Naphthalene Removal Efficiency Research Articles

Enhanced Adsorption of Gaseous Naphthalene by Activated Carbon Fibers at Elevated Temperatures.

This study utilized activated carbon fibers (ACFs) as adsorbents to investigate the removal efficiency of naphthalene and toluene at elevated temperatures and their competitive adsorption behavior. Three types of ACFs, inlet concentrations of naphthalene (343, 457, and 572 mg·Nm-3), and toluene (2055, 2877, and 4110 mg·Nm-3) were investigated to determine the adsorption capacities of naphthalene and toluene. To study the reaction mechanisms of naphthalene and toluene on the ACFs, the BET, SEM, FTIR, and TGA methods were used to examine the physical and chemical characteristics of ACFs. Results showed ACF-A's superior adsorption capacity for naphthalene that was attributed to its mesoporous structure and hydrophobicity. Adsorption equilibrium studies indicated multilayer adsorption behavior. Competitive adsorption experiments demonstrated the displacement of toluene by naphthalene on ACF-A, highlighting its higher selectivity for naphthalene. Functional group analysis revealed changes in ACF surfaces after naphthalene adsorption, suggesting π-π dispersion and electron donor-acceptor interactions. Overall, this study underscores the importance of pore structure and surface properties in designing ACFs for the efficient adsorption of high-boiling-point organic pollutants.

Rice husk composite with polyaniline, sodium alginate and polypyrrole: naphthalene adsorption kinetics, equilibrium and thermodynamic studies

Abstract In this investigation, composites consisting of polypyrrole (PPy), polyaniline (PAN), and sodium alginate combined with rice husk (RH) biomass were fabricated, utilizing them as adsorbents for naphthalene. The optimization of key process variables, including pH, pesticide concentration, composite dosage, contact time, and temperature were systematically undertaken to enhance the removal efficiency of naphthalene. Notably, the composites exhibited promising efficacy in adsorbing naphthalene, with native rice husk and PPy/RH (at pH 4), PAN/RH (at pH 5), and Na-alginate/RH (at pH 6) displaying the highest removal rates. Optimized conditions for composite dosage, temperature, and contact time were determined as 0.05 g, 30 °C, and 90 min, respectively, ensuring efficient removal of naphthalene. The adsorption capacities for naphthalene were found to be 22.04, 23.15, 23.89 and 21.67 (mg/g) for RH, PAN/RH, PPY/RH and Na-alginate/RH, respectively. The Langmuir isotherm and pseudo-first-order kinetics models aptly described the adsorption process onto the composite material. The surface morphology and functional groups involved in the biocomposite formation were examined through scanning electron microscope (SEM) and Fourier-transform infrared (FTIR) techniques. These analyses confirmed that PPy, PAN, and Na-alginate composites with RH biomass exhibit high effectiveness in naphthalene removal, showcasing their potential application in the remediation of naphthalene from effluents.

Advantages of residual phenol in coal chemical wastewater as a co-metabolic substrate for naphthalene degradation by microbial electrolysis cell

The use of co-metabolic substrates is effective for polycyclic aromatic hydrocarbons (PAHs) removal, but the potential of the high phenol concentrations in coal chemical wastewater (CCW) as a co-metabolic substrate in microbial electrolysis cell (MEC) has been neglected. In this study, the efficacy of varying phenol concentrations in comparison to simple substrates for degrading naphthalene in MEC under comparable COD has been explored. Results showed that phenol as a co-metabolic substrate outperformed sodium acetate and glucose in facilitating naphthalene degradation efficiency at 50 mg-COD/L. The naphthalene removal efficiency from RP, RA, and RG was found to be 84.11 ± 0.44 %, 73.80 ± 0.27 % and 72.43 ± 0.34 %, respectively. Similarly, phenol not only enhanced microbial biomass more effectively, but also exhibited optimal COD metabolism capacity. The addition of phenol resulted in a stepwise reduction in the molecular weight of naphthalene, whereas sodium acetate and glucose led to more diverse degradation pathways. Some bacteria with the potential ability to degrade PAHs were detected in phenol-added MEC, including Alicycliphilus, Azospira, Stenotrophomonas, Pseudomonas, and Sedimentibacter. Besides, phenol enhanced the expression of ncrA and nmsA genes, leading to more efficient degradation of naphthalene, with ncrA responsible for mediating the reduction of the benzene ring in naphthalene and nmsA closely associated with the decarboxylation of naphthalene. This study provides guidance for the effective co-degradation of PAHs in CCW with MEC, demonstrating the effectiveness of using phenol as a co-substrate relative to simple substrates in the removal of naphthalene.

Burkholderia cepacia immobilized onto rGO as a biomaterial for the removal of naphthalene from wastewater

As one of the polycyclic aromatic hydrocarbons (PAHs), naphthalene is of serious environmental concern due to its carcinogenicity, persistence and refractory degradation. In this study, a new functional biomaterial based on Burkholderia cepacia (BK) immobilized on reduced graphene oxide (rGO) was prepared, resulting in the removal of 99.0% naphthalene within 48 h. This was better than the 67.3% for free BK and 55.6% for rGO alone. Various characterizations indicated that reduced graphene oxide-Burkholderia cepacia (rGO-BK) was successfully synthesized and secreted non-toxic and degradable surfactants which participated in the degradation of naphthalene. The adsorption kinetics and degradation kinetics conformed best to non-linear pseudo-second-order and pseudo-first-order kinetic models, respectively. Demonstrated in this work is that removing naphthalene by rGO-BK involved both chemically dominated adsorption and biodegradation. As well, GC-MS analysis revealed two things: firstly, that the degraded products of naphthalene were dibutyl phthalate, diethyl phthalate, phthalic acid, and benzoic acid; and secondly, two potentially viable biodegradation pathways of naphthalene by rGO-BK could be proposed. Finally, for practical application experiment, the rGO-BK was exposed to river water samples and generated 99% removal efficiency of naphthalene, so this study offers new insights into biomaterials that can remove naphthalene.

Synthesis of Isoreticular Metal Organic Framework-3 (IRMOF-3) Porous Nanostructure and Its Effect on Naphthalene Adsorption: Optimized by Response Surface Methodology

Naphthalene is a carcinogenic compound and its environmental release poses a major risk to human and aquatic health. Therefore, the application of nanomaterial technologies for naphthalene removal from wastewater has attracted significant attention. In this research, for the first time, the performance of IRMOF-3 for naphthalene removal from aqueous media is evaluated. IRMOF-3 with a specific surface area of 718.11 m2·g−1 has the ability to absorb naphthalene from synthetic wastewater to a high extent. The structures and morphology of IRMOF-3 were determined by FT-IR, XRD, SEM and BET analyses. Thirty adsorption experiments were conducted to obtain the best conditions for naphthalene removal. An optimum naphthalene removal efficiency of 80.96% was obtained at IRMOF-3 amounts of 0.1 g·L−1, a solution concentration of 15 mg·L−1, a contact time of 60 min and a pH = 11. The results indicate that the lower the concentration of naphthalene, the higher its dispersion at the surface of the porous nanostructure. Increasing naphthalene concentration results in its accumulation on porous nanostructures that clog cavities. In addition, high contact time provides ample opportunity for naphthalene to penetrate the cavities and pores which facilitates crystallization phenomena deep in the pores. Finally, the results of this study revealed that IRMOF-3 is one of the most effective adsorbents for naphthalene removal from wastewater.

Removal, migration, and distribution of naphthalene in bioretention facilities: the influences of particulate matter.

Particulate matter (PM), as an important carrier of carrying and transporting runoff pollutants, can significantly affect the behavior and removal efficiency of pollutants in bioretention facilities. In order to control the pollution caused by naphthalene in bioretention facilities, the removal efficiency and migration characteristics of naphthalene were systematically investigated under the influences of PM. The results showed that the removal efficiency of naphthalene was 74 ~ 97% in bioretention facilities under the influences of PM. With the higher concentration, the lower rainfall return period, and the longer antecedent drying period, the removal efficiency of naphthalene in each medium layer were higher. Furthermore, the PM could increase the naphthalene adsorption capacity onto medium in the first 10cm depth, which showed more than 80% removal efficiency and lower mobility of naphthalene. The removal efficiency of naphthalene was significantly higher (90 ~ 97%), when the particle size and concentration of PM were 0 ~ 45μm and 500mg/L, respectively. This study investigated the important role of PM for naphthalene removal in bioretention facilities, and provided effective guidelines for runoff pollution control, design of stormwater facilities, and assessment risk of naphthalene.

Di- and tri- cyclic aromatic hydrocarbons removal using different prepared materials based Sargassum dentifolium algae, and iron oxide

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are highly toxic and carcinogenic compounds as they are low water solubility, hardly degradable and may persist in the environment for many years. Therefore, this study was directed to PAHs ‘anthracene and naphthalene’ removal using a combination method between adsorption and degradation using sunlight. Three adsorbent materials, iron oxide (Fe) alone, Sargassum dentifolium (S) alone, and mixture of Iron oxide and Sargassum dentifolium (FeS) were prepared. Afterwards, optimisation process was performed for the three adsorbent forms through some preliminary experiments followed by full factorial design experiment to get the optimum interacted factors that achieve high PAHs removal efficiency. Some characterisation analyses such as FT-IR, TEM, DLS, zeta potential, specific surface area, magnetisation analysis, isotherm and kinetics studies were performed. The full factorial design showed that, the highest anthracene removal efficiency of 99.15% was obtained at 50 ppm concentration, 3 h contact time by using 1 g/l Sargassum dentifolium, whereas the highest naphthalene removal efficiency of 93.05% was achieved after 4 h contact time at 50 ppm concentration by using 4 g/l Sargassum dentifolium. Moreover, 93.02% naphthalene removal efficiency was stated at 50 ppm concentration after 1 h contact time by using 1 g/l mixed form of Iron oxide/Sargassum dentifolium.

Non-thermal plasma removal of naphthalene as tar model compound from biomass gasification

Gasification of biomass is an industrial process utilized to produce product gas that can be used in electrical power generation with internal combustion engines. However, there remain huge challenges with regards to tar and other pollutants, thus their removal before further use is necessary. Non-thermal plasma method can be considered as a novel and efficient way for treatment of tar from product gas. In this work, a laboratory-scale, reverse vortex flow gliding arc plasma reactor was developed and tested for the removal of tar model compound using naphthalene as surrogate. Effects of total gas feed rate in the range of 20–60 L/min, applied voltage in the range of 50–220 V, hence, power input in the range of 300–460 W with initial naphthalene concentration of 610 ± 50 mg/m3 on removal and energy input were investigated. It was found the tar removal efficiency increased with increasing applied voltage. Maximum naphthalene removal efficiency of 85% was achieved at applied high voltage of 15 kV and specific energy input of 0.13 kWh/m3 with energy utilization efficiency of about 4.60 g/kWh. From the findings, non-thermal plasma technology appeared to offer great potential in the removal of biomass tar from gasification. The technology may be promising for possible application to real biomass tar cracking and upgrading of product gas from gasification.

Enhanced biodegradation and valorization of drilling wastewater via simultaneous production of biosurfactants and polyhydroxyalkanoates by Pseudomonas citronellolis SJTE-3

Pseudomonas citronellolis SJTE-3 was isolated as a highly efficient microorganism for biodegradation and valorization of drilling fluids (DF) wastewater. The strain metabolised DF and oily mud exhibiting up to 93%, 86%, 85% and 88% of chemical oxygen demand (COD), n-dodecane, n-tetradecane and naphthalene removal efficiency respectively. Enhanced bioconversion was enabled through production of biosurfactants that reduced the surface tension of water by 53% and resulted in 43.3% emulsification index (E24), while synthesizing 24% of dry cell weight (DCW) as medium-chain-length polyhydroxyalkanoates (PHA). Expression from the main pathways for alkanes and naphthalene biodegradation as well as biosurfactants and PHA biosynthesis revealed that although the alkanes and naphthalene biodegradation routes were actively expressed even at stationary phase, PHA production was stimulated at late stationary phase and putisolvin could comprise the biosurfactant synthesized. The bioconversion of toxic petrochemical residues to added-value thermoelastomers and biosurfactants indicate the high industrial significance of P. citronellolis SJTE-3.

Molecular and functional analysis of naphthalene-degrading bacteria isolated from the effluents of indigenous tanneries.

During present study, four naphthalene- metabolizing bacteria were isolated from tanneries effluents through enrichment on naphthalene as sole carbon source in minimal salt medium. The bacteria were analyzed to document growth pattern, naphthalene removal efficiency, biochemical and molecular characteristics, antibiotic sensitivity, and metabolic profile. The 16S ribosomal RNA gene sequences were compared through BLAST (basic local alignment search tool) similarity search tool and three isolates were found homologous to Brevibacillus agri strain NBRC 15538 and one similar to Burkholderia lata strain 383. The naphthalene removal efficiencies ranged from 1.16 ± 0.056 mg/h (IUBN1) to 1.379 ± 0.021 mg/h (IUBN26). All isolates were positive for p-nitrophenyl phosphate (PO4 ), esculin, and inulin fermentation tests. Majority were positive for glucosaminidase (IUBN3, 17, and 26) and a few for mannitol and sorbitol fermentation (IUBN1). Identification of metabolites through gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry analysis allowed tracing pathways associated with naphthalene degradation. Intermediates such as cis-dihydrodiolnaphthalene, 2-hydroxychromene-2-carboxylate, 6-hydroxyhexanoic acid, acetyl-CoA confirmed that the present study bacteria can metabolize naphthalene through a pathway which differs from the pathways reported in earlier known bacteria. Due to fast growth rates, high naphthalene removal potentials, and multiple degradation pathways, these bacteria can be exploited for bioremediation of naphthalene.

The Effect of Packing Material Properties on Tars Removal by Plasma Catalysis

Plasma catalysis has been utilized in many environmental applications for removal of various hydrocarbons including tars. The aim of this work was to study the tars removal process by atmospheric pressure DBD non-thermal plasma generated in combination with packing materials of various composition and catalytic activity (TiO2, Pt/γAl2O3, BaTiO3, γAl2O3, ZrO2, glass beads), dielectric constant (5–4000), shape (spherical and cylindrical pellets and beads), size (3–5 mm in diameter, 3–8 mm in length), and specific surface area (37–150 m2/g). Naphthalene was chosen as a model tar compound. The experiments were performed at a temperature of 100 °C and a naphthalene initial concentration of approx. 3000 ppm, i.e., under conditions that are usually less favorable to achieve high removal efficiencies. For a given specific input energy of 320 J/L, naphthalene removal efficiency followed a sequence: TiO2 > Pt/γAl2O3 > ZrO2 > γAl2O3 > glass beads > BaTiO3 > plasma only. The efficiency increased with the increasing specific surface area of a given packing material, while its shape and size were also found to be important. By-products of naphthalene decomposition were analyzed by means of FTIR spectrometry and surface of packing materials by SEM analysis.

Performance evaluation of a continuous packed bed bioreactor: Bio-kinetics and external mass transfer study.

The biodegradation of naphthalene using low-density polyethylene (LDPE) immobilized Exiguobacterium sp. RKS3 (MG696729) in a packed bed bioreactor (PBBR) was studied. The performance of a continuous PBBR was evaluated at different inlet flow rates (IFRs) (20-100mL/h) under 64 days of operation. The maximum naphthalene removal efficiency (RE) was found at low IFR, and it further decreased with increasing IFRs. In a continuous PBBR, the external mass transfer (EMT) aspect was analysed at various IFRs, and experimental data were interrelated between Colburn factor (JD) and Reynolds number (NRe) as [Formula: see text] . A new correlation [Formula: see text] was obtained to predict the EMT aspect of naphthalene biodegradation. Andrew-Haldane model was used to evaluate the bio-kinetic parameters of naphthalene degradation, and kinetic constant νmax, Js, and Ji were found as 0.386 per day, 13.6mg/L, and 20.54mg/L, respectively.

Rapid adsorption of naphthalene from aqueous solution by naphthylmethyl derived porous carbon materials

Abstract In this paper, naphthyl based poly aromatic oligomer was synthesized by Friedel-Crafts alkylation of chloromethyl naphthalene, then the poly aromatic oligomer was carbonized and activated by KOH at high temperature to generate porous carbon materials with high specific surface. The structures and morphologies of intermediates and porous carbon materials were characterized by the FT-IR, XPS, SEM and N2 adsorption–desorption. The specific surface area and pore volume of the material increased with increasing of activation temperature, SBET reached to 1020.06 m2/g. The porous carbon material quickly absorbed naphthalene from aqueous and the adsorption equilibrium was reached in 10 min. The adsorption experimental data fitted well with the Langmuir isothermal model and pseudo-second-order model. The maximum theoretical adsorption capacity estimated by the Langmuir model could reach 186 mg/g. After 1 h of adsorption at 25 °C, the removal efficiency of naphthalene could reach 99.7%, and the removal efficiency was still 91% after four cycles.

Efficient removal of naphthalene from aqueous solutions using a nanoporous kaolin/Fe3O4 composite

The presence of naphthalene in environment has carcinogenic properties and threatens human health. Therefore, the removal of naphthalene from wastewater using eco-friendly materials and novel technologies has received tremendous attention. In this study, the performance of a kaolin/Fe3O4 composite toward the uptake of naphthalene from aqueous media was assessed for the first time. The systematic study of the naphthalene adsorption by the kaolin/Fe3O4 composite, using the central composite design, revealed that an increase in solution pH, contact time, or composite dose improves the removal efficiency of naphthalene. Considering the desirability index of 1.00, the optimum conditions for the removal of naphthalene were found at a composite dose of 4.8 g L−1, contact time of 66 min, and solution pH 6.5 to achieve 97% removal efficiency from a solution containing 10 mg L−1 naphthalene. In comparison with the other clay-based composites, the equilibrium removal efficiency of naphthalene by the kaolin/Fe3O4 composite was significantly high. These results indicated that the kaolin/Fe3O4 composite is one of the most efficient adsorbents for the treatment of naphthalene-contaminated water using the adsorption process.

Degradation of naphthalene with magnetic bio-char activate hydrogen peroxide: Synergism of bio-char and Fe–Mn binary oxides

This study investigated the hydrogen peroxide (H2O2) activation potential of Fe–Mn binary oxides modified bio-char (FeMn/bio-char) for the degradation of naphthalene, the dominant PAHs in drinking water. Results showed that FeMn/bio-char exhibited 80.7- and 2.18-times decomposition rates towards H2O2 than that of pure bio-char and Fe–Mn binary oxides, respectively, and consequently the FeMn/bio-char/H2O2 photo-Fenton system presented highest naphthalene removal efficiency. The enhanced catalytic activity could be ascribed to the synergistic effect of the combination of bio-char and Fe–Mn binary oxides, such as promoting the adsorption capacity towards contaminant, increasing concentration of persistent free radicals (PFRs) and introducing Fe–Mn binary oxides as new activator. According to the batch-scale experiments, FeMn/bio-char/H2O2 photo-Fenton system could degrade naphthalene effectively at a wide pH ranges, and 82.2% of naphthalene was degraded under natural pH of 5.6 within 148 min. Free radicals quenching studies and electron spin resonance (ESR) analyses verified that the dominant free radical within FeMn/bio-char/H2O2 photo-Fenton system was hydroxyl radical (•OH). According to the preliminary analysis, the generation of •OH were ascribed to the activation of H2O2 by Fe (II), Mn (II) and PFRs on the catalyst surface. The mainly degradation intermediates of naphthalene were identified by GC-MS analysis. Consequently, the possible degradation pathways were proposed. Moreover, naphthalene degradation experiments were also conducted in river, tap water, industrial wastewater as well as medical wastewater, and the results indicated that the FeMn/bio-char/H2O2 photo-Fenton system was effective in the treatment of naphthalene in natural waters. This study brings a valuable insight for the potential environmental applications of modified bio-char.

Inhibition of naphthalene leaching from municipal carbonaceous waste by a magnetic organophilic clay.

Municipal solid waste conversion into biofuels via gasification is one of the latest technologies to divert waste from landfills. The byproduct of the process is a carbonaceous material, which is often tainted with polycyclic aromatic hydrocarbons (PAH) such as naphthalene that can leach into the environment and have toxic effects on aquatic organisms. In this paper, we present a novel method to address the issue of leachable naphthalene in a carbonaceous waste produced from a gasification process, using a magnetic sorbent. The sorbent was fabricated by the coprecipitation of iron oxide nanoparticles on an organophilic clay under atmospheric conditions. The characterization results show that the intercalated nanoparticles are predominantly magnetite with a diameter of 15-20 nm, and increase the clay specific surface area from 0.4 to 17 m2 g-1. Toxicity characteristic leaching procedure results indicate that the magnetic composite has a high naphthalene inhibition efficiency comparable to that of the original clay. As opposed to the clay alone, the magnetic hybrid can be separated from the carbonaceous waste with a magnet, regenerated by heat treatment, and reused without compromising its naphthalene removal efficiency. Thus, these composites may provide a cost-effective method to curtail leaching of PAH from contaminated carbonaceous waste.

Tars removal by non-thermal plasma and plasma catalysis

The gasification of a fuel or biomass is an industrial process that is utilized for synthesis gas (syngas) production. The syngas can be used to generate electricity, but after gasification it is often polluted with tars and various other pollutants. Therefore, the syngas must be cleaned before further use. The objective of this paper was to investigate the potential of removing the tars by non-thermal plasma generated by atmospheric pressure dielectric barrier discharge in combination with various packing materials (TiO2, Pt/γ-Al2O3, γ-Al2O3, glass beads). Naphthalene was used as a model polyaromatic tar compound. The effect of discharge power, carrier gas and packing material on naphthalene removal was investigated and gaseous and solid by-products were analysed by means of FTIR spectrometry. In ambient air, a naphthalene removal efficiency of 88% and 40% was achieved for 320 J l−l with and without the catalyst, respectively. The maximum removal efficiency of almost 100% was observed with a TiO2 catalyst and oxygen carrier gas. CO, CO2, H2O and HCOOH were identified among the products, as well as more complex compounds, such as 1,4-naphthoquinone and phthalic anhydride.

Removal of naphthalene from offshore produced water through immobilized nano-TiO2 aided photo-oxidation

In order to increase the applicability of photocatalysis in treating offshore produced water (OPW), an immobilized catalyst was introduced into the UV irradiation system and its performance on the degradation of organic compounds in OPW was evaluated. Naphthalene was selected as the target pollutant owing to its abundance in produced water and its chemical property as a typical polycyclic aromatic hydrocarbon. Aeroxide® P25 nano-scale TiO2 powder was immobilized on glass slides by a heat attachment method and its photocatalytic capacity was compared to that of the original powder in terms of naphthalene removal efficiency. The results of adsorption showed that the reduction of catalysts’ surface area by immobilization was similar to that by agglomeration. The photocatalytic reaction rate constants in the homogeneous and immobilized systems were 0.00219 min−1 and 0.00305 min−1, respectively, indicating that the immobilized catalyst had a better performance in photo-oxidation. The fouling of catalyst surface during the irradiation process came from the deposition of insoluble particles, organic matter, and the scaling of calcium. The immobilization of catalysts was more resistant to the substrate effects of OPW, indicating a promising alternative in treating OPW.

On the Reduction of Gas‐Phase Naphthalene Using Char–Particles in a Packed–Bed Atmospheric Pressure Plasma

AbstractFuel and synthesis gases generated by thermochemical gasification of renewable biomass resources and organic waste fractions are considered to be promising for recent and future energy demands. However, the presence of tar species in the gas mixture is an economic obstacle in the commercialization of this technology. The influence of non‐thermal plasma on gas phase naphthalene which served as tar model compound, in the presence of solids was examined. The naphthalene was evaporated into a N2/H2/CO/CO2 gas atmosphere and led through a packed‐bed, atmospheric plasma reactor operated at a temperature of 350 °C. The influence of two bed materials ‐ glass beads and glass beads mixed with char particles ‐ was studied. The char particles originated from real gasification processes with woody biomass as feedstock. With both reactor fillings, the content of naphthalene in the gas phase was reduced. The characteristic energy β of the naphthalene removal was found to be βno char = 952 ± 77 Jl–1 and βwith char = 232 ± 10 Jl–1, respectively. Consequently, the addition of char material leads to a naphthalene removal efficiency increased by a factor of about four. Furthermore the formation of ammonia (NH3), a by‐product of the plasma reactions, was suppressed in the presence of char. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Biodegradation of naphthalene using Pseudomonas aeruginosa by up flow anoxic-aerobic continuous flow combined bioreactor.

BackgroundNaphthalene is a poly aromatic hydrocarbon (PAH) present in many sediment-water systems. The aim of this study was to evaluate the applicability of an anoxic/aerobic system for the biological treatment of water polluted by naphthalene by Pseudomonas aeruginosa PTCC 1707 to utilize naphthalene. The naphthalene elimination from wastewater was determined in anoxic–aerobic continuous flow combined bioreactor under continuously oxic and anoxic conditions. Experiments were conducted in continues mode, and naphthalene was administered in consecutive spike doses. Then Pseudomonas aeruginosa bacteria suspension with a specific turbidity (0.5-10 NTU) was prepared from growing bacteria on R2A medium and injected to reactor.FindingsAt naphthalene concentration = 0.5-20 mg/L, 33–65.5% naphthalene removal efficiencies were observed. Mean COD removal efficiency in solid retention times of 2, 4, 6, and 8 days was 82.7, 92.45, 95.97 and 96.1%, respectively. Naphthalene removal efficiency by bacterium pseudomonas at pH 8 was 96% and at pH 4, 5.5, 7 and 9.5, 68, 80, 90 and 85%, respectively. As the initial concentration of naphthalene increased from 0.5 to 20 mg/L, the remaining concentration of naphthalene decreased from 33.4% to 65.5% after 3 days.ConclusionBased on experimental results, it was determined that this process can effectively reduce naphthalene under optimal conditions and this method can be used for the removal of similar compounds.