Wastewater treatment by adsorption onto activated carbon is effective because it has a variety of... more Wastewater treatment by adsorption onto activated carbon is effective because it has a variety of benefits. In this work, activated carbon prepared from rice husk by chemical activation using zinc chloride was utilized to reduce chemical oxygen demand from wastewater. The as-prepared activated carbon was characterized by scanning electron microscope, Fourier transform infrared spectroscopy and nitrogen adsorption/desorption analysis. The optimum conditions for maximum removal were achieved by studying the impact of various factors such as solution pH, sorbent dose, shaking time and temperature in batch mode. The results displayed that the optimum sorption conditions were achieved at pH of 3.0, sorbent dose of 0.1 g L−1, shaking time of 100 min and at room temperature (25 °C). Based on the effect of temperature, the adsorption process is exothermic in nature. The results also implied that the isothermal data might be exceedingly elucidated by the Langmuir model. The maximum removal o...
Proceedings of the Institution of Civil Engineers - Ground Improvement
Expansive soils are generally characterised by their volume change when subjected to variation in... more Expansive soils are generally characterised by their volume change when subjected to variation in water content. This may result in significant damage to supported and nearby structures. In this study, the swelling properties of bentonite material as an expansive soil are first determined. The expansive soil is then improved using two different approaches, namely, micro-metakaolin (Mm) and ferric chloride (FeCl3) solution. The optimum percentages for both additives are determined using laboratory experiments, which are 25 and 1% for the Mm and the ferric chloride solution, respectively. The free swell index of the bentonite after being treated with Mm and ferric chloride solution at the optimum percentages is found to decrease by about 54 and 62%, respectively. Meanwhile, the swelling pressure for the expansive soil decreased by 33 and 43% when mixed with the same optimum values of Mm and ferric chloride solution, respectively. On the basis of the results obtained in this study, the...
In this study, zinc oxide nanoparticles (ZnO) and nanohydroxyapatite (NHAP) were prepared in the ... more In this study, zinc oxide nanoparticles (ZnO) and nanohydroxyapatite (NHAP) were prepared in the presence of date palm pits extract (DPPE) and eggshells, respectively. Another four nanocomposites were prepared from ZnO and NHAP in different ratios (ZP13, ZP14, ZP15, and ZP16). DPPE and all nanomaterials were characterized using GC-MS, zeta potentials, particle size distributions, XRD, TEM, EDX, FTIR, and pHPZC. The characterization techniques confirmed the good distribution of ZnO nanoparticles on the surface of NHAP in the prepared composites. Particles were found to be in the size range of 42.3–66.1 nm. The DPPE analysis confirmed the presence of various natural chemical compounds which act as capping agents for nanoparticles. All the prepared samples were applied in the adsorption and photocatalytic degradation of methylene blue under different conditions. ZP14 exhibited the maximum adsorption capacity (596.1 mg/g) at pH 8, with 1.8 g/L as the adsorbent dosage, after 24 h of shak...
In this study, silica nanospheres (S) and trizma base-modified silica nanospheres (ST2, ST4, ST6,... more In this study, silica nanospheres (S) and trizma base-modified silica nanospheres (ST2, ST4, ST6, and ST8) were synthesized for the removal of arsenic from aqueous medium with high efficiency. Characterization of the prepared solid adsorbents was performed with different techniques such as thermogravimetric analysis, scanning electron microscopy, X-ray diffraction patterns, transmission electron microscopy, selected area electron diffraction, fast Fourier transform, nitrogen adsorption, point of zero charge (pH PZC ), and Fourier transform infrared. Adsorption of As +5 was investigated under different application conditions such as adsorbent dosage, pH, shaking time, temperature, and initial As +5 concentration. Maximum adsorption capacity reached 64.5 mg g −1 at pH 6, 0.9 g L −1 as adsorbent dosage, after 60 min of shaking time, and at 25 °C as the optimum adsorption conditions. Adsorption data of As +5 by the prepared nanoadsorbents are best fitted with Langmuir, Temkin, and Dubinin–Radushkevich models. Kinetic studies revealed that the adsorption followed pseudo-second-order and Elovich kinetic models. Thermodynamic studies prove that the adsorption process is endothermic, spontaneous, and chemisorption in nature. The most effective desorption was achieved by nitric acid with 99% desorption efficiency. The prepared silica nanospheres solid adsorbents showed a good reusability with 91% adsorption efficiency after four cycles of adsorption and desorption.
AbstractNatural weak cohesive subgrade soils are considered low quality foundations for pavement ... more AbstractNatural weak cohesive subgrade soils are considered low quality foundations for pavement structures that may lead to significant pavement distresses. Several solutions can be proposed to en...
International Journal of Biological Macromolecules, 2014
The present investigation deals with preparation of three different adsorbent materials namely; p... more The present investigation deals with preparation of three different adsorbent materials namely; potassium hydroxide activated carbon based apricot stone (C), calcium alginate beads (G) and calcium alginate/activated carbon composite beads (GC) were used for the removal of arsenic. The prepared adsorbent materials were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), N2-adsorption at -196°C and point of zero charge. From the obtained results, it was found that the porosity, surface area and total pore volume of the adsorbent material C>GC>G respectively, however, the G adsorbent has more acidic function group than the other adsorbents. The influence of pH, time, temperature and initial concentration of arsenic(V) were studied and optimized. GC exhibits the maximum As(V) adsorption (66.7mg/g at 30°C). The adsorption of arsenic ions was observed to follow pseudo-second order mechanism as well as the thermodynamic parameters confirm also the endothermic spontaneous and a physisorption process.
Three adsorbents, calcium alginate beads (AB), sodium hydroxide activated carbon based coconut sh... more Three adsorbents, calcium alginate beads (AB), sodium hydroxide activated carbon based coconut shells (C), and calcium alginate/activated carbon composite beads (ACB) were prepared. Their textural properties were characterized by N2-adsorption at -196°C and scanning electron microscopy. The porosity, surface area and total pore volume of C>ACB>AB, but AB adsorbent was more acidic function groups more than the other adsorbents. Adsorption experiments were conducted to examine the effects of adsorbent dosage, pH, time, temperature and initial concentration of methylene blue. Methylene blue adsorption on C, AB and ACB was observed at pH>6 to avoid the competition of H(+). The amount of dye adsorbed increases as the adsorbent dosage increase. Adsorption of dye follows pseudo-second order mechanism. Thermodynamic studies show spontaneous and endothermic nature of the overall adsorption process.
A high surface area molybdenum phosphide (MoP) was successfully synthesized by combining citric a... more A high surface area molybdenum phosphide (MoP) was successfully synthesized by combining citric acid (CA) and temperature-programmed reduction (TPR) (CA-TPR) method. Reduction of the precursor which was modified by citric acid produced MoP with a high surface area of 122.0m2g−1 under optimum conditions. Fourier transform infrared (FTIR) results showed that the chelating interaction between the moderate amount of citric acid
In the present study, four solid adsorbents were prepared via green synthesis sources, namely, na... more In the present study, four solid adsorbents were prepared via green synthesis sources, namely, nanohydroxyapatite (NHAP), nanocellulose (NC), nanocellulose/nanohydroxyapatite composite (NPC), and ferric@nanocellulose/nanohydroxyapatite composite (FNPC). Synthesis procedures were based on natural sources such as sea scallop shells and cotton stalks. All the prepared solid adsorbents were characterized by TGA, XRD, nitrogen adsorption/desorption isotherm, FTIR, pHPZC, SEM, and TEM. FNPC exhibited a higher surface area (358.32 m2/g), mesoporous surface (pore diameter, 12.29 nm), TEM particle size of 45 nm, and the availability of various surface functional groups. Static adsorption of Safranin-O (SO) dye was investigated for all the prepared solid adsorbents under different application conditions. Maximum adsorption capacity (239.23 mg/g) was achieved by FNPC after 24 h of equilibrium time, at pH 7, 2 g/L as adsorbent dosage, and 40 ℃. Adsorption of Safranin-O onto all the samples well...
Four solid adsorbents namely nanohydroxyapatite (NP), cetyltrimethyl ammonium bromide modified na... more Four solid adsorbents namely nanohydroxyapatite (NP), cetyltrimethyl ammonium bromide modified nanohydroxyapatite (NPB), and nanohydroxyapatite/chitosan composite either in acidic (NPS1) or basic media (NPS2) were prepared based on egg shell as a biosource. Solid materials were characterized by N2 adsorption/desorption isotherms, scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and point of zero charges. The thermal, textural, and chemical properties of nanohydroxyapatite/chitosan composite prepared in basic medium were found to be more enhanced than the other three solid adsorbents with surface area and pore radius of 152.5 m2/g and 5.11 nm, respectively. pHPZC for all the prepared solid samples ranged between 6.8 and 7.5. Adsorption of hexavalent chromium were studied under different application condition such as the effect of adsorbent dosage, time, pH, initial Cr(VI) concentration, and temperature. The ma...
Wastewater treatment by adsorption onto activated carbon is effective because it has a variety of... more Wastewater treatment by adsorption onto activated carbon is effective because it has a variety of benefits. In this work, activated carbon prepared from rice husk by chemical activation using zinc chloride was utilized to reduce chemical oxygen demand from wastewater. The as-prepared activated carbon was characterized by scanning electron microscope, Fourier transform infrared spectroscopy and nitrogen adsorption/desorption analysis. The optimum conditions for maximum removal were achieved by studying the impact of various factors such as solution pH, sorbent dose, shaking time and temperature in batch mode. The results displayed that the optimum sorption conditions were achieved at pH of 3.0, sorbent dose of 0.1 g L−1, shaking time of 100 min and at room temperature (25 °C). Based on the effect of temperature, the adsorption process is exothermic in nature. The results also implied that the isothermal data might be exceedingly elucidated by the Langmuir model. The maximum removal o...
Proceedings of the Institution of Civil Engineers - Ground Improvement
Expansive soils are generally characterised by their volume change when subjected to variation in... more Expansive soils are generally characterised by their volume change when subjected to variation in water content. This may result in significant damage to supported and nearby structures. In this study, the swelling properties of bentonite material as an expansive soil are first determined. The expansive soil is then improved using two different approaches, namely, micro-metakaolin (Mm) and ferric chloride (FeCl3) solution. The optimum percentages for both additives are determined using laboratory experiments, which are 25 and 1% for the Mm and the ferric chloride solution, respectively. The free swell index of the bentonite after being treated with Mm and ferric chloride solution at the optimum percentages is found to decrease by about 54 and 62%, respectively. Meanwhile, the swelling pressure for the expansive soil decreased by 33 and 43% when mixed with the same optimum values of Mm and ferric chloride solution, respectively. On the basis of the results obtained in this study, the...
In this study, zinc oxide nanoparticles (ZnO) and nanohydroxyapatite (NHAP) were prepared in the ... more In this study, zinc oxide nanoparticles (ZnO) and nanohydroxyapatite (NHAP) were prepared in the presence of date palm pits extract (DPPE) and eggshells, respectively. Another four nanocomposites were prepared from ZnO and NHAP in different ratios (ZP13, ZP14, ZP15, and ZP16). DPPE and all nanomaterials were characterized using GC-MS, zeta potentials, particle size distributions, XRD, TEM, EDX, FTIR, and pHPZC. The characterization techniques confirmed the good distribution of ZnO nanoparticles on the surface of NHAP in the prepared composites. Particles were found to be in the size range of 42.3–66.1 nm. The DPPE analysis confirmed the presence of various natural chemical compounds which act as capping agents for nanoparticles. All the prepared samples were applied in the adsorption and photocatalytic degradation of methylene blue under different conditions. ZP14 exhibited the maximum adsorption capacity (596.1 mg/g) at pH 8, with 1.8 g/L as the adsorbent dosage, after 24 h of shak...
In this study, silica nanospheres (S) and trizma base-modified silica nanospheres (ST2, ST4, ST6,... more In this study, silica nanospheres (S) and trizma base-modified silica nanospheres (ST2, ST4, ST6, and ST8) were synthesized for the removal of arsenic from aqueous medium with high efficiency. Characterization of the prepared solid adsorbents was performed with different techniques such as thermogravimetric analysis, scanning electron microscopy, X-ray diffraction patterns, transmission electron microscopy, selected area electron diffraction, fast Fourier transform, nitrogen adsorption, point of zero charge (pH PZC ), and Fourier transform infrared. Adsorption of As +5 was investigated under different application conditions such as adsorbent dosage, pH, shaking time, temperature, and initial As +5 concentration. Maximum adsorption capacity reached 64.5 mg g −1 at pH 6, 0.9 g L −1 as adsorbent dosage, after 60 min of shaking time, and at 25 °C as the optimum adsorption conditions. Adsorption data of As +5 by the prepared nanoadsorbents are best fitted with Langmuir, Temkin, and Dubinin–Radushkevich models. Kinetic studies revealed that the adsorption followed pseudo-second-order and Elovich kinetic models. Thermodynamic studies prove that the adsorption process is endothermic, spontaneous, and chemisorption in nature. The most effective desorption was achieved by nitric acid with 99% desorption efficiency. The prepared silica nanospheres solid adsorbents showed a good reusability with 91% adsorption efficiency after four cycles of adsorption and desorption.
AbstractNatural weak cohesive subgrade soils are considered low quality foundations for pavement ... more AbstractNatural weak cohesive subgrade soils are considered low quality foundations for pavement structures that may lead to significant pavement distresses. Several solutions can be proposed to en...
International Journal of Biological Macromolecules, 2014
The present investigation deals with preparation of three different adsorbent materials namely; p... more The present investigation deals with preparation of three different adsorbent materials namely; potassium hydroxide activated carbon based apricot stone (C), calcium alginate beads (G) and calcium alginate/activated carbon composite beads (GC) were used for the removal of arsenic. The prepared adsorbent materials were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), N2-adsorption at -196°C and point of zero charge. From the obtained results, it was found that the porosity, surface area and total pore volume of the adsorbent material C>GC>G respectively, however, the G adsorbent has more acidic function group than the other adsorbents. The influence of pH, time, temperature and initial concentration of arsenic(V) were studied and optimized. GC exhibits the maximum As(V) adsorption (66.7mg/g at 30°C). The adsorption of arsenic ions was observed to follow pseudo-second order mechanism as well as the thermodynamic parameters confirm also the endothermic spontaneous and a physisorption process.
Three adsorbents, calcium alginate beads (AB), sodium hydroxide activated carbon based coconut sh... more Three adsorbents, calcium alginate beads (AB), sodium hydroxide activated carbon based coconut shells (C), and calcium alginate/activated carbon composite beads (ACB) were prepared. Their textural properties were characterized by N2-adsorption at -196°C and scanning electron microscopy. The porosity, surface area and total pore volume of C>ACB>AB, but AB adsorbent was more acidic function groups more than the other adsorbents. Adsorption experiments were conducted to examine the effects of adsorbent dosage, pH, time, temperature and initial concentration of methylene blue. Methylene blue adsorption on C, AB and ACB was observed at pH>6 to avoid the competition of H(+). The amount of dye adsorbed increases as the adsorbent dosage increase. Adsorption of dye follows pseudo-second order mechanism. Thermodynamic studies show spontaneous and endothermic nature of the overall adsorption process.
A high surface area molybdenum phosphide (MoP) was successfully synthesized by combining citric a... more A high surface area molybdenum phosphide (MoP) was successfully synthesized by combining citric acid (CA) and temperature-programmed reduction (TPR) (CA-TPR) method. Reduction of the precursor which was modified by citric acid produced MoP with a high surface area of 122.0m2g−1 under optimum conditions. Fourier transform infrared (FTIR) results showed that the chelating interaction between the moderate amount of citric acid
In the present study, four solid adsorbents were prepared via green synthesis sources, namely, na... more In the present study, four solid adsorbents were prepared via green synthesis sources, namely, nanohydroxyapatite (NHAP), nanocellulose (NC), nanocellulose/nanohydroxyapatite composite (NPC), and ferric@nanocellulose/nanohydroxyapatite composite (FNPC). Synthesis procedures were based on natural sources such as sea scallop shells and cotton stalks. All the prepared solid adsorbents were characterized by TGA, XRD, nitrogen adsorption/desorption isotherm, FTIR, pHPZC, SEM, and TEM. FNPC exhibited a higher surface area (358.32 m2/g), mesoporous surface (pore diameter, 12.29 nm), TEM particle size of 45 nm, and the availability of various surface functional groups. Static adsorption of Safranin-O (SO) dye was investigated for all the prepared solid adsorbents under different application conditions. Maximum adsorption capacity (239.23 mg/g) was achieved by FNPC after 24 h of equilibrium time, at pH 7, 2 g/L as adsorbent dosage, and 40 ℃. Adsorption of Safranin-O onto all the samples well...
Four solid adsorbents namely nanohydroxyapatite (NP), cetyltrimethyl ammonium bromide modified na... more Four solid adsorbents namely nanohydroxyapatite (NP), cetyltrimethyl ammonium bromide modified nanohydroxyapatite (NPB), and nanohydroxyapatite/chitosan composite either in acidic (NPS1) or basic media (NPS2) were prepared based on egg shell as a biosource. Solid materials were characterized by N2 adsorption/desorption isotherms, scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and point of zero charges. The thermal, textural, and chemical properties of nanohydroxyapatite/chitosan composite prepared in basic medium were found to be more enhanced than the other three solid adsorbents with surface area and pore radius of 152.5 m2/g and 5.11 nm, respectively. pHPZC for all the prepared solid samples ranged between 6.8 and 7.5. Adsorption of hexavalent chromium were studied under different application condition such as the effect of adsorbent dosage, time, pH, initial Cr(VI) concentration, and temperature. The ma...
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