scholarly journals Effect of limestone and dolomite tailings’ particle size on potentially toxic elements adsorption

2018 ◽  
Vol 10 (1) ◽  
pp. 726-739
Author(s):  
Sofia Farmaki ◽  
Eleni Vorrisi ◽  
Olga K. Karakasi ◽  
Angeliki Moutsatsou
Keyword(s):  
Particle Size ◽  
Taguchi Method ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Toxic Elements ◽  
Fixed Bed ◽  
Solution Concentration ◽  
Potentially Toxic Elements ◽  
Batch Experiments ◽  
Rock Particle

Abstract The aim of the study is the investigation of potentially toxic elements adsorption on limestone, dolomite and marble particles of different size. As parameters, rock particle size, solution concentration, contact time and presence of other elements in the solution have been investigated. Four fractions with different particle size (−4mm + 1mm, −1mm + 315μm, −315μm + 90μm, <90μm) have been studied. Batch experiments have been carried out at 20, 60, 120 min from monoelement and competitive Cd, Cu, Pb, Zn solutions at concentrations 5, 100, 500 mg/L, whereas fixed bed conditions have also been applied. In lower concentrations, adsorption reaches equilibrium after 60 min. 15% difference in Pb adsorption and 15-30% in Zn adsorption has been observed depending on particle size. However, according to Taguchi method particle size has not proven a determinative parameter, so as to make grinding and/or sieving necessary for their further utilisation. Cd and Zn adsorption from a competitive solution is lower, whereas Cu and Pb adsorption is similar. Adsorption capacity of materials rises up to 0.03 mg Cd/g, 0.60 mg Cu/g, 0.03 mg Pb/g, 0.60 mg Zn/g. In fixed bed conditions more than 93% element is adsorbed, of which only 4% is leached.

scholarly journals The Novel Use of Saraca thaipingensis Leaf Powder as Potential Biosorbent Material for the Removal of Chromium(VI)

2015 ◽  
Vol 3 (3) ◽  
pp. 35-39
Author(s):  
Sannasi Palsan ◽  
Chai Swee Fern ◽  
Stephanie Bernardine ◽  
Lim Fan Shiang
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Contact Time ◽  
Low Cost ◽  
Peninsular Malaysia ◽  
The Novel ◽  
Batch Experiments ◽  
Chromium Vi ◽  
Removal Of Heavy Metals ◽  
Leaf Powder

Saraca thaipingensis or ‘Gapis’ tree, classified under the Fabaceae family is a native of Taiping; copious over Peninsular Malaysia and Southeast Asia. The withered and fallen dead leaves were collected from INTI International University’s garden walkway. To date, literature has yet to capture the use of S. thaipingensis tree parts or refuse as potential biosorbent material for the removal of heavy metals thus verifying the novelty of this study. Batch experiments were carried out with the leaf powder to study the effects of dosage, particle size and contact time towards Cr(VI) removal (%) at 1-100 mg/L. Results showed that Cr(VI) removal increased from 52.22% to 99.31% (p < 0.05) with increase in biosorbent dosage (0.005, 0.010, 0.015, 0.020, 0.025 and 0.050 g). The different particle size ranges tested were: 107-125, 126-150, 151-250, 251-500, and 501- 1000 ?m. Highest Cr(VI) removal of 99.53% was obtained with the 151-250 ?m particle size; further size decrease did not yield more removal (p > 0.05). The optimal Cr(VI) removal was recorded after 45 min (99.62%) and 90 min (99.76%) contact time (p > 0.05). Further characterization and optimization studies are being carried out to develop a novel, sustainable, low cost yet effective leaf powder based biosorbent material.

Ammonium nitrogen removal from anaerobically digested effluent of swine wastewater using local sand

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
D. Zheng ◽  
L.W. Deng ◽  
N.N. Liu ◽  
H. Yang ◽  
Y. Liu
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Nitrogen Removal ◽  
Contact Time ◽  
Ammonium Nitrogen ◽  
Langmuir Equation ◽  
Swine Wastewater ◽  
Ammonium Concentration ◽  
High Adsorption ◽  
Removal Capacity

A type of sand selected in Sichuan, China was identified with high adsorption capacity to ammonium nitrogen. The effects of contact time, initial ammonium concentration and particle size on the sand for removing ammonium from digested effluent of swine wastewater were investigated using a static shaker experiment. Results showed that the optimum contact time for sand to adsorb ammonium was 150 min. As initial ammonium concentration increased, the removal capacity of the sand increased, but the removal efficiency decreased. The adsorbed ammonium increased as the particle size decreased. At ammonium concentrations ranging from 27 0 to 553 mg L-1, the maximum ammonium adsorption capacity of the sand was approximately 0 77 mg g-1 according to the Langmuir equation. Based on these findings, the use of this local sand as an adsorption media for ammonium nitrogen removal from digested effluent of swine wastewater is feasible.

Optimization of the Adsorption Process of Bezaktiv Turquoise Blue «VG» Textile Dye onto Diatomite Using the Taguchi Method

2018 ◽  
Vol 762 ◽  
pp. 81-86 ◽  
Author(s):  
Hakim Aguedal ◽  
Abdelkader Iddou ◽  
Janis Locs
Keyword(s):  
Taguchi Method ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Removal Rate ◽  
Textile Dye ◽  
Adsorption Parameters ◽  
Thermal Regeneration ◽  
Factors Affecting ◽  
Relevant Factors

A design of experiments based on the Taguchi method was used to evaluate the main parameters affecting the removal of textile dyes from aqueous solution. By using the adsorption capacity of textile dye as target response, several experiments were carried out using L27 orthogonal array, and the higher-the-better as quality characteristics was applied. The controlling factors, including initial dye concentration, contact time and pH of solution were assessed. Analysis of variance (ANOVA) was used to determine the effects of each factor on the adsorption capacity. The optimum adsorption conditions giving higher adsorption capacity were selected as initial dye concentration of 500 mg.L-1, contact time of 180 min and pH of solution of 2. The analysis results revealed that the most relevant factors affecting the adsorption process of textile dye are the initial dye concentration and pH of solution. After 3 cycles of thermal regeneration, the diatomite behavior did not change and more than 60 % of dye was eliminated from solution after regeneration at 600°C. From the obtained results, the Taguchi method was very successful to optimize of the adsorption parameters for maximum removal rate, and gives more credibility for industrial application.

scholarly journals Removal of Fluoride Ion from Water Using locally Produced Adsorbent

2019 ◽  
Vol 4 (12) ◽  
pp. 78-85
Author(s):  
Aboiyaa A. Ekine ◽  
Patience N. Ikenyiri ◽  
O. Hezekiah-Braye
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Intraparticle Diffusion ◽  
Fluoride Ion ◽  
First Order ◽  
Egg Shells ◽  
Pseudo Second Order ◽  
Pseudo First Order

This Research investigated the adsorption capacity of locally prepared adsorbents from Egg shells for the removal of fluoride ion in well water. It evaluated the performance of these adsorbents calcinated at 3000C and modified with 1.0M HNO3 (trioxonitrate (v)) acid. Batch adsorber was used to allow for interaction between adsorbent (grounded Egg shells) with water containing fluoride ion. The batch experiment was performed with particle size of 2.12 contact time (60, 120, 180, 240, 300min), mass dosage (5g, 10g, 15g, 20g) and temperature (250C, 300C, 400C, 500C). The modified adsorbent was characterized to determine the physiochemical properties of grounded Egg shells (GE). Also the chemical composition of the modified adsorbent was analyzed to determine the percentage of calcium element required for the uptake of the fluoride ions in water for calcium as 39.68% for grounded Egg shells (GE). Percentage adsorption increased with increase in contact time, mass dosage and temperature for the adsorbent. The adsorption capacity was also determined which also increased with increase in contact time, temperature but decreased with increase in mass dosage at constant time of 60minutes. The pseudo first-order, pseudo second order and intraparticle diffusion kinetic models were fitted into the experimental results. The results obtained indicated that the pseudo first order and intraparticle diffusion models for the grounded Egg shells (GE) reasonably described the adsorption process very well whereas the pseudo second order model was not suitable for a calcinations temperature of 3000C and particle size of 2.12m. The adsorption isotherms were obtained from equilibrium experiment Performed at temperature of 25, 35, 45 and 550C. The result showed that Langmuir and Freundlich isotherm fitted perfectly the experimental data. However, the negative values of Gibb’s free energy indicated that adsorption was favourable and the positive enthalpy change H0 revealed that adsorption process was endothermic while the positive value of the entropy change signified increased randomness with adsorption.

scholarly journals ISOTERM ADSORPSI FENOL OLEH LEMPUNG ALAM

2019 ◽  
Vol 7 (1) ◽  
pp. 029
Author(s):  
Nelly Wahyuni ◽  
Imelda H. Silalahi ◽  
Dina Angelina
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Langmuir Adsorption Isotherm ◽  
Batch Experiments ◽  
Natural Clay ◽  
Langmuir Adsorption ◽  
Equilibrium Data ◽  
Initial Phenol Concentration

Abstrak Fenol merupakan polutan yang sangat berbahaya di lingkungan karena bersifat racun dan sulit terdegradasi oleh organisme pengurai. Lempung alam yang berasal dari Kecamatan Capkala, Kabupaten Bengkayang  akan dikaji penggunaannya sebagai adsorben fenol. Adsorpsi dilakukan dengan metoda batch pada variasi waktu kontal dan konsentrasi awal fenol. Data kesetimbangan adsorpsi diuji dengan isoterm Langmuir dan Freundlich. Hasil penelitian menunjukkan waktu kontak optimum adsorpsi adalah 4 jam. Proses adsorpsi fenol  oleh lempung alam  mengikuti model isoterm adsorpsi Langmuir dengan kapasitas adsorpsi sebesar 0,65mg/g. Kata Kunci: fenol, Freundlich, isoterm adsorpsi, Langmuir, lempung alamAbstract Phenol is a pollutant that is very dangerous in the environment because it is toxic and difficult to degrade by decomposing organisms. Natural clay from Capkala District, Bengkayang Regency will be studied as phenol adsorbent. Batch experiments were carried out by varying the parameters like contact time of adsorption and initial phenol concentration. The equilibrium data were tested with Langmuir and Freundlich isotherm. The results showed that the optimum contact time for adsorption was 4 hours. The process of adsorption of phenol by natural clay follows the Langmuir adsorption isotherm model with an adsorption capacity of 0.65mg/g.  Keywords: adsorption isotherm, Freundlich, natural clay, phenol, Langmuir.

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

scholarly journals Preliminary Evaluation of Potassium Extraction from Bamboo Ash

2018 ◽  
Vol 156 ◽  
pp. 03027
Author(s):  
Tjokorde W. Samadhi ◽  
Febrizca Narcia ◽  
Hendro Amril
Keyword(s):  
Contact Time ◽  
Fixed Bed ◽  
Solution Concentration ◽  
Extraction Process ◽  
Thermal Conversion ◽  
Contact Period ◽  
Preliminary Evaluation ◽  
High Potassium ◽  
Counter Current

Bamboo is a potentially economical fuel crop that has not been utilized at a substantial extent for energy generation in Indonesia. As a thermal conversion waste, bamboo ash is particularly interesting due to its high potassium content. This paper discusses the determination of several key parameters of a simple batchwise extraction process to recover potassium in the form of weak solution from bamboo ash. To produce the ash, black bamboo (Gigantochloa atroviolaceae) is charred in a fixed bed combustor. The bamboo char is ground and ashed at 500 °C in an electric furnace. The ash yield is 3.3 %-mass relative to as-received ash, with an ash K2O content of 12.9 %-mass. The ash is ground until passing 100-mesh standard sieve, and extracted by deionized water on a 2-stage laboratory-scale batchwise extractor battery. Process variables include extractror battery configuration (counter-current and co-current), temperature (nominal setting at 45-80 °C), and contact period of 1-6 hours. The concentration of extracted K2O increases asymptotically with temperature and contact time. Counter-current extraction yields more than twice the extract K2O concentration compared to cross-current extraction. The optimum conditions for the counter-current extraction is identified as a temperature of 78 °C and contact time of 4 hours, resulting in a 0.70 %-mass K2O solution concentration. Spot sampling of commercial liquid fertilizer products in Indonesia indicates an equivalent K2O content of 0.08-13.6 %-mass, suggesting the potential of the bamboo ash extract as an intermediate for fertilizer product.

scholarly journals Surficial geochemistry and bioaccessibility of tellurium in semiarid mine tailings

2019 ◽  
Vol 16 (4) ◽  
pp. 251 ◽  
Author(s):  
Sarah M. Hayes ◽  
Nicole A. Ramos
Keyword(s):  
Particle Size ◽  
Mine Tailings ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Health Concern ◽  
Mining District ◽  
Critical Element ◽  
Preliminary Assessment ◽  
High Degree ◽  
X Ray Absorption

Environmental contextTellurium can be more toxic than arsenic, but its fate in the surficial environment is poorly understood. We studied tellurium behaviour in semiarid mine tailings and found that most tellurium is associated with iron (oxy)hydroxides as tellurate (TeVI), the less toxic oxidation state. Iron (oxy)hydroxides are likely to control the fate of Te in the surficial environment and may effectively sequester Te oxyanions released by oxidative weathering. AbstractTellurium (Te) is a critical element owing to its use in solar technology. However, some forms are highly toxic. Few studies have examined Te behaviour in the surficial environment, thus little is known about its potential human and environmental health impacts. This study characterises two physicochemically distinct Te-enriched mine tailings piles (big and flat tailings) deposited by historic gold (Au) mining in the semiarid Delamar mining district, Nevada, USA. The big tailings are characterised by smaller particle size and higher concentrations of potentially toxic elements (up to 290mgTekg−1), which are enriched at the tailings surface. In contrast, the flat tailings have larger particle size and properties that are relatively invariant with depth. Based on the sulfate to sulfide ratio, the tailings were determined to be sulfate dominated, which suggested a high degree of weathering, although the flat tailings did contain significant amounts of sulfides (~40%). Tellurium X-ray absorption spectroscopy of the big tailings indicates that tellurate, the less toxic Te species, is the principal form of Te. Electron microscopy indicates that most of the Te present at the site is associated with iron (oxy)hydroxides, and sometimes with other potentially toxic elements, especially lead and antimony. Physiologically-based extraction tests indicate that substantially more Te is solubilised in synthetic stomach fluids than in lung fluids, with gastric bioaccessibility ranging from 13 to 31% of total Te. This points to low to medium bioaccessibility, which is common for iron (oxy)hydroxide-associated elements. Together, these results represent a preliminary assessment of Te surficial behaviour in a semiarid environment and indicate that Te in these tailings represent a moderate health concern.

Removal of β-Naphthalenesulfonic Acid from Aqueous Solution Using Modified Resin

2012 ◽  
Vol 518-523 ◽  
pp. 2740-2744
Author(s):  
Ying Li ◽  
Chang Hai Li ◽  
Dong Mei Jia ◽  
Yue Jin Li
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Acid Concentration ◽  
Ferric Oxide ◽  
Contact Time ◽  
Equilibrium Adsorption ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Hydrated Ferric Oxide ◽  
Modified Resin

A newly modified resin can be impregnated with hydrated ferric oxide on the base of D301 resin. The article involved batch experiments to investigate the effect of concentration, contact time, pH and temperature. The results showed that the maximum adsorption was found at 6 h,3.0 pH and 298 K temperature. The maximum adsorption capacity was 961.95 mg/g at 1200 mg/L initial β-naphthalenesulfonic acid concentration. The equilibrium adsorption was fitted by Temkin isotherm.

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