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Waste recycling and reuse will result in significant material and energy savings. In this research, usage of hospital sludge as a biochar adsorbent for wastewater treatment plants was investigated. Microwave carbonization was used to carbonize the sludge and then chemically activated with ZnCl2to increase surface area and porosity. A newly designed iron metal doped sludge biochar carbon (SBC) has effective adsorption of inorganic arsenic (As(III), As2O3) in water. The findings clearly demonstrate the viability and utility of using hospital sludge as a source of carbon to generate SBC. The adsorption mechanism of As(III) on SBC’s iron-metal-modified surface has been studied using density functional theory (DFT) to understand the impact of functional complexes on adsorption As(III). Tests showed physical as well as chemical adsorption of As(III) on Fe-SBC surface. Fe’s involvement in functional complexes greatly fostered SBC surface activity and it’s As(III) adsorption ability. The physical adsorption energies of As(III) with Fe functional complexes on the SBC surface were −42.3 KJ mol−1. Other hand, the chemical adsorption energies of As(III) on Fe-SBC surface was −325.5 KJ mol−1. As(III) is capable of interacting in a bidentate fashion with the dopants through the protonated oxygen atoms and this conformation of the cyclic structure is higher in the adsorption energy than the others.

Norfloxacin (NF) is an emerging antibiotic contaminant due to its significant accumulation in the environment. Photocatalytic degradation is an effective method for removing emerging contaminant compounds in aqueous solution; however, it is not commonly applied because of the poor solubility of contaminant compounds in water. In this study, a photocatalytic degradation experiment was carried out on NF using a self-made ceria catalyst. At an initial concentration of NF of 2.5 mg L−1, the dosage of CeO2 was 0.1 g L−1 photocatalyst in water, and the initial pH of the NF solution was 8.0. With a reaction time of 180 min, the total removal rate of NF could reach 95%. Additionally, the studies on hydrogen production show that the maximum hydrogen production with 2% Fe–CeO2 can reach 25,670 μmol h−1 g−1 under close to 8 W of 365 nm, a methanol concentration of 20%, and a catalyst dose of 0.1 g L−1 photocatalyst in water. Furthermore, the intensities of photoluminescence (PL) emission peaks decreased with increased Fe-doped amounts on CeO2, suggesting that the irradiative recombination seemed to be weakened.

Multilayer ZnO sheet-like flakes were synthesized by a simple method of precipitation and characterized by the techniques of X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The findings are proven that the SEM images show the overall morphology of a single sheet-like ZnO nanostructure made from uniformly thick nano-sheets. In an aqueous environment, the acoustic ability of the prepared material was assessed using ultrasound (US) radiation to degrade oxytetracycline (OTC) and norfloxacin (NF). To increase the degradation efficiency, a US/ZnO/peroxodisulfate system was developed by introducing ammonium persulfate ((NH4)2S2O8) and sodium persulfate (Na2S2O8), exhibiting excellent synergistic effects. Result show the decomposition efficiency for NF removal with Na2S2O8 (64%) appeared to be slightly better than with (NH4)2S2O8 (56%). By contrast, the ultrasonic catalytic efficiency of Na2S2O8 (98%) was slightly better than that of (NH4)2S2O8 (94%) for OTC removal. The addition of scavengers to the US/ZnO/peroxodisulfate system through the NF and OTC results in the largest effect of holes. The degradation is considered to be often caused by holes. In this system, the Na2S2O8 can have two roles to increase the rate of degradation: (1) The SO4− formed by Na2S2O8 under ultrasonic irradiation directly degraded to norfloxacin on ZnO surface; and (2) S2O82- behaved as an electron acceptor, inhibiting recombination of electron hole pairs, enabling the development of more ·OH. Therefore, the synergistic effect significantly increases US/ZnO/peroxodisulfate sonocatalytic activity (Hu, S.B., et al., 2017. Aqueous norfloxacin sonocatalytic degradation with multilayer flower-like ZnO in the presence of peroxydisulfate. Ultrasonics Sonochemistry, 38(1), pp.446–454).

Production of Copper (Cu) modified Cadmium sulfide (CdS) nanomaterial, named as Cu–CdS, was successfully synthesized through hydrothermal and photo deposition method to degrade oxytetracycline (OTC) antibiotics in aqueous solution. Uniform surface loading of copper was observed on CdS using Scanning Electron Microscopy-mapping (SEM-mapping). The Cu induced improvement in the visible light absorption was observed using UV-vis absorption spectrum. Thus, this material can exhibit excellent oxytetracycline (OTC) degradation by photocatalysis. The best OTC degradation efficiency of 90% was be achieved under the optimal concentration of 4% Cu–CdS, with 0.1 g L−1 dosage (pH 5) under UV irradiation. 0.167 mg L−1 min−1 was observed as the reaction kL-H on the peripheral of the catalyst. In addition, OTC can also be degraded under visible light with removal efficiency approximately 90%. Moreover, the contribution of main reactive oxygen species (ROS), including hydroxyl radicals, superoxide radical and holes, is evaluated as 18%, 43% and 29%.

As the characterizations of electrode are meaningful for electric catalytic efficiency and mechanism, the improvement of electrode have raised considerable public concern in recent decades. However, the metal electrode have the drawbacks of high price and easy for toxicity, nano electrode restricted by difficulties for electrode coating, possibility of agglomeration, and abscission during reactions. Focus on those defects, the proposed study is going to establish a useful technique for polymer combined nano-electrode preparation. The morphology, functional groups, and other characterization of the Pt/TiO2/graphene particles and organic composite nano Pt/TiO2/graphene sheets were analyzed by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), electrochemical impedance spectroscopy (EIS). To identify the stability of self-prepared electrodes, parameters such as catalysts dosage, current density and pH will be analyzed by using RBK5 as target pollutions. The results shows that after treatment for 50 min under optimized conditions (20 mA, 1 g/L NaCl), the degradation rate of acetaminophen almost reached 100%. After five times recycle, the self-prepared electrode could still maintained a high removal rate of 90%.

This study is the first to use a newly-developed material via hydrothermal method, cerium oxide nanowires doped with reduced graphene oxide (CNW-RGO) for reductive H2 production. The detailed characteristics of the CNW-RGO materials were investigated to explore the capabilities of reductive production. The mean diameter of the CNWs was uniform at 22 nm. Owing to RGO-doping, the energy gap between the valence and conduction bands tended to become narrower that demonstrated by the density functional theory calculation (DFT). Furthermore, the optimum hydrogen production was 7.14 mmol g−1 by the CNW-RGO with a RGO content of 4 wt.% under the visible-light irradiation. This result was consistent with the turnover frequency (TOF) predictions. The introduction of RGO sheets effectively mediated the transfer of photogenerated electrons from the CNW to the sheets. Therefore, it could act as an electron trap to stimulate charge separation, which was corroborated by X-ray photoelectron spectroscopy (XPS) analysis. As indicated by comparative assessment, methanol was the most promising sacrificial agent in the system. Additionally, the formation of the methoxy group after the reaction was clearly demonstrated by Fourier-transform infrared (FTIR) spectroscopy. The number of hydroxyl groups on the alcohols directly determined their activity in reductive production.

This study explored a facile one-step hydrothermal method of preparing a high-performance photocatalyst, namely, graphene-TiO2, for oxytetracycline (OTC) removal. The nanocomposites were characterized by Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy, UV-Vis diffuse reflectance spectroscopy and X-ray diffraction (XRD). The photocatalytic properties of different graphene loading types and various OTC initial concentrations, temperatures, and initial pH values were investigated. Results showed that the material with 10% graphene content exhibited the best performance and removal efficiency (beyond 99%) of OTC within 180 min at 35 °C and pH 5.5. The effects of different reactive oxygen species scavengers on photodegradation and the contributions were evaluated, and a possible reaction mechanism was proposed. Caenorhabditis elegans was used for toxicity testing during the entire degradation process and achieved a favorable result.

Composite electrodes with different graphene (GN)/TiO2 ratios and nano-activated carbon electrodes were prepared for electrocatalytic performance comparison. The electrodes were loaded with platinum (Pt) by use of chloroplatinic acid to promote their performance. Reactive Black 5 (RBk5) dye wastewater was treated as a challenging pollutant by use of advanced electrochemical oxidation technology. The composite materials were characterized by Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Disperse Spectroscopy (EDS). Results showed that the graphene electrode was prepared successfully and verified because all elements were uniformly loaded on the conductive carbon cloth. The effects of several operating parameters including material types, pH, initial concentration of RBk5, and current density on the removal performance of RBk5 were also assessed. The supporting electrolyte was NaCl solution of 1 g L−1. The concentration of RBk5 was detected using an ultraviolet spectrophotometer with a detection wavelength of 600 nm. The optimum parameters of the experiment were GN/TiO2 ratio of 1:4 and pH of 6.6. The removal efficiency of RBk5 could be higher than 95% under an initial concentration of RBk5 of 5 ppm and a current density of 2.5 mA·cm-2 when reaction time was 30 min.

The utilization of sludge from Far Eastern Memorial hospital (New Taipei city, Taiwan) wastewater treatment plants as biochar adsorbent was investigated. The sludge was carbonized using microwave carbonization and then chemically activated at high temperatures by using ZnCl₂ to enhance porosity and surface area. A newly designed Zndoped amino-functionalized sludge biochar (Zn-SBC-DETA) presents effective As adsorption in water. The adsorbent was characterized by nitrogen adsorption-desorption, scanning electron microscopy (SEM) and thermogravimetric analysis. Results show that the surface area and average pore volume of Zn-SBC-DETA are 525 m² g-1 and 0.35 cm³ g-1, respectively. SEM results reveal that Zn-SBC-DETA has uniform pore size. The highest adsorption efficiency of As(III) is 79% at pH 3 with an adsorption capacity of 0.84 mg g-1. In addition, the adsorption efficiency of As(V) is 98% at pH 3 with an adsorption capacity of 1.43 mg g-1. The adsorption data can be described well by the Langmuir model rather than by the Freundlich model The data show good compliance with the pseudo second-order equation, and the correlation coefficient for the linear plots is higher than 0.97. Combined with the As species after reacting with Zn-SBC-DETA, the As transformation and adsorption mechanism are also discussed.

Prior studies mentioned that extracts of polyphenolics-abundant edible flora might provide compositions of reversible electron shuttles for bioenergy extraction; however, detailed mysteries behind such phenomena still remained open to be explored. This first-attempt study selected a medicinal herb Scutellaria baicalensis Georgi and its main flavonoid ingredients to quantitatively decipher their electron-mediating activities for bioenergy applications. The main ingredients with strong shuttling activities (e.g., baicalin, baicalein and wogonin) were chemical structure-associated to disclose electrochemical and bioenergetics characteristics for comparative analysis. Evidently, baicalin owned the most promising electron shuttling capabilities. Although extract of flavonoids-rich S. baicalensis Georgi also showed promising redox-mediating characteristics, typical ingredient-baicalein still exhibited high biotoxicity to bacterial CO2 respirometric production, thereby resisting fully expression of electron transfer capabilities. Supplementation of baicalin and extract of S. baicalensis Georgi to microbial fuel cells (MFCs) was conducted to quantify such stimulating capabilities of bioelectricity generation. That is, with toxicity attenuation, processed flavonoids-rich medicinal herbs were possibly electroactive for bioenergy extraction due to favorable electron-shuttling activities.

T-Ag/ZnO nanoflowers were successfully fabricated via two steps methods on zinc foil. The chemical composition of norfloxacin was investigated by FTIR spectroscopy. The morphology, composition, and structural and optical properties of the as-synthesized materials were characterized. The results show that triangular silver nanoplates exhibit unique surface plasmon resonance (SPR) absorption spectra, and the absorption spectrum range of ZnO nanoflowers are effectively expanded by coating triangular silver nanoplates. The photocatalytic degradation of norfloxacin activity can be obviously improved because of a synergetic effect and unique SPR of triangular silver nanoplates in the T-Ag/ZnO nanoflowers under visible light. In addition, the possible mechanism for T-Ag/ZnO nanoflowers for the photodegradation of norfloxacin are discussed. The stability of T-Ag/ZnO nanoflowers are also studied.

The Pt and graphene (GN) were used to modify TiO2 nanoparticles. GN/TiO2, Pt-TiO2, Pt-GN/TiO2 were successfully synthesized by modified Hummers' method, alcohol thermal and photodeposition method, respectively. The characterizations of the synthesized catalysts by different characterization techniques, including N2 adsorption-desorption isotherm, fourier transform infrared spectroscopy (FTIR), inductively coupled plasma (ICP) technique and element analyzer (EA), respectively. In addition, different sacrificial agents (methanol, ethanol, n-propanol, i-propanol, n-butanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol and glycerol) have been investigated. There is clearly a linear relationship between hydrogen production rate and the polarity of monohydric alcohols. According to the Langmuir-Hinshelwood results, the surface pseudo-first order rate constant k = 15.06 mmol h-1 g-1 and the adsorption coefficient k = 0.50 mol L-1 were obtained. The feasibility of hydrogen production from wastewater obtained from terephthalic acid industry was studied. After reusing the catalyst under the same experimental conditions, the hydrogen production rate has only slightly decreased for 3 more cycles, which indicated the stability of the synthesized catalysts.

A large amount of calcium fluoride sludge is generated by the semiconductor industry every year. It also requires a high amount of fuel consumption using rotor concentrators and thermal oxidizers to treat VOCs. The mesoporous adsorbent prepared by calcium fluoride sludge was used for VOCs treatment. The semiconductor industry employs HMDS to promote the adhesion of photo-resistant material to oxide(s) due to the formation of silicon dioxide, which blocks porous adsorbents. The adsorption of HMDS (Hexamethyldisiloxane) was tested with mesoporous silica materials synthesized from calcium fluoride (CF-MCM). The resulting samples were characterized by XRD, XRF, FTIR, N2-adsorption-desorption techniques. The prepared samples possessed high specific surface area, large pore volume and large pore diameter. The crystal patterns of CF-MCM were similar with Mobil composite matter (MCM-41) from TEM image. The adsorption capacity of HMDS with CF-MCM was 40 and 80 mg g-1, respectively, under 100 and 500 ppm HMDS. The effects of operation parameters, such as contact time and mixture concentration, on the performance of CF-MCM were also discussed in this study.

Response surface methodology was adopted to obtain ternary mixed catalysts of TiO2-loaded ZSM-5 zeolite and graphene. Oxytetracycline was used as challenged toxicant to evaluate the photocatalytic degradation efficiency of the composites. The optimal weight ratio of graphene, TiO2, and ZSM-5 was 1:8:1. The composites were characterized by ultraviolet-visible spectroscopy, X-ray diffraction, fourier transform infrared, N2 adsorption-desorption isotherms, and transmission electron microscope with an energy-dispersive spectroscopy system, etc. Synthesized samples showed high stability and strong visible-light absorption efficiency. The optimal operating conditions of oxytetracycline photocatalytic degradation were achieved over a wide range of pH and temperature. With 0.1 g/L of optimal ternary mixed composite, the photocatalytic degradation of oxytetracycline was nearly reached completion within 150 min at all treatment temperatures at pH 7. Toxicity of degraded oxytetracycline solution was assayed by a boar sperm quality model using fluorescent staining and flow cytometry. During 180 min of photocatalytic treatment, the degraded oxytetracycline solution showed increasing biotoxicity and changed the morphology and function of boar sperm, despite not killing them.

Hydrogen is considered as a promising energy source with its high energy yield, renewable, environment friendly properties. TiO2 modified with noble metal and nonmetal is widely used. In this study, Pt and graphene (GN) were used to modify TiO2 nanoparticles. GN/TiO2 (TG), Pt-TiO2 (PT), Pt-GN/TiO2 (PTG) was successfully synthesized by modified Hummers' method, alcohol thermal and photodeposition method, respectively. The characterizations of the synthesized catalysts by UV-vis/DRS, components analysis, XRD and TEM analysis were conducted. Results showed the maximum hydrogen production rate was approximately 4.71 mmol h-1 g-1 when the Pt content was 1.0 wt.%. Higher and lower than 1.0 wt.% of Pt loading content both result in low efficiency of hydrogen production. The situation of graphene is similar to Pt. The optimal ratio for grapheme is 10 wt.%. The highest hydrogen production rate is 6.58 mmol h-1 g-1 by 1.5 wt.% Pt-5 wt.% GN/TiO2 (1.5PTG5), which is about 1.4 and 2.2 times higher than that of Pt-TiO2 and GN/TiO2 binary composites, respectively. The utilization of low-cost graphene can reduce the use of noble metal Pt in photocatalytic hydrogen production. The mechanism of Pt-GN/TiO2 for the improved photocatalytic activity is proposed. 0.1 g L-1 is found to be the optimum catalyst concentration for optimal hydrogen production.

This study explored a new facile one-step method of preparing magnetically modified biochar (NMBC) with easy separation characteristics for the improvement of Cr (VI) removal. The prepared NMBC was characterized by scanning electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, and superconducting quantum interference device. Results showed that NMBC processed a rough and uneven surface with high N and amine contents, as well as magnetization for the separation. The kinetics, isotherm and thermodynamic analysis of Cr (VI) adsorbed on the prepared materials were also investigated, as well as the effect of initial pH. NMBC showed a high Cr (VI) adsorption capacity of 48 mg g −1 , which is twice higher than that of traditional magnetic biochar (MBC, 19 mg g −1 ). The different mechanisms of MBC and NMBC were also discussed.

Ti-doped MCM-41 with different Si/Ti molar ratios was prepared at room temperature to degrade tetracycline antibiotics in aqueous solution. The Ti was doped into the skeleton structure of MCM-41. The photocatalytic activity of Ti-doped MCM-41 was investigated. The optimal catalyst had Si/Ti molar ratio of 25 and over 99% removal of oxytetracycline in 150 min, and the removal could maintain 98% after 5 reuses. Ions and soluble organic matters in natural water affected the degradation reaction when Ti-doped MCM-41 was used to treat simulated wastewater of chicken farms. The degradation products of oxytetracycline, tetracycline and chlortetracycline were detected by Escherichia coli DH5α and HPLC–MS/MS. No intermediate product with higher toxicity was detected.

A novel category of improved performance membrane consisting of a hydrophobic mat and a hydrophilic electrospun layer for membrane distillation (MD) application has been presented. The nanofibrous non-woven layer was fabricated by electrospinning of polyvinylalcohol (PVA) incorporated with Triton X-100 directly onto the polypropylene (PP) mat. To render the membrane distillation process effective in terms of high permeate flux and salt rejection %, the concept of dual layer membrane is utilized with hydrophobic PP mat on top and hydrophilic PVA layer on bottom. In this study, PVA nanofibrous layer has been fabricated by incorporating non-ionic surfactant Triton X-100 for uniformity and homogeneity in fiber diameter. Additionally, the PP mat acts as a top support layer and PVA-TX nanofiber acts as base layer which absorb the water molecules (condensed vapour), that enhances the vapour flux across the membrane. The modified bilayer PP/PVA-TX membranes were characterized by the pore size distribution, permeate flux, and rejection %, then compared with original PP mat. The salt rejection of the dual layered PP/PVA-TX membrane showed > 99% and still maintained 2 times higher permeate flux compared to PP membrane for long term operation of 15 h.

Carbon dioxide (CO2) resulting from the burning of organic carbons has aroused serious concern because of increasing concentrations in the atmosphere and its effect on global warming. Therefore, finding an efficient method for CO2 utilization is important. In this research, CO2 underwent efficient reduction when graphene (GN)-TiO2 was used as a catalyst under visible light irradiation. The radicals involved in the reaction as intermediates were observed by ESR to identify the reduction pathways. Furthermore, the hypothetical pathways were verified by the steady-state approximation model. The calculated rate constants of the final products and intermediates (including radicals) indicated that the formation of CH3OH was mainly derived from ·CO– rather than from HCOOH. Furthermore, the effects of GN loading, catalyst loading, and light source were also discussed. Optimal performance was achieved at 0.4 g L−1of 40% GN-TiO2 loading under visible light irradiation.

This study synthesizes colloidal silver triangular nanoprisms via dual-reduction method. The particle morphology is controlled by changing the silver nitrate and polyvinylpyrrolidone concentrations. The triangular silver and spherical silver colloids are combined with TiO2 powder for methylene blue (MB) photodegradation in visible light. Comparisons between the spherical Ag (S-Ag) and experimental results show that the triangular silver (T-Ag) significantly promotes MB degradation under visible light, which contributes to the surface plasmon resonance effect on the Ag triangular nanoprisms.

In this study, a new type of molecular sieve/polyacrylonitrile fiber (M-PAN) was prepared by electrospinning to adsorb atmospheric volatile organic compounds (VOCs). The suitable content of molecular sieve in nanocomposites was also determined for achieving maximum VOCs adsorption capacity. SEM, TEM and N2 adsorption/desorption analyzer were performed for characterization of the surface morphology, structural properties, surface area and pore size. A part of molecular sieve is exposed on the fiber surface where VOCs can be adsorbed efficiently in a short time. Acetone was used as a challenge pollutant to evaluate the adsorption of VOCs at different recycling times and types of electrospinning nanofibers. The adsorption capacity of 6M-PAN (60% weight of molecular sieve) nanofiber reached 58.2 μg g−1 and the reused nanofibers nearly had the same adsorption capacity as the newly prepared nanofibers after several times of recirculation.

The objective of this paper is to study the removal of Cr(VI) in aqueous solution by using a new graphene oxide-coated rice husk biochar composite (GO-RHB). GO-RHB is a synthetic material having a porous structure with lots of oxygen-containing functional groups and a large surface area that provide effective adsorption sites. Experiments showed that GO-RHB had higher adsorption capacity under acidic than under alkaline conditions. At pH of 2, GO-RHB has the maximum adsorption capacity(48.8 mg g−1). Equilibrium data obtained by fitting with the Langmuir and Freundlich models indicate that the reaction process was monolayer adsorption. The adsorption of Cr(VI) followed the pseudo-second-order kinetic model that illustrates chemical adsorption. Intraparticlediffusion studies further revealed that film diffusion was taking place. Moreover, the results of thermodynamics showed that the adsorption process was endothermic and spontaneous in nature. The removal mechanism of Cr(VI) was also explained in detail. The prepared adsorbent is highly efficient and might be useful than many other conventional adsorbent used for the removal of Cr(VI) from wastewater.

This first attempt study explored newly prepared materials for promising As(III) treatment with easily recycling characteristics for sustainable uses. Regarding layered GOs they had appropriate capabilities for practicability; significantly increased large GO layers could be served as precursor and stabilizer of other materials due to excellent electron transfer capacities. Titanium nano tube (TNT) catalysts were prepared to augment surface areas for maximal adsorption capacities. TNT-doped graphene (GN-TNT) was then prepared by hydrothermal method. In addition, GN-TNT was coated with magnetic nano particles (MNP) to yield mesoporous composites to be easily recycled under a magnet. Ternary mixture design of experiments was implemented to determine optimal ratios of GN-MNP-TNT to remove As(III) in solutions. To have detailed characteristics of the morphology and composition, X-ray diffraction, atomic force microscopy and transmission electron microscopy were implemented. Resuability of GN-MNP-TNT composites had also been tested for 4 serial cycles of adsorption/desorption of As(III). Compared to graphene-based materials, the most appropriate rate of As(III) adsorption rate was 0.057 min −1 . In addition, treatment efficiency of As(III) after 4 cycle of regeneration still remained at 83%, significantly higher than literature for promising practicability.

Considering economic feasibility and technical effectiveness, polyacrylonitrile/ferrous chloride composite nanofibers prepared by electrospinning was used to remove the Cr(VI). Maximum removal of Cr(VI) by composite nanofibers was observed in weakly acidic environment. The analysis of the reaction kinetics revealed that the adsorption behavior seemed to follow pseudo-second-order kinetic model. Through calculating thermodynamic parameter, the adsorption reaction was proved to be an exothermic and chemical process. The PAN…Fe 1 − x Cr x (OH) 3 and PAN…Fe 1 − x Cr x (OH) x were proposed to be formed after the redox reaction was taken place. The interactive effects of coexisting ions of different metal ions like arsenic, lead and cadmium were also explored for practical consideration. The presence of these metal ions apparently decreased the efficiency of the Cr(VI) adsorption. In addition, the interactive inhibition of arsenic was more significant than other coexisting ions. It was suspected that the valence state ( e.g. , NO 3 − , SO 4 2− , Cl − , Ca 2± , Na ± and Mg 2± ) may play a crucial role during the reaction. Due to the strong electrostatic attraction, anions had the more significant attenuating effect than cations. This study is helpful not only for doping design of iron oxide nanofibers but also for practical application during advanced wastewater treatment.

In this study, a one-step solid dispersion method was used to synthesize titanium dioxide (TiO 2 )/Zeolite Socony Mobil-5 (ZSM-5) composites with substantially reduced time and energy consumption. A degradation efficiency of more than 95% was achieved within 10 min using 50% PTZ (synthesized TiO 2 /ZSM-5 composites with TiO 2 contents of 50 wt% loaded on ZSM-5) at pH 7 and 25 °C. The possible degradation pathway of azo-dye Reactive Black 5 (RB5) was investigated using gas chromatography–mass spectrometry and ion chromatography (IC). The bonds between the N atoms and naphthalene groups are likely attacked first and cleaved by hydroxyl radicals, ultimately resulting in the decolorization and mineralization of the azo dye. A comparative assessment of the characteristics of abiotic and biotic dye decolorization was completed. In addition, the toxicity effects of the degradation intermediates of azo-dye RB5 on cellular respiratory activity were analyzed. The bio-toxicity results showed that the decay rate constants of CO 2 production from the azo-dye RB5 samples at different degradation times increased initially and subsequently decreased, indicating that intermediates of higher toxicity could adhere to the catalyst surface and gradually destroyed by further photocatalytic oxidation. Additionally, EDTA (hole scavengers) and t -BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the hydroxyl radicals are the main oxidation species in the photocatalytic process.

Using wastewater as sacrificial reagent to transfer solar energy and water as clean energy has attracted significant attention because of increasing concerns on environmental pollution and depletion of fossil fuels. In this study, wastewater from terephthalic acid preparation process was used as sacrificial reagent, and raw components and intermediates were identified by GC–MS, IC, and TOC analyzer. The characterizations of the catalyst were analyzed by XRD, TEM, and XPS. Results showed that the metal and metallic ions (Fe 2+ and Fe) in wastewater were more feasible for electron provision than organics. The final products of Fe 3+ were also confirmed by XPS on the surface of the catalyst. By contrast, the rate of photocatalytic H 2 production did not changed with the addition of terephthalic acid. The H 2 production rate could reach 1.8 mmol g −1 h −1 through the use of wastewater and acetic acid as sacrificial reagents.

Norfloxacin (NF) is an effective antimicrobial drug that poses a threat to human health because of its environmental residues. In this research, ZnO nanoflowers and triangular silver nanoplates (T-Ag) were synthesized using a facile sol–gel method. The synergistic photocatalytic effects of the adding different triangular silver nanoplates concentration over ZnO nanoflowers on the NF removal under visible light was studied for the first time. Photodegradation results demonstrated that T-Ag could significantly enhance the activity of ZnO nanoflowers. The degradation efficiency of NF by T-Ag/ZnO nanoflowers was affected in the different water matrices, including ultra-pure, tap, and river water. The effects of the dosage of ZnO nanoflowers, initial NF concentration, and pH on the photocatalytic activity of ZnO nanoflowers were also explored. The results show that the highest rate constant for the degradation of NF is obtained with 1 mg L −1 of T-Ag, 0.1 g L −1 of ZnO, initial NF concentration of 10 mg L −1 , and pH of 11 in ultra-pure water. The possible mechanism of the photocatalytic degradation of NF using T-Ag/ZnO nanoflowers through the addition of scavenger agents (i.e., EDTA and methanol) was also studied.

Large amount of calcium fluoride sludge was generated by semiconductor industry every year. It also needs high requirement of fuel consumption using rotor concentrator and thermal oxidizer to treat VOCs. The mesoporous catalyst prepared by calcium fluoride sludge was used for VOCs treatment in this study. Acetone is a kind of solvent and used in a large number of laboratories and factories. The serious problems will be caused when it exposed to the environmental. Economic and practical technology is needed to eliminate this kind of hazardous air pollutant. In this research, the adsorption of acetone was tested with CF-MCM (mesoporous silica materials synthesized from calcium fluoride). The raw material was mixed with cationic cetyltrimethyl ammonium bromide (CTAB) surfactants, firstly. The prepared mesoporous silica materials were characterized by nitrogen adsorption and desorption analysis, transmission electron microscope (TEM), scanning electron microscopy (SEM), X-ray powder diffractometer (XRPD) and Fourier transform infrared spectroscopy (FTIR). The results showed that the surface area, large pore volume and pore diameter could be up to 862 m2 g(-1), 0.57 cm3 g(-1) and 2.9 nm, respectively. The crystal patterns of CF-MCM were similar with MCM-41 from TEM image. The adsorption capacity of acetone with CF-MCM was 118, 190, 194 and 201 mg g(-1), respectively, under 500, 1000, 1500 and 2000 ppm. Furthermore, the adsorption capacity of MCM-41 and CF-MCM was almost the same. The effects of operation parameters, such as contact time and mixture concentration, on the performance of CF-MCM were also discussed in this study.

This manuscript will provide the successful application of polyurethane-guided solid particles to core-sheath electrospun fibers prepared on the surface of polyacrylonitrile fibers and their application in removing acetone from indoor air pollution. The difference between single-fluid electrospinning and coaxial electrospinning was compared using a coaxial electrospinning process. Through the transmission electron microscope image, the polyurethane-bonded non-spun solid MCM-41 can be well wrapped on the outside of the polyacrylonitrile fiber. By using the functional groups in MCM-41 and PU and the high specific surface area of the fibers, it is used to treat low concentrations of acetone in the chamber. The adsorption results showed that acetone with an initial concentration of 10 ppm achieved effective adsorption using PU@10MCM/PAN, and the maximum adsorption amount was 10.32 μg/g. The Langmuir and Freundlich model can be used to describe the p88rocess. The Experimental value is in good agreement with the Langmuir model. The desorption results show that the adsorption capacity can be even after 5 cycles of reuse. The mechanism of preparation and application of polyurethane/polyacrylonitrile core-sheath electrospun fibers was proposed. This work shows that our new structure of fiber provides a theoretical basis for the adsorption system of air purifiers, effectively preventing the harmful organic gases from invading the human body.

In the process of water treatment adsorption has been proved to be the best, because of its significant advantages. It is recognized that recycling and reuse of waste can result in significant savings in materials cost. In this research, the adsorption of organic and inorganic arsenic using sludge biochar (SBC) made from urban sludge were analyzed. The sludge was carbonized using calciner carbonization and then chemically activated at high temperatures and a newly designed Fe-doped sludge biochar (Fe-SBC) presents effective As adsorption in water. Results show that the surface area and average pore volume of Fe-SBC are 498 m² g-1 and 0.33 cm³ g-1, respectively. The adsorption capacity of p-ASA, As(V) and As(III) on Fe-SBC was calculated as 5.47, 3.83 and 3.24 mg L-1, respectively. The adsorption capacity of As were obviously decreased in presence of PO3-₄. After six times recycles of adsorption-desorption processes, the adsorption capacity of p-ASA, As(V) and As(III) on Fe-SBC obvious reduction.

Recycling and reuse waste can result in significant savings in materials and energy. In this study, the adsorption of Cr(VI) was analyzed using activated carbon (AC) and biochar (BSC) made from sewage sludge. BSC materials were synthesized using zinc chloride as an activator coupled with carbonized sewage sludge. Specific surface area, pore size distribution, and pore volume were determined by measuring nitrogen adsorption-desorption (BET). BSC morphology was measured using field-emission scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). Results showed that the surface area and average pore volume of the BSC were 490 m2 g-1 and 0.8 cm3 g-1, respectively. SEM results revealed that BSC had uniform pore size. Effects of varying the initial Cr(VI) concentrations, pH values, and dosages of BSC on adsorption performance were also determined. Results showed that the maximum removal efficiency of Cr(VI) was above 99%, and adsorption capacity of 50% ZnCl2-BSC was 677 mg g-1.

This first-attempt study revealed mixture design of experiments to obtain the most promising composites of TiO 2 loaded on zeolite and graphene for maximal photocatalytic degradation of oxytetracycline (OTC). The optimal weight ratio of graphene, titanium dioxide (TiO 2 ), and zeolite was 1:8:1 determined via experimental design of simplex lattice mixture. The composite material was characterized by XRD, UV–vis, TEM and EDS analysis. The findings showed the composite material had a higher stability and a stronger absorption of the visible light. In addition, it was uniformly dispersed with promising adsorption characteristics. OTC was used as model toxicant to evaluate the photodegradation efficiency of the GTZ (1:8:1). At optimal operating conditions (i.e., pH 7 and 25 °C), complete degradation (ca. 100%) was achieved in 180 min. The biotoxicity of the degraded intermediates of OTC on cell growth of Escherichia coli DH5α were also assayed. After 180 min photocatalytic treatment, OTC solution treated by GTZ (1:8:1) showed insignificant biotoxicity to receptor DH5α cells. Furthermore, EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the holes are the main oxidation species in the photocatalytic process.

TiO₂ has been studied most commonly because it has high stability, non-toxicity, high catalytic activity, and highly conductivity. Many studies have shown that TiO₂ would generate electron-hole pairs illuminated with UV and surround more energy than that before being illuminated. However, the surface area of TiO₂ is not large enough and the adsorption capacity is small. In this study, the titanium nano tube (TNT) catalysts were prepared to increase the surface area and adsorption capacity. The Fe-TNT was also prepared from slag iron since many slag iron cause waste treatment problems. In this study, the effect of Fe loading, including 0.77%, 1.13%, 2.24% and 4.50%, on acetone removal was also assessed since TNT doped with transitional or precious metals can be used to improve catalytic reaction efficiency. Furthermore, four kinds of VOCs concentration, including 250, 500, 1000 and 1500 ppm were tested. Four kinds of retention time, including 0.4, 0.8, 4.0 and 6.0 sec, and four kinds of dosage, including 0.15, 0.25, 0.30 and 0.45 g cm⁻³, were also assessed. In this study, the adsorption capacity of Fe-TNT was 18.8, 23.3, 28.9 and 32.6 mg g⁻¹ for acetone of 250, 500, 1000 and 1500 ppm, respectively. Four kinds of temperature, including 150, 200, 250 and 300 °C were tested in catalytic reaction system. The results showed removal efficiency increased with increasing temperature. The efficiency can be reached 95% under the conditions with the dosage higher than 0.3 g cm⁻³, temperature higher than 270 °C and retention time higher than 270 °C. Reaction efficiency was 20, 31, 41 and 96% at the temperature of 150, 200, 250 and 300 °C, respectively.

This study tended to decipher the mechanism of photo degradation of azo dyes, which bond was favorable to be broken for application of wastewater decolorization. That is, from chemical structure perspective, the critical substituents to affect electron donor/acceptor for dye degradation would be identified in this research. The model reactive blacks (RB5), reactive blue 171 (RB171) and reactive red 198 (RR198) were degraded by graphene loaded TiO2, indicating how the electron withdrawing and releasing groups affect azo dye degradability. The byproducts and intermediate products were analyzed by ultraviolet–visible spectroscopy (UV–vis), gas chromatography–mass spectrometry (GC–MS) and ion chromatography (IC). Furthermore, the radicals involved in the reaction were found by electron paramagnetic resonance (ESR) to confirm the main oxidized species of hydroxyl radicals rather than the light generated positive holes. The finding revealed that the breakages of the bonds were due to the electron density changes around the bonds. This principle can be applicable not only for RB5 degradation, but also for reactive blue 171 (RB171), reactive red 198 (RR198) and some other textile dyes.

In this study, A novel adsorbent material of polyacrylonitrile (PAN)/ferrous chloride (FeCl2) composite nanofibers is prepared by electrospinning, a simple and effective method. The obtained composite nanofibers have a non-uniform morphology and structure and a large specific surface area of 13.8 m2 g-1. Fourier transform infrared spectroscopy (FTIR) revealed that Fe2+ was successful introduced into the composite nanofibers. Furthermore, the PAN/FeC12 composite nanofibers exhibited excellent performance in Cr removal, especially when reacted with reduction from a Cr(VI) standard containing solution, which has much faster removal efficiency than the previous report of Lin et al. (2011). The results of the adsorption isotherm show that the data fitted well to the Langmuir isotherm model. The maximum adsorption of chromium ions composite nanofibers is 108 mgCr/gFeCl2. An attempted model prediction of the transient dynamics of adsorption-desorption elucidated the feasible kinetic analysis of Cr6+ from the PAN/FeCl2 composite nanofibers. This kinetic modeling can be used both for adsorption of heavy metals wastewater and for organic-adsorption and biosorption of diverse wastewaters. The PAN/FeCl2 composite nanofibers producted in this study exhibit high efficiency in Cr(VI) removal from wastewater, and may be used as a reference for future investigation.

TiO2 photocatalytic reactions not only remove a variety of organic pollutants via complete mineralization, but also destroy the bacterial cell wall and cell membrane, thus playing an important bactericidal role. However, the post-filtration procedures to separate nanometer-levels of TiO2 and the gradual inactivity of photocatalyst during continuous use are defects that limit its application. In this case, we propose loading TiO2 on zeolite for easy separation and 13X is considered as a promising one. In our study, 13X-zeolite was prepared by a hydrothermal method and the source of Si was extracted from waste quartz sand. For comparison, commercial zeolite with different microporous and mesoporous diameters (ZSM-5 and Y-zeolites) were also used as TiO2 supports. The pore size of the three kinds of zeolites are as follows: Y-zeolite > 13X > ZSM-5. Different TiO2 loading content over ZSM-5, 13X and Y-zeolite were prepared by the sol-gel method. XRD, FTIR, BET, UV-vis, TGA and SEM were used for investigation of material characteristics. In addition, the efficiencies of mineralization and photodegradation were studied in this paper. The effects of the loading ratio of TiO2 over zeolites, initial pH, and concentration on photocatalytic performance are investigated. The relationship between best loading content of TiO2 and pore size of the zeolite was studied. The possible roles of the ZSM-5, 13X-zeolites and Y-zeolites support on the reactions and the possible mechanisms of effects were also explored. The best loading content of TiO2 over ZSM-5, 13X and Y-zeolite was found to be 50 wt%, 12.5 wt% and 7 wt%, respectively. The optimum pH condition is 3 with TiO2 over ZSM-5, 13X-zeolites and Y-zeolites. The results showed that the degradation and mineralization efficiency of 12.5 wt%GT13X (TiO2 over 13X) after 90 min irradiation reached 57.9% and 22.0%, which was better than that of 7 wt%GTYZ (TiO2 over Y-zeolites) while much lower than that of 50 wt%GTZ (TiO2 over ZSM-5). The materials were recycled four times while the degradation was remained at a higher level.

In this study, a novel titanium dioxide nanotubes and graphene (GR-TNT) nano-composite was synthesized through a hydrothermal method. The introduction of GR was aimed to reduce the rapid electron-hole recombination of TiO2 thus improving their phtotcatalytic behavior in real application. The catalysts were characterized by using FT-IR, UV-Vis, XRD, TEM. The degradation results showed that the combined GR and TNT composite could obviously increase the photocatalysis efficiency for Reactive Black 5. The RBk5 removal can reach up to 90% under the near visible light irradiation for 3 h with the irradiation intensity less than 1.0 mW cm(-2) and the 10% GR-TNT dosage of 0.1 g L(-1) at original pH (about 5.8). Further experiments were done to probe the mechanism of the photocatalytic reaction catalyzed by GR-TNT composite. EDTA and t-BuOH, which were used as holes and radical scavengers, was used to determine the active oxidative species in the system and the results suggested a holes-driven oxidation mechanism. This study provides a new prospect of using.

Di-n-butyl phthalate (DBP) is a type of phthalate ester, and has been classified as an environmental endocrine disruptor. It causes serious harm to the environment and humans and it is found widely in air, waste water, rivers and soil. In recent years, an increasing number of studies examined the removal of DBP. Photocatalytic degradation has been of particular interest because of its efficient and thorough advantages and is the focus of this study. Here we use a composite material of N-Ti/13X/MCM-41, synthesized, using 13X and tetraethyl orthosilicate as raw material, CTAB as structural template, tetrabutyl titanate and urea under hydrothermal conditions. The optimized experimental conditions, such as, Si/Al (molar ratio), pH value, crystallization time, calcination temperature and N/Ti (molar ratio), were tested using photodegradation experiments of DBP. The samples were characterized by XRD, TEM, FT-IR, N2 adsorption-desorption. Experimental results reveal the surface area of the N-Ti/13X/MCM-41 to be 664 m2 g(-1) and the average pore sizes to be 2.79 nm. TEM micrographs showed the N-Ti/13X/MCM-41 consists of aggregates of spherical particles, similar to the shapes associated with standard MCM-41 synthesized under basic conditions. Photocatalytic degradation experimental results revealed that optimal synthesis of the composite material occurs when Si/Al = 15, pH = 9.0, crystallization time is 48 hours, calcination temperature is 350 °C and the N/Ti ratios is 2.0. Under such conditions, the degradation efficiency of DBP more was found to be more than 90%.

Copper or cobalt incorporated TiO 2 supported ZSM-5 catalysts were prepared by a sol–gel method, and then were characterized by XRD, BET, XPS and UV–vis diffuse reflectance spectroscopy. Ti 3 + was the main titanium specie in TiO 2 /ZSM-5 and Cu–TiO 2 /ZSM-5, which will be oxide to Ti 4 + after Co was doped. With the deposition of Cu or Co, the efficiency of the CO 2 conversion to CH 3 OH was increased under low energy irradiation. The peak production rate of CH 3 OH reached 50.05 and 35.12 μmol g − 1 h − 1 , respectively. High photo energy efficiency (PEE) and quantum yield ( φ ) were also reached. The mechanism was discussed in our study.

Acetaminophen is commonly used as an antipyretic or analgesics agent and poses threat to human health. In this research, TiO 2 and graphite oxide were used as precursors of titanium dioxide nanotubes and graphene respectively. Titanium dioxide nanotube and graphene (GR-TNT) nanocomposites were synthesized through a hydrothermal method. FT-IR, UV-Vis, XRD, and TGA were used to characterize the catalysts. The acetaminophen degradation rate can reach up to 96% under UV light irradiation for 3 h and with the 5% GR-TNT dosage of 0.1 g L −1 . Further experiments were done to probe the mechanism of the photocatalytic reaction catalyzed by the GR-TNT composite. EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the holes are the main oxidation species in the photocatalytic process. This study provides a new prospect for acetaminophen degradation by using high efficiency catalysts.

Graphene-titanium nanotube composites with different ratios of graphite oxide were prepared via the hydrothermal method using ascorbic acid as a reducing agent. Properties of materials were characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy, high resolution transmission electron microscopy and UV–vis diffuse reflectance spectroscopy. The average diameter of the titanium dioxide nanotubes was about 8 nm. The photoresponse of nanocomposites have been extended to visible-light regions. In addition, graphene-titanium nanotube composites showed higher photocatalytic degradation efficiency for reactive black 5 (RBK5) than pure titanium dioxide and the 15%graphene-titanium nanotube composites catalysts possessed the best photocatalytic activity. The degradation efficiency for RBK5 dyes increased with increased dosage of graphite oxide from 3%-15% and decreased with increasing initial RBK5 concentration. This paper not only reports the fabrication of highly active photocatalysts but also ...

TiO2 nanotubes were prepared by hydrothermal process, then characterized using Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Visible spectroscopy measurements. The photodegradation performance assessment of Reactive Red 141 (RR141) with near visible light irradiation (lambda = 380 nm) was carried out under different catalyst doses, dye concentrations, pH and initial Cr(VI) concentrations by TiO2 powder and nanotubes. The results showed that the specific surface area of TiO2 nanotubes were 152 m2 g(-1), about three times larger than that of TiO2 powder which was roughly 51 m2 g(-1). The TiO2 nanotubes did not affect the lattice structure of the TiO2. The adsorption amount increases as the dosage and RR141 concentration increases. However, the decolonization efficiency decreased with increasing initial RR141 concentration. Results also showed that an acidic solution is more favorable for photocatalytic degradation of RR141. On the other hand, Cr(VI) can be adsorbed on the surface of TiO2 nanotubes to affect the decolonization efficiency of RR141.

Polyaniline/titanium nanotube composite (PANI/TNT) photocatalysts were prepared by 'in situ'chemical oxidative polymerization of aniline. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform IR spectra (FTIR) and UV-Visible spectroscopy measurements were used to characterize the obtained photocatalysts, and their photocatalytic activities were investigated by degrading Reactive Green19 (RG19) under near visible light irradiation (lambda = 365 nm). The content of PANI, pH, dosage, and concentration of RG19 were also investigated. The results showed that the inner diameter of the PANI/TNT was 6 nm and that the PANI did not change the structure of the TNT. The PANI was coated on the surface of the TNT. The light response of the PANI/TNT was extended to the visible-light regions. Among the six different kinds of photocatalysts, the 1.17 wt% PANI/TNT had the best performance in treating 10 ppm RG19. The best pH is 3 for the largely protonated surface of the composite at low pH. The adsorption amount was increased as the dosage increased. The decolonization efficiency decreased with increasing initial RG19 concentration. The performance of the photocatalyst in decomposing RG19 was stable after 5 time cycles.

This study used spent diatomaceous earth (SDE) from drink processing as source of Si and cationic surfactant (CTAB) as a template for the synthesis of mesoporous silica Materials (MSM) through hydrothermal method. The MSM was characterized by Small-angle X-ray Diffraction (SXRD), Scanning Electron Microscopy (SEM), Thermo Gravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR) spectroscopy and N2 adsorption-desorption analyzer. The results showed that the surface area, pore volume and pore size was roughly ranged from 880 to 1060 m2 g(-1), 1.05 cm3 g(-1) and 4.0 nm, respectively. The properties of the synthesized MSM were also compared with those prepared from pure silica sources (MCM-41) and got almost the same characteristics. The synthesized MSM was used as adsorbent at 25 degrees C with carrier gas of air. The adsorption equilibrium revealed that adsorption capacity of MSM was 59.6, 65.7, 69.6, 84.9 mg g(-1) while the acetone concentration was 600, 800, 1000 ppm, 1600 ppm respectively. Results showed that breakthrough curves correlate to the challenge vapor concentration, adsorbent loading, and the flow rate. The results obtained in the present work demonstrated that it was feasibility of using the SDE as a potential source of silica to prepare MSM.

A series of mesoporous catalysts (MCM-41) promoted by iron nanoparticles were prepared by the co-precipitation method and tested for the decomposition of carbon tetrafluoride (CF4). The addition of iron oxide nanoparticles to MCM-41 led to an improvement in the catalytic activity for CF4 decomposition. The catalyst was the most active around 5 wt% iron added to MCM-41. Methods of X-ray Powder Diffractometer, Scanning Electron Microscope-Energy Dispersive Spectrometer, BET, and high resolution transmission electron microscopy were used to characterize the MCM-41 catalysts. The analytical results indicated that the addition of over 2 wt% iron nanoparticles increased the surface area of MCM-41, which was the rate-determining factor of CF4 decomposition over MCM-41 catalyst. In conclusion, the addition of iron was responsible for the enhancement of catalytic activity of MCM-41.

Laboratory batch experiments were conducted in order to assess the impacts of temperature on the performance of goethite in removing arsenate from water. All batch experiments were conducted at four temperatures (30, 50, 70 and 90 °C) and pH 4.6. The results showed that both the arsenic uptake rate and capacity were significantly enhanced with increasing temperature from 30 to 90 °C. The adsorption kinetics followed a pseudo-second-order model with coefficients of determination (R2) all above 0.999. The process followed the Langmuir model, and several thermodynamic parameters were calculated. Arsenate adsorption was facilitated more under simulative geothermal water conditions than in RO (reverse osmosis) water. The crystalline structure of goethite was not changed after adsorption at various temperatures. XPS results showed a decrease in the content of iron hydroxyl groups, which demonstrated that arsenate adsorption onto goethite may be realised through the replacement of the iron hydroxyl group to form inner-sphere bidentate/monodentate complexes at pH 4.6.

The recycling of dendrimers using an ultrafiltration membrane during wastewater treatment is extremely inconvenient. With the combination of magnetic nanoparticles (MNP) with dendrimers, the problem of the recovery of tiny particulate matter from an aqueous solution can be overcome using its magnetism. In this study, the coprecipitation method was adopted to prepare MNP, and then MNP-G(n) (n, generations of dendrimers) was prepared with the formation of the dendrimers on the surface of the MNP. The adsorption of reactive black 5 (RBk5) from an aqueous solution using MNP-G(n) was studied. It was shown that the adsorption data of the composite could be fitted using the Langmuir equation with a maximum adsorption capacity of 70.423 mg g(-1) in the aqueous solution of RBk5 at 25 degrees C. The effects of the initial RBk5 concentration, pH and dendrimer generation were studied and the optimized experimental conditions were obtained. The adsorption capacity increased as the generation of MNP-G(n) increased, and decreased with the rise of the solution pH value. The adsorption of RBk5 with the prepared MNP-G(n) composite was very efficient, and the adsorbent could be recycled using magnetic separation.