enhanced Phenol Removal

Establishment of Low-Carbon Microbial Network to Enhance Phenol Removal in Microbial Electrochemical Systems with Whole Process Carbon Source Limitation

Establishment of Low-Carbon Microbial Network to Enhance Phenol Removal in Microbial Electrochemical Systems with Whole Process Carbon Source Limitation

Enhancing phenol removal from waste water by adding powder activated carbon to the lab-scale activated sludge system

In this study, the commercial powder activated carbon (PAC) was added to a bench scale conventional activated sludge (CAS) system to enhance phenol removal. The mixed liquor suspended solid (MLSS) concentration of CAS with adding PAC was stable in all stages of operation, while MLSS concentrations in CAS without PAC addition sharply decreased as the Phenol loading reached 1.8 g phenol/L.day. Higher removal of chemical oxygen demand (COD) and Phenol achieved with the CAS by PAC addition compared with those achieved with CAS without PAC addition. The difference in COD removal efficiency was 7 - 9% in stages 3 and 4 (0.8 and 1.2 g phenol/L.day, respectively), and about 33% in stage 5 (1.8 g phenol/L.day). The advantage of CAS with PAC addition was clearly observed in the highest phenol loading (1.8 g phenol/L.day) because the MLVSS/MLSS ratio of CAS with PAC addition increased and the COD and phenol removal efficiencies kept stable in this stage, while reverse trends were found for CAS without PAC addition. The results indicated that the adaptive ability of the CAS by adding PAC was significantly higher than the CAS without AC addition. This study offers useful preliminary results for applying a hybrid system between CAS and adsorption with PAC for further research and application in future.

Synthesis of Oil Palm Frond (OPF) Based Silica Nanomaterial via Sol-gel Method with Enhanced Phenol Removal

This research investigates the potential of the oil palm frond (OPF), a well-known biomass from the oil palm industry, as a feasible silica precursor that can be utilised in the removal of phenol from an aqueous solution. Dried OPF was combusted to obtain OPF ash that was treated with citric acid before being synthesised as silica nanomaterial via the sol-gel method. The FTIR results of synthesised silica exhibit a similar peak with commercially available silica. Silica material was then used for phenol removal under different parameters including pH, contact time, dosage, concentration, and temperature, then analysed using UV-Vis Spectrophotometer. The optimum condition was obtained at pH 7 within 45 mins of contact time using 0.2 g/L silica dosage under 10 ppm of phenol concentration at 303 K that aid in enhancing phenol removal by the OPF-based silica. At this condition, silica nanomaterial successfully removed up to 68% of phenol in an aqueous solution with adsorption capacity of the adsorbent is within the range of 34 mg/g. These results demonstrate the potential application of silica nanomaterial from OPF as an adsorbent in phenol removal from wastewater.

Monitoring the growth, survival and phenol utilization of the fluorescent-tagged Pseudomonas oleovorans immobilized and free cells

Bioaugmentation in wastewater treatment plants (WWTPs) is challenging due to low survival and persistence of applied microbes. This study aimed to track the capacity and survival of fluorescent-tagged Pseudomonas oleovoransICTN13 as a model organism applicable in bioaugmentation of phenol-containing wastewater. The isolate was immobilized in alginate biopolymer, and enhanced efficacy and survival for biodegradation of phenol against free cells were studied. Encapsulated cells resulted in enhanced phenol removal efficiency (~94%) compared to free cells (~72%). Encapsulation of cells facilitated an extended storage time of 30 days. Remarkably, phenol and COD removal efficacy of encapsulated cells was sustained up to ~ 92–93% in a reactor after 45 days, while free cells could produce ~ 80–84% removal efficiency. Fluorescence microscopy showed high survival of the encapsulated cells, whereas gradual deterioration of free cells was observed. Thus, the findings highlight the importance of bio augmented strain in WWTPs where encapsulation is a crucial factor.

Enhanced phenols removal and methane production with the assistance of graphene under anaerobic co-digestion conditions

Coal gasification wastewater (CGW) contains high concentration phenols which lead to poor anaerobic biodegradability and resource utilization. In this paper, new insights to improve synthetic CGW anaerobic degradation with the help of graphene under co-digestion conditions were investigated. Batch tests showed that with the addition of graphene dosage of 10 g/L and glucose as a co-substrate with chemical oxygen demand (COD) concentration of 2000 mg/L, the average COD concentration decreased from 3995 mg/L on day 1 to 983 mg/L on day 12. The average total phenol (TP) concentration decreased from 431 mg/L on day 1 to 23 mg/L on day 12. The cumulative methane production for 12 days was about 200 mL. Long-term experiments showed the average effluent COD and total phenol reached 1137 mg/L and 200 mg/L, respectively. While methane production stabilized at 500 mL/d. In addition, the coenzyme F420 concentration increased from 1.075 μmol/g/VSS to 2.3 μmol/g/VSS. The analysis of microbial community structure indicated that the performance of phenols removal and methane production was related to the main microbial flora. The enriched Clostridium, Pseudomonas and species from Firmicutes and Chloroflexi participated in the stages of hydrolysis and acidogenesis. The electrogens Pseudomonas and archaea Methanosaeta were likely the major groups taking part in the direct interspecies electron transfer (DIET). The results obtained in this paper provide a theoretical basis for high-efficiency anaerobic degradation of CGW in practical engineering applications.

Perstraction of phenolic compounds via nonporous PEBA membranes

This study deals with removal of phenolic compounds from water by perstraction, and poly(ether-b-amide) (PEBA) membranes were selected because of their excellent permeability to phenolics. The permeability, diffusivity and solubility of model phenolic compounds (including the simplest phenol (PhOH), 4-methylphenol (MePhOH), 4-nitrophenol (O2NPhOH) and 4-chlorophenol (ClPhOH)) in the membrane were investigated. The membrane showed a permeability in the order of ClPhOH > MePhOH > O2NPhOH > PhOH, while the diffusivity followed the order of PhOH > MePhOH > O2NPhOH > ClPhOH. Based on the resistance-in-series model, the mass transfer characteristics of the liquid/membrane/liquid perstraction system was analyzed, and the individual mass transfer resistances from the various steps of the perstraction process were estimated. It was revealed that the membrane resistance was significant, and the mass transfer resistance at the downstream side of the membrane as a result of phenol desorption from the membrane and boundary layer effects was not negligible. While the strong affinity between PEBA and phenolics was responsible for the good phenol permeability in the membrane, it also resulted in a high resistance to phenol desorption from the membrane. The use of an alkaline stripping agent can effectively enhance phenol removal from water by reducing the mass transfer resistances of the liquid boundary layers and phenol desorption at the downstream side of the membrane. For a given phenolic compound, the enhancement in mass transfer rate was affected by the alkaline concentration, and the enhancement was particularly significant when thin membranes were used.

Modification of biochar prepared from olive oil processing waste to enhance phenol removal from synthetic and olive mill wastewater

ABSTRACT Six biochars derived from olive mill solid waste were prepared by varying the temperature and treatment with FeCl3. The adsorption capacity of the biochar increased with the pyrolysis temperature and was in the order pre-treated>post-treated>untreated. The Langmuir isotherm and the pseudo-second-order kinetic models best fit the experimental results. The 550°C pre-treated biochar had the highest adsorption capacity from aqueous solutions (103.9 and 73.9 mg.g−1 at pH = 2 and 5, respectively). Chemisorption was the dominating mechanism. The adsorption capacity using olive mill wastewater was 51.3 mg.g−1. This work demonstrates that waste can be reused within the process to achieve cleaner production.

Engineered bacterial biofloc formation enhancing phenol removal and cell tolerance.

A microbial floc consisting of a community of microbes embedded in extracellular polymeric substances matrix can provide microbial resistances to toxic chemicals and harsh environments. Phenol is a toxic environmental pollutant and a typical lignin-derived phenolic inhibitor. In this study, we genetically engineered Escherichia coli cells by expressions of diguanylate cyclases (DGCs) to promote proteinaceous and aliphatic biofloc formation. Compared with the planktonic E. coli cells, the biofloc-forming cells improved phenol removal rate by up to 2.2-folds, due to their substantially improved tolerance (up to 149%) to phenol and slightly enhanced cellular activity (20%) of phenol hydroxylase (PheH). The engineered bioflocs also improved E. coli tolerance to other toxic compounds such as furfural, 5-hydroxymethylfurfural, and guaiacol. Additionally, the strategy of the engineered biofloc formation was applicable to Pseudomonas putida and enhanced its tolerance to phenol. This study highlights a strategy to form engineered bioflocs for improved cell tolerance and removal of toxic compounds, enabling their universality of use in bioproduction and bioremediation.