scholarly journals Study of the adsorption and photocatalytic properties of copper oxide with different morphologies in removal of Cr(III) ion from aqueous media

2019 ◽  
Vol 80 (5) ◽  
pp. 827-835
Author(s):  
Jamileh Kondabey ◽  
Mohammad Hossein Ghorbani ◽  
Hossien Aghaie ◽  
Reza Fazaeli
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Industrial Wastewater ◽  
Photocatalytic Oxidation ◽  
High Efficiency ◽  
Aqueous Media ◽  
Adsorption Efficiency ◽  
Adsorbent Dosage ◽  
Toxic Pollutant ◽  
Photocatalytic Processes

Abstract Chromium Cr(III) is considered as a toxic pollutant in industrial wastewater. Photocatalytic processes can be used as an efficient method for the treatment of heavy metal wastewaters. This study was conducted to synthesize copper (II) oxide (CuO) with dendrite, leaf and feather morphologies. Synthesized CuO with dendrite and leaf morphologies were characterized by XRD, SEM, and BET/BJH and CuO with feather morphology by XRD, SEM, BET/BJH, FTIR, TEM and DRS techniques. Parameters such as morphology CuO, the contact time (h), and adsorbent dosage (g) in adsorption of Cr(III) and morphology CuO, pH and initial concentration of Cr(III) in the photocatalytic oxidation were investigated. The results demonstrate that CuO feather at 24 h contact time with 0.1 g adsorbent with an adsorption efficiency of 57.24% has the highest efficiency compared to CuO of dendrite and leaf. Oxidation results demonstrate that CuO feather at 2 h with 0.1 g adsorbent dosage and pH = 7 had 89.14% removal efficiency. Also, oxidation results demonstrate that CuO feather at 2 h with 0.1 g adsorbent dosage and pH = 8 had 99.99% removal efficiency, which indicates the high efficiency of the feather.

scholarly journals Selective Removal of Sodium Ions from Aqueous Media Using Effective Adsorbents: Optimization by RSM and Genetic Algorithm

2021 ◽  
Vol 68 (4) ◽  
pp. 791-803
Author(s):  
Lei Yao ◽  
Chao Hong ◽  
Hani Dashtifard ◽  
Hossein Esmaeili
Keyword(s):  
Genetic Algorithm ◽  
Activated Carbon ◽  
Sorption Capacity ◽  
Removal Efficiency ◽  
Contact Time ◽  
Aqueous Media ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Sorption Efficiency

This study aimed to determine the best adsorbent among Moringa oleifera-derived activated carbon (AC), eggshell-derived CaO nanoparticles and CaO/Fe3O4 for sodium (Na+) removal from aqueous media. In the first step, the appropriate adsorbent for sodium adsorption was determined among the three adsorbents, which the results showed that the AC had the highest sorption efficiency. Then, response surface methodology (RSM) was used to evaluate the impact of different factors on the Na+ ion sorption efficiency using the AC. The highest removal efficiency was obtained to be 95.91% at optimum conditions such as pH of 11, contact time of 45 min, temperature of 25 °C, sodium ion concentration of 900 mg/L, and adsorbent dosage of 5 g/L. Also, the best conditions using the genetic algorithm was obtained at contact time of 94.97 min, adsorbent dosage of 3.52 g/L, Na+ ion concentration of 939.92 mg/L and pH value of 10.92. Moreover, the maximum sorption capacity using the Langmuir model was obtained to be 249.67 mg/g, which was a significant value. Besides, the equilibrium and kinetic studies indicated that the experimental data of sodium adsorption process were fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model, respectively. Furthermore, the thermodynamic study indicated that the sorption process was endothermic. Generally, among the three adsorbents used, activated carbon with a high removal efficiency and significant sorption capacity can be considered as a promising adsorbent for the removal of sodium from wastewater on an industrial scale.

scholarly journals Adsorption of High Chromium Concentrations from Industrial Wastewater Using Different Agricultural Residuals

2020 ◽  
Vol 9 (1) ◽  
pp. 122-138
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Langmuir Isotherm ◽  
Contact Time ◽  
Industrial Wastewater ◽  
Chromium Concentration ◽  
Isotherm Model ◽  
High Chromium ◽  
Adsorbent Dosage ◽  
Pseudo Second Order

Hexavalent chromium Cr (VI) is a toxic material used in many industries such as tanneries and electroplating industries. Most of the previous researches studied the removal of chromium at lower concentrations up to 600 mg/L but did not tackle the behavior at higher concentrations, which resemble the real concentration of studied tanneries effluents. The present research is a comparative study of different agricultural low cost adsorbents in the removal of high Chromium concentration from industrial wastewater up to 1000 mg/L, compared to a commercial activated carbon. The tested adsorbents are (Banana Waste (BW), Sawdust (SD), Phragmites Australis (PA), Sugarcane Bagasse (SCB), Pea pod peels (PPP) and Rice straw (RS)). The materials were chemically pretreated with acid-alkali except BW was treated with acid only, to improve adsorbent metal binding capacity. Batch experiments were conducted to study the effect of pH, adsorbent dosage, contact time, initial Chromium concentration and temperature on the removal efficiency of Chromium from wastewater. The experiments were conducted in two sets, one for lower concentration (25-50-100-200-400) mg/L and the other for higher concentration (600-800-1000) to simulate the concentration of Chromium in tannery industry effluents. At 1000 mg/L initial concentration, BW achieved the optimum removal efficiency of 73.28% at pH = 3, adsorbent dosage = 25 g/L and contact time of 3 hours with the adsorption capacity was 39 mg/g. For SD at pH=2, 3 hours contact time, 10 g/L dosage, and 30oC the removal ratio was 64.83% and the adsorption capacity was 86.30 mg/g. The equilibrium data for various agricultural adsorbents was being tested with various adsorption isotherm models such as Langmuir, Freundlich and Tempkin. At low concentrations, AC, BW, PA and SCB follows Freundlich isotherm model while SD follows Langmuir isotherm model. At higher concentrations, BW, SD, PA follows Langmuir isotherm while SCB follows Tempkin isotherm model. To evaluate the mechanism of Cr adsorption on different adsorbents, Pseudo-first-order and Pseudo-second-order equations were used. The adsorption process follows Pseudo-second-order for all adsorbents, which confirms the chemisorption of Cr (VI) on different adsorbents.

scholarly journals Comparison of the Efficiency of Ultraviolet/Ultrasonic (UV/US) and Ultraviolet/Zinc Oxide (UV/ZnO) Technologies as Advanced Oxidation Processes in the Removal of Linear Alkylbenzene Sulfonate (LAS), an Anionic Detergent, from Aqueous Media

2021 ◽  
Vol 10 (1) ◽  
pp. 53-63
Author(s):  
Tahereh Razavi ◽  
◽  
Abdolmajid Fadaei ◽  
Keyword(s):  
Zinc Oxide ◽  
Removal Efficiency ◽  
Contact Time ◽  
Industrial Wastewater ◽  
Aqueous Media ◽  
Inverse Correlation ◽  
Linear Alkylbenzene ◽  
Alkylbenzene Sulfonate ◽  
Detergent Extraction ◽  
Uv Lamp

Surfactants are one of the most commonly found xenobiotics in municipal and industrial wastewater. The purpose of this study was to compare ultraviolet/ultrasonic (UV/US) and ultraviolet/zinc oxide (UV/ZnO) processes in the removal of LAS from aqueous media.In this study, a medium-pressure UV lamp (125 W), an ultrasonic device (400 W and 42 kHz), and ZnO nanoparticles (NPs) were used. The concentration of LAS was 0.5, 14, and 21 mg/L in all experiments. Contact time of 8, 16, and 24 minutes, pH of 3, 7, and 11, and NP concentrations of 50, 100, 150 mg/L were selected. Detergent extraction was performed using methylene blue active substances.The results showed that the efficiency of UV/US process in the removal of LAS was 89.35%, while the removal efficiency of UV/ZnO process was 81.27%. In both processes, the rate of detergent removal increased by elongating the contact time from 8 to 24 minutes. The efficiency of UV/US process in LAS removal was greater than that of the UV/ZnO process. The findings showed that the removal efficiency of UV/US process was directly correlated with pH, while it had an inverse correlation with the removal efficiency of UV/ZnO process.

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

scholarly journals Response surface methodology approach for the optimisation of adsorption of hydrolysed polyacrylamide from polymer-flooding wastewater onto steel slag: a good option of waste mitigation

2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Contact Time ◽  
Interactive Effect ◽  
Steel Slag ◽  
Oxygen Demand ◽  
Polymer Flooding ◽  
High Concentration ◽  
Adsorbent Dosage

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.

scholarly journals Cyclic Sequential Removal of Alizarin Red S Dye and Cr(VI) Ions Using Wool as a Low-Cost Adsorbent

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 556
Author(s):  
Mustafa I. Khamis ◽  
Taleb H. Ibrahim ◽  
Fawwaz H. Jumean ◽  
Ziad A. Sara ◽  
Baraa A. Atallah
Keyword(s):  
Contact Time ◽  
Industrial Wastewater ◽  
Batch Reactor ◽  
Low Cost ◽  
Alizarin Red S ◽  
Alizarin Red ◽  
Simultaneous Reduction ◽  
Adsorbent Dosage ◽  
Adsorption Data ◽  
Sheep Wool

Alizarin red S (ARS) removal from wastewater using sheep wool as adsorbent was investigated. The influence of contact time, pH, adsorbent dosage, initial ARS concentration and temperature was studied. Optimum values were: pH = 2.0, contact time = 90 min, adsorbent dosage = 8.0 g/L. Removal of ARS under these conditions was 93.2%. Adsorption data at 25.0 °C and 90 min contact time were fitted to the Freundlich and Langmuir isotherms. R2 values were 0.9943 and 0.9662, respectively. Raising the temperature to 50.0 °C had no effect on ARS removal. Free wool and wool loaded with ARS were characterized by Fourier Transform Infrared Spectroscopy (FTIR). ARS loaded wool was used as adsorbent for removal of Cr(VI) from industrial wastewater. ARS adsorbed on wool underwent oxidation, accompanied by a simultaneous reduction of Cr(VI) to Cr(III). The results hold promise for wool as adsorbent of organic pollutants from wastewater, in addition to substantial self-regeneration through reduction of toxic Cr(VI) to Cr(III). Sequential batch reactor studies involving three cycles showed no significant decline in removal efficiencies of both chromium and ARS.

Study on the Treatment of Nylon Chemical Industrial Wastewater by AF+ A/O Process

2011 ◽  
Vol 71-78 ◽  
pp. 3133-3136
Author(s):  
Jie Zhang ◽  
Qun Hui Wang ◽  
Peng Li ◽  
Hai Ming Huang ◽  
Wen Jun Wang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Treatment Effect ◽  
Industrial Wastewater ◽  
High Efficiency ◽  
First Grade ◽  
Wastewater Discharge ◽  
N Removal ◽  
New Type ◽  
Nitrogen Treatment ◽  
A Company

A company in Pingdingshan of Henan province using a new type of AF (high-efficiency immobilized biological anaerobic biofilter ) and A/O process to treat nylon chemical industrial wastewater, In this study, we monitored the system for one month (Dec.1.2010-Jan.1.2011). The effect of the conditions of temperature, pH and COD, nitrate, ammonia and total nitrogen treatment effect along the system were investigated, the results showed that: average COD removal efficiency reached 97%, average NH4+-N removal efficiency was higher than 90% and the effect of the system is good. The effluent meets the first grade criteria of integrated wastewater discharge standard (GB8978-1996).

scholarly journals Adsorption of Nickel and Chromium From Aqueous Solutions Using Copper Oxide Nanoparticles: Adsorption Isotherms, Kinetic Modeling, and Thermodynamic Studies

2019 ◽  
Vol 6 (2) ◽  
pp. 66-74 ◽  
Author(s):  
Raziyeh Hosseini ◽  
Mohammad Hossein Sayadi ◽  
Hossein Shekari
Keyword(s):  
Aqueous Solutions ◽  
Copper Oxide ◽  
Removal Efficiency ◽  
Contact Time ◽  
Removal Rate ◽  
Copper Oxide Nanoparticles ◽  
Isotherm Models ◽  
Oxide Nanoparticles ◽  
Initial Concentration ◽  
Adsorbent Dosage

The research was conducted with an aim to assess the efficiency of copper oxide nanoparticles as an adsorbent to remove Ni and Cr. The effect of pH, adsorbent dosage, contact time, initial concentration of metals (Ni and Cr) on the adsorption rate was evaluated and removal of these elements from aqueous solutions was measured using Atomic Absorption Spectrum System (Conter AA700). Moreover, the kinetic and isotherm besides thermodynamic adsorption models were assessed. The highest Ni and Cr removal rate occurred at an optimal pH of 7, and an initial concentration of 30 mg/L, a time period of 30 minutes, and 1 g/L of copper oxide nanoparticles. In fact, with the increase of adsorbent dosage and contact time, the removal efficiency increased and with initial concentration increase of Ni and Cr ions, the removal efficiency reduced. The correlation coefficient of isotherm models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson, and Koble-Corrigan showed that Ni and Cr adsorption via copper oxide nanoparticles better follows the Langmuir model in relation to other models. The results showed that kinetic adsorption of Ni and Cr via copper oxide nanoparticles follows the second order pseudo model with correlation coefficients above 0.99. In addition, the achieved thermodynamic constants revealed that the adsorption process of metals (i.e., Ni and Cr) via copper oxide nanoparticles was endothermic and spontaneous and the reaction enthalpy values for these metals were 17.727 and 11.862 kJ/mol, respectively. In conclusion, copper oxide nanoparticles can be used as effective and environmentally compatible adsorbents to remove Ni and Cr ions from the aqueous solutions

scholarly journals Optimized Sorption of Methyl Orange using Functionalized Carob Plant Pod

2020 ◽  
Vol 45 (6) ◽  
Author(s):  
K. A. ABDULSALAM ◽  
B. H. Amodu ◽  
O. K. Fakorede ◽  
J. M. Adelowo ◽  
A. P. Onifade ◽  
...  
Keyword(s):  
Contact Time ◽  
Industrial Wastewater ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Operational Parameters ◽  
Colour Removal ◽  
Adsorbent Dosage ◽  
Percentage Removal ◽  
Central Composite ◽  
Maximum Decolorization

One of the most problematic groups of water pollutants is dye, a main constituent of textile industrial wastewater, which is carcinogenic. Therefore, this research delved into adsorption of dyes from textiles and wastewater using acid-treated as an adsorbent. The adsorbent was prepared by functionalizing the pod of carob with concentrated H3PO4. The effects of operational parameters such as adsorbent dosage, contact time, initial concentration of dye and temperature were studied and optimized using central composite design of design of experiment (DOE). The effects of process parameters (contact time, concentration, adsorbent dosage and temperature) on the dye adsorption were determined and optimized. It was observed that the colour removal efficiency increased with an increase in adsorbent mass and contact time. The adsorption process is endothermic as the percentage removal increases with temperature. The optimum contact time, concentration, adsorbent dosage and temperature were found to be 60oC, 9.74hr, 10ppm, and 5g respectively for the maximum decolorization.

scholarly journals Layered Rare-Earth Hydroxide Unilameller Nanosheets: Synthesis, Characterization, and Adsorption

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Solomon Omwoma ◽  
Adongo Stephen Odongo ◽  
Zablon Otieno ◽  
Silas Lagat ◽  
Joseph Owuor Lalah
Keyword(s):  
Rare Earth ◽  
High Efficiency ◽  
Colloidal Solution ◽  
Aqueous Media ◽  
Significant Loss ◽  
Adsorption Efficiency ◽  
Material Synthesis ◽  
Langmuir Adsorption ◽  
Sorbent Material ◽  
Adsorption Curve

Unilameller nanosheets with a lateral dimension of one nanometer have been isolated from a colloidal solution of europium-containing layered rare-earth hydroxide (LRH) material by the flocculation method. The nanosheets were achieved by changing pH of the colloidal solution from 6.7 to 11.5. The resultant flocculated nanosheets show high efficiency in sorption of fluoride anions from aqueous media (40 mmol/g), providing a potentially useful sorbent material for water purification technology. The sorbent material is demonstrated to be reusable for at least ten times without a significant loss of adsorption efficiency. And the results fit the Langmuir adsorption curve, indicating the chemisorption nature of the nanosheets. Most importantly, the isolated nanosheets are expected to widen the applicability and flexibility in material synthesis using two-dimensional nanomaterials.

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