scholarly journals Enhanced Selenate Removal in Aqueous Phase by Copper-Coated Activated Carbon

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 468
Author(s):  
Xinhai Zhao ◽  
Aiqing Zhang ◽  
Jianhong Zhang ◽  
Qipeng Wang ◽  
Xuquan Huang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Zeta Potential ◽  
Copper Ion ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Outer Sphere ◽  
Low Salinity ◽  
Adsorption Data ◽  
Salinity Water ◽  
Zeta Potential Analysis

In this study, we prepared a novel sorbent derived from precipitating copper ion onto the surfaces of activated carbon (Cu-AC). The sorbents were comprehensively characterized by Brunauer–Emmett–Teller (BET), zeta potential analysis, SEM, XRD, and FTIR. Batch experiments were conducted to evaluate selenate removal by Cu-AC under different conditions. The results showed that Cu was uniformly coated on the AC surface. Copper pretreatment markedly decreased the specific surface area and total pore volume of AC, and changed its surface zeta potential from highly negative to low negative and even positive. The Cu-AC substantially improved selenate adsorption capacity from the 1.36 mg Se/g AC of raw AC to 3.32, 3.56, 4.23, and 4.48 mg Se/g AC after loading of 0.1, 0.5, 1.0, and 5 mmol Cu/g AC, respectively. The results of toxicity leaching test showed AC coated with ≤1.0 mmol Cu/g was acceptable for potential application. Selenate adsorption was significantly inhibited by high ionic strength (>50 mM NaCl) and pH (>10). The electrostatic attraction between positive surface charge of Cu-AC and selenate ions and hydrogen bonding between CuO and HSeO4− might contribute to selenate sorption. Evidence showed that the selenate adsorption might involve outer-sphere surface complexation. The adsorption data appeared to be better described by Langmuir than Freundlich isotherm. The spent adsorbent could be effectively regenerated by hydroxide for reuse. Only a little decrease of removal efficiency was observed in the second and third run. This study implies that Cu-coated AC is a potential adsorbent for sustainable removal selenate from relative low salinity water/wastewater.

A Comparison of Different Nanoparticles' Effect on Fine Migration by Low Salinity Water Injection for Oil Recovery: Introducing an Optimum Condition

2021 ◽  
pp. 1-22 ◽  
Author(s):  
Ali Madadizadeh ◽  
Alireza Sadeghein ◽  
Siavash Riahi
Keyword(s):  
Porous Media ◽  
Zeta Potential ◽  
Oil Recovery ◽  
Fine Particles ◽  
Production Equipment ◽  
Water Flooding ◽  
Sand Production ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water

Abstract Today, enhance oil recovery (EOR) methods are attracting more attention to increase the petroleum production rate. Some EOR methods such as low salinity water flooding (LSW) can increase the amount of fine migration and sand production in sandstone reservoirs which causes a reduction in permeability and inflict damages on to the reservoir and the production equipment. One of the methods to control fine migration is using nanotechnology. Nanoparticles (NPs) can reduce fine migration by various mechanisms such as reducing the zeta potential of fine particles' surfaces. In this paper, three NPs including SiO2, MgO, and Al2O3 's effects on controlling fine migration and sand production were investigated in two scenarios of pre-flush and co-injection by using sandpack as a porous media sample. When NPs are injected into the porous media sample, the outflow turbidity and zeta potential of particles decreases. Experiments showed that SiO2 has the best effect on controlling fine migration in comparison with other NPs and it could reduce fine migration 69% in pre-flush and 75% in co-injection. Also, MgO and Al2O3 decreased fine migration 65% and 33% in the pre-flush scenario and 49%,13% in the co-injection scenario, respectively.

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

SPE Journal ◽  
2015 ◽  
Vol 20 (03) ◽  
pp. 483-495 ◽  
Author(s):  
M. A. Mahmoud ◽  
K. Z. Abdelgawad
Keyword(s):  
Zeta Potential ◽  
Oil Recovery ◽  
Chelating Agents ◽  
Water Injection ◽  
Chelating Agent ◽  
Carbonate Reservoirs ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water ◽  
Core Permeability

Summary Recently low-salinity waterflooding was introduced as an effective enhanced-oil-recovery (EOR) method in sandstone and carbonate reservoirs. The recovery mechanisms that use low-salinity-water injection are still debatable. The suggested possible mechanisms are: wettability alteration, interfacial-tension (IFT) reduction, multi-ion exchange, and rock dissolution. In this paper, we introduce a new chemical EOR method for sandstone and carbonate reservoirs that will give better recovery than the low-salinity-water injection without treating or diluting seawater. In this study, we introduce a new chemical EOR method that uses chelating agents such as ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA) at high pH values. This is the first time for use of chelating agents as standalone EOR fluids. Coreflood experiments, interfacial and surface tensions, and zeta-potential measurements are performed with DTPA, EDTA, and HEDTA chelating agents. The chelating-agent concentrations used in the study were prepared by diluting the initial concentration of 40 wt% with seawater and injecting it into Berea-sandstone and Indiana-limestone cores of a 6-in. length and a 1.5-in. diameter saturated with crude oil. The coreflooding experiments were performed at 100°C and a 1,000-psi backpressure. Low-salinity-water and seawater injections caused damage to the reservoir because of the calcium sulfate scale deposition during the flooding process. The newly introduced EOR method did not cause calcium sulfate precipitation, and the core permeability was not affected. The core permeability was measured after the flooding process, and the final permeability was higher than the initial permeability in the case of chelating-agent injection. The coreflooding effluent was analyzed for cations with the inductively coupled plasma (ICP) spectroscopy to explain the dissolution-recovery mechanism. The effect of iron minerals on the rock-surface charge was investigated through the measurements of zeta potential for different rocks containing different iron minerals. HEDTA and EDTA chelating agents at 5 wt% concentration prepared in seawater were able to recover more than 20% oil from the initial oil in place from sandstone and carbonate cores. ICP measurements supported the rock-dissolution mechanism because the calcium, magnesium, and iron concentrations in the effluent samples were more than those in the injected fluids. The IFT-reduction mechanism was confirmed by the low IFT values obtained in the case of chelating agents. The type and concentration of chelating agents affected the IFT value. Higher concentrations yielded lower IFT values because of the increase in carboxylic-group concentration. We found that the high-pH chelating agents increased the negative value of zeta potential, which will change the rock toward more water-wet.

scholarly journals Adsorption of binary mixtures of sodium hexadecyl sulfate and ethoxylated octylphenols from aqueous solutions at activated carbon

2019 ◽  
Vol 7 (2) ◽  
pp. 88-95
Author(s):  
Victor Maksin ◽  
Olga Kochkodan ◽  
Lidiya Kovshun
Keyword(s):  
Activated Carbon ◽  
Zeta Potential ◽  
Aqueous Solutions ◽  
Binary Mixtures ◽  
Surface Activity ◽  
Carbon Particles ◽  
Adsorption Data ◽  
Activated Carbon Particles ◽  
Ethoxylated Octylphenols ◽  
Ratio Of Components

Adsorption of binary mixtures of sodium hexadecyl sulfate and oxyethylated octylphenols surfactants from aqueous solutions at activated carbon AG-3 was studied. It is found that the process of mixed adsorption depends on total surfactants concentration in the mixture, the ratio of components in the mixture and their surface activity. Adsorption data is confirmed by measurements of the zeta potential values of activated carbon particles in the surfactants mixtures.

scholarly journals Chitosan-based activated carbon as economic and efficient sustainable material for capacitive deionization of low salinity water

RSC Advances ◽  
2019 ◽  
Vol 9 (46) ◽  
pp. 26676-26684 ◽  
Author(s):  
Qinghao Wu ◽  
Dawei Liang ◽  
Xiumei Ma ◽  
Shanfu Lu ◽  
Yan Xiang
Keyword(s):  
Activated Carbon ◽  
High Performance ◽  
Capacitive Deionization ◽  
Sustainable Material ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water

Chitosan was selected as a carbonaceous precursor to prepare high-performance chitosan-based activated carbon (CTS-AC) for CDI electrode.

scholarly journals Activated carbon from mustard stalk biomass: Synthesis, characterization and application in wastewater treatment

2021 ◽  
pp. 10-10
Author(s):  
Kalpana Patidar ◽  
Manish Vashishtha
Keyword(s):  
Activated Carbon ◽  
Chemical Activation ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Isotherm Study ◽  
Adsorption Rates

Present work is focused on the preparation of mustard stalk activated carbon (MSAC) using chemical activation with H3PO4 and exploring its properties for its use in dye removal from wastewater. Adsorption variable (dosage, contact time, and solution pH), pore structure, morphology, surface functional groups, equilibrium kinetics, and isotherm study for removal of methylene blue (MB) using MSAC were investigated. The present study showed that an adsorption dosage of 0.2 g L-1 and pH 8 can be considered as optimum for the MB removal. SEM result showed that pore of MSAC was larger than the pore of the mustard stalk (MS). BET surface area and total pore volume of MSAC were found as 510 m2 g-1 and 0.33 cm3 g-1, respectively. Equilibrium adsorption data were examined by Langmuir and Freundlich isotherm models. Better correspondence to the Langmuir model with a maximum adsorption capacity of 212.76 mg g-1 (MB onto MSAC) was obtained. Dimensionless factor, RL revealed favourable nature of the sorption in the MSAC - MB system. Adsorption rates were found to conform to the pseudo-second-order kinetics with good correlation. These results show that the MSAC could be used as a renewable and economical alternative to commercial AC in the removal of MB dye from wastewater.

scholarly journals Adsorption feasibility in the cr(total) ions removal from waste printing developer

2013 ◽  
Vol 14 (1) ◽  
pp. 18-23
Keyword(s):  
Activated Carbon ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Experimental Tests ◽  
Batch Mode ◽  
Technical Feasibility ◽  
Good Efficiency ◽  
Adsorption Capacities ◽  
Adsorption Data

In this article, the technical feasibility of various commercial adsorbents (activated carbon, clinoptilolite, and their mixture) for removal of Cr(total) ions from waste printing developer has been represent. Experimental tests were performed in laboratory batch mode. The adsorption data were analyzed using the Freundlich, Langmuir and Dubinin-Kaganer-Radushkevich (DKR) isotherm models. It was found that the Freundlich isotherm gave better results than the Langmiur and DKR models, with the corresponding correlation coefficients (R2): 0.981, 0.996 and 0.997 for mixture (NZ+AC), AC and NZ, respectively. The adsorption capacities of Cr(total) ions followed the order: (NZ+AC)>AC>NZ. The adsorption efficiencies of Cr(total) ions removal were 38.5 to 39.9%. Due to easy availability and good efficiency, the mixture of clinoptilolite and activated carbon is an ideal adsorbents for removal of Cr(total) ions from waste printing developer.

scholarly journals Investigation of Clay Type on Low Salinity Water Flooding Using a Glass Micromodel

2020 ◽  
Vol 8 ◽  
Author(s):  
Xuemei Wei ◽  
Wenchao Jiang ◽  
Yanyu Zhang ◽  
Zhao Wang ◽  
Xiaojun Li ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Clay Minerals ◽  
Oil Recovery ◽  
Wetting Angle ◽  
Water Flooding ◽  
Residual Oil ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Displacement Experiments ◽  
Salinity Water

Clay minerals are usually regarded as an important factor affecting the results of low salinity water (LSW) flooding. However, experiments on clay minerals are mainly in qualitative stage, the mechanism of clay minerals has not been studied completely. In this paper, Zeta potential of four kinds of clay minerals (montmorillonite; chlorite; illite; kaolinite) in different brine was measured, microscopic models of these clay minerals were made to measured wetting angle in different brine, and montmorillonite and kaolinite were chosen to conduct microscopic displacement experiments through customized micro-glass etching models. From experiment results, the following conclusions can be get: 1). With the decrease of salinity of injected water, the negative zeta potential of clay minerals increases and the wetting angle decreases. 2). Clay minerals are more sensitive to monovalent Na+ than bivalent Ca2+. 3). The results of microscopic experiments show that LSW can effectively improve oil recovery, whether kaolinite or montmorillonite. The recovery of montmorillonite is better with a relatively high salinity of LSW and kaolinite is better with a relatively low salinity of LSW. The mechanism of LSW improves kaolinite recovery factor is the change of wettability while that of montmorillonite is the increase of water phase wettability. However, a lot of droplet-like residual oil cannot be displaced in the montmorillonite throat. In filed production, both kaolinite-rich and montmorillonite-rich reservoirs are suitable for LSW flooding to improve oil recovery. However, for kaolinite reservoirs, a lower salinity of injected water would produce a better result, while for montmorillonite reservoirs, residual oil droplets in the throat are noteworthy.

scholarly journals Effective removal of chemical oxygen demand and phosphates from aqueous medium using entrapped activated carbon in alginate

2018 ◽  
Vol 3 (5) ◽  
pp. 227-236
Author(s):  
Soha A Abd El-Gawad ◽  
Hossam M Abd ElAziz
Keyword(s):  
Activated Carbon ◽  
Oxygen Demand ◽  
Operating Parameter ◽  
Freundlich Isotherm ◽  
Operating Conditions ◽  
Phosphate Removal ◽  
Efficient Removal ◽  
Stirring Rate ◽  
Effective Removal ◽  
Adsorption Data

The aim of this study is to decrease different wastewater contaminants using entrapped activated carbon in alginate polymer (AG-AC) by adsorption. Different phosphate concentrations were prepared in the laboratory. The effect of the operating parameter was studied by external factors (e.g., contact time, pH, concentrations, adsorbent dose, and stirring rate). The results were analyzed according to the Freundlich and Langmuir adsorption isotherm. The adsorption data are more appropriate by the Freundlich isotherm. Efficient removal percentages for COD (500 mg\L) at pH 3 using dose 30g of the adsorbent for 60min with a fixed stirring rate at 100rpm were about (79%). Efficient removal percentages for phosphates (5mg\L) at pH 4 using dose 30g of the adsorbent for 45min with a fixed stirring rate at 100rpm were about (89%). The best-operating conditions have been determined to increase phosphate removal efficiency.

scholarly journals Characteristics of Heavy Metals Adsorption Cu, Pb and Cd Using Synthetics Zeolite Zsm-5

2016 ◽  
Vol 20 (2) ◽  
pp. 77 ◽  
Author(s):  
. Priyadi ◽  
. Iskandar ◽  
. Suwardi ◽  
Rino Rakhmata Mukti
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Negative Charge ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Heavy Metal Adsorption ◽  
Batch System ◽  
Adsorption Data

It is generally known that zeolite has potential for heavy metal adsorption. The  objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system with heavy metals of Cu2+, Pb2+ and Cd2+ in various concentrations (50, 100, 150, 200 and 250 ppm) with contact times 30, 60, 90, 120 and 250 minutes. Adsorption data was calculated by Langmuir and Freundlich isotherm. The results showed that the maximum adsorption capacity of zeolite ZSM-5 against heavy metals of Pb2+, Cu2+, and Cd2+, were 74.07, 69.93 and 60.24 mg g-1, respectively. These indicated that synthetic zeolite ZSM-5 had potential to adsorb heavy metals. The results also suggested that the adsorption capacity was affected by the pore size of zeolite, negative charge of zeolite, diameter of hydrated and electronegative ion.

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