Environment
M. Heydari; T. Tabatabaie; F. Amiri; S. E. Hashemi
Abstract
Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. ...
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Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. In this context, using adsorption processes is a potential alternative for treating a wide range of organic pollutants, especially aromatic compounds in industrial wastewater. This study investigated the preparation of MCM-41 from silica; extracted from rice husk ash; MCM-41 was green synthesized to evaluate the effect of mesoporous used in BTEXS removal of an aqueous medium using the Taguchi method. The aqueous solution contains cyclic hydrocarbons was synthetically prepred based on real industrial effluent in concentrations of 50, 100, and 150 mg/l using MCM-41 catalysts, in doses of 0.1, 0.5, and 1g, at different pH values. In the present study, the optimum results obtained by Taguchi method analysis were pH =11, for duration of 60 minutes, the concentration of cyclic hydrocarbon solution BTEXS 100 mg/l, and nanoparticle dose of 0.5 g. The maximum BTEXS removal of 77.36% was achieved by the use of hydrogen peroxide.
Environment
R. A. Olaoye; S. O. Ojoawo; O. Bamigbade; N. Alimi; I. O. Rasaq; T. Oladejo
Abstract
The adhesion of metal ions from wastewater to surface of a material in an adsorption process had proven to be effective for remediation of wastewater before discharge. There is a growing demand to utilize alternative low-cost adsorbents for the removal of heavy metals from galvanic wastewater in most ...
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The adhesion of metal ions from wastewater to surface of a material in an adsorption process had proven to be effective for remediation of wastewater before discharge. There is a growing demand to utilize alternative low-cost adsorbents for the removal of heavy metals from galvanic wastewater in most developing countries. Cow bones are cheap, readily available and can be sourced locally from slaughterhouses and abattoir. Therefore, their use as an alternative adsorbent for remediation of galvanic wastewater had to be assessed. In this study, the efficacy of cow bone char (CBC) was assessed for simultaneous heavy metal ions removal from real life galvanic wastewater in a competitive adsorption process. The galvanic wastewater was characterized using atomic adsorption spectrophotometry while the CBC was characterized using X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR). Batch experiment was performed to determine the effect of adsorbent dose, contact time and agitation speed on the removal efficiency of heavy metal ions from the galvanized wastewater. The concentrations of Mn2+, Fe2+, Zn2+, Pb2+ and Cr2+ in the raw wastewater exceeded the WHO and EPA standards. The adsorbent revealed a significant distribution of well-developed porous, rough surfaces with cracks characterized by different functional groups for the efficient adsorption process. The optimum adsorbent dose for all the metal ions was 0.04 g/100 mL at an optimum contact time of 60 minutes except for Fe2+ with optimum contact time of 20 minutes, and agitation speed of 150 rpm. The maximum metal removal efficiencies obtained for Mn2+, Fe2+, Zn2+, Pb2+ and Cr2were 99.7%, 100%, 99%, 90% and 85% +, respectively. The average adsorption capacity for Mn2+, Fe2+, Zn2+, Pb2+ and Cr2+were 0.44 mg/g, 26.7 mg/g, 78.5 mg/g, 0.133 mg/g for and 10.36 mg/g, respectively. CBC offers efficient and cost-effective removal of selected metal ions from galvanized wastewater.
S. Nasrollahpour; D. Yousefi Kebria; M. Ghavami
Abstract
Phenol and its metabolites are among the hazardous organic compounds, due to their carcinogenicity, toxicity, long term persistence in the environment. The purposes of this study are the synthesis of organoclay as an adsorbent with high physicochemical stability, environmental compatibility and its application ...
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Phenol and its metabolites are among the hazardous organic compounds, due to their carcinogenicity, toxicity, long term persistence in the environment. The purposes of this study are the synthesis of organoclay as an adsorbent with high physicochemical stability, environmental compatibility and its application for remediation of aqueous solutions contaminated with phenol. In this research, organoclay was synthesized by the combination of sodium bentonite and Cetyl Trimethyl Ammonium Bromide (CTAB) surfactant with three different Cation Exchange Capacities (CECs). As well as, adsorption capacity of synthesized organoclay was determined during reuse until saturation. The results revealed that the removal efficiencies of phenol at concentrations of 100, 1000, 2000, and 3000 mg/L were 68, 84, 82, and 80%, respectively. In general, the use of organoclay can be an alternative to the complex and expensive systems for the removal of phenol from aqueous solutions with respect to its simplicity, high performance, and cost-effectiveness.
Wastewater
A. A. Rahman–Al Ezzi; S. H. Alhamdiny
Abstract
In this work, a modified internal loop airlift reactor has been designed to remove the organic pollutants in synthetic wastewater at an efficient and inexpensive treatment technique by means of a synergistic effect combining of (oxidation, stripping and adsorption). The validation of the current style ...
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In this work, a modified internal loop airlift reactor has been designed to remove the organic pollutants in synthetic wastewater at an efficient and inexpensive treatment technique by means of a synergistic effect combining of (oxidation, stripping and adsorption). The validation of the current style was experimentally examined in the treatment of synthetic Wastewater contained chloroform. The experimental testing rig was implemented at various air flow rates range (5-20) (L/min), with total variable residence period (5-60 min) with a different molar ratio of CHCl3 to H2O2 i.e. 1:10, 1:15 and 1:20. The results showed that the best molar ratio of chloroform to hydrogen peroxide was 1:20 for the air flow rate 18 L/min and extended retention period (60 min) having the uppermost results (83.3%) to remove chloroform from the contaminated effluent water. This design complements the research objectives with high efficiency through the synergy of stripping, oxidation and adsorption processes to remove contaminated chloroform from wastewater. This work contributes to a part of the solution of the environmental problems of the contaminated water before recycling, reuse or released to our safe environment.
A. Sumaila; M. M. Ndamitso; A. S. Ambali; Y. A. Iyaka; J. O. Tijani
Abstract
This work presents the green preparation of chitosan stabilized silver nanocomposite using aqueous leaf extracts of Nicotiana tobaccum. The prepared chitosan – silver nanocomposite was characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high resolution scanning ...
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This work presents the green preparation of chitosan stabilized silver nanocomposite using aqueous leaf extracts of Nicotiana tobaccum. The prepared chitosan – silver nanocomposite was characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM) and Fourier transform infrared (FTIR) spectroscopy. The nanocomposite was employed to remove copper and iron metal ions from electroplating effluent via batch adsorptions as a function of contact time, adsorbent dosage and temperature. The XRD results of the nanocomposite showed reflections at 2θ of 38.04°, 44.650 and 64.45° for the presence of silver nanoparticles and 9.29° and 19.300 for chitosan. The HRSEM image of the nanocomposite shows the silver nanoparticles embedded in the chitosan polymer matrix, to create pores on the surface of the chitosan. The maximum percentage removal of copper and iron by chitosan – silver nanocomposite were 94.76 % and 98.80 % respectively at temperature of 363 K in 60 minutes using adsorbent dosage of 25 mg. The results were well fitted by all the tested isotherm models but best fit into jovanovic isotherm models. Kinetic data for Cu and Fe ions followed the Elovich model which implies multilayer adsorption. The result of this study show that chitosan - silver nanocomposite has been prepared and it exhibit high adsorption efficiency for copper and iron from electroplating effluent.
M. Massoud; M. Erhayem; F. Al-Tohami
Abstract
In the present study, batch adsorption experiments of hazardous cadmium ions, Cd(II), onto low-cost Dodonaeae Viscose Legs (DVLs) surface were conducted with respect to contact time, solution pH, adsorbent dosage, initial Cd concentration and temperature. Sorption isotherm, kinetic and thermodynamic ...
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In the present study, batch adsorption experiments of hazardous cadmium ions, Cd(II), onto low-cost Dodonaeae Viscose Legs (DVLs) surface were conducted with respect to contact time, solution pH, adsorbent dosage, initial Cd concentration and temperature. Sorption isotherm, kinetic and thermodynamic models were used to describe the equilibrium stage and their constants were determined. The DVLs were used without chemical or physical activation processes. The results showed that the optimum adsorption capacity of DVLs for Cd(II) ions was found to be 25.29 mg/g at solution pH 5.26, 50 min and 303K. DVL adsorption data was fitted well with Langmuir isotherm. The mean free energy was found to be 1.82E-02 using Dubinin-Radushkevich (DRK) isotherm, which indicates that the adsorption of Cd(II) ions onto DVL surface is physical adsorption. The activation energy (Ea) was 3.06 kJ/mol, which confirms that Cd(II)-DVL adsorption process is physical sorption. Pseudo-first-order, pseudo-second-order, Elovich, intra-particle and extra-particle diffusion models were used to describe the adsorption kinetics. The results show strong correspondence to a pseudo-second-order kinetics. Thermodynamic parameters suggested that the adsorption of Cd(II) ions onto DVL surface is an exothermic process.
D. Basrur; J. Ishwara Bhat
Abstract
In this work, the preparation of activated carbons from agricultural product, the fenugreek seeds by two approaches, chemical and microwave activation methods were studied. The characterization of carbon materials were carried out using different techniques such as Fourier Transform ...
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In this work, the preparation of activated carbons from agricultural product, the fenugreek seeds by two approaches, chemical and microwave activation methods were studied. The characterization of carbon materials were carried out using different techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermo Gravimetric Analysis (TGA), X-Ray Diffraction (XRD). Adsorption experiment was carried out for the adsorption of two different basic dyes, Methylene Blue (MB) and Crystal Violet (CV) under varying conditions such as concentration, agitation time and temperature. The data acquired from concentration variation were found to fit well with Langmuir and also Freundlich isotherms. Kinetic studies revealed the fact that the system followed second order adsorption rate. Thermodynamic parameters such as ΔH≠, ΔS≠ and ΔG≠ were calculated from the obtained data on adsorption at different temperature.
S. S. Pandey; N. B. Singh; S. P. Shukla; M. Tiwari
Abstract
The aim of present study was to investigate the removal of lead and copper from textile wastewater using waste egg shells in a continuous stirred tank reactor. The effect of initial pH, metal concentration, adsorbent dosage and retention time were investigated. Optimum adsorption of lead (80%) was obtained ...
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The aim of present study was to investigate the removal of lead and copper from textile wastewater using waste egg shells in a continuous stirred tank reactor. The effect of initial pH, metal concentration, adsorbent dosage and retention time were investigated. Optimum adsorption of lead (80%) was obtained at pH 6, initial metal concentration 20 mg/L, adsorbent dosage 12.5 g/L and retention time 90 minute. Also, optimum adsorption of copper (71%) was obtained at pH 6, initial metal concentration 15 mg/L, adsorbent dosage 15 g/L and retention time 75 minute. Langmuirs, Freundlich and Temkin isotherms were used for the mathematical description of adsorption equilibrium. Langmuir isotherm showed the best fitting to the isotherm equilibrium data, with a maximum adsorption capacity (qm) of 4.33 mg/g and 3.54 mg/g for lead and copper, respectively. Results revealed that pseudo-second order adsorption kinetic equation fit the data with a high correlation coefficient (R2 more than 0.97). Based on the results of the present study, egg shells is suitable to be used for the removal of lead and copper from textile wastewater.
S. N. Larimi; B. Ayati
Abstract
The present study used the adsorption process of activated carbon produced from agricultural wastes and the photocatalytic process of nano-ZnO to break down complex compounds available in removing Direct Blue 71 (henceforth, DB71). The two processes were done under three varied circumstances- adsorption/photocatalytic, ...
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The present study used the adsorption process of activated carbon produced from agricultural wastes and the photocatalytic process of nano-ZnO to break down complex compounds available in removing Direct Blue 71 (henceforth, DB71). The two processes were done under three varied circumstances- adsorption/photocatalytic, photocatalytic/ adsorption, and simultaneous use of the processes. First, DB71 was exposed to activated carbon produced from walnut and almond shells and the efficiency achieved at equilibrium time (45 and 60 minutes) was 55 and 60 percent, respectively. Then, DB71 was exposed to different dosages of nano-ZnO to remove the dye completely. The result showed that amount of AC/ZnO in an optimum condition for two walnut and almond shell absorbents were 0.75/0.096 and1/0.096 g/L. Second, (photocatalytic/ adsorption) the complex compound of DB71 with a dosage of 0.024 g/L was broken down as a result of UV radiation. The experiment proceeded with different dosages of walnut and almond shells after achieving the efficiency of 50% in removing DB71 in the second process. The amounts of AC/ZnO were 0.75/0.024 and 1/0.024 for walnut and almond shells respectively under the optimum condition for the second process. In the third process advantages of the simultaneous use of photocatalytic and adsorption processes were taken in which different dosages of AC/ ZnO were used. Given the smaller dosages of nano-ZnO and less dye removal time, amounts of 0.75/ 0.288 g/L and 0.75/0.288 g/L were measured for walnut and almond shells. The findings show that photocatalytic/adsorption process was the more optimal process because of the less dosages of nano-ZnO, efficiency of removing DB71 and shorter dye removing time. Furthermore, the effect of the intensity of UV radiant on the efficiency and time of removing DB71 was also examined. The experiment revealed that removing COD in the optimum conditions were 47.22 and 49.6 and 62.23 and 63.15 percent using walnut and almond shell respectively both in the first experiment and the simulations use of adsorption and photocatalytic processes after 30 hours. While, in the second experiment (photocatalytic/ adsorption) 42.21 and 39.18 percent of COD were removed using walnut and almond shell respectively after 30 hours. The LC-mass test of photocatalytic/adsorption process also showed the degradation of DB 71 complex compounds.
D. Basrur; J. Ishwara Bhat
Abstract
In this study the preparation of activated carbon from agricultural product were reported. The fenugreek seeds were activated by chemical and microwave activation methods. The characterization of carbon materials were carried out using different techniques like Fourier Transform Infrared Spectroscopy ...
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In this study the preparation of activated carbon from agricultural product were reported. The fenugreek seeds were activated by chemical and microwave activation methods. The characterization of carbon materials were carried out using different techniques like Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermo Gravimetric Analysis (TGA), X-Ray Diffraction (XRD). Adsorption experiment was carried out for the adsorption of two different basic dyes, Methylene Blue (MB) and Crystal Violet (CV) under varying conditions such as concentration of dye, mixing time and adsorption temperature. The data acquired from concentration variation were found to fit well with Langmuir and also Freundlich isotherms. Kinetic studies revealed the fact that the system follows second order. Thermodynamic parameters like ΔH≠, ΔS≠ and ΔG≠ were calculated from the study on adsorption at different temperature. The adsorbent preparation via microwave technology is a desired methods which is resulted in conservation of energy for an efficient production of activated carbon.
P. Chaithra; K. Hemashree; J. I. Bhat
Abstract
The activated charcoal (AC) was synthesized from banana leaf rim (BLR) through three activation methods; physical (BLRC), chemical (Z BLRC, zinc chloride) and microwave activation (MW BLRC). The AC was characterised using powder X-ray diffraction (XRD) and field emission scanning electron microscope ...
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The activated charcoal (AC) was synthesized from banana leaf rim (BLR) through three activation methods; physical (BLRC), chemical (Z BLRC, zinc chloride) and microwave activation (MW BLRC). The AC was characterised using powder X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The Z BLRC has better adsorbent character compared to BLRC or MW BLRC. Adsorption of acetic acid (AA) onto synthesized activated charcoals (BLRC, Z BLRC & MW BLRC) were performed. This experimental data satisfied Freundlich adsorption isotherm equations. Second-order kinetics study holds good for the present adsorption system. Thermodynamic parameters were evaluated. Based on the result it may be concluded that chemical activated charcoal has maximum adsorption efficiency among the three synthesized types of carbons.
P. Chaithra; K. Hemashree; J. Ishwara Bhat
Abstract
Activated carbon (AC) was synthesized from raw cocoa pod (RCP) by three activation methods; physical (CPC), chemical (Z CPC, zinc chloride) and microwave activation (MW-CPC). The synthesized AC was characterized using powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), ...
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Activated carbon (AC) was synthesized from raw cocoa pod (RCP) by three activation methods; physical (CPC), chemical (Z CPC, zinc chloride) and microwave activation (MW-CPC). The synthesized AC was characterized using powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopic technique (FT-IR), thermal analysis and differential thermal analysis (TGA-DTA), atomic absorption spectroscopic technique (AAS) and flame photometer instrument. The characterization data reveals that microwave activated carbon having good adsorbent character than physical and chemical activated carbon. Adsorption of malachite green on CPC, Z CPC and MW-CPC were studied at various experimental condition. Freundlich adsorption isotherm model holds good for the adsorption process. The mechanism of adsorption followed the second order kinetics. Thermodynamics of adsorption were studied. The amount of dye adsorbed onto activated carbons varies in the order MW-CPC (29.3632mg/g) > CPC (29.3537mg/g) > Z CPC (27.9905mg/g).
M. Anbia; F. Rahimi
Abstract
The current study adsorption characteristics of platinum(IV) onto the ethylenediamine-modified magnetic cellulose nanoparticles (MCNGE) have been investigated. The prepared adsorbentwere characterized using Fourier transform spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy ...
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The current study adsorption characteristics of platinum(IV) onto the ethylenediamine-modified magnetic cellulose nanoparticles (MCNGE) have been investigated. The prepared adsorbentwere characterized using Fourier transform spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) techniques. Optimization the experimental parameters namely Pt(IV) concentration (15-35 mg/l), temperature (34–50 °C), pH of solution (2–5), and particles dose (0.03-0.06 g) were performed using a means of central composite design (CCD) and response surface methodology (RSM). Analysis of variance (ANOVA) was conducted to evaluation the model, the main of the independent variables and their interactions for adsorption of Pt(IV) from aqueous solution. The results of the quadratic model indicated that the model was highly significant with F-value (F model = 55.09) and value of prob> F (<0.0001).The optimum adsorption conditions were determined as initial pH 2.5, temperature 46°C, adsorbent dosage 0.05 g and initial platinum(IV) ion concentration 22mg/l.The maximum capacity of MCNGE for Pt(IV) was found to be 19.45 mg/g. The magnetic cellulose nanoparticle is an environmental friendly product with low energy costs in adsorption of heavy metals from aqueous phase.
R. J. Jawad; M. H. Shah Ismail; S. I. Siajam
Abstract
This study was about the investigation of the removal of iron ions from Palm Oil Mill Effluent (POME) by using novel adsorbent which is Alginate–Mangrove Composite Beads Coated by Chitosan (AMCBCC). The adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron ...
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This study was about the investigation of the removal of iron ions from Palm Oil Mill Effluent (POME) by using novel adsorbent which is Alginate–Mangrove Composite Beads Coated by Chitosan (AMCBCC). The adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDX) to prove the successful coating by Chitosan and also to provide an evidence of iron ions were adsorbed on the surface of the beads. Batch studies were conducted by using different parameters, such as pH, dosage, contact time, and initial concentration. It was found that at pH value of 3, 300 g/L of AMCBCC concentration, and a contact time of 72 hours the maximum removal of iron ions was 92.7%. The isotherm equilibrium data were followed Freundlich isotherm model and the adsorption kinetic data were well fitted by the pseudo second order.
V. Garshasbi; M. Jahangiri; M. Anbia
Abstract
Synthesis of zeolite 13X from modified natural Iranian kaolin at 65˚C for 72 h at various concentration of NaOH solution was investigated. Metakaolinization process was done at 900˚C for 2 h. NaOH solution with different concentrations, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4 M were separately mixed with ...
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Synthesis of zeolite 13X from modified natural Iranian kaolin at 65˚C for 72 h at various concentration of NaOH solution was investigated. Metakaolinization process was done at 900˚C for 2 h. NaOH solution with different concentrations, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4 M were separately mixed with metakaolins. A mixture of zeolite 13X, A, quartz and hydroxysodalite (HS) was obtained. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The prepared zeolite 13X has been used to study the adsorption of carbon dioxide, and the results are compared with commercial zeolite 13X.
R. Alrozi; N. S. Anuar; F. Senusi; M. A. Kamaruddin
Abstract
In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The adsorption ...
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In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The adsorption experiments were carried out under different conditions of initial concentration (25-250 mg/L), adsorption time (0-2h), solution pH (2-12), and temperature (300-353 K) to determine optimum conditions for the highest RBBR removal. The influence of these parameters on the adsorption capacity was studied using the batch process. The results indicated that the solution pH was observed to be a key factor of the RBBR adsorption process. The maximum dye adsorption was achieved with Zn-CL adsorbent at pH~6 and the corresponding adsorption capacity was found to be 42.2 mg/g, which was higher than R-CL (12.5 mg/g). Lower adsorption capacity of RBBR was found by Zn-CL between pH 8 and 12 opposite to R-CL which showed a marginal increase in adsorption capacity within the same pH range. The results proved that Zn-CL which is a modified clinoptilolite is an effective adsorbent for the removal of RBBR from aqueous solution.
S. Sasikala; Govindaraju Muthuraman
Abstract
The potential of economically cheaper Tribulus terrestris was assessed for iron adsorption from aqueous solutions. The effects of pH, Contact time, sorbent dose, initial metal ion concentration and temperature on the uptake of iron were studied in batch process. Chemical treatment processes are ineffective ...
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The potential of economically cheaper Tribulus terrestris was assessed for iron adsorption from aqueous solutions. The effects of pH, Contact time, sorbent dose, initial metal ion concentration and temperature on the uptake of iron were studied in batch process. Chemical treatment processes are ineffective and produce large quantity of sludge which requires further treatment. A simple and efficient treatment process for the removal of heavy metals is essentially required. Maximum iron removal was observed at pH 6 with adsorbent dosage of 0.6 g. The adsorbent data has been correlated with Langmuir and Freundlich adsorption models. FTIR and SEM before and after adsorption were recorded to explore the number and position of the functional groups available for iron binding onto the studied adsorbent and changes in surface morphology. The maximum percentage of iron removal was achieved at 87%. The results revealed that iron is considerably adsorbed on Tribulus terrestris and it could be economical method for the removal of iron from aqueous solutions. Pseudo second order model explains the iron kinetics more effectively.
