Calcination Time Research Articles

Purification of Waste Graphite from Crucibles Used in Photovoltaic Crystallization by an Alkali-Acid Method

The photovoltaic industry generates large amounts of waste graphite (WG) that contains useful metals that can be recycled into high-value products. This study elucidated the impurity elements and their existence states in WG, analyzed and verified the source of the main impurity phase SiC, and determined the SiC content to be 4.66%. WG was purified using an alkaline-acid method, whose optimal process parameters were a solid alkali ratio of 3, calcination temperature of 600 °C, calcination time of 120 min, HCl concentration of 1 M, and acid leaching time of 40 min. Under these conditions, a graphite product with a fixed carbon content of 98.45% was obtained. Impurities were determined to migrate via three pathways: (1) Most main elements (Al, K, and Si) in silicates were removed by alkaline roasting, while the remaining elements were dissolved in acid. (2) Impurities containing metal elements such as Fe, Mg, Ca, and Zn were decomposed in NaOH to form hydroxides or oxides that were dissolved in HCl. (3) Silicon carbide impurities were removed by the alkaline-acid method without decomposition and often existed with graphite in the acid-leaching slag.

Effect of Synthetic Conditions on the Structure and Properties of Nb14W3O44 Anode for Lithium‐Ion Batteries

AbstractNiobium tungsten oxide is a potential replacement for graphite in fast‐charge lithium‐ion batteries due to its high rate performance and high stability. Herein, Nb14W3O44 anode was synthesized by hydrothermal reaction of niobium oxalate and ammonium tungstate and sequent calcination of niobium tungsten oxide precursors. Compared with the traditional solid‐state method, the particle size and calcination time of Nb14W3O44 obtained by the modified method are greatly reduced. Through orthogonal experiments, the optimal synthesis conditions were determined, and it was found that hydrothermal conditions have an important influence on the particle size of the final product, while the calcination temperature and time greatly affect the purity of the product and thus influence its specific capacity during cycles.

Enhanced alpha-amylase inhibition activity of amine-terminated PAMAM dendrimer stabilized pure copper-doped magnesium oxide nanoparticles

The present work aims to prepare copper-doped MgO nanoparticles via a sol-gel approach and study their antidiabetic alpha-amylase inhibition activity with undoped MgO nanoparticles. The ability of G5 amine-terminated polyamidoamine (PAMAM) dendrimer for the controlled release of copper-doped MgO nanoparticles to exhibit alpha-amylase inhibition activity was also evaluated. The synthesis of MgO nanoparticles via sol-gel approach and optimization of calcination temperature and time has led to the formation of nanoparticles with different shapes (spherical, hexagonal, and rod-shaped) and a polydispersity in size ranging from 10 to 100 nm with periclase crystalline phase. The presence of copper ions in the MgO nanoparticles has altered their crystallite size, eventually modifying their size, morphology, and surface charge. The efficiency of dendrimer to stabilize spherical copper-doped MgO nanoparticles (ca. 30 %) is higher than in other samples, which was confirmed by UV–Visible, DLS, FTIR, and TEM analysis. The amylase inhibition assay emphasized that the dendrimer nanoparticles stabilization has led to the prolonged enzyme inhibition ability of MgO and copper-doped MgO nanoparticles for up to 24 h.

RECOVERY OF MANGANESE FROM MANGANESE ORE REDUCTIVELY ACID LEACHING PROCESS USING REEDS (IMPERATA CYLINDRICA) AS REDUCING AGENT

Recovery of manganese from manganese ores was investigated by reductive leaching method using reeds as a reductant in the sulfuric acid medium. Cellulose, hemicellulose, and lignin are natural reducing agents which are widely used as reducing agents to recover manganese. Effects of calcination temperature and the holding time calcination on the leaching efficiency of manganese and impurities were examined. The calcination temperature and the holding time calcination have a significant effect on the extraction of manganese. The experimental results demonstrated that the higher the calcination temperature used, the higher the percentage of manganese obtained, namely 79.58% and 87.38%, respectively. The XRD (x-ray diffraction) pattern shows that the manganese phases formed at 700 and 800 °C are Mn3O4 (hausmannite) and Mn2O3 (bixbite), respectively. The morphology in the sample with calcination temperature at 700 °C showed agglomerate- shaped particles and unevenly dispersed. Meanwhile, the sample with calcination temperature at 800 °C exhibited agglomerated particles of inhomogeneous size and were more evenly distributed. Variation of holding time in the manganese ores recovery process also affects the results of manganese recovery. The composition of the manganese recovery in the samples using holding time calcination variations of 3 and 4 hours was 83.88% and 89.24%, respectively. The results of the XRD analysis showed that the manganese phase formed using 3 hours of calcination holding time was dominated by Mn3O4 (hausmannite). Meanwhile, the manganese phase formed using 4 hours of holding time of calcination was dominated by Mn2O3 (bixbite).

Potassium Poisoning Effects on Sol‐gel Mn/TiO2Catalyst for Selective Catalytic Reduction (SCR) of NOx with NH3at Low Temperature

AbstractMn/TiO2catalysts exhibited more excellent activity and higher selectivity in low‐temperature SCR of NOx with NH3. Alkali metal, particularly potassium presented in the ash, could severely deactivate SCR catalyst and then reduce its lifetime. In this study, sol‐gel Mn/TiO2catalyst was employed to evaluate its SCR activity with and without the presence of KNO3at 100–300 °C. The influence of various parameters such as KNO3loading amount, calcination time, temperature and catalyst deactivation was investigated. The characterization results indicated that the doping of potassium on Mn/TiO2surface obviously resulted in a great decrease of reducibility, surface acidity and NH3adsorption capacity. XPS spectra revealed the decrease of Mn4+atomic concentration and chemisorbed oxygen species caused by potassium doping. In addition, obvious variation of potassium states (K1.04Ti8O16) was detected for K−Mn/TiO2catalyst after calcining treatment, which may lead to a poorer performance of SCR catalyst.

Polyoxometalates as highly efficient adsorbents for ciprofloxacin removal: The key role of oxygen vacancies

In this study, various silver phosphomolybdates (x-y-z-AgPMo) with oxygen vacancies were successfully prepared through H2 calcination and subsequent chemical precipitation and used for the adsorption of ciprofloxacin (CIP) in water. The microstructures of x-y-z-AgPMo were analyzed by a series of characterization methods. The effects of calcination time, calcination temperature, hydrogen flow rate, and external adsorption conditions on the adsorption performance were investigated. The results showed that the adsorption performance of 1–0.1–250-AgPMo toward CIP could reach 91% within 20 min with a maximum adsorption capacity of 45.5 mg∙g − 1, which was about 1.7 times as that of silver phosphomolybdate (Y-AgPMo) without H2 calcination. The improved adsorption performance of 1–0.1–250-AgPMo was mainly attributed to the presence of oxygen vacancies, which induced more negative surface charges and larger specific surface area in 1–0.1–250-AgPMo. This work provided an excellent adsorbent for CIP removal and forcefully confirmed the important role of oxygen vacancies in the adsorption process.

Heterogeneously catalyzed transesterification reaction using waste snail shell for biodiesel production

Biodiesel as an attractive energy source; a low-cost and green synthesis technique was utilized for biodiesel preparation via waste cooking oil methanolysis using waste snail shell derived catalyst. The present work aimed to investigate the production of biodiesel fuel from waste materials. The catalyst was greenly synthesized from waste snail shells throughout a calcination process at different calcination time of 2–4 h and temperature of 750–950 °C. The catalyst samples were characterized using X-Ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), Energy Dispersive X-ray (EDX), and Fourier Transform Infrared (FT-IR). The reaction variables varying in the range of 10:1–30:1 M ratio of MeOH: oil, 3–11 wt% catalyst loading, 50–70 °C reaction temperature, and 2–6 h reaction time. The designed model optimization was set its parameters at 21.5 methanol molar ratio, 9.8 wt% catalyst loading, 4.8 h reaction time, and 62.2 °C reaction temperature, resulting in a mixture comprised of 95% esters content.

Crystallographic Nanojunctions of Bismuth Ferrite for Unconventional Detection of Carbon Monoxide

The present work reported, for the very first time, a crystallographic junction formed of (002) and (110) oriented crystals of bismuth ferrite (BFO) for ultrasensitive carbon monoxide (CO) detection. Growth orientation and crystallinity of the solution-processed BFO were controlled by varying calcination times. The sensor demonstrated a maximum response of six times for 30 ppm of CO, with response and recovery times of 149 and 226 s, respectively, with a significant specificity over other chemically compatible species. The device showed excellent stability when tested continuously for a period of 150 days with a maximum response deviation of ±0.35 times for 30 ppm of CO. The sensitivity of the sensor significantly increased in comparison to other polycrystalline variants with less or no junctions. In order to understand the effect of crystallographic junctions on sensing performance, an analytical model was put forward. The proposed model established the dependency of the sensor response pattern on the carrier diffusion coefficient (Dg) of the exposed gas and the ease of carrier diffusion through the gas–surface junction, which is controlled by the junction bias and the drift current. Hence, the proposed junction-based sensor provides additional control over the sensor efficiency in comparison to its resistive counterparts, thereby significantly improving the device performance without significantly complicating the device.

Oxygen-vacancy hydroxyapatite for visible-light photocatalytic degradation of tetracycline with online spectral monitoring

In this study, OV-HAp with abundant oxygen vacancies (OVs) were prepared by calcining carbonate-doped HAp (CHAp), and the effects of calcination temperature, time and atmosphere on the formation of OVs in OV-HAp and the influence of OVs concentration on its photoelectrochemical properties were investigated in detail. The results showed that the calcination temperature and atmosphere play a major role in the generation of OVs in OV-HAp. Through changing the temperature or atmosphere, the optical absorption range of OV-HAp can be broadened to the visible light and the band gap can be reduced to 1.6 eV. OV-HAp obtained by calcining CHAp at 600℃ for 5 h under H2 atmosphere (OV-HAp-H2) exhibited the highest efficiency for tetracycline (TC) photocatalytic degradation (65.4%). h+ and ·O2– were demonstrated to be the main active species in the degradation process by radical trapping experiments. Meanwhile, an integrated platform for photocatalytic degradation of TC with online spectral monitoring was constructed, and the feasibility of online spectral monitoring the TC degradation was tentatively explored. This work will provide a theoretical and technical basis for the development of HAp-based high-efficient photocatalysts, and this is favorable for promoting their use by a large scale for water pollutant removal. Moreover, it will also open a new path for online spectral monitoring and kinetic study of photocatalytic degradation of organic pollutants.

Effect of Chemical Pre-Treatment on the Catalytic Performance of Oil Palm EFB Fibre Supported Magnetic Acid Catalyst

The development of heterogenous catalysts using renewable materials has received wide attention. A heterogenous catalyst has been a preferred choice as it evades the disadvantages of homogeneous catalysts, nevertheless, heterogenous catalysts has limited activity and a longer separation process. The current study emphasises the preparation of a new magnetic catalyst using oil palm empty fruit bunch (EFB) fibre as a carbon-based support material. The effect of different alkaline pre-treatments over the methyl ester conversion rate were investigated. The catalyst preparation parameters were studied by using the single factor optimisation approach, including the fibre loading, impregnation time, calcination temperature, and calcination time. Their effects in the esterification of oleic acid were investigated in this study. The optimisation study shows that the Na2CO3-treated(T)-EFBC magnetic catalyst had the highest esterification rate of 93.5% with 7 g EFB fibre loading, a 2 h impregnation time and a calcination temperature of 500 °C for 2 h. The catalyst possessed a good acidity of 3.5 mmol/g with excellent magnetism properties. This study showed that the catalysts are magnetically separable and exhibited good stability with 82.1% after five cycles. The oil palm EFB supported magnetic acid catalyst indicates it as a potential option to the existing solid catalysts that is economical and environmentally friendly for the esterification process.

Defects characteristic investigation of bismuth ferrite nanocrystallites through positron annihilation and supportive methods

Phase pure bismuth ferrite (BFO) nanocrystallites were synthesized by sol-gel method. The variation in the time of calcination at 600 °C is used as the parameter to vary the sizes of the nanocrystallites. X-ray diffraction and electron microscopic studies revealed the formation of BFO nanocrystallites of well-defined sizes and morphology. The elemental stoichiometric compositions of the samples were verified using energy dispersive analysis of X-rays and further by X-ray photoelectron spectroscopy. The UV–visible diffuse reflectance spectra showed strong absorption at the wavelength ∼556 nm (2.23 eV) for BFO nanocrystallites of dimensions 20 nm. For nanocrystallites of sizes smaller than this limit, the band gap energies showed remarkable increase due to the onset of quantum confinement effects. The band gap energies showed increase at larger crystallites sizes as well, indicating defects formation due to oxygen deficiencies. Positron annihilation spectroscopy is used to characterize and monitor the defects. The formation of Bi3+-O2- divacancies significantly altered the positron annihilation characteristics at larger crystallite sizes.

Evaluation of Performances of Calcined Laterite and Oyster Shell Powder Based Blended Geopolymer Binders

This work consisted in characterizing of calcined laterite and oyster shell powder based blended geopolymer binders. To do this, raw laterite taken from Soa in the city of Yaoundé and oyster shells extracted from Mouanko in the Sanaga-Maritime were initially air-dried, then dried at 105 °C, before being calcined at 500 °C and 200 °C respectively for 2 hours. These samples were subjected to preliminary studies, i.e. determination of their chemical and mineralogical compositions, particle size distributions, densities, as well as thermal analysis for the synthesis of geopolymer binders. X-ray diffractometry, thermal and gravimetric analysis were carried out on the oyster shell powder and laterite, in order to elucidate the time and degree of calcination of the two samples, the evolution of the linear shrinkage, the setting time as well as the compressive and flexural strengths of the geopolymer binders. The results obtained show that oyster shells are rich in CaCO3 and contain crystalline phases, while laterite is rich in silica, iron (FeCO3) and alumina (Al2O3). The geopolymer samples: Lat + 0% oyster shells have a setting time between 125 and 168 min for a compressive strength of about 47 MPa. The peak strength is observed around 15% addition of oyster shell powder, i.e. 53.5 MPa at 28 days with an increased setting time. This strength was decreased from 25 % of addition of oyster shells, despite the increase observed in the setting time. It appears from this study that the addition of 15% oyster shell increases the compressive strength of the geopolymer, but also leads to a considerable decrease in absorption rate. Above this rate, the compressive strength decreases drastically and concomitantly the setting time increases.

Effect of Ammonia on the Synthesis of NMC541 Cathode Materials with the Sol-Gel Method

The research studied about the effect of ammonia on the synthesis of lithium-ion battery cathode materials LiNi0.5Mn0.4Co0.1O2 (NMC541) through a sol-gel method by modifying the mole ratio of ammonia to metal forming ratios (0.5; 1.0; 1.5; and 2.0). The precipitation formed at pH 11 and at temperature of 80oC. Characterization was carried out on samples resulting from pyrolysis (pyrolysis result), with calcination for once and twice at 850oC for 3 hours, X-ray diffraction pattern characterization, morphological characterization using scanning electron microscope (SEM), and conductivity characterization using an impedance capacitance conductance (LCR) meter. The result of the synthesis is in the form of spherical particles. The addition of ammonia affected the particle size distribution and stoichiometry of the metal forming NMC541, eventhough it was not significant. The ammonia to metal ratio of 1.5 (Sample N1.5-K) resulted in the distribution with the optimum particle homogeneity. The morphology of the pyrolysis and 3 hours-850oC calcined samples was dominated by spherical particles and agglomeration. Particle growth in the material is affected by heat treatment time. Samples with ammonia to metal ratio of 2.0 (N2.0-K) have the closest stoichiometry to NMC541. The total conductivity of the sample at a measurement frequency of 42Hz-1MHz is in the value range of 10-7–10-5 S.cm-1. The particle size is also affected by the calcination temperature. The effect of using ammonia in the synthesis process is not directly related to the electrical properties. However, it is related to the purity of NMC541. Samples of N1.5-K pyrolyzed result and samples of N1.0-K (3 hour 850 oC calcined) have optimum conductivity values. Agglomeration as a calcination effect lowers the conductivity value. The addition of 3 hours of calcination time does not significantly increase the conductivity value

Nanosilica from Averrhoa bilimbi juice pre-treated rice husk: Preparation and characterization

The preparation of nanosilica from rice husk without using any concentrated mineral acids is a novel concept. This work proposes a bioleaching strategy to remove metallic impurities from rice husk for the preparation of nanosilica. Herein, nanosilica (BJRHS) was prepared by calcinating Averrhoa bilimbi juice pre-treated rice husks in a muffle furnace. The chemical and atomic structures of commercial precipitated silica (CS), rice husk ash (RHA), and BJRHS were analyzed using different analytical techniques. The optimal leaching time, calcination temperature, and calcination time were 1 h, 500 °C, and 6 h respectively. The particle size of BJRHS was found to be 6–12 nm, which is less than that of RHA and CS. The BET surface area of BJRHS (204 m2/g) was found to be greater than RHA (110.5 m2/g) and CS (172.1 m2/g). Mesoporous nanosilica with excellent surface area and purity was produced sustainably from rice husk which could be recommended to use in the field of catalysis, polymer technology, etc.

Synthesis and modification of graphene oxide-like carbon for conversion of hemicellulose to furfural from bagasse

The utilization of biomass to convert into valuable chemicals has been receiving research interest recently. In this study, the catalyst with a similar structure to graphene oxide was synthesized from bagasse (B-GO) by calcination using cellulose as the main carbon source. The influences of calcination temperature, calcination time, and cellulose:ferrocene ratios on the FTIR and furfural yield of B-GO were investigated, respectively. The sulfonated graphene oxide-like catalyst (B-SGO) was prepared from B-GO by sulfonation method with sulfuric acid for the application of converting hemicellulose in bagasse into furfural. The characteristics of B-GO and B-SGO materials were analyzed via modern analytical methods. The characteristic analysis of B-SGO results indicated that −SO3H was successfully attached to the B-GO with a sulfur mass ratio of 0.79%, increasing the acidity of the material and enhancing the catalytic efficiency. The effects of reaction temperature, reaction time, catalyst content, NaCl content, and hemicellulose dosage on the furfural yield of B-SGO were also investigated, respectively. The result showed the highest furfural yield achieved at 75.55% when conducting the reaction at 190°C in 120 min with the catalyst content at 1%, 0.1 mol/L NaCl, and a hemicellulose dosage of 1.5 g. Thereby, showing the potential application of synthesized materials from biomass in the process of converting hemicellulose into furfural along with utilizing the brackish water and wastewater containing low salt content as the solvent for the conversion process.

Water treatment waste as supplementary cementitious material

The increase in demand for treated water causes the generation of waste from its process - Water Treatment Plant Sludge - WTS, to rise gradually. Alternatives are needed for the reuse of this waste in other chains, with Civil Construction being a segment that incorporates waste in techniques and products. This sludge is composed of soils that incorporate lime and aluminates in the phase of physical treatment of water. This work exposes the viability of using water treatment sludge with secondary cementitious potential, where sludge sample was calcined at 750 °C for three hours. Tests were produced comparing the finely ground calcined material with blast furnace slag. The results of X-ray diffractogram analysis showed that the material formed with calcination is metakaolinite. Thermogravimetric analyses indicated that the temperature plateau and the applied energy rate (calcination time) provided adequate dehydroxylation of the residue in the range of 507 °C to 580 °C. The effective pozzolanic was evaluated in the methods of Brazilian standards under the performance for compression with partial replacement of cement by 25%. The test results showed a high pozzolanic strength of WTS, close to the minimum standards required (90%) by the methods used, reaching 89% of the reference strength with the 100% calcined material sample and 92% and 96% obtained with WTS samples mixed with 32% and 50% of blast furnace slag, respectively. Demonstrating the technical feasibility of using the waste as a supplementary cementitious material in the incorporation of cement and in the production of mortars and concretes. The results obtained also expose that this waste can be used in low environmental impact concrete technology - LC3 for example, to be further studied in future research.

Perovskite-Like Strontium Bismuth Oxyhalides: Synthesis, Characterisation, Photocatalytic Activity and Degradation Mechanism

Recent studies have demonstrated that bismuth oxyhalides with a 2D structure inhibit the recombination of electron–hole pairs. Further, perovskite-like strontium bismuth-based compounds with a special layered Sillen X1 structure have shown potential for use as effective visible-light photocatalysts. Here, a series of strontium bismuth oxyhalide composites were prepared under different calcination conditions. The sample compositions were controlled by modulating the calcination temperature and the secondary calcination time. The synthesised catalysts were characterised by various techniques to identify the product compositions. Under visible-light irradiation, the degradation efficiencies and photocatalytic activities of the different catalysts towards rhodamine B (RhB) and 2-hydroxybenzoic acid (2-HBA) were measured via UV–Vis PDA and electron paramagnetic resonance analyses. To explore the degradation mechanism, scavengers were utilised to detect the radicals produced in the photodegradation test. SrBiO2Cl exhibited the best RhB degradation efficiency, of 0.0685 h−1, and SrBiO2Br exhibited a rate of 0.0984 h−1. At 25 °C and 1 atm, the CO2–CH4 photocatalytic conversion efficiencies of the optimised SrBiO2Cl and SrBiO2Br samples increased to 0.037 and 0.053 μmol g−1 h−1, respectively. The findings confirm that the catalysts are highly recyclable and effective for environmental remediation, achieving the objectives of green chemistry.

Adsorption performance of calcined coal gangue for ethyl mercaptan

ABSTRACT The modified coal gangue with different structures were used as the adsorbents which were prepared via the calcination process with the different temperature, time and atmosphere. The calcined coal gangues were characterized by XRD, FT-IR, TGA, SEM-Mapping, EDS, nitrogen adsorption-desorption isotherms and XPS. The adsorption performance of calcined coal gangue was evaluated via the adsorption of ethyl mercaptan in methane gas. The results show that the internal structures of coal gangue are affected by the calcination temperature and calcination time. The main components in the coal gangue are changed from kaolin to amorphous metakaolin, and the adsorption activity of coal gangue is greatly improved. The carbon content, especially the content of functional groups C-O and C=O in the coal gangue is changed in the difference of calcination atmosphere. When the calcination temperature, time and air content are set at 600°C, 3 h and 0.1 respectively, the breakthrough adsorption capacity of calcined coal gangue for ethyl mercaptan is 39.32 mg·g−1. The coal gangue modified by a simple calcination method has strong adsorption desulfurization performance and this is a typical example of treating waste by waste.

Synergistic effects of ZnO–ZrO2@SAPO-34 core-shell catalyst in catalyzing CO2 hydrogenation for the synthesis of light olefins

As a method for valorizing CO2 emissions, hydrogenation of CO2 into olefins remains viable. Herein, ZnO–ZrO2 and SAPO-34 were prepared and used as bifunctional catalysts in light olefins synthesis through CO2 hydrogenation. The combination of the two components includes layered filling, physically mixing, physically grinding, and core-shell composite. Based on the evaluation, different combinations resulted in diverse product distributions. ZnO–ZrO2@SAPO-34 core-shell catalysts are better suited for promoting synergistic effects, which facilitate light olefin production. Due to the unique core-shell structure, appropriate weak acidity, and moderate basicity, the light olefins selectivity was enhanced. Further, the calcination time and core-shell mass ratio were optimized over the ZnO–ZrO2@SAPO-34 core-shell catalyst to investigate the synergistic effects between catalytic structure and catalytic performance. With a 3:1 core-shell mass ratio and 3 h of calcination at 550 °C, the optimal ZnO–ZrO2@SAPO-34 (3:1) catalyst was obtained, which exhibited 73% selectivity to light olefins with CO2 conversion of 16.1%, whereas the selectivity of CO and CH4 was lower than 44% and 1.5%, respectively. This study provides new insights into the design and optimization of ZnO–ZrO2@SAPO-34 core-shell catalysts for CO2 hydrogenation and synthesis of light olefins.

Adsorption of Pyrethroids in Water by Calcined Shell Powder: Preparation, Characterization, and Mechanistic Analysis

Pyrethroids are common contaminants in water bodies. In this study, an efficient mussel shell-based adsorbent was prepared, the effects of factors (calcination temperature, calcination time, and sieved particle size) on the pyrethroid adsorption capacity from calcined shell powder were investigated via Box-Behnken design, and the prediction results of the model were verified. By characterizing (scanning electron microscopy, X-ray diffraction, Fourier infrared spectroscopy, and Brunauer-Emmett-Teller measurements) the adsorbent before and after the optimized preparation process, the results showed that calcined shell powder had a loose and porous structure, and the main component of the shell powder under optimized condition was calcium oxide. The adsorption mechanism was also investigated, and the analysis of adsorption data showed that the Langmuir, pseudo second-order, and intra-particle diffusion models were more suitable for describing the adsorption process. The adsorbent had good adsorption potential for pyrethroids, the adsorption capacity of the two pesticides was 1.05 and 1.79 mg/g, and the removal efficiency was over 40 and 70% at the maximum initial concentration, respectively.