Magnetically modified sugarcane bagasse biochar as cadmium removal agent in water

Heavy metals are hazardous to health at certain levels. Currently, heavy metals are removed by physicochemical treatments, such as adsorption, flotation, and electrochemical deposition, and also biological treatments, such as algal biofilm reactor and anaerobic ammonium oxidation. In this study, magnetic biochar was produced to enhance the effectiveness and performance of the adsorbent for heavy metal removal. This study aimed to synthesise high-performance magnetic biochar, to determine the optimum parameters and conditions for high yield of magnetic biochar and high removal of cadmium (Cd2+) from aqueous solution, and to determine the adsorption kinetics and isotherms for Cd2+ removal. Nickel oxide (NiO)-impregnated sugarcane bagasse was subjected to slow pyrolysis to produce magnetic biochar. The impregnated metal, pyrolysis temperature, and pyrolysis time were varied to determine the optimum parameters and conditions to produce high-performance magnetic biochar. The removal of Cd2+ from aqueous solution and batch adsorption study were conducted. The synthesised magnetic biochar was characterised using field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, Fourier transform infrared (FTIR), and vibrating sample magnetometer (VSM). The adsorption data agreed well with the pseudo-second-order model and followed the Langmuir isotherm model. This study achieved 88.47% removal efficiency of Cd2+ from aqueous solution. Thus, the removal of this heavy metal as a human carcinogen reduces the hazardous effects on human health and reduces the toxicity in the environment

Plam oil empty fruit bunch based magnetic biochar composite comparison for synthesis by microwave-assisted and conventional heating

One of the most abundant residues is empty fruit bunch (EFB), which are left behind after removal of oil palm fruits in the oil refining process. In this study, we investigated the potential of converting palm oil residue into magnetic biochar composite (MBC) using microwave-assisted and conventional heating. The effect of process parameters for the production of MBC using microwave-assisted and the conventional method are compared. The results revealed that magnetic biochar composite exhibited excellent ferromagnetic property with a saturation magnetization of 8.16 and 4.20 emu/g using microwave and conventional heating respectively. Microwave-assisted instead of the conventional heating in the muffle furnace can be applied to reduce production cost of magnetic pyrolytic char preparation. Finding the optimal operating conditions to prepare magnetic pyrolytic char, preparation time 11 min against 2-5 h of reactivation for conventional method. Microwave-assisted offers several advantages over conventional heating, as it is often more controllable energy and cost efficient and therefore in many cases may offer a potentially attractive alternative to "conventional" pyrolysis. Furthermore, textural properties were investigated using nitrogen adsorption, and found microwave-assisted MBC is higher than conventional heating. The novelty is that the MBC can be directly produced using microwave-assisted by single stage of activation compared to the conventional method which requires multiple stage heating

Removal of heavy metals from wastewater using carbon nanotubes

The discovery of carbon nanotubes (CNTs) and the prospect of developing novel carbon-based nanomaterials have attracted researchers worldwide. CNTs have great potential as a novel type of adsorbent due to their unique properties such as chemical stability, mechanical and thermal stability, and the high surface area, which leads to various applications including hydrogen storage, protein purification and water treatment. Removal of heavy metals from industrial wastewater leads to the biggest challenge nowadays. To reduce environmental problems, the CNTs are promising candidates for the adsorption of heavy metals. In this study, extremely brief summaries of liquid pollutant purification are reviewed

Agricultural biomass-derived magnetic adsorbents: Preparation and application for heavy metals removal

This paper discusses the synthesis of magnetic adsorbents from agricultural waste and their applications in heavy metals removal. The general methods for preparing magnetic adsorbents and the mechanisms of heavy metal sorption are also reviewed in detail. These mechanisms are related to the utilization of magnetic adsorbents, particularly sugarcane bagasse in heavy metals removal, such as nickel, cadmium, lead, and arsenic. Converting sugarcane bagasse into magnetic adsorbents could solve environmental problems, such as agricultural waste and water pollution. A brief summary of the synthesis of magnetic biochar from sugarcane bagasse and its applications in heavy metals removal is also presented. Thus, this study proposes magnetic-based materials as potential candidates for wastewater treatment, and this adds new dimensions to numerous applications of the carbon family

An overview on methods for the production of carbon nanotubes

Carbon nanotubes (CNTs) are one of the most exciting discoveries in nanoscale sciences. A brief survey of experimental work directed towards the synthesis of CNTs has been discussed. The various methods of production of CNTs are explained outlining their capabilities, efficiencies and possible exploitation as economic large scale production. Among the discussed techniques, the chemical vapor deposition (CVD) appears to be the most potential way to produce high quality of CNTs at high yield. The advantages of CVD over other techniques are also explained and the effects of process parameter on the synthesis of these nanomaterials are discussed

Mass production of carbon nanofibers using microwave technology

Copyright © 2015 American Scientific Publishers All rights reserved.Carbon nanotubes (CNFs) were produced by gas phase single stage microwave assisted chemical vapour deposition (MA-CVD) using ferrocene as a catalyst and acetylene (C2H2) and hydrogen (H2) as precursor gases. The effect of the process parameters such as microwave power, radiation time, and gas ratio of C2H2/H2 was investigated. The CNFs were characterized using scanning and transmission electron microscopy (TEM), and by thermogravimetric analysis (TGA). Results reveal that the optimized conditions for CNF production were 1000 W reaction power, 35 min radiation time, and 0.8 gas ratio of C2H2/H2. TEM analyses revealed that the uniformly dispersed CNFs diameters ranging from 115-131 nm. The TGA analysis showed that the purity of CNF produced was 93%

Synthesis of palm oil empty fruit bunch magnetic pyrolytic char impregnating with FeCl3 by microwave heating technique

Empty fruit bunch (EFB) is one of the most abundant residues of the Palm oil mill industry in Malaysia. The novel magnetic bio-char was synthesized by single stage microwave heating technique, using EFB in the presence of ferric chloride hexahydrate. The effect of microwave powers, radiation time and impregnation ratio (IR) of ferric chloride hexahydrate to biomass were studied. Also the process parameters such as microwave powers, radiation times and IR were optimized using response surface method. The statistical analysis revealed that the optimum conditions for the high porosity magnetic bio-char production were at 900W microwave power, 20min radiation time and 0.5 (FeCl 3 : biomass) impregnation ratio. These newly produced magnetic bio-char have a high surface area of 890m 2 g -1 and that leads to highly efficient in the removal of methylene blue (MB) with an efficiency of 99.9% from aqueous solution with a maximum adsorption capacity of 265mgg -1

Single stage production of carbon nanotubes using microwave technology

Carbon nanotubes (CNTs) were produced by gas phase single stage tubular microwave chemical vapor deposition (TM–CVD) using ferrocene as a catalyst and acetylene (C2H2) and hydrogen (H2) as precursor gasses. The effect of the process parameters such as microwave power, radiation time, and gas ratio of C2H2/H2 was investigated. The CNTs were characterized using scanning and transmission electron microscopy (TEM), and by thermogravimetric analysis (TGA). Results reveal that the optimized conditions for CNT production were 900 W reaction power, 35 min radiation time, and 0.6 gas ratio of C2H2/H2. TEM analyses revealed that the uniformly dispersed vertical alignment of multiwall carbon nanotubes (MWCNTs) have diameters ranging from 16 to 23 nm. The TGA analysis showed that the purity of CNT produced was 98%

Microwave assisted multiwall carbon nanotubes enhancing Cd(II) adsorption capacity in aqueous media

Novel multiwall carbon nanotubes (MWCNTs) have been successfully synthesized using tubular microwave chemical vapour deposition technique and proved to be an outstanding adsorbent for the removal of Cd(II) from aqueous solution. The effect of process parameters such as pH, MWCNTs dosage, agitation speed and time were investigated. The maximum adsorption capacities of Cd(II) were found to be 88.62. mg/g and a statistical analysis reveals that the optimum conditions for the highest removal (98%) of Cd(II) are at pH 5, MWCNTs dosage 0.1. g, agitation speed and time of 160. rpm and 50. min, respectively with the initial concentration of 10. mg/L. The Langmuir and Freundlich isotherm models match the experimental data very well and adsorption kinetic obeyed pseudo-second order. Our results proved that MWCNTs can be used as an effective Cd(II) adsorbent due to the high adsorption capacity as well as the short adsorption time needed to achieve equilibrium

Microwave assisted carbon nanofibers for removal of zinc and copper from waste water

Copyright © 2017 American Scientific Publishers All rights reserved.Removal of toxic metals is one of the biggest challenges in ensuring safe water for all as well as protecting the environment. To reduce environmental problems, the carbon nanofibers (CNFs) are the most promising candidates for the adsorption of heavy metals. CNFs have been successfully synthesized by microwave heating technique and improved to be an outstanding adsorbent for the removal of heavy metal from waste water. A comparative study of the adsorption capacity of carbon CNFs in removal of Zn2+ and Cu2+ was investigated. Statistical analysis revealed that the optimum conditions for the highest removal of Zn2+ and Cu2+ are at pH 9.5 and 6, adsorbent dosage 100 and 50 mg, agitation speed of 150 and 100 rpm and adsorption time for both 20 minutes respectively. The removal efficiency of Zn2+ and Cu2+ for an initial concentration of 2 mg/L was 94.5% 98.8% respectively. The maximum adsorption capacities (qm) of 1.049 and 1.07 mg/g for CNFs were obtained to remove Zn2+ and Cu2+ respectively. The adsorption isotherms are well described by both Langmuir and Freundlich models and adsorption kinetic obeyed pseudo-second order. Hence, CNFs are the most promising candidate for removal of heavy metal from wastewater treatment and separation process