scholarly journals Acid – treated activated carbon for phenolic compound removal in acid pre-treatment of lignocellulosic biomass for biogas production

2020 ◽  
Vol 10 (3) ◽  
pp. 5466-5471

Phenolic compound can be an inhibitor during acid pre-treatment process in the conversion of biomass into bioenergy and consequently reduces the production yield. Thus, this study aimed to investigate the potential use of activated carbon from coconut shell for phenolic compound removal and gallic acid was used as model phenolic. Granular activated carbon was treated by using 20% concentration of phosphoric acid to its properties and function. Acid treated and untreated activated carbon were characterized in term of morphology, surface functionalities and material phase by means of SEM, FT-IR and XRD. Few parameters that influenced the removal of gallic acid were studied which included the effect of adsorbent dosage, initial concentration, contact time, and pH. It is observed that the acid treated activated carbon was successfully remove the gallic acid for about 97% using of 0.5g/L adsorbent dosage, with initial concentration of 100 mg/L, at pH value of 4 and 150 minutes contact time. The adsorption behavior was fixed with Langmuir isotherm fixed the experiment data which indicates homogenous adsorption. These experimental results also revealed that coconut shell based activated carbon is viable cheaper adsorbent for phenolic compound removal.

2013 ◽  
Vol 330 ◽  
pp. 112-116 ◽  
Author(s):  
Nabilah A. Lutpi ◽  
N. Najihah Jamil ◽  
C.K. Kairulazam C.K. Abdullah ◽  
Yee Shian Wong ◽  
Soon An Ong ◽  
...  

The adsorption of Methylene Blue (MB) and Acid Orange 7 (AO7) dye onto Ananas Comosus Mixed Peels and Leaves (ACMPL) were carried out by conducting four different parameters such as initial concentration, pH, dosage of adsorbent, and contact time. Effect of initial concentration for both dyes showed that higher initial concentration would take longer contact time to attain equilibrium due to higher amount of adsorbate molecules. The effect of pH showed highest percentage removal for MB is at pH 9 which is 95.81%. Meanwhile for AO7 the highest percentage removal is 31.06% at pH 3. The percentage removal of MB had reached the equilibrium at dosage 0.5g while AO7 keep increasing with the increment of adsorbent dosage. The percentage removal of MB and AO7 had increased until hour 2.5 which was from 72.5% to 86.93% and 19.441% to 36.89% respectively and reached equilibrium at 3 hour contact time.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
T. Shanthi ◽  
V. M. Selvarajan

Carbon prepared from leaves of henna (Lawsonia inermis) was used to study the adsorption of Cr(VI) and Cu(II) ions from their aqueous solutions. The experimental conditions which include pH, contact time, initial concentration, and adsorbent dosage on the metal removal were investigated. The capacity of adsorption depends on pH value; it increases with an increase in pH value from 1 to 7 and then decreases. The highest percentage of metal removal was achieved in the adsorbent dosage of 0.7 g and at an initial concentration of 100 ppm metal ion. The adsorption isotherm studies revealed that data was confirmed with both the Langmuir and Freundlich isotherm models. The removal percentage was found to be higher for Cu(II) when compared with Cr(VI). The potential of carbon prepared from henna leaves for the removal of these two solutions containing heavy metals was substantiated.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Aderonke Adetutu Okoya ◽  
Olasunkanmi Olalekan Olaiya ◽  
Abimbola Bankole Akinyele ◽  
Nnenneh Oruada Ochor

Trihalomethanes (THMs) are formed when excess chlorine during chlorination of water reacts with organic material in water. They have mutagenic and carcinogenic properties. Moringa oleifera (MO) has found wide acceptance by many people in Nigeria who have used it for food for both humans and fauna, for health purposes, and as a coagulant for water treatment. However, the seed husks are currently discarded as waste and they have not been used as adsorbent to remove THMs from water. The physicochemical properties of both the treated and raw surface water were determined using standard methods, and the concentration of THMs was determined from the water treatment plant at different stages of treatment using gas chromatography with flame ionization detector (GC-FID). Recovery experiments were carried out to validate the procedure. The efficiencies of activated carbon of Moringa oleifera seed husk (MOSH) adsorbent for the removal of THMs in the water and as a coagulant for water treatment were also assessed. Batch adsorption experiments were carried out, and different parameters such as pH (5, 7, and 9), adsorbent dosage (0.2, 0.4, and 0.8 g), contact time (30, 60, and 90 minutes), and initial concentration (0.2, 0.4, and 0.6 mg/l) were optimized for the removal of trichloromethane and tribromomethane using the MOSH activated carbon. Experimental adsorption data from different initial concentrations of trichloromethane and tribromomethane were used to test conformity with Langmuir and Freundlich adsorption isotherms. The percentage recovery from our procedures ranged from 96.0 ± 1.41 to 100.0 ± 0.00 for trichloromethane while for tribromomethane the range was 60 ± 2.82 to 100.0 ± 0.00. The mean percentage adsorption efficiencies for the simulation experiment ranged from 34.365 ± 1.41 to 93.135 ± 0.57 and from 41.870 ± 0.27 to 94.655 ± 0.41 for trichloromethane and tribromomethane, respectively. The optimum conditions for both trichloromethane and tribromomethane were pH 9, 0.8 g adsorbent dosage, 60-minute contact time, and 0.6 mg/l initial concentration. The optimum values of these parameters used for the adsorption of the two THMs in the surface water serving the treatment plant gave an efficiency of 100.00 ± 0.00%. The turbidity values for the coagulation experiment reduced from 9.76 ± 0.03 NTU in the raw water before coagulation to 5.92 ± 0.13 NTU after coagulation while all other physicochemical parameters of the surface water decreased in value except conductivity and total dissolved solid which increased from 104.5 ± 3.54 to 108.0 ± 2.83 μS/cm and 63.00 ± 11.31 to 83.0 ± 8.49 mg/l, respectively. The experimental data best fit into Langmuir than Freundlich adsorption isotherm. The study concluded that MOSH activated carbon could serve as an adsorbent for the removal of THMs, calcium, and sulphur from water samples.


2021 ◽  
Vol 6 (7) ◽  
pp. 11-19
Author(s):  
Igbemi Arthur Igbemi ◽  
Ify L. Nwaogazie ◽  
Onyewuchi Akaranta ◽  
G. O. Abu

This study investigated the removal of Lead and Cadmium ions from aqueous solution using activated carbons from agricultural wastes. Activated carbons prepared by chemical activation using Phosphoric acid were characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The influence of contact time, initial concentration and adsorbent dose which governed the efficiency of the process was ascertained through batch adsorption studies. Adsorption isotherms were determined by correlating with Langmuir and Freundlich isotherms and the kinetic studies were correlated with pseudo first order and pseudo second order equations. The results showed that the amount of Lead and Cadmium adsorbed decreased as the adsorbent dose increased while the adsorption capacity increased with increased in contact time and initial concentration. Activated carbons prepared from Coconut shell and palm kernel (shell and cake) competed favorably with the commercial activated carbon in percentage removal of the metal ions as all the activated carbons had over 90 % removal within 60 minutes when 1g of adsorbent was used. The equilibrium data fitted best into Freundlich isotherms for both metal ions. The rate of adsorption could be described by pseudo second order for all the adsorbents except Coconut shell activated carbon in the adsorption of Lead while intra-particle diffusion was the limiting step for Cadmium adsorption. Therefore, the agricultural by-products can be used as effective, low-cost, and environmentally friendly adsorbents for domestic water treatment in many parts of the world.


2021 ◽  
Vol 06 (03) ◽  
Author(s):  
Nora Seghairi ◽  

Phosphates in natural waters and whatever their origin, promote the formation of algae, reduce dissolved oxygen and reduce biodiversity in aquatic ecosystems. At high doses, phosphate salts can cause health problems. The objective of our study was to develop a simple, efficient and environmentally friendly sorption depollution technique on available and inexpensive media. We have studied the adsorption of phosphate on activated carbons prepared from date kernels. Batch tests were carried out in order to study different operating parameters such as the effect of contact time, pH, initial phosphate concentration and adsorbent dosage and adsorption kinetic. The sorption equilibrium was analyzed by Langmuir, Freundlich isotherms model. Results show that the phosphate adsorption was reversible and the quantity adsorbed reached its maximum value (14.49 mg/g) after 40 minutes. It was also found that phosphate uptake was affected by variation of pH, initial concentration of phosphate and activated carbon dosage. The adsorption improved with an acidic pH (pH = 6), initial concentration and adsorbent dosage. The results of kinetic studies revealed that adsorption phosphate on activated carbon based on date kernels (Biocar) and the intra-particle diffusion involved in the adsorption mechanism. Also, isotherm study showed that Langmuir isotherm best fit the data and the adsorption was a physical type.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0,enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.


NANO ◽  
2019 ◽  
Vol 14 (02) ◽  
pp. 1950027
Author(s):  
Ziyan Yang ◽  
Xiaoli Yang ◽  
Rui Hu ◽  
Junfeng Wu

Many current sorbents are limited for U(VI) concentration from aqueous solutions due to their inappropriate structures and surface chemistry. Herein, we report the rapid sorption of U(VI) with high capacities and selectivity by amidoxime modified ordered mesoporous SBA-15 with two typical morphologies (i.e., rods and plates) via a post-grafting method. Variables of the geochemical conditions (contact time, pH value, initial concentration, temperature and coexisting metal ions) are investigated. The results show that the mesostructures including morphologies and pore length of SBA-15 perform the dominant function for the fast sorption kinetics (10[Formula: see text]min for plates, 20[Formula: see text]min for rods), while the modified amidoxime groups make the excellent U(VI) sorption capacities (646.2[Formula: see text]mg[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] for plates, 499.8[Formula: see text]mg[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] for rods at pH 5.0 and [Formula: see text] 298.15[Formula: see text]K) and high selectivity possible. U(VI) adsorbed amidoxime-functionalized SBA can also be effectively regenerated by HCl solutions and reused well after six cycles.


2013 ◽  
Vol 807-809 ◽  
pp. 1343-1346
Author(s):  
Yi Fan Li ◽  
Ying Liu ◽  
Hou Qi Liu ◽  
Li Li

The research used activated carbon fiber (ACF) as adsorbent to remove atrazine, a kind of herbicide. It set a series of static adsorption experiments under different solution temperature, pH value and initial concentration to get a optimum adsorption condition. The experiment shows that the optimum pH for the removal of atrazine is 7. The adsorption rate is highest at 20°C. The adsorption rate decreases while the initial concentration increases.


2014 ◽  
Vol 587-589 ◽  
pp. 616-619
Author(s):  
Zheng Wang ◽  
Dong Zhang ◽  
Ping Xia ◽  
Hui Ye ◽  
Wen Qi Zhou

The removal of geosmin by powered activated carbon (PAC) was studied at laboratory to select suitable PAC type and the removal efficiencies of geosmin by PAC in different application point as an emergency method were evaluated. The adsorption efficiency of coal-based PAC on geosmin was superior to that of bamboo-based PAC. The contact time and PAC dose were two important factors that affect the removal effect of geosmin. Geosmin could be controled below 10ng/L at 200ng/L of initial concentration.


2019 ◽  
Vol 14 (4) ◽  
pp. 897-907 ◽  
Author(s):  
Hosseinali Asgharnia ◽  
Hamidreza Nasehinia ◽  
Roohollah Rostami ◽  
Marziah Rahmani ◽  
Seyed Mahmoud Mehdinia

Abstract Phenol and its derivatives are organic pollutants with dangerous effects, such as poisoning, carcinogenicity, mutagenicity, and teratogenicity in humans and other organisms. In this study, the removal of phenol from aqueous solution by adsorption on silica and activated carbon of rice husk was investigated. In this regard, the effects of initial concentration of phenol, pH, dosage of the adsorbents, and contact time on the adsorption of phenol were investigated. The results showed that the maximum removal of phenol by rice husk silica (RHS) and rice husk activated carbon (RHAC) in the initial concentration of 1 mgL−1 phenol, 2 gL−1 adsorbent mass, 120 min contact time, and pH 5 (RHS) or pH 6 (RHAC) were obtained up to 91% and 97.88%, respectively. A significant correlation was also detected between increasing contact times and phenol removal for both adsorbents (p &lt; 0.01). The adsorption process for both of the adsorbents was also more compatible with the Langmuir isotherm. The results of this study showed that RHS and RHAC can be considered as natural and inexpensive adsorbents for water treatment.


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