Removal of hydrogen sulfide using palygorskite in a fixed bed adsorber

2012 ◽  
Vol 66 (8) ◽  
pp. 1794-1798
Author(s):  
T. Higuchi ◽  
Q. Zhang ◽  
M. Sekine ◽  
T. Imai ◽  
K. Yamamoto
Keyword(s):  
Hydrogen Sulfide ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Fixed Bed ◽  
High Specific Surface Area ◽  
Raw Material ◽  
H2s Adsorption ◽  
Silicate Clay ◽  
Efficient Adsorbent ◽  
Aluminium Silicate

This work describes the use of a novel palygorskite, a type of magnesium aluminium silicate clay possessing a high specific surface area and pore surface activity, as a low cost and highly efficient adsorbent for hydrogen sulfide (H2S) removal. Adsorption of H2S on palygorskite pretreated with acid or base was investigated in a fixed bed adsorber. The samples after base pretreatment had better dynamic adsorption performances than raw material and samples pretreated with acid. The H2S adsorption capacity decreased with an increase in inlet H2S concentration. This can be interpreted by the fact that H2S adsorption on the surface of palygorskite is chemisorption. The adsorption capacity increased from 25 to 50 °C, then decreased from 50 to 100 °C, which indicates that chemisorption took place and its better reaction temperature was around 50 °C.

Removal of VOCs Using Sludge-Based Adsorbents

2012 ◽  
Vol 599 ◽  
pp. 305-308 ◽  
Author(s):  
Ping Fang ◽  
Chao Ping Cen ◽  
Hong Tao Zhang ◽  
Zi Jun Tang ◽  
Ding Sheng Chen ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Physical Adsorption ◽  
Low Cost ◽  
Fixed Bed ◽  
Cost Effective ◽  
Langmuir Adsorption Isotherm ◽  
Fixed Bed Reactor ◽  
Dynamic Adsorption ◽  
Langmuir Adsorption ◽  
Isotherm Equations

Efficient and cost-effective sludge-based adsorbents were developed and the adsorption of VOCs on the sludge-based adsorbents was studied in a fixed bed reactor. The results indicate that the adsorption of VOCs on sludge-based adsorbents is typical physical adsorption, the dynamic adsorption capacity of VOCs on adsorbents sharply increases as the VOCs concentration is increased at first, then increasing gradually, at last retains stable with the change of VOCs concentration. The dynamic adsorption capacity of sludge-based adsorbents for VOCs is O-Xylene > Butylcetate > Toluene > Ethylacetate > Benzene > Propanone > n-Hexane, the maximum dynamic adsorption capacity is 0.247, 0.225, 0.192, 0.186, 0.180, 0.176, 0.133g/g, respectively. Meanwhile the adsorption of VOCs on sludge-based adsorbents corresponds to the Langmuir adsorption isotherm equations. The sludge-based adsorbent is a low-cost alternative to activated carbon for VOCs treatment, and this technology is a promising method for the VOCs removal.

scholarly journals H-Clinoptilolite as an Efficient and Low-Cost Adsorbent for Batch and Continuous Gallium Removal from Aqueous Solutions

2021 ◽  
Author(s):  
P. Sáez ◽  
A. Rodríguez ◽  
J. M. Gómez ◽  
C. Paramio ◽  
C. Fraile ◽  
...  
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Fixed Bed ◽  
Particle Size Effect ◽  
Breakthrough Curves ◽  
Maximum Adsorption Capacity ◽  
Fixed Bed Column ◽  
Gallium Concentration ◽  
Best Fit

AbstractIn this paper, the gallium (III) ions’ adsorption onto protonated clinoptilolite (H-CLP) was investigated both in batch and fixed-bed column experiments. Regarding batch experiments, the influence of some parameters such as adsorbent dosage, size particle, and temperature was studied, determining that a dosage of 10 g/L for an initial pollutant concentration of 40 mg/L leads to a removal percentage over 85% regardless of particle size and temperature. On the other hand, adsorption of gallium onto H-CPL is an endothermic and spontaneous process in the studied temperature range, concluding that the maximum adsorption capacity was 16 mg/g for 60 °C. Concerning to the effect of the presence of other cations in solution, such as Na+, K+, or Ca2+, gallium adsorption capacity only drops by 20%, although the initial concentration of other cations in the solution is 50 times higher than gallium concentration. This means that clinoptilolite has a high affinity for gallium which can be very favorable for further selectivity tests. A crucial factor for this high selectivity could be the protonation of clinoptilolite which allows working without modifying the pH of the aqueous solution with acid. In the fixed-bed experiments, breakthrough curves were obtained, and the effect of operation variables was determined. A breakpoint value of 254 min for 64 g of adsorbent and flow rate of 9.0 mL/min (7.0 BV/h) were obtained, when treating a pollutant volume of 33 BV. Additionally, the breakthrough curves were fitted to different models to study the particle size effect, being the best fit corresponding to the Adams–Bohart model. This fact confirmed the influence of particle size on adsorption kinetics. Graphical Abstract

Adsorption of Cadmium(II) Ion from Aqueous Solution onto a Raw Material of Bamboo Powder and its Surface Modification

2018 ◽  
Vol 879 ◽  
pp. 131-136 ◽  
Author(s):  
Woravith Chansuvarn ◽  
Yuttapoom Pandee ◽  
Ariya Saechim ◽  
Kritsana Habunmee
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Raw Material ◽  
Wastewater Sample ◽  
Adsorption Parameters ◽  
Freundlich Isotherms ◽  
Monolayer Adsorption ◽  
Adsorptive Behavior ◽  
Bamboo Powder

This work was focused on evaluating the potential of bamboo powder modified with manganese oxide (MnO-BP) as a low-cost byproduct adsorbent for the adsorption of cadmium(II) ion. A batch method was carried out at room temperature and the optimized conditions. The optimization of adsorption parameters including pH, equilibrium time, dosage and initial Cd(II) concentration was also systematically studied for the removal of cadmium(II) ion. The maximum monolayer adsorption capacity of MnO-BP was estimated as 8.57 mg/g that it more adsorption capacity than untreated-bamboo powder by about 5 times. The Langmuir and the Freundlich isotherms were used to describe the adsorptive mechanism and calculated the maximum monolayer adsorption capacity. It was found that the data from MnO-BP fitted well to the Freundlich isotherm with R2>0.99. It indicated that the adsorptive behavior of MnO-BP to cadmium(II) ion is preferable. In this work, MnO-BP was used for the removal of cadmium(II) ion in wastewater sample. The MnO-BP is a low-cost adsorbent that can be used to remove cadmium(II) effectively.

Synthesis and Characterization of Carbon/Bentonite Composite

2012 ◽  
Vol 549 ◽  
pp. 703-706
Author(s):  
De Yi Zhang ◽  
Jing Wu ◽  
Bai Yi Chen ◽  
He Ming Luo ◽  
Kun Jie Wang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Heavy Metal Ions ◽  
Low Cost ◽  
Raw Material ◽  
Hydroxyl Groups ◽  
Carbon Particles ◽  
Prepared Composite

In this paper, a novel carbon/bentonite composite was prepared using sucrose as carbon source and bentonite as raw material. The characterization results shown that plenty of carbon particles distribute on the surface of the composite, and an abundant of functional groups, such as SO3H, carboxylic and hydroxyl groups, were successfully introduced onto the surface of the prepared composite. The adsorption capacity of the prepared composite for typical heavy metal ions and methylene blue deys also was investigated and compared with activated carbon and bentonite, the results show that the composite shows excellent adsorprion performance for heavy metal ions, and the adsorption capacity for Cu2+and Ni2+ increase by 136% and 591% than natural bentonite, respectSuperscript textively. The prepared composite with excellent adsorption performance could be used as a low-cost alternative to activated carbon for the treatment of heavy metal ions polluted wastewater.

Preparation of Calcium Silicate Using Hazardous Solid Wastes and its Application in Treatment of Phosphate-Containing Wastewater

2014 ◽  
Vol 937 ◽  
pp. 652-658
Author(s):  
Xin Hua Zhu ◽  
Zhao Zhang ◽  
Jun Shen
Keyword(s):  
Adsorption Capacity ◽  
Calcium Silicate ◽  
Hydrated Lime ◽  
High Specific Surface Area ◽  
Raw Material ◽  
Molar Ratio ◽  
Residual Concentration ◽  
P Adsorption ◽  
Preparation Conditions ◽  
Silicate Sample

The silica, one of the by-products of fluorine industry, contains soluble fluoride which is harmful to the environment. Therefore, a study on fixing soluble fluoride was conducted by hydrothermal method with the silica as raw material and adding hydrated lime (HL), and the nanowires-reticulated calcium silicate with high specific surface area up to 143.8m2/g was prepared at the same time. The prepared calcium silicate was used as adsorbent in the experiments of phosphorus (P) adsorption from aqueous solution, the adsorption capacity, adsorption rate and P removability were characterized. The results show that the preparation conditions affect distinctly the adsorption performances of calcium silicate, especially, the dosage Ca/Si molar ratio. For the optimized calcium silicate sample, the total P adsorption capacity is 125.7mg/g and the exchange rate of Ca2+reaches 95.8%, the P residual concentration is only 0.3mg/L, the saturated adsorption time is 3900 min, when the simulation solution with P concentration of 100 mg/L is treated. The P residual concentration is only 0.1mg/L for the simulation solution of 56.12mg/L.

scholarly journals Performane of Activated Carbon Adsorption in Removing of Organic Pollutants from River Water

2018 ◽  
Vol 7 (4.20) ◽  
pp. 356 ◽  
Author(s):  
Iqbal Khalaf Erabee ◽  
Saleem M. Ethaib
Keyword(s):  
Activated Carbon ◽  
River Water ◽  
Low Cost ◽  
Fixed Bed ◽  
Oxygen Demand ◽  
Total Suspended Solid ◽  
Raw Material ◽  
Activated Carbon Adsorption ◽  
Removal Efficiencies ◽  
Date Pits

This study presents a water treatment process by using a down-flow fixed bed activated carbon contractor model. Two types of activated carbon (AC) used,  powder and granular activated carbon from date pits as a raw material, the parameters tested are biochemical oxygen demand (BOD),  chemical oxygen demand (COD), total suspended solid (TSS), total dissolved solid (TDS) and pH. The column  diameter and bed depths are made constant, whereas the size of activated carbon is varies. The obtained removal efficiencies for sample of river water are 39.8% of BOD, 41.8% of  COD, 81.8% of TSS  and 67.7% of TDS for granular AC. For powdered AC the removal efficiencies of parameters are 34.7% of BOD, 17.6% of COD, 72.7% of TSS and 50% of TDS. The granular AC made from date pits is the best activated carbon because of low cost of raw material and it is widely applied for usage in the water or wastewater treatment, as it is very effective in terms of cost and performance to cater the increasing demand of clean water.  

scholarly journals Removal of Cd(II) from Water by HPEI Modified Humin

2020 ◽  
Vol 12 (19) ◽  
pp. 7931
Author(s):  
Sanmei Li ◽  
Mingda Wu ◽  
Linghong Lu ◽  
Jiabao Zhu
Keyword(s):  
Humic Acid ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Raw Material ◽  
Flame Atomic Absorption Spectroscopy ◽  
X Ray ◽  
Adsorption Performance ◽  
Flame Atomic Absorption ◽  
Weathered Coal ◽  
Cost Treatment

Humin is the waste residue from the process of preparing humic acid, which accounts for a large proportion of the raw material (weathered coal humic acid). Its Cd(II) adsorption performance is far inferior to that of humic acid. How to regenerate humin is of great significance to the low-cost treatment of Cd(II) pollution in wastewater. In this study, humin was modified by hyperbranched polyethyleneimine to enhance the adsorption capacity for Cd(II). Fourier transform infrared spectroscopy and the X-ray photoelectron spectrometer showed that hyperbranched polyethyleneimine was grafted to the surface of humin. Flame atomic absorption spectroscopy showed that the saturated Cd(II) adsorption capacity of the modified humin was increased to 11.975 mg/g, which is about 5 times than that of humin and is also higher than that of humic acid. The adsorption kinetics, adsorption isotherm, and thermodynamic properties of humic acid, humin, and modified humin were also studied. This study may provide a foundation for research utilizing natural resources to reduce heavy metal pollution in the environment.

scholarly journals Characterization and modification of natural clay deposits to develop clay-based adsorbent to remove phosphorus from contaminated water

2021 ◽  
Author(s):  
◽  
Farzana Nargis
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Continuous Process ◽  
Fixed Bed ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Natural Clay ◽  
Phosphorus Adsorption ◽  
Modified Clay ◽  
Clay Deposits

Modification of natural clays may be a useful approach to produce an effective and low-cost adsorbent to control phosphorous, which is a key factor in controlling the eutrophication of surface waters. In this study, natural clay samples were collected, characterized, modified with ZrCl4, and then their adsorption capacity for removing phosphorus from contaminated water was studied. XRD analysis showed that the natural clay consists of kaolinite, illite, and nontronite as dominant clay mineral phases. The maximum adsorption capacity of the modified clay increased from 0.493 to 11.83 mg P/g compared to the unmodified clay. The adsorption process was fast for both natural and modified samples, achieving more than 80% and 90% phosphorus removal with natural and modified samples, respectively in less than 4 hours. The adsorption data for both clays best fit the Langmuir isotherm, and the rate of phosphorus adsorption was found to follow a pseudo-secondorder kinetic model. The adsorption capacity of both adsorbents decreased with increasing pH, and for the modified clay the change was more significant. Full factorial design and response surface methodology were applied to evaluate and optimize the effects of initial P concentration, contact time, pH, and dose. From the model, the maximum P removal efficiency predicted for the synthetic solution was 91.5% and 99.9% by natural and modified clay, respectively. R2(≈0.98) indicates that the observed results fitted well with the model prediction. Similar to the batch studies, the fixed bed column study showed the developed adsorbents are efficient in removing phosphorus from water in a continuous process as well.

scholarly journals Facial Synthesis of Adsorbent from Hemicelluloses for Cr(VI) Adsorption

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1443
Author(s):  
Yi Wei ◽  
Wei Chen ◽  
Chuanfu Liu ◽  
Huihui Wang
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Waste Water Treatment ◽  
Ammonia Solution ◽  
Langmuir Model ◽  
Raw Material ◽  
Maximum Adsorption Capacity ◽  
Chemical Fiber

It is challenging work to develop a low-cost, efficient, and environmentally friendly Cr(VI) adsorbent for waste water treatment. In this paper, we used hemicelluloses from chemical fiber factory waste as the raw material, and prepared two kinds of carbon materials by the green hydrothermal method as adsorbent for Cr(VI). The results showed that hemicelluloses hydrothermally treated with citric acid (HTC) presented spherical shapes, and hemicelluloses hydrothermally treated with ammonia solution (HTC-NH2) provided spongy structures. The adsorption capacity of the samples can be obtained by the Langmuir model, and the adsorption kinetics could be described by the pseudo-second-order model at pH 1.0. The maximum adsorption capacity of HTC-NH2 in the Langmuir model is 74.60 mg/g, much higher than that of HTC (61.25 mg/g). The green hydrothermal treatment of biomass with ammonia solution will provide a simple and feasible way to prepare adsorbent for Cr(VI) in waste water treatment.

scholarly journals Removal of Copper from Mining Wastewater Using Natural Raw Material—Comparative Study between the Synthetic and Natural Wastewater Samples

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 753
Author(s):  
Sonja Milićević ◽  
Milica Vlahović ◽  
Milan Kragović ◽  
Sanja Martinović ◽  
Vladan Milošević ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Natural Zeolite ◽  
Fixed Bed ◽  
Raw Material ◽  
Copper Removal ◽  
Maximum Adsorption Capacity ◽  
High Concentration ◽  
Saturation Point ◽  
Synthetic Solution ◽  
Flow Through

The intent in this paper is to define how the batch equilibrium results of copper removal from a synthetic solution on natural zeolite can be used for prediction of the breakthrough curves in the fixed-bed system for both a synthetic solution and wastewater. Natural zeolite from the Vranjska Banja deposit, Serbia, has been fully characterized (XRD, chemical composition, DTA/TG, SEM/EDS) as a clinoptilolite with cation exchange capacity of 146 meq/100 g. The maximum adsorption capacity (qm) in the batch of the mono-component system (synthetic copper solution) obtained using the Langmuir isotherm model was 7.30 and 6.10 mg/g for particle size below 0.043 and 0.6–0.8 mm, respectively. Using the flow-through system with the 0.6–0.8 mm zeolite fixed-bed, almost double the adsorption capacity (11.2–12.2 mg/g) has been achieved in a saturation point for the copper removal from the synthetic solution, compared to the batch. Better results are attributed to the constant high concentration gradient in flow-through systems compared to the batch. The complex composition of wastewater and large amounts of earth alkaline metals disturb free adsorption sights on the zeolite surface. This results in a less effective adsorption in flow-through systems with adsorption capacity in breakthrough point of 5.84 mg/g (~0.95 × qm) and in a saturation point of 7.10 mg/g (~1.15 × qm).

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